Interaction of H-2 and Non-H-2 Genes in Spontaneous Resistance to Adenocarcinoma ADK-1t in F1 Mice

The genetic control of spontaneous resistance in vivo to increasing doses of a poorly immunogenic spontaneous adenocarcinoma (ADK-1t) of BALB/c origin was studied in F1 hybrid mice. The spontaneous resistance of homozygous parental BALB/c mice was not increased in F1 hybrids of BALB/c and BALB.B or BALB.K mice, even with small tumor challenges (103 cells). By contrast, it was significantly enhanced in F1 hybrids of BALB/c and several strains on A or B10 background. Resistance due to the acquisition of a new set of background genes was, however, markedly enhanced or suppressed by the presence of particular alleles located within or closely linked to the H-2 complex, as demonstrated by increasing the tumor challenge to 104 or 105 cells. Spontaneous resistance, effective even with high tumor inocula, thus depended on a complex interplay between background andH-2 genes.