More complement disorders and cytokines Flashcards
C3 deficiency
increases risk of severe, recurrent pyogenic sinus and resp. tract infections. Incr. susceptibility to type III hypersensitivity. (this is basically a total complement deficiency, so you will have more infections, more reliance of PMNs, and more reliance on antibodies)
DAF deficiency
DAF helps prevent complement activation of self-cells
DAF deficiency causes complement-mediated lysis of RBCs and paroxysmal nocturnal hemoglobinuria
What is the mnemonic for cytokines?
Hot T-bone stEAK IL-1: fever IL-2: T cell stimulation IL-3: stimulates bone marrow IL-4: IgE ( and IgG) class switching IL-5: IgA production and eosinophil growth and differentiation IL-6 aKute phase protein production
What does IL-1 do? Who secretes IL-1?
secreted by macrophages
fever, promotes acute inflammation, cuases endothelium to express adhesion molecs, recruits leukocytes
What does IL-6 do? Who secretes it?
fever, acute phase proteins
made by Th2 cells and macrophages
What does IL-8 do? Who secretes it?
attract neutrophils
What does IL-12 do? Who secretes it?
activates differentiation of T cells to Th1 cells. activates NK cells. Secreted by macrophages (and b cells)
What does TNF-alpha do?
mediates septic shock. activates endothelium. recruits leukocytes and causes vascular leak
What does IL-2 do
stimulates T cell growth. esp. important for CD8 t cells.
What does IFN gamma do?
antiviral and anti-tumor properties. actives NK cells. increases MHC expression and antigen presentation.
What does IL-4 do?
differentiation into Th2 cells, promotes B cell growth and class switching to IgE and IgG.
What does IL-5 do?
enhances class swithcing to IgA and stimulates the growth and differention of eosinophils
What does IL-10 do?
modulates inflammatory response. inhibits T cells. similar to TGF-beta
What are IFN alpha and beta?
part of innate host against viruses. they are synthesized by viral infected cells and act locally on uninfected cells to prime them for viral defense. Primed cells respond to viral dsRNA by degrating viral/host mRNA and inhibiting viral/host protein synthesis. This causes apoptosis but helps halt viral spread.
How do superantigens work? Who makes superantigens?
superantigens are made by S. pyrogenes and S. aureus (S. aureas does TSS, S. pyrogenes does TSS-like syndrome). these crosslink the beta region of the T cell receptor to the MHC class II molecule on ANY APC. This can cause a huge cytokine storm.
