HIV-1 TRANSMISSION FROM SEMEN TO CERVICO-VAGINAL TISSUE EX VIVO Andrea Introini 1, Christophe Vanpouille 1, Andrea Lisco 1, Jean-Charles Grivel, Arshi.

HIV-1 TRANSMISSION FROM SEMEN TO CERVICO-VAGINAL

TISSUE EX VIVO

Andrea Introini1, Christophe Vanpouille1, Andrea Lisco1, Jean-Charles Grivel,

Arshi Munawwar2, Sarman Singh2, and Leonid Margolis1

1National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States, 2All India

Institute of Medical Sciences, New Delhi, India

Vaginal intercourse is the main route of HIV-1 sexual

transmission

HIV- infection of human cervico-vaginal tissue ex vivo

rectosigmoid

tonsillar

exocervicalHIV-1 in seminal fluid

Semen and blood from 50 HIV-1-

infected and 33 HIV-uninfected

men

SEMEN AND BLOOD ARE SEPARATE IMMUNOLOGICAL COMPARTMENTS

IL-1α

IL-1β

IL-6

IL-7

IL-8

IL-1

5

IL-2

Eota

xin

IFN

-γ

IL-1

6

MIG

IP-1

0

MC

P-1

MIP

-1α

MIP

-3α

MIP

-1β

SDF-

1βTN

F-α

TGF-β

GM

-CSF

SemenBlood

Sem

en:

Blo

od

pla

sma

rati

o

(S:B

ra

tio

)

HIV-1-UNINFECTED INDIVIDUALS

(HIV-1-uninfected)

seminal plasma blood plasma

The 2-way hierarchical cluster analysis confirms that blood and semen have 2 distinct cytokine profiles

Cytokine levels: high; low

IL-1aIL1-aIL-7

MCP-1IP-10IL-8MIG

MIP-3aSDF-1b

IL-6TGF-bIL-15IL-1b

MIP-1aGM-CSF

IL-2IGN-gIL-16

EotaxinMIP-1bTNF-a

20 c

orre

lati

ons

Correlations between cytokine levels in seminal plasma

HIV+-0.25 ≤ ≤ -0.5

+0.5 ≤ ≤ +0.7 ≥ +0.7

+0.25 ≤ ≤ +0.5No correlation

-0.5 ≤ ≤ -0.7 ≥ -0.7

HIV

¯71 correlations

HERPESVIRUSES REACTIVATION IN SEMINAL PLASMA

0%

2000%

4000%

6000%

8000%

HIV-1-infected%

of p

osi

tive

sa

mp

les

40

20

0

60

80

1

2

3

4

5

6

7

8

9

CMV

1

2

3

4

5

6EBV

Vir

al lo

ad

[lo

g 10 c

opie

s/m

L]

Vir

al lo

ad

[l

og10

cop

ies/

mL

]

blood semen blood semen

CMV and EBV seminal shedding occurs in absence of plasma viremia in 75 and 54% of the patients, respectively

EBV and CMV reactivation is compartmentalized

IL-7 is increased in semen ofchronically HIV-1-infected individuals

IL-7

(pg

/ml)

IL-7

(pg

/ml)

Blood Semen

IL-7

IL-7 role in HIV-1 transmission

to cervico-vaginal tissue?

IL-7

IL-7IL-7

Thymus

Naïve T-cell

Memory T-cell

Stromal cell

Survival Proliferation

HIV-1 infection of human tissue ex vivo

HIV-1IL-7

Collagen raft

3 6 9 121

2

3

Days

IL-7 enhances HIV-1 replication in cervico-vaginal tissue ex vivo

HIV

-1 p

24ga

g (

ng/m

l)

3 6 9 120

1

2

3

4

Days

HIV-1BaL

HIV-1BaL + IL-7

[BaL

+IL

-7]

[BaL

]

HIV-1BaL HIV-1BaL+ IL-7

CD4

HIV-1 p24gag

Day 6

IL-7 increases the number of HIV-1-infected CD4 T-cells

0.0

10.0

20.0

30.0

40.0

50.0

CD

4+ d

eple

tion

(%)

p=0.0005

IL-7 decreases HIV-1-induced CD4 T-cells depletion

Day 9

- +IL-7

HIV-1LAI.04

0.00

4.00

8.00

12.00

IL-7 decreases apoptosis ofHIV-1-infected CD4 T-cells

IL-7

- +

Day 6 p=0.0049

HIV-1LAI.04

p24 g

ag+ A

PO

2.7+

(% o

f C

D4+

)

IL-7 decreases apoptosis ofHIV-1-infected CD4 T-cells

Day 9

Bcl-2

HIV-1LAI.04

HIV-1LAI.04 + IL-7C

um

ula

tive

dis

trib

uti

on

fun

ctio

n

Conclusions

• Semen and blood are immunologically separate compartment which differ in their cytokine spectra.

• HIV-1 infection enhances this difference changing the entire pattern of cytokine networks.

• IL-7 is one of the seminal cytokines greatly upregulated in HIV-1 infected men

• Upon deposition on cervico-vaginal tissue IL-7 enhances HIV-1 transmission

• Enhancement of HIV-1 infection is associated with IL-7-mediated prevention of death of HIV-1-infected CD4 T-cells, due to suppression of apoptosis

• Cervico-vaginal tissue contains much less CD4 T cells than lymph nodes or other lymphoid organs, which may be one of the reasons for a relatively low probability of male-to-female HIV-1 sexual transmission. By preventing the death of the small initial pool of infected cells, IL-7 gives HIV more time to find and infect target cells in cervix/vagina and to start dissemination

• Concentration of IL-7 in the semen of an HIV-1 infected man may be a determinant of infectiousness for his uninfected female partner.

Speculations