Overview : Innate Immune Response

Overview:

InnateImmune Response

Receptors Detect Infection

Toll-like Receptors

Toll-like Receptors

Signal Transduction

Signal Transduction

Ubiquity of Innate Immunity

Review: Cells of the Immune SystemLeukocytes – White blood cells

Myelocytes –macrophage, neutrophil, eosinophil,basophil

Lymphocytes – B, T and NK cells

From Larsson and Karlsson (2005)

Review: Myelocytes•Macrophages – phagocytes, antigen presenting cells (APCs), specialized cells different organs, secrete cytokines, produce complement proteins, can produce ROS/RNS.

•Neutrophils – phagoctyes, can produce ROS/RNS, secrete antimicrobial peptides, 1st cell type to migrate from blood to infections, main targets are bacteria and fungi

•Eosinophils – phagocyte, targets parasites

•Basophils – secrete cytokines, involved in allergic response

• B cells – naïve B cells: contain antigen binding receptor (or membrane bound antibody), once activated –

memory cells: provides memory of antigen/antibody interaction; plasma cells: secrete soluble antibody

Review: Lymphocytes

• T cells - contain antigen binding receptor (TCR)TH cells: secretes cytokines that activate B cells, TC cells,

macrophages and others.TC cells: eliminates altered/damaged self cells (particularly

those infected by viruses), fights tumors cells, secrete cytotoxins.Treg cells: helps suppress immune response, plays a role in

tolerance.

Review: Lymphocytes

T reg cell

•Natural killer cells – distinct from T and B cells due to lack of an antigen binding receptor, similar in function to TC cells, macrophage activation, defense against viruses, fight tumor formation, secrete cytotoxins.

Review: Cells of the Immune System

Derived from both lymphoid and myeloid precursors

•Dendritic cells – phagoctyes, antigen presenting cells (APCs), can produce ROS, secrete proinflammatory cytokines, secrete antimicrobial peptides.

Review: Cells of the Immune System

Review: Organs of the Immune SystemPrimary and secondary lymphoid organs:

1°- maturation of lymphocytes

2°- sites where mature lymphocytes interact with antigen.

Level of organization:

collection of cells vs.

lymphoid follicle

Review: Innate and adaptive immunity

Review: Innate Immune Response