lect 13- effector mechanisms of humoral immunity Flashcards
what is the protective mechanism of polio vaccine
neutralization of virus by mucosal IgA Ab
what is the protective mechanism of tetanus & diphtheria
neutralization of toxin by systemic IgG Ab
what is the protective mechanism of Hep A and B
neutralization of virus by mucosal IgA or systemic IgG Ab
what is the protective mechanism of pneumococcal pneumonia, haemophilus
opsonization and phagocytosis mediated by IgM and IgG Abs, directly or secondary to complement activation
how do influenza viruses infect respiratory epithelial cells
their envelope hemagglutin
how do gram negative bacteria infect host cells
pili
how do IgG isotope coat opsonize microbes and promote their phagocytosis by binding to ______ on phagocytes
Fc receptors
what is the cell distribution of FcgammaRI and function
cell distribution: macrophages, neutrophils, eosinophils and function is phagocytosis and cell activation
what is the cell distribution and function of FcgammaRII
macrophages, neutrophils, DCs, B cells, NK cells and function is phagocytosis, cell activation, and feedback inhibition
what is the function and cell distribution of FcgammaRIII
NK cells and Ab-dependent cell-mediated cytotoxicity
what is the function and cell distribution of FcepsilonRI
mast cells, basophils, eosinophils and cell activation is function
what are the most efficient opsonins for promoting phagocytosis and how
IgG1 and IgG3 via high affinity FcgammaRI
what does perforin do
induces uptake of granzymes into target cell endosome and release into cytosol, activating caspases
how can worms be killed
by toxic cationic protein (major basic protein)
what is the function of factor B
Bb is a serine protease and the actin enzyme of the C3 and C5 convertases
what is the function of factor D
plasma serine protease cleaves factor B when it is bound to C3b
what is the function of properdin
stabilizes C3 convertases (C3bBb) on microbial surfaces
what is the function of MASP3
associates with collections or ficolins and MASP1 and cleaves C4
what is the function of MASP2
forms complex with lectins, especially ficolin-3
what is the function of MASP1
forms complex with MASP2 and collections and ficolins and activates MASP3
what is the function of MBL
agglutinin, opsonin, complement fixing
what are the functions of CR1
phagocytosis, clearance of immune complexes, promotes dissociation of C3 converses by acting as cofactor for cleavage of C3b, C4b
what is the function of CE2
coreceptor for B cell activation, trapping of Ags in GCs, receptor for EBC
what is the function of C1 inhibitor
serine protease inhibitor
