Cytokines

Question 1

IL-1

Answer 1

• -Fever
• -Acute inflammation
• -Activates endothelium to express adhesion molecules
• -Induces chemokine secretion to recruit RBCs
• -Secreted by macrophages

Question 2

IL-2

Answer 2

• -Stimulates growth of helper, cytotoxic, and regulatory T cells and NK cells.
• -Major growth factor for T lymphocytes
• -Secreted by all T cells

Question 3

IL-3

Answer 3

• -Supports growth and differentiation of bone marrow stem cells.
• -Functions like GM-CSF.
• –Secreted by all T cells

Question 4

IL-4

Answer 4

• -Induces differentiation of T cells into Th2 cells.
• -Promotes growth of B cells
• -Enhances class switching to IgE and IgG.
• -From Th2 cells
• -Th0 –> Th2

Question 5

IL-5

Answer 5

• -Promotes growth and differentiation of B cells.
• -Enhances class switching to IgA
• -Stimulates growth and differentiation of eosinophils
• -From Th2 cells

Question 6

IL-6

Answer 6

• -Fever
• -Stimulates production of acute-phase proteins
• -Secreted by macrophages

Question 7

IL-8

Answer 7

• -Major chemotactic factor for neutrophils
• -Help clear infections
• -Secreted by macrophages

Question 8

IL-10

Answer 8

• -Ends inflammatory response
• -Decreases expression of MHC class II and Th1 cytokines
• -Inhibits activated macrophages and dendritic cells
• -Also secreted by regulatory T cells
• -From Th2 cells

Question 9

IL-12

Answer 9

• -Induces differentiation of T cells into Th1 cells
• -Activates NK cells
• -Secreted by macrophages
• -Th0 –> Th1

Question 10

TNF-alpha

Answer 10

• -Mediates septic shock
• -Activates endothelium
• -Causes WBC recruitment, vascular leak
• -Causes cachexia in malignancy
• -Secreted by macrophages

Question 11

IFN-gamma

Answer 11

• -Secreted by NK cells and T cells in response to IL-12 from macrophages
• -Stimulates macrophages to kill phagocytosed pathogens
• -Inhibits differentiation of Th2 cells
• -Activates NK cells to kill virus-infected cells.
• -Increases MHC expression and antigen presentation by all cells
• -Mediates TB granuloma formation.
• -From Th1 cells

Question 12

IFN-alpha and IFN-beta

Answer 12

• -Part of innate host defense against both RNA and DNA viruses
• -Interferons are glycoproteins synthesized by virus-infected cells that act locally on uninfected cells, “priming them” for viral defense by helping to selectively degrade viral nucleic acid and protein
• -“Interfere” with viruses

Question 13

Th1 stimulates what cytokines?

Answer 13

IL-2 and IFN-gamma

Question 14

Th2 stimulates what cytokines?

Answer 14

IL-4, IL-5, IL-10, and IL-13

Question 15

Macrophages stimulate what cytokines?

Answer 15

IL-12