Dose-Dependent Prophylactic Efficacy of Filarial Antigens Glutathione-S-Transferase and Abundant Larval Transcript-2 against Brugia malayi Challenge in Mastomys

To identify the most effective dose of filarial r ALT-2 and r GST alone or in combination against infection and . ( = 5-7/group) received intramuscular (i.m.) injection with three different doses (25, 50, and 100 g) of r ALT-2 or r GST, either alone or in combination with alum as the adjuvant. Protective immunity was studied by and cytotoxicity assay. To evaluate the cellular immune response, splenocyte proliferation and cytokine profile were assessed. Serological results revealed a substantial ( < 0.005) induction of IgG1, IgG2a, and IgG3 responses in vaccinated . immunized with 50 g r ALT-2 + alum induced 79-81% killing against the L3 larvae challenge and ADCC assay ( < 0.005); whereas r GST + alum alone or in combination with r ALT-2 + alum induced 63-68% killing ( < 0.005) and . Antigen-specific cytokine profiles of vaccinated with either ALT-2, GST or a combination showed elevated IL-10, IL-4, and IFN- levels, signifying both Th1 and Th2 immune response. These findings suggest that immunization of with a 50 g/dose of r ALT-2 + alum four times at a 4-week interval demonstrated considerable protection against infection.