Studies on a filarial antigen with collagenase activity

We examined the ability of two filarial species, Onchocerca volvulus and Brugia malayi, to solubilize collagen molecules from native collagen fibrils. Collagenolytic activity was detected in extracts of adult worms, in living microfilariae of O. volvulus and in live infective larvae and adult female worms of B. malayi. Excretion-secretion factors produced in vitro by infective larvae of B. malayi also contained large amounts of collagenase. Studies with enzyme inhibitors suggest that the latter may be a metallo-protease. Antibodies to filarial collagenase were present in sera from patients with onchocerciasis and brugian filariasis and from mice immunized with B. malayi. These antibodies and a monoclonal antibody raised against O. volvulus antigens immunoprecipitate filarial collagenase but appear not to be directed against the active site of the enzyme.