ROLE OF A GENETIC REGION ON CHROMOSOME-4 IN THE REGULATION OF NATURAL-KILLER-CELL ACTIVITY IN MICE

Natural killer cell (NK) activity is regulated by both the H-2 and non -H-2 genes. Using bilineal congenic HW26C and HW13 mice which differ f rom the background strain C57BL/6By (B6) in a region of chromosome 4, we investigated the role played by a gene/genes in a segment of chromo some 4 of BALB/cBy on NK cell activity. Percoll separated low density spleen cells from young HW26C and HW13 mice showed a 3.5 fold higher N K activity than the B6. We also observed that the increase in NK activ ity of HW26C was not due to an increase in the number of NK cells. Usi ng five other bilineal congenics containing different regions of chrom osome 4 of BALB/cBy, we observed that the putative gene(s) regulating NK activity may be located between b and IFN-alpha/beta genes of chrom osome 4. The level of NK activity of (B6xHW26C)F1 ranked between the H W26C and B6 suggesting that the gene product described is inherited in an incompletely dominant fashion.