IMMUNE-RESPONSE PROFILES IN VACCINATED AND NON-VACCINATED HIGH-RESPONDER AND LOW-RESPONDER MICE DURING INFECTION WITH THE INTESTINAL NEMATODE TRICHINELLA-SPIRALIS

NIH and C57 BL/10 (B10) mice show genetically determined differences in their response to Trichinella spiralis infection. This study examines the influence of these on parameters of the immune response to infection after vaccination using muscle-larval excretory-secretory antigen in Freund's complete adjuvant. Serum antibody levels were greatly elevated when mice of both strains were vaccinated prior to infection; however, NIH produced significantly higher-level antibody responses than B10. Vaccination accelerated and increased the capacity of mesenteric lymph node T-cells to proliferate in vitro in response to specific antigen stimulation in both mouse strains but, in general, the stimulation indices of NIH cells were higher than those of the B10. The capacity of mesenteric lymph node cells (MLNC) and spleen cells (SC) to produce IL-5 and gamma IFN was measured after specific in vitro stimulation and early gamma IFN secretion was noted in the supernatants of NIH MLNC and SC, but not in B10 SC. Concentrations of IL-5 rose steadily over the first 10-14 days after infection in cell cultures from both strains. Prior vaccination of these animals appeared to enhance cytokine levels. It is postulated that the efficacy of Vaccination in NIH mice is a consequence of their genetically determined capacity to produce early and high-level responses to the antigens of T. spiralis and to express these in intestinal effector mechanisms.