these results show that complement activation is not an essential mechanism in pv igg-induced acantholysis in vivo , but it does have an amplifying effect on the development of cutaneous lesions under certain conditions , and lesions can be induced in vivo by bivalent f ( ab ' ) 2 fragments of pv igg , but not by the monovalent fab ' fragments , suggesting that cross-linking of the cell surface antigen is an initiating signal in acantholysis .
C0009528
complement activation
C0003320
antigen