Transplantation behavior of allotransplantable tumor lines derived from immunologically modified hosts.

The strain-specific BALB/c tumor C4092 was conditioned to grow in H-2 incompatible DBA/1 mice by prior maintenance in vitro as an organ culture explant. It then was serially transplantable in DBA/1 mice and regained its specificity with one passage in BALB/c mice. Changes in transplantation behavior were similar in vivo if the recipients were conditioned by neonatal thymectomy, immunologic enhancement, rabbit antimous serum treatment, or immunization with mitomycin C-inactivated C4092 tumor cells. In vivo- and in vitro-modified tumors differed in degree of transplantability and in the stability of immunogenic changes. However, because of conspicuous similarities in the behavior of these lines, it was concluded that ADAPTations of both host and graft ultimately contribute to graft survival.