Cytokines and Receptors Flashcards
WHat cells produce IL-2?
Activated CD8+ and CD4+ T cells. Naive ones do not secrete it.
What is the function of IL-2?
Stimulate T-cell proliferation and clonal expansion
What cells produce IFN-gamma?
TH1 and CD8 T cells
What is the function of ITN-gamma?
Required for macrophage and NK cell activation.
It also preps host cells for antimicrobial function (remember PEGINTERFERON?)
Lymphotoxin is abbreviated as what? It’s also sometimes called….
LT, TNF-beta
What does lymphotoxin do, and what T cells secrete it?
Stimulates the production of NO by macrophages, aiding in the bactericidal response.
Th1 and CTLs secrete it. Think intracellular response!
Which cells secrete IL-4 and what does it do?
Th2 cells. IL-4 supports growth and survival of the Th2 cell
PROMOTES CLASS SWITCHING TO IgE!!!
Other than IgE, what other Ab isotopes does IL-4 cause class switching to?
weakly opsonizing forms of IgG: IgG2, IgG4
What cytokine causes antibody class switching to IgA? What cell secretes it?
IL-5 secreted by Th2 cells
Th1 cells secrete IFN-gamma. This causes Antibody class switching to what isotopes?
Opsonizing forms of IgG: IgG1 and IgG3
Which antibody isoform is found everywhere in the body?
IgG
Which antibody isotope is found ONLY in circulation?
IgM
Which antibody isotope is found in mucosa and mucosal secretions? Where else is it found?
IgA - found in GI tract and respiratory tract (mucosa and secretions) low levels in circulation.
Where in the human body will you find IgE antibody isotopes? Why?
Epithelium underlying the skin, and in the GI tract linings and respiratory linings. IgE goes where mast cells go, because IgE exists bound to mast cells.
What receptor on mast cells binds to IgE? Why is this antibody receptor special, compared to all other antibody receptors?
FceRI receptor! Has affinity for IgE even when its cognate antigen isn’t bound.
Most antibodies must bind their cognate antigen before their Fc portions are exposed, allowing binding to Fc receptors on APCs.
What does the Poly-IG receptor do?
Binds to IgA and transports it across the epithelial linings of the git and respiratory tract, into mucosal secretions via active vesicular transport.