PASSIVELY TRANSFERABLE PROTECTION AGAINST SCHISTOSOMA-JAPONICUM INDUCED IN THE MOUSE BY MULTIPLE VACCINATION WITH ATTENUATED LARVAE - THE DEVELOPMENT OF IMMUNITY, ANTIBODY ISOTYPE RESPONSES AND ANTIGEN RECOGNITION

Vaccination of mice with attenuated S. japonicum cercariae induces pro tection against secondary infection which can be transferred to naive mice with serum (VMS). The presence of antibody does not per se impart protection as serum from mice carrying non-attenuated infections (CIS ), contains high levels of specific antibody, but confers no protectio n. Here we describe the increased protection transferred (20 to 68%) w ith increased number of vaccinations (one to five) given to the donors , and its decline with time after the final vaccination. We also descr ibe the development of IgM, IgA, IgE, total IgG and IgG subclass respo nses in VMS, giving different levels of protection and CIS, directed a gainst sodium periodate-sensitive and -resistant epitopes in 'skin-sta ge', 'lung-stage' and 'liver-stage' schistosomula, adult worms and egg s. In addition, antibody affinity maturation, development of S. japoni cum species-specific responses, and vaccination-specific responses wer e examined. No response developed in parallel with serum-mediated immu nity, suggesting immunity may be due to responses against individual a ntigens. Preliminary examination of antigens recognized in Western blo t showed that two schistosomal membrane antigens, of 13 and 40 kDa, we re recognized by VMS from mice vaccinated five times (68% protection), but not by twice vaccinated VMS (27% protection). Neither antigen was recognized by non-protective CIS.