Aberrant MHC antigens in a sarcoma virus-induced mouse tumour

From a series of mouse sarcomata, newly induced by Rous sarcoma virus (RSV), the DOH cell line was shown to lack expression of syngeneic H-2Kd and Dk antigens (Noll et al., 1986). It unexpectedly displayed determinants specific for H-2Kk molecules. Interferon treatment of DOH stimulated the expression of H-2Kk determinants and also the display of some, but not all, determinants of the syngeneic H-2Kd molecules. H-2Dk expression was not stimulated. Southern blot hybridization of genomic DNA digests from DOH cells confirmed the identity of the H-2K region with that from syngeneic C3H.OH liver cells, but also showed changes in the pattern of restriction fragments that contain class I genes from the D and Qa regions. These results suggest that aberrant MHC class I molecules that carry H-2Kd- and H-2Kk-like determinants are expressed by DOH sarcoma cells. These molecules may act as target antigens for tumour-specific cytotoxic T cells elicited by injection of DOH cells into syngeneic mice.