ANTIBODY-RESPONSE TO A PROTEASE SECRETED BY TRICHINELLA-SPIRALIS MUSCLE LARVAE

In the present study we analyzed the humoral response of Trichinella s piralis-infected mice to a 35-kDa protease (purified from the excretor y-secretory products of T. spiralis muscle larvae) by a Western-blot p rocedure and an enzyme-linked immunosorbent assay (ELISA) technique us ing a panel of postinfection mouse anti-Trichinella sera. The results demonstrated that this response was time-dependent and that infected m ice could be distinguished from controls. In addition, inhibition assa ys demonstrated that these antisera were capable of abolishing the pro teinase activity of the 35-kDa protease in vitro. The occurrence of pr oteases seems to be a very common feature in parasite crude extracts a nd 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 (Hot ez etal. 1985; Yamasaki etal. 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 (E S) products of Trichinella Spiralis (GM-1 strain) muscle larvae and es tablished some of the biochemical properties of this protease (Armas-S erra et al. 1994). The present study was undertaken to determine wheth er this protease would be recognized as an antigenic molecule by the h ost immune system, as occurs in the case of other parasites, and which effect the host immune response could have on the biochemical activit y of the enzyme.