Reduced allorecognition of adenovirus-2 infected cells.

The early region 3 of adenovirus 2 encodes the membrane glycoprotein E19. This protein specifically binds class I transplantation antigens of a variety of species. Concomitant with this interaction the intracellular transport of newly synthesized class I heavy chains is abrogated. At late stages of the virus infection this leads to a notable decrease in the cell surface expression of class I antigens. We have studied how infection with adenovirus 2 influences target cell recognition by alloreactive cytolytic T lymphocytes. We found that the E19 protein-induced reduction of the HLA-B7 cell surface expression led to a greatly reduced lysis of the infected cells. These findings support our hypothesis that the E19 protein has evolved to facilitate the in vivo replication of the virus by reducing the expression of HLA class I antigens.