THE EFFECTS OF VARIOUS IMMUNOSUPPRESSIVE AGENTS ON ANTIBODY POPULATIONS PRODUCED IN GUINEA PIGS

Abstract

Effects of immunosuppressive agents on immunochemical properties of antibody populations produced in guinea pigs were studied with Methotrexate, cyclophosphamide, hydrocortisone, Bredinin (4-carbamoyl-1-β-D-ribofuranosyl imidazolium-5-olate), azathioprine and 6-mercaptopurine. Among these agents, Methotrexate and cyclophosphamide alone suppressed strongly the antibody responses, not depending on the degree of the T cell-dependency of antigens used. Hydrocortisone, Bredinin and azathioprine also suppressed the antibody responses slightly, and no effect was observed with 6-mercaptopurine. With cyclophosphamide and hydrocortisone, no substantial difference in the susceptibility was observed between the IgG1 and IgG2 antibody responses. On the other hand, the IgG1 antibody response appeared to be slightly more sensitive to the immunosuppressive activities of Bredinin and azathioprine, compared with the IgG2 antibody response. With Methotrexate, the difference in the susceptibility between these two responses seemed to vary depending on the kind of antigens used. In addition, the antigen-binding abilities of antibodies produced were not influenced by the treatment with Methotrexate and cyclophosphamide.