Plasticity of T Cell Differentiation and Cytokine Signature: A Double-Edged Sword for Immune Responses

90 Immun., Endoc. & Metab. Agents in Med. Chem., 2009, 9, 90-105

1871-5222/09 $55.00+.00 © 2009 Bentham Science Publishers Ltd.

Plasticity of T Cell Differentiation and Cytokine Signature: A Double-Edged Sword for Immune Responses

Mohamed Labib Salem1,2,*, Faris Q. Alenzi

3, Narender Nath

4, Sabry A. El-Naggar

2,

Amir A. Al-Khami2, Ali A. Al-Jabri

5, Jamal Arif

6, Iman M. El-Nashar

7,

Iman El-Tounsi8, and Richard K.H. Wyse

9

1Departments of Surgery, Medical University of South Carolina, Charleston, SC, USA

2Zoology Department, Faculty of Science, Tanta University, Egypt

3Department of Med. Lab. Sci. College of Applied Medical Sciences Al-Kharaj, King Saud University, Saudi

Arabia

4Department of Pediatrics, Medical University of South Carolina, Charleston, SC, USA

5Department of Microbiology and Immunology, College of Medicine and Health Sciences, Sultan Qaboos

University, Oman

6Department of Biotechnology, Integral University, Lucknow 226026, India

7College of Medicine, King Khalid University, Abha, Saudi Arabia

8Department of Clinical Pathology, Menoufeya Faculty of Medicine, Egypt

9Imperial College, London, UK

Abstract: Preventing or curing an immune-mediated disease requires functional immune cells, in particular

T cells, including helper (CD4+; Th) and cytotoxic (CD8

+; Tc) T cells. Based on the type of the antigen

presenting cells, the nature of antigens, and the cytokine milieu, CD4+

T cells exhibit high plasticity to diffe-

rentiate into different subsets with stimulatory or regulatory functions. For instance, Th cells can differentiate

into Th1 and Th2 type cells, which produce inflammatory (IL-2, IFN- , TNF- , IL-12) and anti-inflammatory

(IL-4, IL-10, and TGF-ß) cytokines, respectively. Th cells can also differentiate into a third type of Th cells

designated as Th17 type cell that produces IL-17 and mimics the effects of Th1 cells. Similar to Th cells,

Tc can differentiate into Tc1, Tc2, and Tc17 subsets that produce cytokine profiles similar to those produced

by Th1, Th2, and Th17 cells, respectively. Under certain condition, Th type cells can also differentiate into a

regulatory (Treg) type cell, which produces immunosuppressive cytokines such as TGF-ß and IL-10. Similarly,

Th17 and Tc1 type cells can acquire immunoreglatory properties. This article sheds a light on how this T cell

plasticity shapes the nature of the immune cell responses to inflammation, infection, and cancer.

Key Words: Adoptive cell therapy, autoimmunity, cancer, cytokines, inflammation, immunity, regulatory cells, suppressor T cells, Th1, Th2, Th17.

INTRODUCTION

In the last three decades, preclinical studies have shown that cytokines are central mediators in initiation and/or progression of different forms of immune res-ponses with significant impact on health and diseases [1, 2]. Although cytokines are produced by different

*Address correspondence to this author at the Hollings Cancer

Center, 86 Jonathan Lucas Street, Charleston, SC 29425, USA;

Tel: +1-843-792-7576; Fax: +1-843-792-2556;

E-mail: [email protected]

cell types, including immune and non-immune cells, those produced by immune cells are critical since they are released immediately in a large quantity in response to inflammation. Among immune cells, CD4

+ and

CD8+ T cells are important producers of several

cytokines that shape both the quality and quantity of immune responses to pathogens and cancer. Although naïve CD4

+ and CD8

+ T cells circulate in a resting

state, they can show plasticity to acquire different phenotypes with stimulatory and regulatory functions Fig. (1). This plasticity of T cells provides a fine-tuned mechanism for the host to combat diseases as well as

Plasticity of T Cell Differentiation and Cytokine Signature Immun., Endoc. & Metab. Agents in Med. Chem., 2009, Vol. 9, No. 2 91

to ameliorate the intensity of an immune response as a means to prevent the coincidence of autoimmune diseases.

1. DIFFERENTIATION OF T CELLS INTO

HELPER CELLS

1.1. Differentiation of a Th Cell Into Th1 or Th2 Subset

Upon their activation, CD4+

T cells can show plasti-city to differentiate into either Th1 cells secreting IL-2, IL-12, IFN- , and TNF- or to Th2 cells secreting IL-4, IL-5, IL-10, IL-13, and TGF- [3, 4]. Induction of a Th1 type cell associates with strong T cell responses, whereas induction of a Th2 type cell associates with antibody-mediated immune responses [1]. Th1 and Th2

type cells express mutual inhibitory effects in such a way that generation of a Th1 type response can down-regulate a Th2 type response and vice versa [3-5]. Differentiation of Th cells to Th1 and Th2 subtypes are under the control of distinct transcription factors, including STAT4 and T-bet (for Th1 cells) and STAT6 and GATA3 (for Th2). Although the initial findings of Th1 and Th2 cells were with CD4

+ T cell subsets Fig.

(1), CD8+ T cells can also differentiate into a type 1

(Tc1) and a type 2 (Tc2) cell, which produces cytokine profiles similar to those produced by Th1 and Th2 type cells, respectively [6]. Functionally, however, Tc1 and Tc2 CD8 subsets are the only specific effector cells capable of killing pathogens and cancer cells. Although Th cells are incapable of killing target cells, they are critical for the cytolytic function of Tc cells [7, 8].

Fig. (1). Schematic layout of CD4+

T cell differentiation. Most of T cells (CD4+ and CD8

+) circulate in the host in a naïve

status, but they can show high plasticity to differentiate into different subsets upon stimulation. The phenotype and function of the differentiated T cells depends on different factors present during the initial stimulation. Upon recognition of an antigen presented by an APC in the presence of costimulation, naïve CD4

+ T helper cells can differentiate into four different subtypes

(Th1, Th2, Th17, or Treg) depending on the cytokine microenvironment and transcription factors as well as the type and activa-tion of APCs (e.g. myeloid dendritic cells, plasmacytoid dendritic cells, macrophages, or B cells) during the initial priming of T cells. The Th1 cell differentiation pathway can be induced by IL-12 through induction of STAT4 and T-bet transcription factors. The Th2 cell differentiation pathway requires IL-4 and the induction of STAT6 and GATA3 transcription factors. The Th17 cell differentiation pathway requires TGF- , IL-6, and IL-23 cytokines with the involvement of STAT3 and ROR / transcription factors. Similar differentiation pathways can be applied for CD8

+ T cells.

92 Immun., Endoc. & Metab. Agents in Med. Chem., 2009, Vol. 9, No. 2 Salem et al.

The proximal signals that drive the intrinsic mecha-

nisms of T cells to differentiate into Th1/Tc1 or

Th2/Tc2 types are IL-12 and IL-4, respectively [9].

Recent studies, however, indicated that IL-21 can

suppress differentiation of CD4+

T cells into Th1 type

cells and can promote their differentiation into Th2

type cells [10]. Additional studies indicated that IL-18

can also be considered as a Th1 inducer since it can

block IL-4 suppression of type 1 responses and can

promote IL-12 receptor (IL-12R) expression and type 1

responses [11]. Overall, polarization of type 1/type

2 subsets can be stabilized [12], postponed [13], or

reversed [4] by certain factors. Therefore, the quality

of Th1/Th2 or Tc1/Tc2, although programmed, can

be significantly altered during the phase of T cell

differentiation in responses to antigen stimulation. The

fine-tuned plasticity of a T cell to quantitatively and

qualititatively develop into a Th1/Tc1 or into a Th2/

Tc2 axis would lead to the concept that cytokines

produced by these T cell subsets can serve as a finger-

print with regard to probing the identity of an immune-

based disease and can help prediction of the suitable

treatment strategy.

1.2. Differentiation a Th Cell Into a Th17 Type Cell

In addition to Th1 and Th2 cells, a third subset of

CD4+

Th cells designated as Th17 has recently been

characterized based on their production of IL-17A

and IL-17F cytokines [5] Fig. (1). These cytokines are

not produced by either Th1 or Th2 cells. The differen-

tiation and growth of Th17 cells are directed by a

combination of the cytokines TGF- , IL-6, and IL-23.

The interaction between IL-12 and its receptor (which

mediates Th1 differentiation) and IL-23 and its recep-

tor (which mediates Th17 differentiation), together

with additional differentiating or cofactor signals,

supports their distinct roles in the development of

Th1 and Th17 T cells, respectively. Recent studies also

demonstrated an important function for IL-1 receptor

signaling in IL-23-induced IL-17 production [14].

Th17 cells produce a range of other factors known to

drive inflammatory responses, including TNF- , IL-6,

GM-CSF, CXCL1 and CCL20, where IL-23 is a central

player in the expansion and survival of these cells [15].

Several recent studies have revealed that Th17 cells are

required for the protection from bacterial and viral

infections and for the induction of tissue inflammation

and pathology

during autoimmune diseases once

attributed to Th1 cells [16] such as experimental

autoimmune encephalomyelitis (EAE) [17], a typical

Th1-dependent animal model of multiple sclerosis in

human. Th17 cells also secrete IL-21 to communicate

with the other cells of the immune system.

2. DIFFERENTIATION OF T CELLS INTO REGULATORY CELLS

2.1. Differentiation of CD4+

T Cells Into T Regulatory (Treg) Cells

Treg cells, which represent about 5 to 10% of CD4+

T-cells in the steady state, play a central role in immu-

ne homeostasis and in preventing autoimmune diseases

[18, 19]. Treg cells exist naturally and are called natural

Treg cells expressing CD25 and Foxp3. T cells can also

convert into Treg cells Fig. (1) upon certain antigen

recognition and are called antigen-specific Treg cells

that secrete IL-10 and/or TGF- . Although Treg cells

are required to control the infection-induced immuno-

pathology in a host [20], their presence is also conside-

red as one of the escape mechanisms by which cancer

cells and microbes overcome the effectiveness of the

host immune responses [21, 22]. Therefore, expansion

of natural Treg cells and the plasticity of CD4+ T cells

to differentiate into antigen-specific Treg cells would

explain the failure of many immunotherapeutic approa-

ches to cancer and infectious diseases [21-23]. Given

the detrimental effects of Treg cells on T cell responses,

various potential strategies that can deplete these

cells or can block their regulatory function have

been reported, including the anti-cancer drug

cyclophosphamide, denileukin diftitox (DD; ONTAK),

and anti-CD25 antibodies, namely PC61 [24-27].

Ultimately, depletion

of Treg cells can enhance the

development of protective Th1 cell responses during

chronic infection and can enhance the induction of anti-

tumor immunity [21-23]. Interestingly, Treg cells can

induce naïve conventional (CD4+CD25

-) T cells or Treg

cells themselves to differentiate into Th17 in the pre-

sence of IL-6 and/or IL-23 at sites of inflammation

[28]. These studies not only indicate to the complexity

of the interaction between the different subsets of

Th cells, but also show that one population can be

converted into another favorable population based on

the cytokine milieu.

2.2. Differentiation of CD8+ T Cells Into Suppressor

(TS) Cells

Similar to the differentiation of CD4+

T cells into

Treg cells, recent studies suggest that CD8+ T cells can

also differentiate into T suppressor cells (TS), characte-

rized by their CD8

+CD28

– phenotype and the lack of

cytolytic activity, which is the effector function for

the conventional CD8+ T cells [29]. CD8

+CD28

TS

and Treg cells share expression of molecular markers,

especially FOXP3 [30]. TS cells have shown antigen-

specific immunoregulatory activities in vitro [31-33]

and in vivo in human transplant recipients [34, 35], in

Plasticity of T Cell Differentiation and Cytokine Signature Immun., Endoc. & Metab. Agents in Med. Chem., 2009, Vol. 9, No. 2 93

human cancer [36], and in murine autoimmune diseases

[37]. The induction of transplantation tolerance by TS

cells is mediated by mechanisms different from those

mediated by CD4+CD25

+ Treg cells [38]. In vitro studies

showed that human TS cells can induce an antigen

specific MHC class I-restricted suppression by interac-

ting directly with antigen presenting cells (APCs) [39,

40], inducing the latter to express low levels of

costimulatory receptors and high levels of inhibitory

receptors. This phenotype of APCs renders them to be

tolerogenic rather than stimulatory [32, 41, 42]. There

is an indication that the presence of donor-specific

TS cells in the circulation may characterize transplant

recipients, in whom graft function can be maintained

with minimal or no immunosuppression [43, 44].

