Immuno - Immune Responses (Cytokines & Cell Surface Proteins) Flashcards
Pg. 205-206 in First Aid 2014 Pg. 200-201 in First Aid 2013 Sections include: -Important cytokines -Interferon alpha and Beta (mechanism) -Cell surface proteins
What are 5 cytokines that are secreted by macrophages?
(1) IL-1 (2) IL-6 (3) IL-8 (4) IL-12 (5) TNF-alpha
What kind of cytokine is IL-1? What other cytokine is like this?
An endogenous pyrogen; IL-6
What 3 effects does IL-1 have?
(1) Causes fever, acute inflammation. (2) Activates endothelium to express adhesion molecules; (3) induces chemokine secretion to recruit leukocytes.
What kind of cytokine is IL-6? What other cytokine is like this?
An endogenous pyrogen; IL-1
What cells secrete IL-6?
Macrophages; Also secreted by Th2 cells.
What effects does IL-6 have?
Causes fever and stimulates production of acute-phase proteins.
What major role does IL-8 play?
Major chemotactic factor for neutrophils; “Think: “Clean up on aisle 8. Neutrophils are recruited by IL-8 to clear infections.”
What cells secrete IL-12?
Macrophages; Also secreted by B cells.
What effects does IL-12 have?
Induces differentiation of T cells into Th1 cells. Activates NK cells.
What effects does TNF-alpha have?
Mediates septic shock. Activates endothelium. Causes leukocyte recruitment, vascular leak.
What major function do IL-1, IL-2, IL-3, IL-4, IL-5, and IL-6 have?
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; Think: “Hot T-Bone stEAK”
What cytokines do all T cells secrete?
(1) IL-2 (2) IL-3
What function does IL-2 have?
Stimulates growth of helper, cytotoxic, and regulatory T cells
What function does IL-3 have? What other factor does it function like?
Supports the growth and differentiation of bone marrow stem cells. Functions like GM-CSF
What cytokine do Th1 cells specifically secrete?
Interferon-gamma
What cells secrete Interferon-gamma? What are its functions?
From Th1 cells; Has antiviral and antitumor properties. Activates NK cells to kill virus-infected cells, Increases MHC expression and antigen presentation in all cells.
What cytokines do Th2 cells specifically secrete?
(1) IL-4 (2) IL-5 (3) IL-10
What major 3 functions does IL-4 have?
Induces differentiation into Th2 cells. Promotes growth of B cells. Enhances class switching to IgE and IgG.
What major 3 functions does IL-5 have?
Promotes differentiation of B cells. Enhances class switching to IgA. Stimulates the growth and differentiation of eosinophils.
What functions does IL-10 have? What other cytokine has similar actions to IL-10, and how so?
Modulates inflammatory response. Inhibits actions of activated T cells and Th1; TGF-Beta has similar actions to IL-10, because it is involved in inhibiting inflammation.
What cells secrete IL-10?
From Th2 cells. Also secreted by regulatory T cells.
Which cytokines enhance class switching to the following: (1) IgA (2) IgE (3) IgG.
(1) IL-5 (2) IL-4 (3) IL-4
Which cytokine suppresses Th2 cells? What other functions does it have?
Interferon-gamma; Activates macrophages and Th1 cells. Suppresses Th2 cells. Has antiviral and antitumor properties.
Which cytokine promotes growth of B cells? What other functions does it have?
IL-4; Induces differentiation into Th2 cells. Promotes growth of B cells. Enhances class switching to IgE and IgG.
Which cytokine modulates the inflammatory response? How does it do this?
IL-10; Modulates inflammatory response. Inhibits actions of activated T cells and Th1.
What role do interferons alpha and beta play in the immune system? How do they function in general?
A part of innate host defense against both RNA and DNA viruses. Interferons are glycoproteins synthesized by viral-infected cells that act locally on uninfected cells, “priming them” for viral defense. (Think: “Interferon Interferes with viruses.”
What is the interferon mechanism? What is its ultimate result?
Interferons induce the production of a ribonuclease that inhibits viral protein synthesis by degrading viral mRNA (but not host mRNA). When a virus infects “primed” cells, viral nucleic acids activate: (1) RNAase L –> degradation of viral/host mRNA (2) Protein kinase –> inhibition of viral/host protein synthesis; Essentially results in apoptosis, thereby interrupting viral amplification
What are the differences in function between alpha, beta, and gamma interferons? What function do they all share?
Alpha and Beta interferons inhibit viral protein synthesis; Gamma interferons increase MHC I and II expression and antigen presentation in all cells & Activates NK cells to kill virus-infected cells; All part of innate immune system antiviral defenses
Which cells have MHC I?
All cells except mature RBCs have MHC I.
What are the cell surface proteins that all T cells have? What is each of their purposes?
(1) TCR - binds antigen-MHC complex (2) CD3 - associated with TCR for signal transduction (3) CD28 - binds B7 on APC
What cell surface proteins do helper versus cytotoxic T cells have?
HELPER T CELLS - CD4, CD40 ligand; CYTOTOXIC T CELLS - CD8
What clusters of differentiation cell surface proteins do B cells have? Which is the receptor for EBV?
CD19, CD20, CD21 (receptor for EBV), CD40; Think: “you can drink Beer at the Bar when you’re 21: B cells, Epstein-Barr virus, CD-21”
Besides clusters of differentiation, what other 3 cell surface proteins do B cells have?
(1) Ig (2) MHC II (3) B7
What clusters of differentiation cell surface proteins do macrophages have?
CD14, CD40
Besides clusters of differentiation, what other 4 cell surface proteins do macrophages have?
(1) MHC II (2) B7 (3) Fc receptors and (4) C3b receptors (enhanced phagocytosis)
Which cell surface proteins on macrophages promote enhanced phagocytosis?
Fc and C3b receptors (enhanced phagocytosis)
What cell surface proteins do NK cells have, and what is the purpose of each?
(1) CD16 (binds Fc of IgG) (2) CD56 (unique marker for NK)
What is another name for IL-1?
Also called osteoclast-activating factor
