Identification of hookworm (Necator americanus) antigens and their translation in vitro

During in vitro culture adult (day 35) Necator americanus synthesise a wide range of protein species many of which are excreted or secreted into the culture medium. Both post infection (day 117) hamster sera and sera from infected humans precipitate antigens of 15, 30, 33, 44, 46 and 69 kDa although individual human sera exhibit some variability in absolute specificity. In immunoblotting experiments antigens of 33 kDa are routinely recognised by human sera although two-dimensional gel analysis suggests that more than one polypeptide is involved. RNA isolated from adult worms direct the in vitro synthesis of numerous polypeptides possessing antigenic determinants recognised by sera from infected hamsters and humans. Post-translational modification of N. americanus encoded polypeptides is not, therefore, a prerequisite for antigenicity.