Cytokine Functions

Question 1

Interleukin-2 (IL-2)

Answer 1

T cells

T cells: proliferation and differentiation into effector and memory cells; promotes regulatory T cell development, survival, and function NK cells: proliferation, activation B cells: proliferation, antibody synthesis (in vitro)

Question 2

Interleukin-3 (IL-3)

Answer 2

T cells

Immature hematopoietic progenitors: induced maturation of all hematopoietic lineages

Question 3

Interleukin-4 (IL-4)

Answer 3

CD4 + T cells (T H2), mast cells

B cells: isotype switching to IgE T cells: T H2 differentiation, proliferation Macrophages: alternative activation and inhibition of IFN-γ–mediated classical activation Mast cells: proliferation (in vitro)

Question 4

Interleukin-5 (IL-5)

Answer 4

CD4 + T cells (T H2)

Eosinophils: activation, increased generationB cells: proliferation, IgA production (in vitro)

Question 5

Interleukin-6 (IL-6)

Answer 5

Macrophages, endothelial cells, T cells

Liver: synthesis of acute-phase protein B cells: proliferation of antibody-producing cells. Isotype switch from IgM to IgG. Responsible for IgG burst.

Question 6

Interleukin-7 (IL-7)

Answer 6

Fibroblasts, bone marrow stromal cells

Immature lymphoid progenitors: proliferation of early T and B cell progenitors T lymphocytes: survival of naive and memory cells

Question 7

Interleukin-12 (IL-12)

Answer 7

IL-12A (p35) IL-12B (p40)

Macrophages, dendritic cells

T cells: T H1 differentiation NK cells and T cells: IFN-γ synthesis, increased cytotoxic activity

Question 8

Interleukin-13 (IL-13)

Answer 8

CD4 + T cells (T H2), NKT cells, mast cells

B cells: isotype switching to IgE Epithelial cells: increased mucus production Fibroblasts: increased collagen synthesis Macrophages: alternative activation

Question 9

Interleukin-15 (IL-15)

Answer 9

Macrophages, others

NK cells: proliferation T cells: survival and proliferation of memory CD8 + cells

Question 10

Interleukin-16 (IL-16)

Answer 10

T cells, mast cells, eosinophils, epithelial cells

CD4 + T cells, monocytes, and eosinophils: chemoattractant

Question 11

Interleukin-17

Answer 11

T cells

Endothelial cells: increased chemokine production Macrophages: increased chemokine and cytokine production Epithelial cells: GM-CSF and G-CSF production

Question 12

Interleukin-21 (IL-21)

Answer 12

T H2 cells, T H17 cells, T FH cells

B cells: activation, proliferation, differentiation T FH cells: development T H17 cells: increased generation? NK cells: functional maturation

Question 13

Interleukin-23 (IL-23) Heterodimer: IL-23A (p19), IL-12B (p40)

Answer 13

Macrophages, dendritic cells

T cells: maintenance of IL-17–producing T cells

Question 14

Interleukin-25 (IL-25)

Answer 14

T cells, mast cells, eosinophils, macrophages, mucosal epithelial cells

T cells and various other cell types: expression of IL-4, IL-5, IL-13

Question 15

Stem cell factor (c-Kit ligand)

Answer 15

Bone marrow stromal cells

Pluripotent hematopoietic stem cells: induced maturation of all hematopoietic lineages

Question 16

Granulocyte-monocyte CSF (GM-CSF)

Answer 16

T cells, macrophages, endothelial cells, fibroblasts

Immature and committed progenitors, mature macrophages: induced maturation of granulocytes and monocytes, macrophage activation

Question 17

Monocyte CSF (M-CSF, CSF1)

Answer 17

Macrophages, endothelial cells, bone marrow cells, fibroblasts

Committed hematopoietic progenitors: induced maturation of monocytes

Question 18

Granulocyte CSF (G-CSF, CSF3)

Answer 18

Macrophages, fibroblasts, endothelial cells

Committed hematopoietic progenitors: induced maturation of granulocytes

Question 19

Interferon-γ (IFN-γ)

Answer 19

T cells (T H1, CD8 + T cells), NK cells

Macrophages: classical activation (increased microbicidal functions) B cells: isotype switching to opsonizing and complement-fixing IgG subclasses (established in mice) T cells: T H1 differentiation Various cells: increased expression of class I and class II MHC molecules, increased antigen processing and presentation to T cells

Question 20

Interleukin-10 (IL-10)

Answer 20

Macrophages, T cells (mainly regulatory T cells)

Macrophages, dendritic cells: inhibition of expression of IL-12, costimulators, and class II MHC

Question 21

Interleukin-19 (IL-19)

Answer 21

Macrophages

Macrophages: stimulates IL-1 and TNF secretion Keratinocytes: proliferation

Question 22

Interleukin-22 (IL-22)

Answer 22

T H17 cells

Epithelial cells: production of defensins, increased barrier functionHepatocytes: survival

Question 23

Tumor necrosis factor (TNF)

Answer 23

Macrophages, NK cells, T cells

Endothelial cells: activation (inflammation, coagulation) Neutrophils: activation Hypothalamus: fever Liver: synthesis of acute-phase proteins Muscle, fat: catabolism (cachexia)

Question 24

BAFF

Answer 24

Dendritic cells, monocytes, follicular dendritic cells B cells

B cells: survival, proliferation

Question 25

APRIL

Answer 25

T cells, dendritic cells, monocytes, follicular dendritic cells

B cells: survival, proliferation

Question 26

Transforming growth factor-β (TGF-β)

Answer 26

T cells (mainly Tregs), macrophages, other cell types

T cells: inhibition of proliferation and effector functions; differentiation of T H17 and Treg B cells: inhibition of proliferation; IgA production Macrophages: inhibition of activation; stimulation of angiogenic factors Fibroblasts: increased collagen synthesis

Question 27

Interleukin-1α (IL-1α)

Answer 27

Macrophages, dendritic cells, fibroblasts, endothelial cells, keratinocytes, hepatocytes

Endothelial cells: activation (inflammation, coagulation) Hypothalamus: fever Liver: synthesis of acute-phase proteins

Question 28

Interleukin-1β (IL-1β)

Answer 28

Macrophages, dendritic cells, fibroblasts, endothelial cells, keratinocytes, hepatocytes

Endothelial cells: activation (inflammation, coagulation) Hypothalamus: fever Liver: synthesis of acute-phase proteins