Immunoprophylactic studies with a 43 kDa human circulating filarial antigen and a cross reactive 120 kDa Brugia malayi sodium dodecyl sulphate soluble antigen in filariasis

Bancroftian filariasis is a major public health problem affecting about 120 million people all over the world, Immunoprophylaxis may serve as an additional adjunct along with chemotherapy and anti larval measures for successful filaria control. Circulating filarial antigen fraction (CFA(2)-6) containing 43 kDa antigen and adult Brugia malayi sodium dodecyl sulphate (SDS) soluble antigen fraction BmA-2 with a 120 kDa molecule were earlier shown to be reactive with endemic normal sera by immunoblotting and indirect ELISA techniques. BmA-2 was found to be highly cross reactive with CFA,d. Sera raised against both the antigen fractions showed about 90% cytotoxicity to the parasites in the presence of jird peritoneal cells in in vitro as well as by in situ micropore chamber implantation technique. Further in in vivo studies using animal model, jirds CFA(2)-B and BmA-2 could induce about 90% protection to infection in immunized animals. In passive transfer studies of immunity it has been observed that BmA-2 induced protection is mainly antibody mediated.