IMMUNOPROPHYLACTIC POTENTIAL OF A 120 KDA BRUGIA-MALAYI ADULT ANTIGENFRACTION, BMA-2, IN LYMPHATIC FILARIASIS

A 120 kDa antigen containing SDS-PAGE fraction BmA-2 isolated from Bru gia malayi adult parasite was highly reactive with normal ser a front filarial endemic area. BmA-2 was analysed for its propylactic potentia l in in vitro and in vivo. Ser a collected om BmA-2 immunized jirds in duced a significant level (80 to 90%) of protection against infective larvae and microfilariae in in vitro ADCC assay as well as in in situ micropore chamber implantation studies. Mastomys natalensis immunized with BmA-2 showed a significant level of protective response against c irculating microfilariae by clearing 90% of them front circulation by fifth day after challenge infection. Immunization of jirds with BmA-2 resulted in an enhanced level of antibody response against BmA-2 and 8 8% reduction in the development of the parasites to the adult stage. P assive transfer of immunesera from jirds immunized wth BmA-2 to naive jirds resulted in 71% reduction in adult worm recovery as observed 90 days after challenge infection with B. malayi. On the other hand the p assive transfer of nonadherent spleen cells from immune jirds did not show any significant effect on the development of parasite. Administra tion of jirds anti BmA-2 serum to microfilaraemic jirds showed a tempo rary decrease in microfilarial count which was increased to pretherape utic level within 100 days and there was Ilo effect on the adult worms . This intplies that the immune protective effect of BmA-2 is mainly a ntibody dependent and active immunization with BmA-2 is effective agai nst filarial infection.