Recent studies have also shown a regulatory role for TS

in autoimmune diseases [45]. For instance, in a

xenograft model of human synovium, CD8+CD28

-

CD56+ T cells have been found to effectively suppress

rheumatoid inflammation through IFN- -mediated

modulation of the tryptophan metabolism in APCs. In

systemic lupus erythematosus animal models, TS cells

induced suppressive activity through the TGF- -

Foxp3-PD1 pathway [46]. Another study showed that

adoptive transfer of human CD8+CD28

-CD56

+ T clones

generated from synovial tissues into NOD-SCID

mice engrafted with synovial tissues from patients

with rheumatoid arthritis resulted in a strong anti-

inflammatory activity against synovitis through inhibi-

tion production of IFN- , TNF- , and chemokines

as well as down-regulation of the costimulatory

molecules CD80 and CD86 on synovial fibroblasts

[47]. These studies indicate to the potential role of TS

cells in regulation of immune responses in autoimmune

diseases. Therefore, future studies are required to

analyze the role of TS cells in induction of T cell

tolerance in cancer and to investigate the interrelation-

ship and interaction between TS and Treg cells.

3. BENEFICIAL EFFECTS OF TH CELLS

Th1/Th2 cytokine fingerprinting is obvious at all

levels in health and disease [2, 48]. At the physiolo-

gical level, endogenous levels of sex hormones contri-

bute to the gender difference in the development of

inflammatory diseases by influencing the balance of

Th1/Th2 cytokines [49]. At supra-physiological level,

such as in pregnancy, there is a switch from Th1- to

Th2-type of cytokines at the maternal-fetal interface

that is important in avoiding rejection of the semi-

allogenic fetus [6, 50, 51]. At the pathological level,

the roles of Th1/Th2 cytokines are reflected by upregu-

lation of the tissue expression of these cytokines in

animal and human with autoimmune diseases, allergy,

and allograft rejection [52-56]. As discussed above, Th

and Tc have the potential to differentiate into subsets

with different functions based on their cytokine signa-

ture. How a host benefits from such cytokine signature

depends on the desired effects. On one hand, Th1 and

Tc1 cytokine products can be used to enhance the

anti-microbial and anti-cancer immunity. On the other

hand, Th2 and Tc2 cytokine products can be used

to suppress autoimmune diseases. For instance,

preclinical studies have shown the beneficial adjuvant

effects of Th1 cytokines in cancer, fungal, viral, and

bacterial infections [1, 52, 57, 58], whilst Th2 type

cytokines are detrimental [59]. These preclinical

studies have led to several clinical studies ended with

successful applications of Th1/Th2-based therapy in

different disease settings.

3.1. Th1 Type Cytokines and Anti-Cancer Immuno- therapy

Provision of Th1 cytokines during cancer treatment

can significantly enhance the anti-tumor immune

responses through enhancing proliferation, activation,

trafficking, and survival of T cells [60]. Th1 cytokines

capable of inducing T cell survival include common

cytokine receptor gamma-chain, in particular IL-7

and IL-15 [61-64]. These cytokines also enhance the

turnover of the tumor-specific T cell memory respon-

ses, which is crucial for the longevity of efficacious

antitumor immunity [65, 66]. Co-administration of

common cytokine receptor gamma-chain Th1 cytoki-

nes, in particular IL-2 and IL-15, along with antigen-

specific immunotherapy also induced marked increases

in the proliferation of T cells and favor their differ-

entiation into Th1/Tc1 subsets [1, 58, 67-70]. Recent

studies provided solid evidence for the efficacy of

new cytokines, including IL-15, IL-21, and IL-23,

and different chemokines and growth factors to favor

differentiation of T cells into Th1/Tc1 subsets [2].

Several chemokines, in particular secondary lymphoid

chemokine (SLC, CCL21), have been utilized to target

trafficking of Th1 cells and dendritic cells to lymph

nodes, a perquisite site for these cells to meet and to

mount immune responses upon vaccination [71-79].

Given these adjuvant effects of Th1 cytokines in

preclinical studies, several treatment regimens based

on the use of one or more of these cytokines have

been extensively applied in clinical use to patients

with cancer [80, 81]. There are a large number of

Th1 cytokines being tested in humans for anticancer

therapy, including IL-2, IL-7, IL-11, IL-12, macrophage

inflammatory protein (MIP)-1 , IFN- and IFN- .

Th1 cytokine therapy can lead to the destruction of

tumors by one of two general mechanisms: (1) a direct

antitumor effect or (2) an indirect modulation of the

94 Immun., Endoc. & Metab. Agents in Med. Chem., 2009, Vol. 9, No. 2 Salem et al.

antitumor immune responses [82]. In the first, cytoki-

nes directly interact with tumor cells leading to either

apoptosis, inhibition of cell division, or blocking tumor

angiogenesis. Typical Th1 cytokines such as IL-2,

TNF- , IFN- , and IL-12 have all been implicated in

this mechanism. Although effective as singular agents,

the combination of multiple cytokines can be even

more beneficial by acting against tumor cells in

an additive or synergistic fashion. Cytokines utilizing

the indirect mechanism mediate tumor regression by

stimulating or activating immune cells, which can

then mediate an antitumor response through a variety

of pathways. Some Th1 cytokines can enhance or

activate particular types of immune cells, such as

IL-2, which promotes T-cell and NK cell growth [82].

Other cytokines such as the IFNs and GM-CSF can

act on professional APCs and upregulate markers

such as major histocompatibility complex (MHC)

molecules and the co-stimulatory molecules CD80/

CD86 (B7 family) and CD40 that have important roles

in facilitating the activation of lymphocytes [1, 83].

Cytokines that are in clinical applications now

include GM-CSF, type IFNs, TNF- , IL-1, IL-2, and

thymosine- 1 [1, 83]. IL-2 is approved by the US Food

and Drug Administration (FDA) for the treatment of

patients with metastatic melanoma or renal cell carci-

noma. In these patients, intravenous administration of

IL-2 can induce objective tumor regression in 17%

and 20% of cases, respectively [84]. IFN- is FDA

approved for the treatment of malignant melanoma,

chronic myelogenous leukaemia, hairy cell leukaemia

and Kaposi sarcoma. Combination of IL-2 with IFN-

leads to higher anti-tumor immune responses than

administration of either of them alone. IL-2 can also

mediate conversion of ovarian cancer-associated Treg

cells into proinflammatory IL-17-producing helper T

cells [85], suggesting that local IL-2 treatment in

cancer may result in the conversion of tumor-

associated Treg into Th17 cells, relieve Treg-mediated

suppression, and enhance antitumor immunity. Another

cytokine, TNF- , although toxic systemically at thera-

peutic doses, can be effective when administered

regionally via isolated limb perfusion to treat extremity

melanomas and sarcomas [86-92]. Other FDA-

approved cytokines that can support differentiation of

Th to Th1 type cells include GM-CSF, G-CSF, Flt3

ligand, and IL-7. These cytokines play an important

role in supportive therapy following bone marrow

transplantation by facilitating quicker reconstitution of

the immune system and improving patient survival. In

addition, GM-CSF and Flt3 ligand indirectly support

active immunotherapy in cancer patients through

mobilization of dendritic cells from bone marrow [93].

Combinatorial treatment with multiple cytokines

can also induce higher anti-tumor responses than single

treatment. In this context, a novel cytokine treatment

composed of a natural type-1 cytokine mixture has

been developed and shown substantial correction of the

immunodeficiency associated with cancer [83].

3.2. Th1 Cytokines and T Cell Adoptive Immuno- therapy

Because CD8+ T cells are the main killers of cancer

and virus infection, they have been used successfully

for adoptive immunotherapy to treat kidney cancer and

melanoma. In this T cell adoptive therapy setting, T

cells are harvested from the peripheral blood or from

the tumor bed, and then stimulated in vitro with multip-

le cycles of anti-CD3 mAb and IL-2 treatment to favor

the generation and proliferation of Tc1 [94]. These Tc1

are then infused back to the same host [80]. Although

some preclinical studies showed that both Tc1 and Tc2

cells can mount anti-tumor immunity [95-98], Tc1

cells, especially with central memory (TCM) phenotype

are more effective [99]. Th1 cytokine conditioning of

CD8+ T cells prior to their adoptive transfer has been

considered not only as a means to increase the prolife-

ration and function of tumor reactive T cells but also to

induce Tc cell to acquire TCM versus effector memory

(TEM) phenotypes. Perhaps the most studied cytokines

are those that share the receptors of the common

cytokine-receptor -chain family, e.g. IL-2, IL-4, IL-7,

IL-15, and IL-21 [100]. For example, culture of

activated CD8+

T cells in the presence of IL-2 skews

their differentiation towards TEM, while addition of IL-

15 skews T cells to differentiate into TCM phenotype,

which after ACT showed enhanced anti-tumor capabili-

ties [101]. These cells have been found to induce

effective antitumor responses when used for adoptive

immunotherapy. Similar to IL-15, we have made the

observation that IL-12 conditioning during in vitro

priming is able to promote the acquisition of a TCM-like

phenotype in antigen-specific T cells. These cells are

characterized by increased expression of lymph node

homing receptors, robust proliferation in vitro, an

augmented survival, and increased anti-tumor activity

in vivo [102]. Recent clinical studies have shown

that treatment of patients with chemotherapeutic drugs,

namely cyclophosphamide and fludarabine, before

adoptive cell transfer of Tc1 in concomitant treatment

with the Th1 cytokine IL-2 resulted in a marked

improvement in the survival and anti-tumor efficacy of

these Tc1 [80, 103]. Although it has not been tested in

clinical trials yet, recent preclinical studies including

ours revealed that the anti-tumor immune responses of

Tc1 cells adoptively transferred into a host pretreated

Plasticity of T Cell Differentiation and Cytokine Signature Immun., Endoc. & Metab. Agents in Med. Chem., 2009, Vol. 9, No. 2 95

with chemotherapy can be further enhanced when

adoptive T cell transfer is followed by vaccination with

tumor antigens [82, 104, 105].

3.3. Th Cells and Microbial Infection: Human Immunodeficiency Virus (HIV) as an Example

Although highly active antiretroviral therapy

(HAART) is changing the course of HIV infection, the

reality is that the toxicity of the drugs and the emergen-

ce of drug-resistant escape mutants indicate that

alternative immunologic therapies are encouraged to be

pursued. Moreover, the realization that discontinuation

of therapy results in a rebound of viral burden, empha-

sizing the need for immunologic forms of therapy.

Clinical trials have mainly focused on using cytokines

such as GM-CSF, IL-2, and IL-12 that would enhance

polarization of T cell development toward CD4+ Th1

cells. Larger randomized trials have shown an increase

in plasma viral load rather than the expected decrease.

In vitro studies have shown that latently infected cells

are activated and induce viral replication in the presen-

ce of some cytokines such as IL-2, IL-6, and TNF-

[106]. IL-2 has previously been used as a therapy to

increase the number of CD4+ Th1 cells in conjunction

with HAART as this would activate latent cells with

the net effect being their eradication while the patient is

being protected by HAART. This approach implicates

that the virus strains are not resistant to HAART

and that all the latent cells are CD4+ cells. IL-15 is

another Th1 cytokine that has been recommended for

immunotherapy, based on the advantage that it does not

enhance HIV replication but does play an important

role in NK cell and CD8+ T cell cytotoxicity, CD4

+

Th1 cell development and activation of dendritic cells,

monocytes, and neutrophils [106]. Although HIV patho-

genesis leads to CD4+ T cell depletion, it associates

with a significant increase in IL-17 production in CD4+

T cells in peripheral blood. Recent studies have started

to investigate the roles of IL-17 and Th17 in HIV

viral replication and immunopathogenesis [107-109];

however, more investigations are required to determine

the potential therapeutic role of Th17 cells in this

disease.

3.4. Th Cells and Inflammatory Diseases

In contrast to Th1 type, Th2 type cytokines,

although protect the host against parasitic infections,

underlie the pathological immune response in allergy

[2, 110]. In this regard, we have reported that the

immunomodulatory effects of estrogens on T cell-

independent and T cell-dependent immune responses

[111], bacterial infection [112], and delayed type

hypersensitivity reaction [111] is controlled by the

balance between Th1 and Th2 type cytokines. Accor-

dingly, we have proposed a mechanism for the immu-

nomodulatory effects of female sex hormone. These

hormones act as a double-edged sword, modulating

Th1- and Th2-mediated inflammations by differential

regulation of Th1/Th2 cytokine profile [49]. In addi-

tion, we have demonstrated a similar concept (i.e.

skewing the Th1 type cytokine to Th2 type) for the

prophylactic and therapeutic anti-inflammatory effects

HMG-CoA reductase inhibitors (lovastatin) and

activators of AMP-activated protein kinase toward

EAE [113], as well as on the immunomodulatory

effects of n-3 [114] and n-6 polyunsaturated fatty

acids [115]. Therefore, Th1 and Th2 cytokines could be

useful therapeutic targets in the future management of

allergic diseases.

