Om Singla

Immunosuppressive Properties of Heterologous Antilymphocytic Sera Prepared Against Thymocyte Soluble Fraction

Summary Soluble, cell-free fractions of mouse thymocytes were potent immunogens capable of evoking the production of immunosuppressive antilymphocytic antibodies in rabbits. These sera were capable of prolonging survival times of CBA to C57B1/6 skin allografts, and depressing humoral antibody production and splenic plaque forming cells in mice immunized with sheep erythrocytes. Disruption of thymus cells prior to solubilization was absolutely essential for the release of antigens. Freezing, prolonged storage and thawing of the soluble fractions obtained from disrupted cells did not alter their immunogenicity. Antisera prepared against thymocyte soluble fractions were equally as immunosuppressive as those prepared against intact cells.