Enhanced Antibody Response of Mice to Polyinosinic Polycytidylic Acid by Antithymocyte Serum and its Age-Dependent Loss in NZB/W Mice

Abstract

Abstract A single injection of a double stranded RNA antigen, polyinosinic·polycytidylic acid (rI·rC), in aqueous solution leads to an antibody response which is augmented when heterologous antithymocyte serum (ATS) is given with the antigen. Since the response to rI·rC is largely thymic independent, the enhancement is explainable by the elimination of regulator cells by the ATS. An additional mechanism, an adjuvant-like action of ATS, was suggested by the enhancement of the antibody response by ATS despite prior thymectomy and ATS treatment. NZB/W mice which spontaneously develop an autoimmune disease characterized by antibodies to nucleic acids demonstrate an age-dependent loss of the ATS-mediated enhancement of the response to rI·rC. This loss of regulation of the response to nucleic acid antigens could explain their spontaneous antibody production and may be caused by spontaneously occurring antithymocyte antibody.