The graft-versus-host [GvH] reaction and experimental trichinellosis. I. Functional reactivities of T lymphocytes during experimental trichinellosis in irradiated mice developing the GvH reaction

The activity of splenocytes obtained from C3H/w mice during various phases of infection with T. spiralis was assessed using the GvH reaction in irradiated B6C3F₁ recipients of spleen cells. It was found that splenocytes obtained from mice during the intestinal phase of infection (i.e. on day 10 of infection) stimulated the GvH reaction whereas splenocytes obtained during later periods of infection (i.e. on days 20 or 30 of infection) inhibited the GvH reaction. The inhibitory effect persisted until day 60 of infection. Decreased function of T cells in the GvH reaction, as observed during the early muscle phase of trichinellosis (i.e. 30 days post injection of the larvae) was less pronounced in hosts infected with T. spiralis than in those infected with T. pseudospiralis. In addition, significant impairment of the GvH reaction was observed following the mixed transplant of splenocytes obtained from both uninfected C3H/w mice as well as from B6C3F₁ mice infected with T. pseudospiralis. The results indicate that the activity of T lymphocytes in mice infected with T. spiralis changes significantly during different phases of infection.