title: Specific neutralization of defective spleen focus-forming virus in Friend virus complex by rat antiserum.
abstract: The spleen focus-forming virus (SFFV), a rapidly transforming, replication-defective virus in Friend virus (FV) complex that is readily neutralized by antisera directed against its helper virus, was examined for the presence of SFFV-specific antigens. Antisera prepared in Fisher rats against an SFFV-infected Fisher rat embryo fibroblast line (SFFV-FRE) neutralized SFFV effectively, but not Friend-associated murine leukemia virus (F-MuLV) whether the latter was tested alone or was mixed with SFFV in the FV complex. In contrast, serum from mice immunized with SFFV-infected nonproducer mouse cells had little or no neutralizing activity against SFFV. Both absorption and immunoprecipitation studies indicate that the SFFV-specific antigen is immunologically related to xenotropic murine leukemia virus antigens. The role of both SFFV- and F-MuLV-specific antigens in the neutralization of SFFV suggests that this defective virus could be an antigenic mosaic and that viruses in the FV complex may participate in a undirectional form of phenotypic mixing.
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000032:analysis*; D003673:Defective Viruses / Q000276:immunology*; D000939:Epitopes; D005260:Female; D005622:Friend murine leukemia virus / Q000276:immunology*; D007106:Immune Sera; D008297:Male; D051379:Mice / Q000276:immunology; D009500:Neutralization Tests; D011863:Radioimmunoassay; D051381:Rats / Q000276:immunology
chemical_list: D000956:Antigens, Viral; D000939:Epitopes; D007106:Immune Sera