title: New cell surface gp70 related to Friend mink cell focus-inducing virus is expressed on Friend virus-induced erythroleukemic spleen cells after elimination of ecotropic Friend virus gp70 in Rfv-3r/s mice.
abstract: Spleen cells from Rfv-3r/s mice with Friend virus-induced erythroleukemia were analyzed for expression of virus-induced proteins with monoclonal antiviral antibodies and conventional antisera. Leukemic spleen cells, 30-60 d after virus inoculation, expressed decreased amounts of ecotropic Friend murine leukemia helper virus gag- and env-encoded cell surface and intracellular proteins compared with leukemic cells tested 8-10 d after virus inoculation. In contrast, the spleen focus-forming virus-induced protein, gp55, was present on both leukemia cell populations. This difference appeared to be mediated by the humoral antibody response in Rfv-3r/s mice, which could recognize only ecotropic gag and env proteins, and not gp55. A new gp70 molecule cross-reactive with a recombinant Friend mink cell focus-inducing virus was found in large quantities on late leukemic cells. This protein appeared to be derived from a recombinant virus produced during the course of Friend virus infection. The appearance of this new gp70 suggests that recombinant viruses other than spleen focus-forming virus may play a role in Friend virus-induced erythroleukemia.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000956:Antigens, Viral / Q000032:analysis* / Q000276:immunology*; D003429:Cross Reactions; D003602:Cytotoxicity, Immunologic; D005622:Friend murine leukemia virus / Q000276:immunology; D004915:Leukemia, Erythroblastic, Acute / Q000276:immunology*; D007942:Leukemia, Experimental / Q000276:immunology*; D051379:Mice; D011498:Protein Precursors / Q000378:metabolism; D012367:RNA, Viral / Q000276:immunology*; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D013997:Time Factors; D014759:Viral Envelope Proteins
chemical_list: D000911:Antibodies, Monoclonal; D000956:Antigens, Viral; D011498:Protein Precursors; D012367:RNA, Viral; D014759:Viral Envelope Proteins