MHC gene control of growth of avian sarcoma virus-induced tumours in chickens: a study on the role of virus strains.

A comparison was made of growth patterns (progression/regression) of tumours induced by different strains of avian sarcoma virus in two partially congenic inbred lines of chickens homozygous for different MHC haplotypes. In each instance studied, the ability to regress tumours was shown to be a dominant trait controlled by MHC-linked genes. The results also demonstrate a difference in growth pattern between tumours induced by different strains of virus in an inbred line as well as different growth patterns of tumours induced by the same strain of virus in the two inbred lines. We conclude that the MNC-linked resistance gene is part of a polymorphic genetic region and, in addition, that there is immunogenic heterogeneity of the viral gene product expressed on tumour cells induced by closely related viral strains which is relevant to tumour regression. We suggest that the product of the src gene, p60src, is a plausible candidate for the immunogenic target of the MHC-linked rejection response.