Complementation of major histocompatibility haplotypes in regression of Rous sarcoma virus-induced tumors in noninbred chickens.

Relative responses to Rous sarcoma virus (RSV)-induced tumors were studied in UNH 105 chickens, a noninbred line of New Hampshires. A total of 799 chickens blood typed for B alloantigens were classified into six genotypes: B23/B23, B24/B24, B26/B26, B23/B24, B23/B26, and B24/B26. Chickens were inoculated with subgroup A Rous sarcoma virus in the left wingweb at 6 weeks of age. The in vivo response was evaluated and given a tumor profile index (TPI) based on the change in tumor size over a 10-week period postinoculation. The TPI's ranged from 1 (regressor) to 3 (progressor). The mean TPI of B23/B26 hosts (1.7) was significantly smaller than that of all other genotypes studied. The mean TPI's of the homozygous genotypes B23/B23, B26/B26, and B24/B24, were 2.0, 2.3, and 2.9, respectively, and differed significantly in all comparisons. These results suggest complementation of haplotypes influencing the anti-Rous sarcoma response.