Anti-Th1 cytokines based therapy has been utilized

to block the inflammatory properties of several Th1

cytokine-mediated inflammations [1, 52, 116]. For

instance, TNF- in Crohn's disease, rheumatoid arthri-

tis and psoriasis and IL-6/IL-6R in Crohn's disease

and rheumatoid arthritis are among the most clinically

validated conditions using inhibitor compounds [117].

Encouraging data are emerging from clinical studies

in psoriasis and Crohn's disease using neutralizing

monoclonal antibodies against the IL-12p40 subunit,

an approach that is likely to block both the IL-12

(Th1/IFN- ) and the IL-23 (Th17) pathways [118].

Although IFN- has been widely considered as a

pro-inflammatory effector cytokine, recent studies

would suggest that it can be a target Th1 cytokine.

For example, in EAE and collagen-induced arthritis

models, which have been historically associated

with IFN- -producing Th1-dominant responses [15],

deficiency in IFN- or its receptor has been found

to accelerate the development of EAE [119-122] and

worsen arthritis and render non-susceptible strains

to be susceptible to arthritis [123-125]. This immuno-

regulatory role of IFN- has been directly demonstrated

in adoptive transfer system, where adoptive transfer of

IFN- -stimulated monocyte-derived cells favors the

generation of Treg cells and the resolution of experi-

mental colitis [126]. In organ transplantation, in which

allograft rejection immune response is mediated by the

Th1 type response and high levels of IFN- , absence of

IFN- associated with a long-term graft survival rejec-

tion. On the other hand, IFN- accelerated the rejection

of skin allografts [127, 128] or at least in part had no

impact on the cardiac allograft rejection [129]. IFN-

has been also found to be required for successful

engraftment [129-131]. Further, ex vivo exposure of

CD4+

T cells to allogeneic dendritic cells in the pre-

sence of IFN- results in the emergence of Treg cells

96 Immun., Endoc. & Metab. Agents in Med. Chem., 2009, Vol. 9, No. 2 Salem et al.

capable of preventing skin allograft rejection [132],

which was found to be mediated by nitric oxide syntha-

se. These studies indicate that IFN- favors the genera-

tion of Treg cells on account of Th1 cells. A further

consideration regarding the relevance of Th1/IFN-

biology as a therapeutic target is the apparent discre-

pancy between mouse and human concerning the role

of IFN- in autoimmune inflammatory diseases. In the

mouse system, blockade of IFN- or IL-12 activities

tends to increase disease severity especially in colla-

gen-induced arthritis [133], whereas clinical trials

using anti-IFN- in multiple sclerosis and rheumatoid

arthritis indicate some therapeutic effect, but apparent-

ly no worsening of disease [134].

Recent preclinical and clinical studies have also

revealed significant roles for Th17 cells in inflammati-

on and allograft rejection, indicating that cells could

be another potential therapeutic target [16, 135]. For

instance, abundant numbers of CD161+ CD4 T (Th17)

cells were found in circulation and in the gut of

patients with Crohn's disease [136]. These CD161+

cells displayed an activated Th17 phenotype, as indica-

ted by increased expression of IL-17, IL-22, and IL-23

receptor and readily produced IL-17 and IFN- upon

stimulation with IL-23. Recently, emergence of Th17

cells has been associated with disease-affected sites in

psoriasis, rheumatoid arthritis, and Crohn's disease

[137, 138]. In allograft rejection, rapid high levels of

IL-17 were observed in the in the mononuclear cells

infiltrating the renal allograft [139-142] and in human

lung organ transplantation during acute rejection [143].

In cardiac allograft models, blocking of IL-17 signaling

resulted in significant reduction in the intragraft

production of the Th1 inflammatory cytokine IFN-

and prolongation in the graft survival [144, 145].

Partial deficiency in IFN- , in T-bet-deficient reci-

pients, accelerated allograft rejection accompanied

by infiltration of IL-17-producing CD4 T cells [146];

neutralization of IL-17 inhibited allograft rejection.

Further, in vitro-differentiated Th17 cells mediated

lethal acute graft-versus-host disease with severe cuta-

neous and pulmonary pathologic manifestations [147],

whilst absence of donor Th17 leads to aug-

mented Th1 differentiation and exacerbated acute

graft-versus-host disease [148]. Taken together, these

studies suggest that skewing of responses towards

Th17 or Th1 may be responsible for the development

and/or progression of autoimmune disease or acute

transplant rejection in humans. Blocking IL-17 signa-

ling pathway, however, may result in a shift from

a Th17 towards a regulatory phenotype and induce

quiescence of autoimmune disease or prevent

transplant rejection [135]. Taken together, it appears

that identifying specific signaling molecules that

can control the generation of Th cytokines would be

beneficial or detrimental based on the nature of the

disease.

4. IMPROVING TH1 CELL FUNCTIONS

4.1. Improving Cytokine Delivery

Generation of Th1 cells can be favorably induced by

exogenous administration of Th1 cytokines. However,

systemic administration of Th1 cytokines often associa-

tes with significant toxicities [1]. In contrast, paracrine

release, defined as targeted local delivery, of these

cytokines has the potential to enhance efficacy while

decreasing the likelihood of associated toxicities. The

problem, however, is how to effectively accomplish

their paracrine delivery. One approach is to introduce

Th1 cytokine by gene therapy using viral vector deli-

very, which unfortunately does not satisfy all the

criteria of an ideal gene therapeutic system [149].

Alternative approaches of gene therapy include injecti-

on of naked DNA encoding the desired cytokine(s)

[150]. Although effective, there is still no unequivocal

proof of their clinical efficacy. Seeking a simple,

effective, and inexpensive methodology, several non-

viral approaches, including liposomes, polymers,

lipids, and alum, has been found to successfully deliver

functional cytokines [151]. In our own experience, we

have developed a delivery system utilizing a gel (F2

gel matrix) generated from poly-N-acetyl glucosamine

fiber purified from marine diatom cultures. F2 gel

component is biocompatible, biodegradable, and

nontoxic and has recently been FDA approved as a

topical haemostatic agent [152]. We have established

that F2 gel can deliver lower systemic levels of GM-

CSF and IL-12, associated with less toxicity, but with

enhanced post vaccination Th1 cytokine production

and cytotoxicity and preventive anti-tumor immunity

toward tumor challenge [153] and schistosomiasis-

induced liver fibrosis1. F2 gel matrix was also able

to deliver functional naked DNA plasmid encoding

p37 HIV-1, inducing efficacious anti-p37 immunity

[154]. Recently, we have compared the advantages

of non-viral delivery systems, including F2 gel, for

the typical Th1 cytokine IL-12, showing their potential

applications as an alternative for improving the

delivery of therapeutic Th1 cytokines [151].

4.2. Provision of Adjuvants that are Th1 Inducers

New approaches to tumor immunotherapy and

vaccination have focused on enhancing effector T cell

1Attia, W.Y.; Al-Bolkiny, Y.E.; Al-Sharkawi, I.M.; Vournakis, J.; Demcheva, M.;

Salem, M.L. Paracrine delivery of IL-12 released from poly-N-acetyl glucosamine gel matrix induces comparable adjuvant effects to its systemic delivery in schistosomiasis

setting without toxicity. Unpublished.

Plasticity of T Cell Differentiation and Cytokine Signature Immun., Endoc. & Metab. Agents in Med. Chem., 2009, Vol. 9, No. 2 97

responses by targeting innate and adaptive immune

cells to generate functional immune responses [68,

155-157]. A direct and immediate recognition of

pathogens is primarily mediated by a set of germline-

encoded receptors known as pattern recognition recep-

tors (PRRs). These receptors, which include TLRs,

are able to recognize pathogen-associated molecular

patterns (PAMPs) that are unique to pathogenic

microorganisms and induce specific immune responses

against them. In contrast to pathogenic microbes,

however, cancer cells do not encode PAMPs. There-

fore, one potential approach to link innate and adaptive

arms of immunity against cancer would be by trig-

gering TLRs expressed in innate immune cells [157].

Induction of TLR signaling induces immediate release

of a plethora of inflammatory cytokines (most impor-

tantly IL-12) and chemokines, resulting in activation

and full maturation of dendritic cells and NK cells

[157-159]. These events are prerequisite for the genera-

tion and activation of Th1/Tc1 mediated anti-tumor

immunity. Indeed, several preclinical and clinical

studies, including ours, have shown that different TLR

agonists are potent

adjuvants for infectious disease

and cancer [82, 105, 158, 160-166]. The beneficial

effects of TLRLs to T cell responses can be attributed

to their effects on innate immune cells, in particular

NK cells and dendritic cells, on T cell themselves, and

on Treg cells. Effects of TLRLs are discussed in section

4.3. below. Recent studies, including ours, have shown

that T cells express TLRs [164, 167] and that ligation

of TLRs in CD4+ and CD8

+ T cells can costimulate

these cells and increase their proliferation, IFN-

secretion, and survival [164, 168-170]. Beside the

capability of TLRLs, in particular the TLR2L and

TLR9L, to costimulate T cells, they have been also

found to induce partial abrogation in the suppressive

activity of Treg cells [171-174]. Taken together, it can

be suggested that TLRLs can directly and indirectly

target and costimulate CD4+ and CD8

+ T cells and

instruct them to generate Th1 and Tc1 responses,

respectively.

4.3. Improving Antigen Presentation

Professional APCs, including dendritic cells, macro-

phages, and B cells, are critical components of the

immune system that are required to uptake, process,

and present antigen epitopes to T cells. The type and

activation status of APCs, however, are crucial for

shaping the quality and quantity of a T cell response

[175]. For instance, presentation of antigens by

immature plasmacytoid and conventional (i.e. myeloid)

dendritic cells can induce antigen-specific T cell

tolerance or Th2 responses. By contrast, presentation of

antigens by mature (i.e. highly activated) APCs license

T cells to differentiate into Th1/Tc1 type responses,

resulting in profound anti-microbial and anti-cancer

immune responses [176, 177]. Beside plasmacytoid and

myeloid dendritic cells, a new type of APCs that has

been emerged as a regulatory element is the peripheral

blood fibrocytes. These cells play an important role

in the pathogenesis of Lyme disease by skewing the

immune response during Borrelia infection from the

pathogenic Th1 type to the protective Th2 response

[178, 179]. Therefore, although immature APCs

can hinder the Th1 cell responses required to fight

against cancer and infectious diseases, they could be

a useful approach to control autoimmune diseases. In

this context, different strategies have been applied to

induce the activation and full maturation of APCs,

in particular dendritic cells, in order to enhance the

generation of optimal immunity.

One approach to increase the activation and matura-

tion phenotypes of different types of APCs is by trigge-

ring the signaling pathways of different TLRs expres-

sed in dendritic cells [180]. Several studies, including

ours, have established that treatment a host with

different TLR agonists, in particular TLR3 (poly(I:C)),

TLR7 (imiquimod), and TLR9 (CpG ODN) agonists

can induce activation of dendritic cells in situ [105,

177, 181]. Furthermore, in vitro treatment of ex vivo

bone marrow generated dendritic cells with these TLR

agonists can induce the full maturation of these cells,

resulting in substantial increases in antigen-specific T

cell responses [182-186]. These initial studies led to the

application of treatment with TLR agonists in different

clinical setting that require the development of strong

Th1 type responses [162, 187-192]. Increasing acti-

vation of dendritic cells can also be induced by their

transduction with GM-CSF, IL-12, and IL-18, which

are known as dendritic cell maturational factors [193-

201] or with the chemokine CCL21 or its receptor

CCR7, which induces the migration of dendritic cells

into the secondary lymphoid compartment such as

lymph nodes and spleen [71-79]. Interaction of matured

dendritic cells and T cells in lymph nodes induces

in most cases Th1 type responses. Besides increasing

activation and maturation of dendritic cells, increasing

the numbers of these cells in vivo is an interesting

approach. For instance, systemic administration of

Flt3L for consecutive 10 days was found to be a very

effective approach to increase the numbers of myeloid

DCs in circulation through mobilizing DC precursors

from bone marrow [93, 202, 203]. These mobilized

myeloid DCs were able to mount therapeutic Th1

responses [202].

98 Immun., Endoc. & Metab. Agents in Med. Chem., 2009, Vol. 9, No. 2 Salem et al.

5. FINAL REMARKS AND FUTURE CONSI-

DERATION

Preclinical studies accumulated explosive growth

in understanding the mechanisms governing the

differentiation of CD4+ T cells into Th1, Th2, or Th17

subtype and CD8+ T cells into Tc1 or Tc2 subtype.

The cytokine signature of these cell subsets and

the mode of action of these cytokines, in particular

those produced by Th1 and Th2 cells, have been

characterized in different disease settings and resulted

in potential relevant applications. Yet, several cytoki-

nes with potential adjuvant effects, in particular those

produced by Th17 cells, are being under evaluation

in preclinical studies, whereas they are awaiting

promising application in clinical settings in near future.

