[Comparative study of the protective immunity activated by antigens of adult worms and muscle larvae of Trichinella spiralis].

AIM: To compare the immune protective effects of the mice immunized by antigens derived from adult worms and muscle larvae of Trichinella spiralis. METHODS: The adult worm and muscle larvae antigens of Trichinella spiralis were prepared and two groups of mice (adult worm antigen group and muscle larvae antigen group) were immunized with them, respectively. After 10 days of the final vaccination, the mice in each group were challenged with infective larvae of Trichinella spiralis. The number of intestinal adult worms and muscle larvae were examined and their reduction rate was calculated. Meanwhile, the level of serum IgG in each group was detected by ELISA. RESULTS: Compared with control group, the number of intestinal adult worms and muscle larvae in adult worm group and muscle larvae antigen group was lower(P<0.05) and number of intestinal adult worms and muscle larvae in adult worm antigen group was at the lowest(P<0.01). When the mice in the two groups were challenged with infective larvae of Trichinella spiralis, the titer of serum IgG detected on the same day was higher than that before they were vaccinated with the antigens(P<0.01, P<0.05) and it was also higher than that in control group(P<0.01, P<0.05). The level of serum IgG of the mice detected on the day when they were challenged with infective larvae of Trichinella spiralis was significantly higher than that before the mice were vaccinated and it was also higher than that in adult worm antigen group(P<0.01). CONCLUSION: Both the adult worm and muscle larvae antigens of Trichinella spiralis can stimulate mice to produce protective immunity and the mice immunized with adult worm antigens have stronger resistance to the subsequent challenge infection.