A follow-up study of the development of Rauscher erythroleukemia.

Expression of cell membrane antigens recognized by antiserum raised against purified Friend murine leukemia virus (Fr-MuLV) envelope glycoprotein (gp71) and by xenotropic MuLV-coded cell surface antigen (XenCSA) specific antibodies was studied in the course of the development of Rauscher erythroleukemia in the spleen of Balb/c mice. DNA content vs immunofluorescence or light scattering of cells were simultaneously analyzed. At early stages of the disease (4-5 days after infection) the gp71 and XenCSA-related antigen expression is enhanced mainly on S-G2/M-phase cells as compared to the majority of G1-phase cells or to the endogenous background of uninfected cells. Later (around 10 days after infection) an approximately ten-fold increased gp71-related antigen density is reached in every phase of the cell cycle. These data show that the virus-induced transition from resting to proliferating state is coupled to enhanced expression of both helper and defective viral env-gene products in the cell membrane of mitotic and G1-phase cells as well.