High levels of protection induced by a 40-mer synthetic peptide vaccine against the intestinal nematode parasite Trichinella spiralis.

Parenteral vaccination, using a 40-mer synthetic peptide from a 43,000 MW immunodominant glycoprotein secreted by the intestinal nematode parasite Trichinella spiralis, induced high levels of protection against a subsequent challenge infection in mice. The expulsion of adult worms from the gut was accelerated following vaccination with peptide 40-80, but peptides 81-120 and 121-160 were not protective. Mesenteric lymph node cells taken from T. spiralis-infected mice showed some proliferation in response to in vitro stimulation with peptide 40-80, but were unaffected by peptide 81-120. As expulsion of T. spiralis is known to be brought about by T-cell-mediated inflammatory events in the intestine, the ability of the 40-80 sequence to promote accelerated worm expulsion upon challenge infection may reflect induction of a specific and appropriate T-cell response. To our knowledge, this is the first report of a protective synthetic peptide vaccine against an intestinal nematode.