Depending on the nature of the disease, cytokine

profile can be beneficial or detrimental. On one hand,

application of Th1 cytokines can act as adjuvants to

patients with cancer and microbial infections. On the

other hand, blocking of Th1 cytokine can attenuate

Th1-mediated autoimmune diseases. The vice versa

is for Th2 cytokines. Future studies are required to

identify novel adjuvant cytokines, optimize delivery of

cytokines to their target in order to minimize toxicity,

optimize dosing and timing of cytokine treatment

for optimal activation and survival of T cells, and

define the proper combination of cytokines for optimal

adjuvanticity. Findings generated from these studies

would lead to significant improvement in the treatment

of autoimmune, infectious and cancer diseases.

REFERENCES

[1] Villinger, F. Cytokines as clinical adjuvants: how far are we? Expert Rev. Vaccines, 2003, 2(2), 317-326.

[2] Elenkov, I.J.; Iezzoni, D.G.; Daly, A.; Harris, A.G.; Chrousos, G.P. Cytokine dysregulation, inflammation and

well-being. Neuroimmunomodulation, 2005, 12(5), 255-269.

[3] Mosmann, T.R. Cytokines, differentiation and functions of subsets of CD4 and CD8 T cells. Behring Inst. Mitt., 1995,

(96), 1-6. [4] Ahmadzadeh, M.; Farber, D.L. Functional plasticity of an

antigen-specific memory CD4 T cell population. Proc. Natl. Acad. Sci. USA, 2002, 99(18), 11802-11807.

[5] Weaver, C.T.; Murphy, K.M. T-cell subsets: the more the merrier. Curr Biol., 2007, 17(2), R61-R63.

[6] Chaouat, G.; Ledee-Bataille, N.; Dubanchet, S.; Zourbas, S.; Sandra, O.; Martal, J. TH1/TH2 paradigm in pregnancy:

paradigm lost? Cytokines in pregnancy/early abortion: reexamining the TH1/TH2 paradigm. Int. Arch. Allergy

Immunol., 2004, 134(2), 93-119. [7] Behrens, G.; Li, M.; Smith, C.M.; Belz, G.T.; Mintern, J.;

Carbone, F.R.; Heath, W.R. Helper T cells, dendritic cells

and CTL Immunity. Immunol. Cell Biol., 2004, 82(1), 84-

90.

[8] Kennedy, R.; Celis, E. Multiple roles for CD4+ T cells in anti-tumor immune responses. Immunol. Rev., 2008, 222,

129-144.

[9] Woodland, D.L.; Dutton, R.W. Heterogeneity of CD4(+)

and CD8(+) T cells. Curr. Opin. Immunol., 2003, 15(3), 336-342.

[10] Wurster, A.L.; Rodgers, V.L.; Satoskar, A.R.; Whitters, M.J.; Young, D.A.; Collins, M.; Grusby, M.J. Interleukin

21 is a T helper (Th) cell 2 cytokine that specifically inhibits the differentiation of naive Th cells into interferon

gamma-producing Th1 cells. J. Exp. Med., 2002, 196(7), 969-977.

[11] Smeltz, R.B.; Chen, J.; Ehrhardt, R.; Shevach, E.M. Role of IFN-gamma in Th1 differentiation: IFN-gamma regulates

IL-18R alpha expression by preventing the negative effects of IL-4 and by inducing/maintaining IL-12 receptor beta 2

expression. J. Immunol., 2002, 168(12), 6165-6172. [12] Zhang, Y.; Apilado, R.; Coleman, J.; Ben-Sasson, S.;

Tsang, S.; Hu-Li, J.; Paul, W.E.; Huang, H. Interferon gamma stabilizes the T helper cell type 1 phenotype. J. Exp.

Med., 2001, 194(2), 165-172. [13] Wang, X.; Mosmann, T. In vivo priming of CD4 T cells that

produce interleukin (IL)-2 but not IL-4 or interferon (IFN)-gamma, and can subsequently differentiate into IL-4-

or IFN-gamma-secreting cells. J. Exp. Med., 2001, 194(8), 1069-1080.

[14] Chang, J.H.; McCluskey, P.J.; Wakefield, D. Toll-like receptors in ocular immunity and the immunopathogenesis

of inflammatory eye disease. Br. J. Ophthalmol., 2006, 90(1), 103-108.

[15] Weaver, C.T.; Murphy, K.M. The central role of the Th17 lineage in regulating the inflammatory/autoimmune axis.

Semin. Immunol., 2007, 19(6), 351-352. [16] Awasthi, A.; Kuchroo, V.K. Th17 cells: from precursors to

players in inflammation and infection. Int. Immunol., 2009, 21(5), 489-498.

[17] Aranami, T.; Yamamura, T. Th17 Cells and autoimmune encephalomyelitis (EAE/MS). Allergol. Int., 2008, 57(2),

115-120. [18] Sakaguchi, S.; Sakaguchi, N.; Asano, M.; Itoh, M.; Toda,

M. Immunologic self-tolerance maintained by activated T cells expressing IL-2 receptor alpha-chains (CD25). Break-

down of a single mechanism of self-tolerance causes various autoimmune diseases. J. Immunol., 1995, 155(3),

1151-1164. [19] Taams, L.S.; Akbar, A.N. Peripheral generation and func-

tion of CD4+CD25+ regulatory T cells. Curr. Top. Micro- biol. Immunol., 2005, 293, 115-131.

[20] Mills, K.H.; McGuirk, P. Antigen-specific regulatory T cells--their induction and role in infection. Semin. Immu-

nol., 2004, 16(2), 107-117. [21] Murakami, M.; Sakamoto, A.; Bender, J.; Kappler, J.;

Marrack, P. CD25+CD4+ T cells contribute to the control

of memory CD8+ T cells. Proc. Natl. Acad. Sci. USA, 2002,

99(13), 8832-8837.

[22] Mills, K.H. Regulatory T cells: friend or foe in immunity to

infection? Nat. Rev. Immunol., 2004, 4(11), 841-855.

[23] Curiel, T.J. Regulatory T cells and treatment of cancer.

Curr. Opin. Immunol., 2008, 20(2), 241-246.

[24] Mahnke, K.; Schonfeld, K.; Fondel, S.; Ring, S.; Karakhanova, S.; Wiedemeyer, K.; Bedke, T.; Johnson,

T.S.; Storn, V.; Schallenberg, S.; Enk, A.H. Depletion

of CD4+CD25+ human regulatory T cells in vivo: kinetics

of Treg depletion and alterations in immune functions

in vivo and in vitro. Int. J. Cancer, 2007, 120(12), 2723-

2733.

[25] Dannull, J.; Su, Z.; Rizzieri, D.; Yang, B.K.; Coleman, D.;

Yancey, D.; Zhang, A.; Dahm, P.; Chao, N.; Gilboa, E.;

Vieweg, J. Enhancement of vaccine-mediated antitumor

Plasticity of T Cell Differentiation and Cytokine Signature Immun., Endoc. & Metab. Agents in Med. Chem., 2009, Vol. 9, No. 2 99

immunity in cancer patients after depletion of regulatory T

cells. J. Clin. Invest., 2005, 115(12), 3623-3633.

[26] Schabowsky, R.H.; Madireddi, S.; Sharma, R.; Yolcu, E.S.;

Shirwan, H. Targeting CD4+CD25+FoxP3+ regulatory T-cells for the augmentation of cancer immunotherapy. Curr.

Opin. Investig. Drugs, 2007, 8(12), 1002-1008. [27] Audia, S.; Nicolas, A.; Cathelin, D.; Larmonier, N.;

Ferrand, C.; Foucher, P.; Fanton, A.; Bergoin, E.; Maynadie, M.; Arnould, L.; Bateman, A.; Lorcerie, B.; Solary, E.;

Chauffert, B.; Bonnotte, B. Increase of CD4+ CD25+ regulatory T cells in the peripheral blood of patients

with metastatic carcinoma: a Phase I clinical trial using cyclophosphamide and immunotherapy to eliminate CD4+

CD25+ T lymphocytes. Clin. Exp. Immunol., 2007, 150(3), 523-530.

[28] Kitani, A.; Xu, L. Regulatory T cells and the induction of IL-17. Mucosal. Immunol., 2008, 1(Suppl. 1), S43-S46.

[29] Pomie, C.; Menager-Marcq, I.; van Meerwijk, J.P. Murine CD8+ regulatory T lymphocytes: the new era. Hum.

Immunol., 2008, 69(11), 708-714. [30] Scotto, L.; Naiyer, A.J.; Galluzzo, S.; Rossi, P.; Manavalan,

J.S.; Kim-Schulze, S.; Fang, J.; Favera, R.D.; Cortesini, R.; Suciu-Foca, N. Overlap between molecular markers

expressed by naturally occurring CD4+CD25+ regulatory T cells and antigen specific CD4+CD25+ and CD8+CD28-

T suppressor cells. Hum. Immunol., 2004, 65(11), 1297-1306.

[31] Liu, J.; Liu, Z.; Witkowski, P.; Vlad, G.; Manavalan, J.S.; Scotto, L.; Kim-Schulze, S.; Cortesini, R.; Hardy, M.A.;

Suciu-Foca, N. Rat CD8+ FOXP3+ T suppressor cells mediate tolerance to allogeneic heart transplants, inducing

PIR-B in APC and rendering the graft invulnerable to rejection. Transpl. Immunol., 2004, 13(4), 239-247.

[32] Manavalan, J.S.; Kim-Schulze, S.; Scotto, L.; Naiyer, A.J.; Vlad, G.; Colombo, P.C.; Marboe, C.; Mancini, D.;

Cortesini, R.; Suciu-Foca, N. Alloantigen specific CD8+ CD28- FOXP3+ T suppressor cells induce ILT3+ ILT4+

tolerogenic endothelial cells, inhibiting alloreactivity. Int. Immunol., 2004, 16(8), 1055-1068.

[33] Waldmann, H.; Graca, L.; Cobbold, S.; Adams, E.; Tone, M.; Tone, Y. Regulatory T cells and organ transplantation.

Semin. Immunol., 2004, 16(2), 119-126. [34] Ciubotariu, R.; Colovai, A.I.; Pennesi, G.; Liu, Z.; Smith,

D.; Berlocco, P.; Cortesini, R.; Suciu-Foca, N. Specific suppression of human CD4+ Th cell responses to pig MHC antigens by CD8+CD28- regulatory T cells. J. Immunol., 1998, 161(10), 5193-5202.

[35] Colovai, A.I.; Liu, Z.; Ciubotariu, R.; Lederman, S.; Cortesini, R.; Suciu-Foca, N. Induction of xenoreactive CD4+ T-cell anergy by suppressor CD8+CD28- T cells. Transplantation, 2000, 69(7), 1304-1310.

[36] Filaci, G.; Fenoglio, D.; Fravega, M.; Ansaldo, G.; Borgonovo, G.; Traverso, P.; Villaggio, B.; Ferrera, A.; Kunkl, A.; Rizzi, M.; Ferrera, F.; Balestra, P.; Ghio, M.; Contini, P.; Setti, M.; Olive, D.; Azzarone, B.; Carmignani, G.; Ravetti, J.L.; Torre, G.; Indiveri, F. CD8+ CD28- T regulatory lymphocytes inhibiting T cell proliferative and cytotoxic functions infiltrate human cancers. J. Immunol., 2007, 179(7), 4323-4334.

[37] Najafian, N.; Chitnis, T.; Salama, A.D.; Zhu, B.; Benou, C.; Yuan, X.; Clarkson, M.R.; Sayegh, M.H.; Khoury, S.J. Regulatory functions of CD8+CD28- T cells in an auto- immune disease model. J. Clin. Invest., 2003, 112(7), 1037-1048.

[38] Akl, A.; Luo, S.; Wood, K.J. Induction of transplantation tolerance-the potential of regulatory T cells. Transpl. Immunol., 2005, 14(3-4), 225-230.

[39] Li, J.; Liu, Z.; Jiang, S.; Cortesini, R.; Lederman, S.; Suciu-

Foca, N. T suppressor lymphocytes inhibit NF-kappa B-

mediated transcription of CD86 gene in APC. J. Immunol.,

1999, 163(12), 6386-6392.

[40] Chang, C.C.; Ciubotariu, R.; Manavalan, J.S.; Yuan, J.;

Colovai, A.I.; Piazza, F.; Lederman, S.; Colonna, M.;

Cortesini, R.; Dalla-Favera, R.; Suciu-Foca, N. Tolerization

of dendritic cells by T(S) cells: the crucial role of inhibitory

receptors ILT3 and ILT4. Nat. Immunol., 2002, 3(3), 237-

243. [41] Manavalan, J.S.; Rossi, P.C.; Vlad, G.; Piazza, F.; Yarilina,

A.; Cortesini, R.; Mancini, D.; Suciu-Foca, N. High

expression of ILT3 and ILT4 is a general feature of

tolerogenic dendritic cells. Transpl. Immunol., 2003, 11(3-

4), 245-258.

