PRELIMINARY STUDIES ON SHARED ANTIGENS AMONGCERCARIA,ADULT WORM AND EGG OF SCHISTOSOMA JAPONICUM

The pooled sera of inbred C57BL/6 mice in-fected with Schistosoma japonicum, the antiseraagainst gut-associated antigen (GAA) from artificiallyimmunized rabbits (RAGAA20) and the antiseraagainst soluble egg antigen (RASEA) purified by im-munoaffinity chromatography were tested with cercaria-stuck-slides, adult worm sections and liver-eggsections by immunohistochemical studies with peroxi-dase-linked protein A (PPA method). In mice antibody against eggs was detected before oviposition.Eggs containing late developmental stage of embryostarted to secrete SEA 37 days after infection whenthe titer of the antibody against eggs reached l:256.GAA20 and SEA were proved to be at the samelocation within mature eggs, and RAGAA20 0nlyreacted with eggs exuding SEA. RASEA reactedstrongly with the membrane of cercaria. The results showed that S japonicum SEAshared its antigens with GAA and membrane-asso.ciated antigens (MAA). GAA might play a role ofprcsensitizing in egg granuloma formation.