Adult 175 kDa collagenase antigen ofSetaria cerviin immunoprophylaxis againstBrugia malayiin jirds

Abstract

AbstractA 175 kDa antigen fraction with collagenase activity was isolated and purified from somatic extracts of adultSetaria cervifemales using column chromatography involving consecutive steps of DEAE-Sepharose CL6B and Sephadex G-100. The optimum pH for 175 kDa collagenase was found to be pH 7.0. Sensitivities to a variety of inhibitors and activators indicated that the 175 kDa coIlagenolytic enzyme was metalloserine in nature. The enzyme hydrolysed a variety of protein substrates such as haemoglobin, casein, azocasein (general substrates) and collagen, FALGPA (furanoyl-acryloyl-leu-gly-pro-ala), the specific substrate of collagenase. The enzyme showed 57% inhibition by jird anti-somatic collagenase antibodies and reacted insignificantly with normal jird sera. Further analysis was undertaken on the immunoprophylactic potential of 175 kDa collagenase in inducing immunity againstBrugia malayi(a human filarial parasite) in jirds (Meriones unguiculatus)in vitroandin situ. Immune sera of jirds raised against this antigen promoted partial adherence of peritoneal exudate cells toB. malayimicrofilariae (mf) and infective larvae (L3)in vitroand induced partial cytotoxicity to the parasites within 48 h. The anti-S. cervi175 kDa antigen serum was more effective in inducing cytotoxicity toB. malayiL3, than mf. In the microchambers implanted inside immune jirds, host cells could migrate and adhere to the mf and infective larvae thereby killing them partially within 48 h.