[42] Liu, Y.; Chen, N.; Chen, G.; You, P. The protective effect

of CD8+CD28- T suppressor cells on the acute rejection

responses in rat liver transplantation. Transplant. Proc.,

2007, 39(10), 3396-3403.

[43] Sindhi, R.; Manavalan, J.S.; Magill, A.; Suciu-Foca, N.;

Zeevi, A. Reduced immunosuppression in pediatric liver-

intestine transplant recipients with CD8+CD28- T-suppressor cells. Hum. Immunol., 2005, 66(3), 252-257.

[44] Mueller, T.F. Phenotypic changes with immunosuppression

in human recipients. Front. Biosci., 2003, 8, d1254-1274.

[45] Zozulya, A.L.; Wiendl, H. The role of CD8 suppressors

versus destructors in autoimmune central nervous system

inflammation. Hum. Immunol., 2008, 69(11), 797-804.

[46] Suzuki, M.; Konya, C.; Goronzy, J.J.; Weyand, C.M.

Inhibitory CD8+ T cells in autoimmune disease. Hum.

Immunol., 2008, 69(11), 781-789.

[47] Davila, E.; Kang, Y.M.; Park, Y.W.; Sawai, H.; He, X.;

Pryshchep, S.; Goronzy, J.J.; Weyand, C.M. Cell-based

immunotherapy with suppressor CD8+ T cells in rheumatoid arthritis. J. Immunol., 2005, 174(11), 7292-

7301.

[48] Argiles, J.M.; Lopez-Soriano, F.J. The role of cytokines in

cancer cachexia. Med. Res. Rev., 1999, 19(3), 223-248.

[49] Salem, M.L. Estrogen, a double-edged sword: modulation

of TH1- and TH2-mediated inflammations by differential

regulation of TH1/TH2 cytokine production. Curr. Drug

Targets Inflamm. Allergy, 2004, 3(1), 97-104.

[50] Piccinni, M.P.; Scaletti, C.; Maggi, E.; Romagnani, S.

Role of hormone-controlled Th1- and Th2-type cytokines in

successful pregnancy. J. Neuroimmunol., 2000, 109(1), 30-

33. [51] Piccinni, M.P. T cells in normal pregnancy and recurrent

pregnancy loss. Reprod. Biomed. Online, 2006, 13(6), 840-

844.

[52] Andreakos, E.T.; Foxwell, B.M.; Brennan, F.M.; Maini,

R.N.; Feldmann, M. Cytokines and anti-cytokine biolo-

gicals in autoimmunity: present and future. Cytokine

Growth Factor Rev., 2002, 13(4-5), 299-313.

[53] O'Shea, J.J.; Ma, A.; Lipsky, P. Cytokines and auto-

immunity. Nat. Rev. Immunol., 2002, 2(1), 37-45.

[54] Ichinose, M.; Barnes, P.J. Cytokine-directed therapy in

asthma. Curr. Drug Targets Inflamm. Allergy, 2004, 3(3),

263-269. [55] Arai, K.I.; Lee, F.; Miyajima, A.; Miyatake, S.; Arai,

N.; Yokota, T. Cytokines: coordinators of immune and

inflammatory responses. Annu. Rev. Biochem., 1990, 59,

783-836.

[56] Wadia, P.P.; Tambur, A.R. Yin and yang of cytokine

regulation in solid organ graft rejection and tolerance. Clin.

Lab. Med., 2008, 28(3), 469-479, vii-viii.

100 Immun., Endoc. & Metab. Agents in Med. Chem., 2009, Vol. 9, No. 2 Salem et al.

[57] Brewer, J.M.; Alexander, J. Cytokines and the mechanisms

of action of vaccine adjuvants. Cytokines Cell Mol. Ther., 1997, 3(4), 233-246.

[58] Rizza, P.; Ferrantini, M.; Capone, I.; Belardelli, F. Cytoki-nes as natural adjuvants for vaccines: where are we now?

Trends Immunol., 2002, 23(8), 381-383. [59] Estaquier, J.; Idziorek, T.; Zou, W.; Emilie, D.; Farber,

C.M.; Bourez, J.M.; Ameisen, J.C. T helper type 1/T helper type 2 cytokines and T cell death: preventive effect of inter-

leukin 12 on activation-induced and CD95 (FAS/APO-1)-mediated apoptosis of CD4+ T cells from human immuno-

deficiency virus-infected persons. J. Exp. Med., 1995, 182(6), 1759-1767.

[60] Chamoto, K.; Kosaka, A.; Tsuji, T.; Matsuzaki, J.; Sato, T.; Takeshima, T.; Iwakabe, K.; Togashi, Y.; Koda, T.;

Nishimura, T. Critical role of the Th1/Tc1 circuit for the generation of tumor-specific CTL during tumor eradication

in vivo by Th1-cell therapy. Cancer Sci., 2003, 94(10), 924-928.

[61] Lai, Y.G.; Gelfanov, V.; Gelfanova, V.; Kulik, L.; Chu, C.L.; Jeng, S.W.; Liao, N.S. IL-15 promotes survi-

val but not effector function differentiation of CD8+ TCRalphabeta+ intestinal intraepithelial lymphocytes. J.

Immunol., 1999, 163(11), 5843-5850. [62] Tsuda, K.; Toda, M.; Kim, G.; Saitoh, K.; Yoshimura, S.;

Yoshida, T.; Taki, W.; Waga, S.; Kuribayashi, K. Survival-promoting activity of IL-7 on IL-2-dependent cytotoxic T

lymphocyte clones: resultant induction of G1 arrest. J. Immunol. Methods, 2000, 236, (1-2), 37-51.

[63] Schluns, K.S.; Kieper, W.C.; Jameson, S.C.; Lefrancois, L. Interleukin-7 mediates the homeostasis of naive and

memory CD8 T cells in vivo. Nat. Immunol., 2000, 1(5), 426-432.

[64] Fry, T.J.; Mackall, C.L. Interleukin-7: master regulator of peripheral T-cell homeostasis? Trends Immunol., 2001,

22(10), 564-571. [65] Berard, M.; Brandt, K.; Bulfone Paus, S.; Tough, D.F. IL-

15 promotes the survival of naive and memory phenotype CD8+ T cells. J. Immunol., 2003, 170(10), 5018-5026.

[66] Bulfone-Paus, S.; Ungureanu, D.; Pohl, T.; Lindner, G.; Paus, R.; Ruckert, R.; Krause, H.; Kunzendorf, U., Interleu-

kin-15 protects from lethal apoptosis in vivo. Nat. Med., 1997, 3(10), 1124-1128.

[67] Vella, A.T.; Dow, S.; Potter, T.A.; Kappler, J.; Marrack, P. Cytokine-induced survival of activated T cells in vitro and

in vivo. Proc. Natl. Acad. Sci. USA, 1998, 95(7), 3810-3815.

[68] Belardelli, F.; Ferrantini, M. Cytokines as a link between innate and adaptive antitumor immunity. Trends Immunol.,

2002, 23(4), 201-208. [69] Nguyen, C.L.; Salem, M.L.; Rubinstein, M.P.; Demcheva,

M.; Vournakis, J.N.; Cole, D.J.; Gillanders, W.E. Mecha-nisms of enhanced antigen-specific T cell response follo-

wing vaccination with a novel peptide-based cancer vaccine and systemic interleukin-2 (IL-2). Vaccine, 2003, 21(19-

20), 2318-2328. [70] Rubinstein, M.P.; Kadima, A.N.; Salem, M.L.; Nguyen,

C.L.; Gillanders, W.E.; Cole, D.J. Systemic administration of IL-15 augments the antigen-specific primary CD8+ T

cell response following vaccination with peptide-pulsed dendritic cells. J. Immunol., 2002, 169(9), 4928-4935.

[71] Terando, A.; Roessler, B.; Mule, J.J. Chemokine gene modification of human dendritic cell-based tumor vaccines

using a recombinant adenoviral vector. Cancer Gene Ther., 2004, 11(3), 165-173.

[72] Riedl, K.; Baratelli, F.; Batra, R.K.; Yang, S.C.; Luo, J.; Escuadro, B.; Figlin, R.; Strieter, R.; Sharma, S.; Dubinett,

S. Overexpression of CCL-21/secondary lymphoid tissue

chemokine in human dendritic cells augments chemotactic activities for lymphocytes and antigen presenting cells. Mol.

Cancer, 2003, 2, 35. [73] Tolba, K.A.; Bowers, W.J.; Muller, J.; Housekneckt, V.;

Giuliano, R.E.; Federoff, H.J.; Rosenblatt, J.D. Herpes simplex virus (HSV) amplicon-mediated codelivery of

secondary lymphoid tissue chemokine and CD40L results in augmented antitumor activity. Cancer Res., 2002, 62(22),

6545-6551. [74] Wiley, H.E.; Gonzalez, E.B.; Maki, W.; Wu, M.T.; Hwang,

S.T. Expression of CC chemokine receptor-7 and regional lymph node metastasis of B16 murine melanoma. J. Natl.

Cancer Inst., 2001, 93(21), 1638-1643. [75] Vicari, A.P.; Ait-Yahia, S.; Chemin, K.; Mueller, A.;

Zlotnik, A.; Caux, C. Antitumor effects of the mouse chemokine 6Ckine/SLC through angiostatic and immunolo-

gical mechanisms. J. Immunol., 2000, 165(4), 1992-2000. [76] Yang, S.C.; Hillinger, S.; Riedl, K.; Zhang, L.; Zhu, L.;

Huang, M.; Atianzar, K.; Kuo, B.Y.; Gardner, B.; Batra, R.K.; Strieter, R.M.; Dubinett, S.M.; Sharma, S. Intra-

tumoral administration of dendritic cells overexpressing CCL21 generates systemic antitumor responses and confers

tumor immunity. Clin. Cancer Res., 2004, 10(8), 2891-2901.

[77] Baratelli, F.; Takedatsu, H.; Hazra, S.; Peebles, K.; Luo, J.; Kurimoto, P.S.; Zeng, G.; Batra, R.K.; Sharma, S.;

Dubinett, S.M.; Lee, J.M. Pre-clinical characterization of GMP grade CCL21-gene modified dendritic cells for appli-

cation in a phase I trial in non-small cell lung cancer. J. Transl. Med., 2008, 6, 38.

[78] Yang, S.C.; Batra, R.K.; Hillinger, S.; Reckamp, K.L.; Strieter, R.M.; Dubinett, S.M.; Sharma, S. Intrapulmonary

administration of CCL21 gene-modified dendritic cells reduces tumor burden in spontaneous murine bronchoal-

veolar cell carcinoma. Cancer Res., 2006, 66(6), 3205-3213.

[79] Okada, N.; Mori, N.; Koretomo, R.; Okada, Y.; Nakayama, T.; Yoshie, O.; Mizuguchi, H.; Hayakawa, T.; Nakagawa,

S.; Mayumi, T.; Fujita, T.; Yamamoto, A. Augmentation of the migratory ability of DC-based vaccine into regional

lymph nodes by efficient CCR7 gene transduction. Gene Ther., 2005, 12(2), 129-139.

[80] Rosenberg, S.A.; Restifo, N.P.; Yang, J.C.; Morgan, R.A.; Dudley, M.E. Adoptive cell transfer: a clinical path to

effective cancer immunotherapy. Nat. Rev. Cancer, 2008, 8(4), 299-308.

[81] Dudley, M.E.; Rosenberg, S.A. Adoptive cell transfer therapy. Semin. Oncol., 2007, 34(6), 524-531.

[82] Salem, M.L.; Kadima, A.N.; El-Naggar, S.A.; Rubinstein, M.P.; Chen, Y.; Gillanders, W.E.; Cole, D.J. Defining the

ability of cyclophosphamide preconditioning to enhance the antigen-specific CD8+ T-cell response to peptide vaccina-

tion: creation of a beneficial host microenvironment involving type I IFNs and myeloid cells. J. Immunother.,

2007, 30(1), 40-53. [83] Hadden, J.; Verastegui, E.; Barrera, J.L.; Kurman, M.;

Meneses, A.; Zinser, J.W.; de la Garza, J.; Hadden, E. A trial of IRX-2 in patients with squamous cell carcinomas of

the head and neck. Int. Immunopharmacol., 2003, 3(8), 1073-1081.

[84] Cole, D.J.; Sanda, M.G.; Yang, J.C.; Schwartzentruber, D.J.; Weber, J.; Ettinghausen, S.E.; Pockaj, B.A.; Kim, H.I.;

Levin, R.D.; Pogrebniak, H.W.; Balkissoon, J.; Fenton, R.M.; DeBarge, L.R.; Kaye, J.; Rosenberg, S.A.; Parkinson,

D.R. Phase I trial of recombinant human macrophage colony-stimulating factor administered by continuous

Plasticity of T Cell Differentiation and Cytokine Signature Immun., Endoc. & Metab. Agents in Med. Chem., 2009, Vol. 9, No. 2 101

intravenous infusion in patients with metastatic cancer. J.

