Immunogenicity of Trinitrophenyl-Hemocyanin: Production of Primary and Secondary Anti-Hapten Precipitins

Abstract

The ability of soluble TNP-KLH conjugates to induce production of precipitating antibody was studied in rabbits early in the immune response. A hapten/carrier mole ratio of 800 to 1000:1 was found optimal. Such conjugates induced an average of 375 µg of anti-TNP antibody and up to 2.5 mg of anti-KLH antibody per ml serum within a week after second injection. Some rabbits produced nearly a mg of anti-hapten antibody/ml. Antibody titers obtained here without adjuvants are thus comparable to those obtained to other haptenated proteins when adjuvants are employed. Primary precipitins also were obtained both to hapten and to carrier, but the frequency of primary anti-hapten precipitin detection was only one-fourth that of the anti-carrier response. Less heavily haptenated conjugates failed to induce anti-hapten precipitins while heavily substituted KLH was only poorly antigenic for either type of determinant. Preimmunization with KLH appeared to reduce the anti-hapten response subsequent to injections of TNP-KLH. The depressed anti-hapten response in this case was accompanied by a normal secondary response to the carrier.