Antibody response to a protease secreted by Trichinella spiralis muscle larvae.

In the present study we analyzed the humoral response of Trichinella spiralis-infected mice to a 35-kDa protease (purified from the excretory-secretory products of T. spiralis muscle larvae) by a Western-blot procedure and an enzyme-linked immunosorbent assay (ELISA) technique using a panel of postinfection mouse anti-Trichinella sera. The results demonstrated that this response was time-dependent and that infected mice could be distinguished from controls. In addition, inhibition assays demonstrated that these antisera were capable of abolishing the proteinase activity of the 35-kDa protease in vitro. The occurrence of proteases seems to be a very common feature in parasite crude extracts and excretory-secretory products (McKerrow 1989). It is also known that these enzymes are implicated in important host-parasite interactions, and for this reason, recent reports have proposed the use of parasite proteases both as alternative targets for an induced immune response and as a rich source of antigenic material for diagnostic testing (Hotez et al. 1985; Yamasaki et al. 1989; Song et al. 1990; Frank and Grieve 1991; Britton et al. 1992; Song and Chappell 1993). We have recently purified a protease (mol. wt., 35 kDa) from the excretory-secretory (ES) products of Trichinella spiralis (GM-1 strain) muscle larvae and established some of the biochemical properties of this protease (Armas-Serra et al. 1994).(ABSTRACT TRUNCATED AT 250 WORDS)