Complement activation by measles virus cytotoxic antibodies: alternative pathway C activation by hemagglutination-inhibition antibodies but classical activation by hemolysin antibodies.
Antibodies against measles virus hemagglutinating (HA particles and hemolysin were shown to activate C differently. HA antibodies of rabbit or human origin activated C via the alternative pathway in cytotoxicity against chronically measles-infected cells. This cytotoxicity was expressed in C-4 deficient guinea-pig C or in rabbit C in the presence of 3 mM EGTA (ethylene-glycol-tetraacetic-acid) but not in 3 mM EDTA (ethylene-diamine-tetraacetic-acid). In contrast, human hemolysin antibodies activated C only via the classical way. F (ab')2 fragments from rabbit or human anti-HA IgG antibodies were as efficient in C activation via the alternative pathways as intact IgG antibodies with a corresponding hemagglutination-inhibition titer.
D000818:Animals; D000914:Antibodies, Viral; D000918:Antibody Specificity; D002118:Calcium / Q000378:metabolism; D002413:Cations, Divalent; D003165:Complement System Proteins / Q000378:metabolism*; D003601:Cytotoxicity Tests, Immunologic; D004492:Edetic Acid / Q000494:pharmacology; D004533:Egtazic Acid / Q000494:pharmacology; D006385:Hemagglutination Inhibition Tests; D006460:Hemolysin Proteins / Q000378:metabolism*; D006801:Humans; D007140:Immunoglobulin Fab Fragments; D008274:Magnesium / Q000378:metabolism; D008459:Measles virus / Q000276:immunology*; D011817:Rabbits
D000914:Antibodies, Viral; D002413:Cations, Divalent; D006460:Hemolysin Proteins; D007140:Immunoglobulin Fab Fragments; D004533:Egtazic Acid; D003165:Complement System Proteins; D004492:Edetic Acid; D008274:Magnesium; D002118:Calcium