Cytokines Flashcards
IL-1
macrophage acute
Causes fever, acute inflammation. Activates endothelium to express adhesion molecules. Induces chemokine secretion to recruit WBCs. Also called osteoclast-activating factor.
“Hot T-bone stEAK”: IL-1: fever (hot). IL-2: stimulates T cells. IL-3: stimulates bone marrow. IL-4: stimulates IgE production. IL-5: stimulates IgA production. IL-6: stimulates aKute-phase protein production.
IL-6
macrophage acute
Causes fever and stimulates production of acute- phase proteins.
TNF-alpha
macrophage acute
Activates endothelium. Causes WBC recruitment, vascular leak.
Causes cachexia in malignancy.
Maintains granulomas in TB.
IL-1, IL-6, TNF-α can mediate fever and sepsis.
IL-8
macrophage recruit
Major chemotactic factor for neutrophils.
“Clean up on aisle 8.” Neutrophils are recruited by IL-8 to clear infections.
IL-12
macrophage recruit
Induces differentiation of T cells into Th1 cells. Activates NK cells.
Facilitates granuloma formation in TB.
IL-2
secreted by t cells
Stimulates growth of helper, cytotoxic, and regulatory T cells, and NK cells.
IL-3
secreted by T cells
Supports growth and differentiation of bone marrow stem cells. Functions like GM-CSF.
IFN-gamma
secreted by Th1 cells
Secreted by NK cells and T cells in response to antigen or IL-12 from macrophages; stimulates macrophages to kill phagocytosed pathogens. Inhibits differentiation of Th2 cells.
Induces IgG isotype switching in B cells.
Also activates NK cells to kill virus-infected cells. Increases MHC expression and antigen presentation by all cells. Activates macrophages to induce granuloma formation.
IL-4
Induces differentiation of T cells into Th (helper) 2 cells. Promotes growth of B cells. Enhances class switching to IgE and IgG.
Ain’t too proud 2 BEG 4 help.
IL-5
Promotes growth and differentiation of B cells. Enhances class switching to IgA. Stimulates growth and differentiation of Eosinophils.
I have 5 BAEs.
IL-10
Attenuates inflammatory response. Decreases expression of MHC class II and Th1 cytokines. Inhibits activated macrophages and dendritic cells. Also secreted by regulatory T cells.
TGF-β and IL-10 both attenuate the immune response.
IL-13
Promotes IgE production by B cells. Induces alternative macrophage activation.
T Cell Surface
TCR (binds antigen-MHC complex) CD3 (associated with TCR for signal
transduction)
CD28 (binds B7 on APC)
Helper T surface
CD4, CD40L, CXCR4/CCR5 (co-receptors for HIV)
T reg surface
CD4, CD25
B cell surface
Ig (binds antigen)
CD19, CD20, CD21 (receptor for Epstein-Barr
virus), CD40 MHC II, B7
Must be 21 to drink Beer in a Barr
Macrophages surface
CD14 (receptor for PAMPs, eg, LPS), CD40 CCR5
MHC II, B7 (CD80/86)
Fc and C3b receptors (enhanced phagocytosis)
NK cells surface
CD16 (binds Fc of IgG), CD56 (suggestive marker for NK)
Type III Hypersensitivity
Immune complex—antigen-antibody (mostly IgG) complexes activate complement, which attracts neutrophils; neutrophils release lysosomal enzymes.
Can be associated with vasculitis and systemic manifestations.
Anti Double stranded DNA antibodies anti Sm antibody o Clinical manifestations o Treatments Avoid sunlight Glucocorticoids Other immunosuppressive agents o Drug induced SLE Antihistone antibodies- characteristic Hydralazine, procainamide, and isoniazide common causes Treat: remove drug Rheumatoid Arthritis Anti-Sm antibody
In type III reaction, imagine an immune complex as 3 things stuck together: antigen- antibody-complement. Examples: SLE Rheumatoid arthritis Reactive arthritis Polyarteritis nodosa Poststreptococcal glomerulonephritis Fever, urticaria, arthralgia, proteinuria, lymphadenopathy occur 1–2 weeks after antigen exposure. Serum sickness-like reactions are associated with some drugs (may act as haptens, eg, penicillin, monoclonal antibodies) and infections (eg, hepatitis B).