Some data concerning immune processes in concomitant tumor immunity experimental models. Comparative in vivo and in...

Concomitant tumor immunity evinced by C57BL/6 mice, bearing a MC-induced sarcoma, was evaluated by graded challenge doses for different primary tumor sizes (2-3,4-6,8-12% tumor weight of the total body weight TW/TBW). 100% of mice bearing tumors, representing 2--6% of total body weight, rejected doses from 0.2--1 X 10(4) cells. The gradual curtailment of the concomitant tumor immunity, depending on increasing TW/TBW ratio, could be evaluated, using adequately increasing challenge doses. The immune equipotency of the whole s.c. body area, the failure to modify the concomitant tumor immunity by drainin node excision and the demonstration of its dependency upon the total challenge-dose and its independency upon fractionated multilocular inoculation of the challenge, showed clearly that the concomitant tumor immunity is a local expression of general immunity. The experimental model allows a valuable biological assessment of the tumor-beareer immune status and represents likewise an adequate tool for immunotherapeutic effects estimation.