In vivo effects of antibodies to immune response gene products. I. Haplotype-specific suppression of humoral immune responses with a monoclonal anti-I-A.

Abstract

Immune response (Ir) gene products control immunologic function at several critical sites. A monoclonal antibody reactive with I-Ak was administered in vivo to F1 mice with the genotype H-2k/b. These treated mice made a markedly reduced antibody response to an antigen under the control of I-Ak, but not to an antigen under the control of I-Ab. This relative specificity was lost if the antigen was given in complete Freund''s adjuvant rather than aqueous solution. The monoclonal antibody also reduced the antibody titer in an ongoing, secondary response. Several potential mechanisms can be postulated for this effect. This haplotypic specificity might ultimately be relevant to human disease.