The antigens evoking immunosuppressive antithymocyte globulin.

Amethod of producing antithymocyte globulin is outlined. The in vitro and in vivo activities of the preparation were assessed. Two methods were used to obtain soluble antigen from freeze dried thymocyte membrane preparations. Atigens obtained from platelets were also tested. The experiments suggest that antigens evoking antilymphocyte globulin which give a high rosette inhibition titre can be partially separated from those evoking cytotoxic antibody. It is also possible that the antigens capable of evoking rosette inhibiting antibodies are not entirely confined to the lymphocyte population.