Immunology Flashcards
what are cytokine signals?
signals usually generated by noncovalent binding of a ligand to a complementary cell bound receptor >
change in the transcriptional program of the target cell (change in metabolic or proliferative state)
what are cytokines?
proteins that mediate the effector functions of the immune system
what are the ways in which cytokines can act?
- endocrine action: released into the bloodstream to affect distant cells
- paracrine action: released to affect nearby cells
- autocrine action: released, but then bind to receptors on the cell that produced them
define pleiotropic activity of cytokines
induces different biologic effect dependent on target cell
define redundant activity of cytokines
mediates similar effects on target cell
define synergy activity of cytokines
combines two cytokine activities to be greater than additive effect
define antagonistic activity of cytokines
effect inhibits one cytokines effect by anothers action
define cascade activity of cytokines
effect of one cytokine on one target cell to produce additional cytokine(s)
what are the classes of cytokines?
- IL 1
- class 1 (hematopoietin)
- class 2 (interferon)
- TNF
- IL 17
- chemokines
IL-1 Family functions, stimulation, secretion, and action
- promote inflammation
- stimulated by viral, parasitic, or bacterial antigens
- secreted early in immune responses by macrophages and dendritic cells
- act locally on capillary permeability and to pull leukocytes to infected tissues
- acts systemically to signal liver to produce acute phase proteins
- help initiate adaptive immune response
cytokines secreted by macrophages
acute: IL1, IL6, TNFa
then recruit IL8 and IL12
cytokines secreted by T cells
IL2
IL3
cytokines secreted by Th1 cells
IFN-y (gamma)
cytokines secreted by Th2
IL4
IL5
IL10
IL13
what are the ILs (1-6)
Hot T-bone stEAK
IL…
- fever (hot)
- stim T cells
- stim bone marrow
- stim IgE production
- stim IgA production
- stim aKute-phase protein production
IL-1
- osteoclast activating factor
- causes fever and acute inflammation
- activates endothelium to express adhesion molecules
- induces chemokine secretion to recruit WBC (via vasodilation)
IL-2
- secreted by T cells
- stim growth of helper, cytotoxic, and regulatory T cells
- stim growth of NK cells
IL-3
- secreted by T cells
- stim growth and differentiation of bone marrow stem cells
IL-4
- secreted from Th2 cells
- induces differentiation of T cells in Th (helper) 2 cells
- promotes growth of B cells
- enhances class switching to IgE and IgG
Aint too proud 2 BEG 4 HELP
IL-5
- secreted from Th2 cells
- promotes growth and differentiation of B cells
- enhances class switching to IgA
- stim growth and diff of eosinophils
I have 5 BAEs
IL-6
- causes fever and stim production of acute phase proteins
- secreted by macrophages
IL-8
- major chemokine factor for recruitment of neutrophils
- secreted by macrophages
Clean up on aisle 8! (clean up infection)