Natl. Cancer Inst., 1994, 86(1), 39-45. [85] Leveque, L.; Deknuydt, F.; Bioley, G.; Old, L.J.; Matsuza-

ki, J.; Odunsi, K.; Ayyoub, M.; Valmori, D. Interleukin 2-mediated conversion of ovarian cancer-associated CD4+

regulatory T cells into proinflammatory interleukin 17-producing helper T cells. J. Immunother., 2009, 32(2), 101-

108. [86] Balkwill, F.R.; Griffin, D.B.; Lee, A.E. Interferons alpha

and gamma differ in their ability to cause tumour stasis and regression in vivo. Eur. J. Cancer Clin. Oncol., 1989,

25(10), 1481-1486. [87] Belardelli, F.; Ferrantini, M.; Proietti, E.; Kirkwood, J.M.

Interferon-alpha in tumor immunity and immunotherapy. Cytokine Growth Factor Rev., 2002, 13(2), 119-134.

[88] Brassard, D.L.; Grace, M.J.; Bordens, R.W. Interferon-alpha as an immunotherapeutic protein. J. Leukoc. Biol.,

2002, 71(4), 565-581. [89] Legha, S.S. Durable complete responses in metastatic

melanoma treated with interleukin-2 in combination with interferon alpha and chemotherapy. Semin. Oncol., 1997,

24(1 Suppl. 4), S39-S43. [90] Mitchell, M.S. Combinations of anticancer drugs and

immunotherapy. Cancer Immunol. Immunother., 2003, 52(11), 686-692.

[91] Mitchell, M.S. Immunotherapy as part of combinations for the treatment of cancer. Int. Immunopharmacol., 2003, 3(8),

1051-1059. [92] Yi, T.; Pathak, M.K.; Lindner, D.J.; Ketterer, M.E.; Farver,

C.; Borden, E.C. Anticancer activity of sodium stiboglu- conate in synergy with IFNs. J. Immunol., 2002, 169(10),

5978-5985. [93] Peretz, Y.; Zhou, Z.F.; Halwani, F.; Prud'homme, G.J.

In vivo generation of dendritic cells by intramuscular codelivery of FLT3 ligand and GM-CSF plasmids. Mol.

Ther., 2002, 6(3), 407-414. [94] Rosenberg, S.A.; Yang, J.C.; Robbins, P.F.; Wunderlich,

J.R.; Hwu, P.; Sherry, R.M.; Schwartzentruber, D.J.; Topalian, S.L.; Restifo, N.P.; Filie, A.; Chang, R.; Dudley,

M.E. Cell transfer therapy for cancer: lessons from sequen-tial treatments of a patient with metastatic melanoma. J.

Immunother., 2003, 26(5), 385-393. [95] Dobrzanski, M.J.; Reome, J.B.; Hollenbaugh, J.A.; Dutton,

R.W. Tc1 and Tc2 effector cell therapy elicit long-term tumor immunity by contrasting mechanisms that result in

complementary endogenous type 1 antitumor responses. J. Immunol., 2004, 172(3), 1380-1390.

[96] Dobrzanski, M.J.; Reome, J.B.; Hollenbaugh, J.A.; Hylind, J.C.; Dutton, R.W. Effector cell-derived lymphotoxin alpha

and Fas ligand, but not perforin, promote Tc1 and Tc2 effector cell-mediated tumor therapy in established pulmo-

nary metastases. Cancer Res., 2004, 64(1), 406-414. [97] Hollenbaugh, J.A.; Reome, J.; Dobrzanski, M.; Dutton,

R.W. The rate of the CD8-dependent initial reduction in tumor volume is not limited by contact-dependent perforin,

Fas ligand, or TNF-mediated cytolysis. J. Immunol., 2004, 173(3), 1738-1743.

[98] Reome, J.B.; Hylind, J.C.; Dutton, R.W.; Dobrzanski, M.J. Type 1 and type 2 tumor infiltrating effector cell subpopula-

tions in progressive breast cancer. Clin. Immunol., 2004, 111(1), 69-81.

[99] Klebanoff, C.A.; Gattinoni, L.; Torabi-Parizi, P.; Kerstann, K.; Cardones, A.R.; Finkelstein, S.E.; Palmer, D.C.;

Antony, P.A.; Hwang, S.T.; Rosenberg, S.A.; Waldmann, T.A.; Restifo, N.P. Central memory self/tumor-reactive

CD8+ T cells confer superior antitumor immunity compared

with effector memory T cells. Proc. Natl. Acad. Sci. USA,

2005, 102(27), 9571-9576. [100] Schluns, K.S.; Lefrancois, L. Cytokine control of memory

T-cell development and survival. Nat. Rev. Immunol., 2003, 3(4), 269-279.

[101] Klebanoff, C.A.; Finkelstein, S.E.; Surman, D.R.; Lichtman, M.K.; Gattinoni, L.; Theoret, M.R.; Grewal, N.;

Spiess, P.J.; Antony, P.A.; Palmer, D.C.; Tagaya, Y.; Rosenberg, S.A.; Waldmann, T.A.; Restifo, N.P. IL-15

enhances the in vivo antitumor activity of tumor-reactive CD8+ T cells. Proc. Natl. Acad. Sci. USA, 2004, 101(7),

1969-1974. [102] Diaz-Montero, C.M.; El Naggar, S.; Al Khami, A.; El

Naggar, R.; Montero, A.J.; Cole, D.J.; Salem, M.L. Priming of naive CD8+ T cells in the presence of IL-12 selectively

enhances the survival of CD8+CD62Lhi cells and results in superior anti-tumor activity in a tolerogenic murine model.

Cancer Immunol. Immunother., 2008, 57(4), 563-572. [103] Muranski, P.; Boni, A.; Wrzesinski, C.; Citrin, D.E.;

Rosenberg, S.A.; Childs, R.; Restifo, N.P. Increased inten- sity lymphodepletion and adoptive immunotherapy-how

far can we go? Nat. Clin. Pract. Oncol., 2006, 3(12), 668-681.

[104] Finkelstein, S.E.; Heimann, D.M.; Klebanoff, C.A.; Antony, P.A.; Gattinoni, L.; Hinrichs, C.S.; Hwang, L.N.;

Palmer, D.C.; Spiess, P.J.; Surman, D.R.; Wrzesiniski, C.; Yu, Z.; Rosenberg, S.A.; Restifo, N.P. Bedside to bench

and back again: how animal models are guiding the development of new immunotherapies for cancer. J.

Leukoc. Biol., 2004, 76(2), 333-337. [105] Salem, M.L.; Diaz-Montero, C.M.; Al-Khami, A.A.;

El-Naggar, S.A.; Naga, O.; Montero, A.J.; Khafagy, A.; Cole, D.J. Recovery from cyclophosphamide-induced

lymphopenia results in expansion of immature dendritic cells which can mediate enhanced prime-boost vaccination

antitumor responses in vivo when stimulated with the TLR3 agonist poly(I:C). J. Immunol., 2009, 182(4), 2030-2040.

[106] Agrawal, L.; Lu, X.; Jin, Q.; Alkhatib, G. Anti-HIV therapy: Current and future directions. Curr. Pharm. Des.,

2006, 12(16), 2031-2055. [107] Ndhlovu, L.C.; Chapman, J.M.; Jha, A.R.; Snyder-

Cappione, J.E.; Pagan, M.; Leal, F.E.; Boland, B.S.; Norris, P.J.; Rosenberg, M.G.; Nixon, D.F. Suppression of HIV-1

plasma viral load below detection preserves IL-17 produ-cing T cells in HIV-1 infection. AIDS, 2008, 22(8), 990-

992. [108] Alfano, M.; Crotti, A.; Vicenzi, E.; Poli, G. New players in

cytokine control of HIV infection. Curr. HIV/AIDS Rep., 2008, 5(1), 27-32.

[109] Maek, A.N.W.; Buranapraditkun, S.; Klaewsongkram, J.; Ruxrungtham, K. Increased interleukin-17 production both

in helper T cell subset Th17 and CD4-negative T cells in human immunodeficiency virus infection. Viral Immunol.,

2007, 20(1), 66-75. [110] Fowler, D.H.; Gress, R.E. Th2 and Tc2 cells in the regula-

tion of GVHD, GVL, and graft rejection: considerations for the allogeneic transplantation therapy of leukemia and

lymphoma. Leuk. Lymphoma, 2000, 38(3-4), 221-234. [111] Salem, M.L.; Matsuzaki, G.; Kishihara, K.; Madkour, G.A.;

Nomoto, K. beta-estradiol suppresses T cell-mediated delayed-type hypersensitivity through suppression of

antigen-presenting cell function and Th1 induction. Int. Arch. Allergy Immunol., 2000, 121(2), 161-169.

[112] Salem, M.L.; Matsuzaki, G.; Madkour, G.A.; Nomoto, K. Beta-estradiol-induced decrease in IL-12 and TNF-alpha

expression suppresses macrophage functions in the course

102 Immun., Endoc. & Metab. Agents in Med. Chem., 2009, Vol. 9, No. 2 Salem et al.

of Listeria monocytogenes infection in mice. Int. J. Immuno-

pharmacol., 1999, 21(8), 481-497. [113] Nath, N.; Giri, S.; Prasad, R.; Salem, M.L.; Singh, A.K.;

Singh, I. 5-aminoimidazole-4-carboxamide ribonucleoside: a novel immunomodulator with therapeutic efficacy in

experimental autoimmune encephalomyelitis. J. Immunol., 2005, 175(1), 566-574.

[114] Salem, M.L.; Kishihara, K.; Abe, K.; Matsuzaki, G.; Nomoto, K. N-3 polyunsaturated fatty acids accentuate B16

melanoma growth and metastasis through suppression of tumoricidal function of T cells and macrophages. Anti-

cancer Res., 2000, 20(5A), 3195-3203. [115] Salem, M.L. Systemic treatment with n-6 polyunsaturated

fatty acids attenuates EL4 thymoma growth and metastasis through enhancing specific and non-specific anti-tumor

cytolytic activities and production of TH1 cytokines. Int. Immunopharmacol., 2005, 5(6), 947-960.

[116] Dinarello, C.A. Anti-cytokine therapeutics and infections. Vaccine, 2003, 21(Suppl. 2), S24-34.

[117] Andreakos, E. Targeting cytokines in autoimmunity: new approaches, new promise. Expert Opin. Biol. Ther., 2003,

3(3), 435-447. [118] Kauffman, C.L.; Aria, N.; Toichi, E.; McCormick, T.S.;

Cooper, K.D.; Gottlieb, A.B.; Everitt, D.E.; Frederick, B.; Zhu, Y.; Graham, M.A.; Pendley, C.E.; Mascelli, M.A. A

phase I study evaluating the safety, pharmacokinetics, and clinical response of a human IL-12 p40 antibody in subjects

with plaque psoriasis. J. Invest. Dermatol., 2004, 123(6), 1037-1044.

[119] Ferber, I.A.; Brocke, S.; Taylor-Edwards, C.; Ridgway, W.; Dinisco, C.; Steinman, L.; Dalton, D.; Fathman, C.G. Mice

with a disrupted IFN-gamma gene are susceptible to the induction of experimental autoimmune encephalomyelitis

(EAE). J. Immunol., 1996, 156(1), 5-7. [120] Chu, C.Q.; Wittmer, S.; Dalton, D.K. Failure to suppress

the expansion of the activated CD4 T cell population in interferon gamma-deficient mice leads to exacerbation of

experimental autoimmune encephalomyelitis. J. Exp. Med., 2000, 192(1), 123-128.

[121] Dalton, D.K.; Haynes, L.; Chu, C.Q.; Swain, S.L.; Wittmer, S. Interferon gamma eliminates responding CD4 T cells

during mycobacterial infection by inducing apoptosis of activated CD4 T cells. J. Exp. Med., 2000, 192(1), 117-

122. [122] Willenborg, D.O.; Fordham, S.A.; Staykova, M.A.;

Ramshaw, I.A.; Cowden, W.B. IFN-gamma is critical to the control of murine autoimmune encephalomyelitis and

regulates both in the periphery and in the target tissue: a possible role for nitric oxide. J. Immunol., 1999, 163(10),

5278-5286. [123] Manoury-Schwartz, B.; Chiocchia, G.; Bessis, N.; Abehsira-

Amar, O.; Batteux, F.; Muller, S.; Huang, S.; Boissier, M.C.; Fournier, C. High susceptibility to collagen-induced

arthritis in mice lacking IFN-gamma receptors. J. Immunol., 1997, 158(11), 5501-5506.

