lmmunofluorescent Analysis of Expression of the RNA Tumor Virus Major Glycoprotein, gp71, on the Surfaces of Normal Murine Cells

The expression of the major glycoprotein, gp71, of murine leukemia virus was studied on the surfaces of a variety of normal murine cell lines with a monospecific rabbit antiserum raised against purified Friend murine leukemia virus gp71. Using viable cell membrane immunofluorescence, most established and early passage normal murine cell lines were significantly reactive with the antiserum, irrespective of neoplastic transformation, strain genotype, or whether they were of embryonic or adult tissue origin. The only murine cells tested not detectably expressing gp71 determinants were BALB/3T3 lines. Although some Friend gp71 interspecies reactivity was discernible on normal murine cells, the principal reactivity was shown to be group specific. Fresh thymocytes from BALB/cJ (G_IX), C57BL/6J (G_IX), and 129/J (G_IX+) mouse strains were also reactive with Friend gp71 antiserum, and this activity, as well as that of an antiserum prepared against purified AKR gp71, were also group specific. An activity discriminating G_IX+ from G_Ix-thymocytes was not observed with either Friend or AKR gp71 antisera.