Immune responses in guinea pigs to dietary protein. I. Induction of tolerance by feeding with ovalbumin.

Introduction of ovalbumin into the diet of guinea pigs initially evoked the production of circulating antibody. With continued feeding, antibody levels declined in animals fed with ovalbumin from 2-4 days or 6-8 weeks of age, but remained constant in guinea pigs commencing the feeding regimen at 5-6 months of age. All animals receiving dietary ovalbumin became hyporesponsive to parenteral injection with ovalbumin in adjuvant, and suppression of IgG1 and IgG2 antibody subclasses was observed. The results demonstrated that delayed hypersensitivity to ovalbumin was more readily suppressed by the feeding regimen than the systemic antibody response.