Fundamentals of Immunology - Cytokines

Flashcards on Cytokines and their roles in the immune system.

Cytokines

Variety of proteins secreted by cells of the immune system that regulate immune responses, such as proliferation, differentiation, and maturation of nearby cells.

Lymphokines

Cytokines produced by T cells.

Monokines

Cytokines produced by monocytes.

Pleiotropy

The ability of one cytokine to act on different cell types.

Redundancy

Many different cytokines may have similar effect

Synergy

Cytokines work optimally only when in association with other cytokines.

Antagonism

Cytokines may prevent or inhibit the action of others.

Autocrine

Cytokines bind to receptors on the cell that produced them.

Paracrine

Cytokines bind to receptors on cells in close proximity to the cell origin.

Endocrine

Cytokines spread throughout the body, affecting cells in distant locations.

Interleukins

Cytokines that regulate the interactions between lymphocytes and other leukocytes.

Interferons

Antiviral cytokines that are produced in response to virus infection or immune stimulation.

Tumor Necrotic Factors (TNFs)

Cytokines derived from macrophages and T cells that can kill tumor cells.

Growth Factors

Cytokines that control leukocyte production by regulating stem cell growth.

Chemokines

Cytokines that play an important role in leukocyte circulation and migration, especially in inflammation, acting as chemotactic factors and leukocyte activators.

Interleukin 1

Plays a critical role in inflammation, fever, hematopoiesis, appetite control, bone metabolism and acquired immunity and its major source is macrophage

Interleukin-2

Produced by Th1 cells and targets T cells, B cells and NK cells and activates helper and cytotoxic T cells and NK cells.

Interleukin 3

Stimulates the growth and maturation of bone marrow stem cells for eosinophils, neutrophils and monocytes.

Interleukin 4

Stimulates the growth and differentiation of B cells and of major importance in the development of allergic reactions by inducing B cells to switch to IgE production.

Interleukin 5

Controls the eosinophil production by stimulating growth and differentiation of eosinophil precursors in the bone marrow.

Interleukin 6

Promotes IL-2 production and T cell differentiation and required for the final maturation of B cells into plasma cells.

Interleukin 7

Regulates the activity of lymphoid stem cells and has a major role to control lymphocyte function.

Interleukin 9

Promotes the growth of helper T cells and mast cells and contributes to the development of allergic diseases

Interleukin 10

An immunosuppressive and anti-inflammatory cytokine that regulates inflammation as well as T cell, NK cells and macrophage function

Interleukin 11

Stimulates B cell growth in association with IL-6 and also stimulates megakaryocyte colony formation in association with IL-3 and promotes the production of acute-phase proteins.

Interleukin 12

Promotes Th1 activity by inducing secretion of IL-2 and IFN-γ and enhances T and NK cell proliferation and cytotoxicity.

Interleukin 13

Required for optimal induction of IgE and enhances macrophage expression of integrins and is a chemoattractant for monocytes.

Interleukin 14

Inhibits immunoglobulin secretion and selectively expands some B cell subpopulations

Interleukin 15

Essential for the prolonged survival of memory cells

IL-16

Regulates CD4+ T cell recruitment and activation and stimulates chemotaxis and cell adhesion

IL-17

Induce the production of cytokines by cells and proliferation of T cells and myeloid stem cells. It is also Proinflammatory

Interferon α

A potent stimulator of both innate and adaptive immunity and activates NK cell-mediated cytotoxicity activity

Interferon β

Interferes with viral RNA and protein synthesis.

Interferon-γ

Stimulated B cell production and enhances T cell production of MHC class I molecules but not production of MHC class II molecules

TNF-α

A potent proinflammatory molecule and many of its activities are shared with IL-1

TNF-β

Kills tumor cells and activates neutrophils, macrophages, endothelial cells and B cells

Granulocyte Colony-stimulating factor (G-CSF)

Regulates the maturation of granulocyte progenitors into mature neutrophils

Macrophage Colony-stimulating factors (M-CSF)

Act on monocyte progenitors to induce their proliferation and differentiation and promote macrophage cytotoxicity

Transforming Growth Factors β (TGF- β)

Regulate cell division, enhance the deposition of extracellular matrix proteins and most importantly, they are immunosuppressive