Suppression of transplant immunity in experimental trichinellosis

Skin allograft rejection in Balb/c and C57BL/6J mice following experimental infection with 300 larvae of Trichinella spiralis or Trichinella pseudospiralis was studied. Skin grafts from normal C57BL/6J mice were transplanted to infected Balb/c mice and vice versa at days 3, 10, 20 and 30 post-infection. The clinical criteria for graft rejection, scarring and graft falling, were followed. The results indicated that T. spiralis and T. pseudospiralis infections induced a significant delay in graft rejection when compared to the control groups. A maximum rejection time of 24 days was observed in T. spiralis infected C57BL/6J mice which received skin grafts from Balb/c mice on day 3 post-infection. The rejection in the uninfected control group was on day 7 post transplant. The mean rejection times for transplants on various days post-infection, with both species were very similar. Also, the rejection profiles in Balb/c mice were comparable to that observed in C57BL/6J mice, with a maximum delay of 26 days to rejection again obtained in mice transplanted on day 3 post-infection, for both species. When the skin grafts were performed 5 or 10 days prior to infection, the rejection occurred on day 7, as in the control group. The effect of T. spiralis and T. pseudospiralis soluble larval extracts (TSE or TPE) on graft rejection was also examined. Four intraperitoneal injections of 50 micrograms each of TSE or TPE every 48 h for 7 days did not induce any significant delay in graft rejection. In contrast, secretory antigens prepared from cultured larvae in vitro induced significant delays in graft rejection.(ABSTRACT TRUNCATED AT 250 WORDS)