[124] Vermeire, K.; Heremans, H.; Vandeputte, M.; Huang, S.; Billiau, A.; Matthys, P. Accelerated collagen-induced

arthritis in IFN-gamma receptor-deficient mice. J. Immunol., 1997, 158(11), 5507-5513.

[125] Ortmann, R.A.; Shevach, E.M. Susceptibility to collagen-induced arthritis: cytokine-mediated regulation. Clin. Immunol.,

2001, 98(1), 109-118. [126] Brem-Exner, B.G.; Sattler, C.; Hutchinson, J.A.; Koehl,

G.E.; Kronenberg, K.; Farkas, S.; Inoue, S.; Blank, C.; Knechtle, S.J.; Schlitt, H.J.; Fandrich, F.; Geissler, E.K.

Macrophages driven to a novel state of activation have

anti-inflammatory properties in mice. J. Immunol., 2008,

180(1), 335-349. [127] Markees, T.G.; Phillips, N.E.; Gordon, E.J.; Noelle, R.J.;

Shultz, L.D.; Mordes, J.P.; Greiner, D.L.; Rossini, A.A. Long-term survival of skin allografts induced by donor

splenocytes and anti-CD154 antibody in thymectomized mice requires CD4(+) T cells, interferon-gamma, and

CTLA4. J. Clin. Invest., 1998, 101(11), 2446-2455. [128] Bishop, D.K.; Chan Wood, S.; Eichwald, E.J.; Orosz, C.G.

Immunobiology of allograft rejection in the absence of IFN-gamma: CD8+ effector cells develop independently

of CD4+ cells and CD40-CD40 ligand interactions. J. Immunol., 2001, 166(5), 3248-3255.

[129] Saleem, S.; Konieczny, B.T.; Lowry, R.P.; Baddoura, F.K.; Lakkis, F.G. Acute rejection of vascularized heart allografts

in the absence of IFNgamma. Transplantation, 1996, 62(12), 1908-1911.

[130] Konieczny, B.T.; Dai, Z.; Elwood, E.T.; Saleem, S.; Linsley, P.S.; Baddoura, F.K.; Larsen, C.P.; Pearson, T.C.;

Lakkis, F.G. IFN-gamma is critical for long-term allograft survival induced by blocking the CD28 and CD40 ligand T

cell costimulation pathways. J. Immunol., 1998, 160(5), 2059-2064.

[131] Guillonneau, C.; Hill, M.; Hubert, F.X.; Chiffoleau, E.; Herve, C.; Li, X.L.; Heslan, M.; Usal, C.; Tesson, L.;

Menoret, S.; Saoudi, A.; Le Mauff, B.; Josien, R.; Cuturi, M.C.; Anegon, I. CD40Ig treatment results in allograft

acceptance mediated by CD8CD45RC T cells, IFN-gamma, and indoleamine 2,3-dioxygenase. J. Clin. Invest., 2007,

117(4), 1096-1106. [132] Feng, G.; Gao, W.; Strom, T.B.; Oukka, M.; Francis, R.S.;

Wood, K.J.; Bushell, A. Exogenous IFN-gamma ex vivo shapes the alloreactive T-cell repertoire by inhibition

of Th17 responses and generation of functional Foxp3+ regulatory T cells. Eur. J. Immunol., 2008, 38(9), 2512-

2527. [133] Murphy, W.J.; Welniak, L.; Back, T.; Hixon, J.; Subleski,

J.; Seki, N.; Wigginton, J.M.; Wilson, S.E.; Blazar, B.R.; Malyguine, A.M.; Sayers, T.J.; Wiltrout, R.H. Synergistic

anti-tumor responses after administration of agonistic antibodies to CD40 and IL-2: coordination of dendritic and

CD8+ cell responses. J. Immunol., 2003, 170(5), 2727-2733.

[134] Sigidin, Y.A.; Loukina, G.V.; Skurkovich, B.; Skurkovich, S. Randomized, double-blind trial of anti-interferon-gamma

antibodies in rheumatoid arthritis. Scand. J. Rheumatol., 2001, 30(4), 203-207.

[135] Afzali, B.; Lombardi, G.; Lechler, R.I.; Lord, G.M. The role of T helper 17 (Th17) and regulatory T cells (Treg) in

human organ transplantation and autoimmune disease. Clin. Exp. Immunol., 2007, 148(1), 32-46.

[136] Kleinschek, M.A.; Boniface, K.; Sadekova, S.; Grein, J.; Murphy, E.E.; Turner, S.P.; Raskin, L.; Desai, B.; Faubion,

W.A.; de Waal Malefyt, R.; Pierce, R.H.; McClanahan, T.; Kastelein, R.A. Circulating and gut-resident human Th17

cells express CD161 and promote intestinal inflammation. J. Exp. Med., 2009, 206(3), 525-534.

[137] Annunziato, F.; Cosmi, L.; Santarlasci, V.; Maggi, L.; Liotta, F.; Mazzinghi, B.; Parente, E.; Fili, L.; Ferri, S.;

Frosali, F.; Giudici, F.; Romagnani, P.; Parronchi, P.; Tonelli, F.; Maggi, E.; Romagnani, S. Phenotypic and

functional features of human Th17 cells. J. Exp. Med., 2007, 204(8), 1849-1861.

[138] Pene, J.; Chevalier, S.; Preisser, L.; Venereau, E.; Guilleux, M.H.; Ghannam, S.; Moles, J.P.; Danger, Y.; Ravon, E.;

Lesaux, S.; Yssel, H.; Gascan, H. Chronically inflamed

Plasticity of T Cell Differentiation and Cytokine Signature Immun., Endoc. & Metab. Agents in Med. Chem., 2009, Vol. 9, No. 2 103

human tissues are infiltrated by highly differentiated Th17

lymphocytes. J. Immunol., 2008, 180(11), 7423-7430. [139] Hsieh, H.G.; Loong, C.C.; Lin, C.Y. Interleukin-17 induces

src/MAPK cascades activation in human renal epithelial cells. Cytokine, 2002, 19(4), 159-174.

[140] Loong, C.C.; Hsieh, H.G.; Lui, W.Y.; Chen, A.; Lin, C.Y. Evidence for the early involvement of interleukin 17 in

human and experimental renal allograft rejection. J. Pathol., 2002, 197(3), 322-332.

[141] Van Kooten, C.; Boonstra, J.G.; Paape, M.E.; Fossiez, F.; Banchereau, J.; Lebecque, S.; Bruijn, J.A.; De Fijter, J.W.;

Van Es, L.A.; Daha, M.R. Interleukin-17 activates human renal epithelial cells in vitro and is expressed during renal

allograft rejection. J. Am. Soc. Nephrol., 1998, 9(8), 1526-1534.

[142] Yoshida, S.; Haque, A.; Mizobuchi, T.; Iwata, T.; Chiyo, M.; Webb, T.J.; Baldridge, L.A.; Heidler, K.M.;

Cummings, O.W.; Fujisawa, T.; Blum, J.S.; Brand, D.D.; Wilkes, D.S. Anti-type V collagen lymphocytes that

express IL-17 and IL-23 induce rejection pathology in fresh and well-healed lung transplants. Am. J. Transplant., 2006,

6(4), 724-735. [143] Vanaudenaerde, B.M.; Dupont, L.J.; Wuyts, W.A.;

Verbeken, E.K.; Meyts, I.; Bullens, D.M.; Dilissen, E.; Luyts, L.; Van Raemdonck, D.E.; Verleden, G.M. The

role of interleukin-17 during acute rejection after lung transplantation. Eur. Respir. J., 2006, 27(4), 779-787.

[144] Li, J.; Simeoni, E.; Fleury, S.; Dudler, J.; Fiorini, E.; Kappenberger, L.; von Segesser, L.K.; Vassalli, G. Gene

transfer of soluble interleukin-17 receptor prolongs cardiac allograft survival in a rat model. Eur. J. Cardiothorac.

Surg., 2006, 29(5), 779-783. [145] Tang, J.L.; Subbotin, V.M.; Antonysamy, M.A.; Troutt,

A.B.; Rao, A.S.; Thomson, A.W. Interleukin-17 antagonism inhibits acute but not chronic vascular rejection. Transplan-

tation, 2001, 72(2), 348-350. [146] Yuan, X.; Paez-Cortez, J.; Schmitt-Knosalla, I.; D'Addio,

F.; Mfarrej, B.; Donnarumma, M.; Habicht, A.; Clarkson, M.R.; Iacomini, J.; Glimcher, L.H.; Sayegh, M.H.; Ansari,

M.J. A novel role of CD4 Th17 cells in mediating cardiac allograft rejection and vasculopathy. J. Exp. Med., 2008,

205(13), 3133-3144. [147] Carlson, M.J.; West, M.L.; Coghill, J.M.; Panoskaltsis-

Mortari, A.; Blazar, B.R.; Serody, J.S. In vitro-differen- tiated TH17 cells mediate lethal acute graft-versus-host

disease with severe cutaneous and pulmonary pathologic manifestations. Blood, 2009, 113(6), 1365-1374.

[148] Yi, T.; Zhao, D.; Lin, C.L.; Zhang, C.; Chen, Y.; Todorov, I.; LeBon, T.; Kandeel, F.; Forman, S.; Zeng, D. Absence of

donor Th17 leads to augmented Th1 differentiation and exacerbated acute graft-versus-host disease. Blood, 2008,

112(5), 2101-2110. [149] Rochlitz, C.F. Gene therapy of cancer. Drugs Today (Barc),

2000, 36(9), 619-629. [150] Ferrantini, M.; Belardelli, F. Gene therapy of cancer with

interferon: lessons from tumor models and perspectives for clinical applications. Semin. Cancer Biol., 2000, 10(2), 145-

157. [151] Salem, M.L.; Gillanders, W.E.; Kadima, A.N.; El-Naggar,

S.; Rubinstein, M.P.; Demcheva, M.; Vournakis, J.N.; Cole, D.J. Review: novel nonviral delivery approaches for

interleukin-12 protein and gene systems: curbing toxicity and enhancing adjuvant activity. J. Interferon Cytokine

Res., 2006, 26(9), 593-608. [152] Cole, D.J.; Connolly, R.J.; Chan, M.W.; Schwaitzberg,

S.D.; Byrne, T.K.; Adams, D.B.; Baron, P.L.; O'Brien, P.H.; Metcalf, J.S.; Demcheva, M.; Vournakis, J. A pilot

study evaluating the efficacy of a fully acetylated poly-N-

acetyl glucosamine membrane formulation as a topical hemostatic agent. Surgery, 1999, 126(3), 510-517.

[153] Salem, M.L.; Kadima, A.N.; Zhou, Y.; Nguyen, C.L.; Rubinstein, M.P.; Demcheva, M.; Vournakis, J.N.; Cole,

D.J.; Gillanders, W.E. Paracrine release of IL-12 stimulates IFN-gamma production and dramatically enhances the

antigen-specific T cell response after vaccination with a novel peptide-based cancer vaccine. J. Immunol., 2004,

172(9), 5159-5167. [154] Salem, M.L.; EL-Naggar, S.; Kadima, A.N.; Vournakis,

J.N.; Cole, D.J.; Gillanders, W.E. Novel non-viral delivery system enhances the efficacy of DNA vaccines targeting

cytotoxic T lymphocytes. 4th Annual Research Retreat, November 11th, Charleston; SC, USA, 2004.

[155] Bendelac, A.; Medzhitov, R. Adjuvants of immunity: harnessing innate immunity to promote adaptive immunity.

J. Exp. Med., 2002, 195(5), F19-F23. [156] Durand, V.; Wong, S.Y.; Tough, D.F.; Le Bon, A. Shaping

of adaptive immune responses to soluble proteins by TLR agonists: a role for IFN-alpha/beta. Immunol. Cell Biol.,

2004, 82(6), 596-602. [157] Schnare, M.; Barton, G.M.; Holt, A.C.; Takeda, K.; Akira,

S.; Medzhitov, R. Toll-like receptors control activation of adaptive immune responses. Nat. Immunol., 2001, 2(10),

947-950. [158] van Duin, D.; Medzhitov, R.; Shaw, A.C. Triggering TLR

signaling in vaccination. Trends Immunol., 2006, 27(1), 49-55.

[159] Takeda, K.; Akira, S. Roles of Toll-like receptors in innate immune responses. Genes Cells, 2001, 6(9), 733-742.

[160] Seya, T.; Akazawa, T.; Uehori, J.; Matsumoto, M.; Azuma, I.; Toyoshima, K. Role of toll-like receptors and their

adaptors in adjuvant immunotherapy for cancer. Anticancer Res., 2003, 23(6a), 4369-4376.

