Antibody production in guinea pigs with genetically determined high and low responsiveness to Trichostrongylus colubriformis.

Antibody levels were compared in guinea pigs with genetically determined differences in their ability to generate protective immunity against the small-intestine nematode parasite Trichostrongylus colubriformis. Animals with the most effective immune response (high responders) developed significantly higher anti-T. colubriformis IgG1 antibody titres than low-responder animals. However, there were no significant differences between their IgG1 antibody responses to a systemically administered protein antigen (ovalbumin). High-titre anti-T. colubriformis serum from high-responder animals did not transfer significant passive protective immunity to low-responder recipients. It is suggested that anti-T. colubriformis IgG1 antibodies mediate the release of mast-cell and basophil products at the site of infection and thus contribute to the more effective immunity expressed by high-responder animals.