Induction of transplantation resistance to murine L1210 leukemia cells in BCG-primed mice by immunization with tuberculin protein-coupled L1210 cells.

By priming with Bacillus Calmette-Guérin (BCG) and subsequent immunization with L1210 leukemia cells to which purified protein derivative of tuberculin (PPD) had been coupled, a resistance to L1210 leukemia but not to syngeneic P388 leukemia was induced in DBA/2 and CDF1 mice. Separate injections of mitomycin C-treated L1210 cells and PPD also induced the resistance, but it was established only when they were administered simultaneously. PPD-coupled cells seemed to play a more important role than BCG, since the immunoprophylaxis was observed when L1210 challenge was made at the sites of PPD-L1210 immunization, but was not observed when L1210 challenge was made at the sites of BCG priming.