[161] Schwarz, K.; Storni, T.; Manolova, V.; Didierlaurent, A.; Sirard, J.C.; Rothlisberger, P.; Bachmann, M.F. Role

of Toll-like receptors in costimulating cytotoxic T cell responses. Eur. J. Immunol., 2003, 33(6), 1465-1470.

[162] Gearing, A.J. Targeting toll-like receptors for drug develop- ment: a summary of commercial approaches. Immunol. Cell

Biol., 2007, 85(6), 490-494. [163] Ishii, K.J.; Uematsu, S.; Akira, S. 'Toll' gates for future

immunotherapy. Curr. Pharm. Des., 2006, 12(32), 4135-4142.

[164] Salem, M.L.; Diaz-Montero, C.M.; El-Naggar, S.A.; Chen, Y.; Moussa, O.; Cole, D.J. The TLR3 agonist poly(I:C)

targets CD8+ T cells and augments their antigen-specific responses upon their adoptive transfer into naive recipient

mice. Vaccine, 2009, 27(4), 549-557. [165] Salem, M.L.; El-Naggar, S.A.; Kadima, A.; Gillanders,

W.E.; Cole, D.J. The adjuvant effects of the toll-like receptor 3 ligand polyinosinic-cytidylic acid poly (I:C)

on antigen-specific CD8+ T cell responses are partially dependent on NK cells with the induction of a beneficial

cytokine milieu. Vaccine, 2006, 24(24), 5119-5132. [166] Salem, M.L.; Kadima, A.N.; Cole, D.J.; Gillanders, W.E.

Defining the antigen-specific T-cell response to vaccination and poly(I:C)/TLR3 signaling: evidence of enhanced

primary and memory CD8 T-cell responses and antitumor immunity. J. Immunother., 2005, 28(3), 220-228.

[167] Kabelitz, D. Expression and function of Toll-like receptors in T lymphocytes. Curr. Opin. Immunol., 2007, 19(1), 39-

45. [168] Tabiasco, J.; Devevre, E.; Rufer, N.; Salaun, B.; Cerottini,

J.C.; Speiser, D.; Romero, P. Human effector CD8+ T

104 Immun., Endoc. & Metab. Agents in Med. Chem., 2009, Vol. 9, No. 2 Salem et al.

lymphocytes express TLR3 as a functional coreceptor. J.

Immunol., 2006, 177(12), 8708-8713. [169] Gelman, A.E.; Zhang, J.; Choi, Y.; Turka, L.A. Toll-like

receptor ligands directly promote activated CD4+ T cell survival. J. Immunol., 2004, 172(10), 6065-6073.

[170] Cottalorda, A.; Verschelde, C.; Marcais, A.; Tomkowiak, M.; Musette, P.; Uematsu, S.; Akira, S.; Marvel, J.; Bonnefoy-

Berard, N. TLR2 engagement on CD8 T cells lowers the threshold for optimal antigen-induced T cell activation. Eur.

J. Immunol., 2006, 36(7), 1684-1693. [171] Sutmuller, R.P.; Morgan, M.E.; Netea, M.G.; Grauer, O.;

Adema, G.J. Toll-like receptors on regulatory T cells: expanding immune regulation. Trends Immunol., 2006,

27(8), 387-393. [172] Wang, R.F. Regulatory T cells and toll-like receptors in

cancer therapy. Cancer Res., 2006, 66(10), 4987-4990. [173] Sutmuller, R.P.; den Brok, M.H.; Kramer, M.; Bennink,

E.J.; Toonen, L.W.; Kullberg, B.J.; Joosten, L.A.; Akira, S.; Netea, M.G.; Adema, G.J. Toll-like receptor 2 controls

expansion and function of regulatory T cells. J. Clin. Invest., 2006, 116(2), 485-494.

[174] Wang, R.F.; Peng, G.; Wang, H.Y. Regulatory T cells and Toll-like receptors in tumor immunity. Semin. Immunol.,

2006, 18(2), 136-142. [175] Banchereau, J.; Fay, J.; Pascual, V.; Palucka, A.K. Dendritic

cells: controllers of the immune system and a new promise for immunotherapy. Novartis Found. Symp., 2003, 252,

226-235; discussion 235-228, 257-267. [176] Albert, M.L.; Jegathesan, M.; Darnell, R.B. Dendritic cell

maturation is required for the cross-tolerization of CD8+ T cells. Nat. Immunol., 2001, 2(11), 1010-1017.

[177] Banchereau, J.; Palucka, A.K. Dendritic cells as therapeutic vaccines against cancer. Nat. Rev. Immunol., 2005, 5(4),

296-306. [178] Grab, D.J.; Salem, M.L.; Dumler, J.S.; Bucala, R. A role

for the peripheral blood fibrocyte in leishmaniasis? Trends Parasitol., 2004, 20(1), 12.

[179] Grab, D.J.; Salim, M.; Chesney, J.; Bucala, R.; Lanners, H.N. A role for peripheral blood fibrocytes in Lyme

disease? Med. Hypotheses, 2002, 59(1), 1-10. [180] Takeda, K.; Akira, S. Toll-like receptors in innate immunity.

Int. Immunol., 2005, 17(1), 1-14. [181] Fajardo-Moser, M.; Berzel, S.; Moll, H. Mechanisms of

dendritic cell-based vaccination against infection. Int. J. Med. Microbiol., 2008, 298(1-2), 11-20.

[182] Lore, K.; Betts, M.R.; Brenchley, J.M.; Kuruppu, J.; Khojasteh, S.; Perfetto, S.; Roederer, M.; Seder, R.A.;

Koup, R.A. Toll-like receptor ligands modulate dendritic cells to augment cytomegalovirus- and HIV-1-specific T

cell responses. J. Immunol., 2003, 171(8), 4320-4328. [183] Edwards, A.D.; Diebold, S.S.; Slack, E.M.; Tomizawa, H.;

Hemmi, H.; Kaisho, T.; Akira, S.; Reis e Sousa, C. Toll-like receptor expression in murine DC subsets: lack of TLR7

expression by CD8 alpha+ DC correlates with unresponsi-veness to imidazoquinolines. Eur. J. Immunol., 2003, 33(4),

827-833. [184] Datta, S.K.; Redecke, V.; Prilliman, K.R.; Takabayashi, K.;

Corr, M.; Tallant, T.; DiDonato, J.; Dziarski, R.; Akira, S.; Schoenberger, S.P.; Raz, E. A subset of Toll-like receptor

ligands induces cross-presentation by bone marrow-derived dendritic cells. J. Immunol., 2003, 170(8), 4102-4110.

[185] Kadowaki, N.; Ho, S.; Antonenko, S.; Malefyt, R.W.; Kastelein, R.A.; Bazan, F.; Liu, Y.J. Subsets of human

dendritic cell precursors express different toll-like receptors and respond to different microbial antigens. J. Exp. Med.,

2001, 194(6), 863-869.

[186] West, M.A.; Wallin, R.P.; Matthews, S.P.; Svensson,

H.G.; Zaru, R.; Ljunggren, H.G.; Prescott, A.R.; Watts, C. Enhanced dendritic cell antigen capture via toll-like

receptor-induced actin remodeling. Science, 2004, 305 (5687), 1153-1157.

[187] Spaner, D.E.; Masellis, A. Toll-like receptor agonists in the treatment of chronic lymphocytic leukemia. Leukemia,

2007, 21(1), 53-60. [188] Foldes, G.; von Haehling, S.; Anker, S.D. Toll-like receptor

modulation in cardiovascular disease: a target for inter- vention? Expert Opin. Investig. Drugs, 2006, 15(8), 857-

871. [189] Horner, A.A. Update on toll-like receptor ligands and

allergy: implications for immunotherapy. Curr. Allergy Asthma Rep., 2006, 6(5), 395-401.

[190] Baldridge, J.R.; McGowan, P.; Evans, J.T.; Cluff, C.; Mossman, S.; Johnson, D.; Persing, D. Taking a Toll on

human disease: Toll-like receptor 4 agonists as vaccine adjuvants and monotherapeutic agents. Expert Opin. Biol.

Ther., 2004, 4(7), 1129-1138. [191] Stockfleth, E.; Trefzer, U.; Garcia-Bartels, C.; Wegner, T.;

Schmook, T.; Sterry, W. The use of Toll-like receptor-7 agonist in the treatment of basal cell carcinoma: an over-

view. Br. J. Dermatol., 2003, 149(Suppl. 66), 53-56. [192] Krieg, A.M. Antiinfective applications of toll-like receptor

9 agonists. Proc. Am. Thorac. Soc., 2007, 4(3), 289-294. [193] Grohmann, U.; Bianchi, R.; Belladonna, M.L.; Silla, S.;

Surace, D.; Fioretti, M.C.; Puccetti, P. Dendritic cells and interleukin 12 as adjuvants for tumor-specific vaccines.

Adv. Exp. Med. Biol., 1997, 417, 579-582. [194] Ahonen, C.L.; Doxsee, C.L.; McGurran, S.M.; Riter, T.R.;

Wade, W.F.; Barth, R.J.; Vasilakos, J.P.; Noelle, R.J.; Kedl, R.M. Combined TLR and CD40 triggering induces potent

CD8+ T cell expansion with variable dependence on type I IFN. J. Exp. Med., 2004, 199(6), 775-784.

[195] Zhu, X.P.; Chen, Z.Z.; Li, C.T.; Lin, X.; Zhuang, J.L.; Hu, J.D.; Yang, T.; Xu, Z.S. In vitro inducing effect of

dendritic cells cotransfected with survivin and granulocyte-macrophage colony-stimulating factor on cytotoxic T cell to

kill leukemic cells. Chin. Med. J. (Engl.), 2008, 121(21), 2180-2184.

[196] Tatsumi, T.; Takehara, T.; Yamaguchi, S.; Sasakawa, A.; Miyagi, T.; Jinushi, M.; Sakamori, R.; Kohga, K.; Uemura,

A.; Ohkawa, K.; Storkus, W.J.; Hayashi, N. Injection of IL-12 gene-transduced dendritic cells into mouse liver tumor

lesions activates both innate and acquired immunity. Gene Ther., 2007, 14(11), 863-871.

[197] Satoh, Y.; Esche, C.; Gambotto, A.; Shurin, G.V.; Yurkovetsky, Z.R.; Robbins, P.D.; Watkins, S.C.; Todo, S.;

Herberman, R.B.; Lotze, M.T.; Shurin, M.R. Local administration of IL-12-transfected dendritic cells induces

antitumor immune responses to colon adenocarcinoma in the liver in mice. J. Exp. Ther. Oncol., 2002, 2(6), 337-

349. [198] Tanaka, F.; Hashimoto, W.; Robbins, P.D.; Lotze, M.T.;

Tahara, H. Therapeutic and specific antitumor immunity induced by co-administration of immature dendritic cells

and adenoviral vector expressing biologically active IL-18. Gene Ther., 2002, 9(21), 1480-1486.

[199] Bontkes, H.J.; Kramer, D.; Ruizendaal, J.J.; Kueter, E.W.; van Tendeloo, V.F.; Meijer, C.J.; Hooijberg, E. Dendritic

cells transfected with interleukin-12 and tumor-associated antigen messenger RNA induce high avidity cytotoxic T

cells. Gene Ther., 2007, 14(4), 366-375. [200] Vujanovic, L.; Ranieri, E.; Gambotto, A.; Olson, W.C.;

Kirkwood, J.M.; Storkus, W.J. IL-12p70 and IL-18 gene-

Plasticity of T Cell Differentiation and Cytokine Signature Immun., Endoc. & Metab. Agents in Med. Chem., 2009, Vol. 9, No. 2 105

modified dendritic cells loaded with tumor antigen-derived

peptides or recombinant protein effectively stimulate specific Type-1 CD4+ T-cell responses from normal donors

and melanoma patients in vitro. Cancer Gene Ther., 2006, 13(8), 798-805.

[201] Iinuma, H.; Okinaga, K.; Fukushima, R.; Inaba, T.; Iwasaki, K.; Okinaga, A.; Takahashi, I.; Kaneko, M. Superior protec-

tive and therapeutic effects of IL-12 and IL-18 gene-transduced dendritic neuroblastoma fusion cells on liver

metastasis of murine neuroblastoma. J. Immunol., 2006, 176(6), 3461-3469.

[202] Encke, J.; Bernardin, J.; Geib, J.; Barbakadze, G.; Bujdoso,

R.; Stremmel, W. Genetic vaccination with Flt3-L and GM-CSF as adjuvants: Enhancement of cellular and humoral

immune responses that results in protective immunity in a murine model of hepatitis C virus infection. World J.

Gastroenterol., 2006, 12(44), 7118-7125. [203] Pillarisetty, V.G.; Miller, G.; Shah, A.B.; DeMatteo, R.P.

GMCSF expands dendritic cells and their progenitors in mouse liver. Hepatology, 2003, 37(3), 641-652.

Received: September 9, 2008 Revised: March 30, 2009 Accepted: June 9, 2009