Control of synthesis and expression of H-2 heavy chain and beta-2 microglobulin in AKR leukemias.

In a series of newly isolated AKR leukemias, some tumors expressed large amounts of both H-2K and H-2D molecules, while others had reduced levels of both antigens. The number of H-2 antigens expressed in steady state showed a consistent correlation with the rate of synthesis of the H-2 class I heavy chain and the beta-2 microglobulin (beta 2m) light chain, and with the amount of H-2- and beta 2m-specific mRNA present in the tumors. Stimulation of leukemic cells with interferon induced an increased transcription of both H-2 and beta 2m mRNA. These results suggest that there is a mechanism that regulates, at the transcriptional level, the coordinate expression of H-2K and H-2D heavy chains, and the beta 2m light chains encoded by genes on chromosomes 17 and 2, respectively.