Immune Status of the Primary Host Toward Its Own Methylcholanthrene-Induced Sarcomas

Summary

The immune status of 55 mice toward their own sarcomas induced by 3-methylcholanthrene (MCA) was tested by immediate transplantation of small graded doses of tumor cells after the primary tumor was removed by radical surgery. An increased susceptibility was found in comparison with that of untreated syngeneic controls whose right hind legs were amputated and, to a lesser extent, with that of MCA-exposed syngeneic hosts. Mice preirradiated with 350–400 R before tumor transplantation supported the growth of the isografts slightly better than MCA-exposed hosts. Pretreatment of syngeneic hosts with Bacillus-Guérin 6–72 hours before tumor transplantation also facilitated takes. First-generation isografts of another MCA-induced primary tumor were not accepted as well by the host whose primary tumor had been excised, as were its own autografts. Thus the increased susceptibility to the autochthonous tumor possibly reflects partial tolerance in the primary host to its own MCA-induced sarcoma.