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 di fferences in their ability to generate protective immunity against the smal l-intestine nematode parasite Trichostrongylus colubriformis. Animals with the most effective immune response (high responders) developed significantl y higher anti-T. colubriformis IgG(1) antibody titres than low-responder an imals. However, there were no significant differences between their IgG(1) antibody responses to a systemically administered protein antigen (ovalbumi n). High-titre anti-T. colubriformis serum from high-responder animals did not transfer significant passive protective immunity to low-responder recip ients. It is suggested that anti-T. colubriformis IgG(1) antibodies mediate the release of mast-cell and basophil products at the site of infection an d thus contribute to the more effective immunity expressed by high-responde r animals. (C) 1999 Australian Society for Parasitology. Published by Elsev ier Science Ltd. All rights reserved.