Expression of a class I MHC transgene: effects of in vivo α/β-interferon treatment

Abstract

Transgenic mice containing a swine class I major histocompatibility complex (MHC) gene,PD1, express swine MHC (SLA) antigen. The tissue distribution of PD1 RNA parallels that observed in the swine, indicating that the expression ofPD1 is regulated and thattrans-acting factors involved in this regulation have been conserved between the species. Although PD1 RNA levels were much greater in transgenic spleen than in thymus, no difference in the chromatin organization of thePD1 gene was detected. In both tissues, a single DNase I hypersensitive site mapped within the 5′ flanking region. In vivo treatment of the transgenics with mouse α, β-interferon increases PD1 expression in a number of tissues. In the spleen, this increase parallels that observed for the endogenous transplantation antigen, K^b, but differs markedly from the differentiation antigen, Qa-2. Increases in cell surface expression of both PD1 and K^b occurred equally in splenic T- and B-cell populations following α,β-interferon treatment. In contrast, Qa-2 expression in B cells was enhanced by α,β-interferon, whereas it was unaffected in T cells and thymocytes.