Further Studies of the Immunological Properties of Gross Virus-induced Lymphomas.

The previously demonstrated antigenicity of Gross virus-induced lymphomas was further investigated. It was found that Gross virus homogenate was less potent than living lymphoma cells. When, however, concentrated fractions of the same homogenate were used for pretreatment, both cytotoxic sera and resistance against isogenic trans plantation were provoked. Evidence was obtained that cellular constituents rather than virus in its pure form are responsible for the induction of specific cytotoxic anti bodies and transplantation resistance. When cytotoxic sera were assayed for virusneutralizing capacity, no effect was found. When cross experiments were performed between Gross and polyoma virus and Gross and polyoma tumor antigens no serological relationship could be detected.