Regulatory effect of temperature and antigen upon immunity in ectothermic vertebrates. III. Establishment of immunological suppression in fish

Carp were primed with various doses (0.01, 0.1, 1, 10 mg) of native and biologically filtered BSA, introduced directly into the blood stream. In most fish, no antibody response to any of these antigen doses nor to a high dose (700 mg) was observed 30 days following the priming. Most primed fish displayed specific immune suppression when challenged with a known immunizing dose (1 mg) of BSA, Penicilloyl-BSA conjugate or RGG, in CFA. In spite of the suppression developed to the carrier, the anti-penicilloyl titer was not affected and the anti-RGG response was normal as in control fish. No tolerance was induced when the native molecule was injected outside the circulation, near the heart, nor when the fish were preimmunized with acetylated BSA. Perhaps the establishment of specific suppression is dependent mainly upon the route of injection and the physicochemical nature of the antigen, and does not depend on antigen dosage, nor on its being biologically filtered.