Properties of syngeneic and allogeneic antisera raised to tumor-specific suppressor factor from DBA/2J mice

Tumor-specific suppressor factor was prepared by injecting soluble membrane extracts of the syngeneic mastocytoma, P815, into DBA/2J mice 4 days prior to sacrifice. The suppressor factor was purified by passage of spleen extracts over an immunoadsorbent containing P815 membrane components. Antisera raised in syngeneic and allogeneic (C57Bl/6) mice by repeated injections of suppressor factor were tested. It was found that these antisera, but not their controls, were capable of absorbing out the suppressor factor. The antisera were also capable, in the presence of complement, of eliminating suppressor cells from suppressive spleen cell populations. However, the antisera were not capable of eliminating syngeneic tumor-specific in vitro-generated killer cells, indicating that the receptor molecules on suppressor and effector cells in this system are distinct from each other.