Retrovirus transduction: segregation of the viral transforming function and the herpes simplex virus tk gene in infectious Friend spleen focus-forming virus thymidine kinase vectors.
A series of deletions and insertions utilizing the herpesvirus thymidine kinase gene (tk) were constructed in the murine retrovirus Friend spleen focus-forming virus (SFFV). In all cases, the coding region for the SFFV-specific glycoprotein (gp55), which is implicated in erythroleukemic transformation, was left intact. These SFFV-TK and SFFV deletion vectors were analyzed for expression of tk and gp55 after DNA-mediated gene transfer. In addition, virus rescued by cotransfection of these vectors with Moloney murine leukemia virus was analyzed for infectious TK-transducing virus, gp55 expression, and erythroleukemia-inducing ability. The experiments demonstrated that deletions or insertions within the intron for the gp55 env gene can interfere with expression of gp55 after both DNA-mediated gene transfer and virus infection. In contrast, the gene transfer efficiency of the tk gene was unaffected in the SFFV-TK vectors, and high-titer infectious TK virus could be recovered. Revertant viruses capable of inducing erythroleukemia and expressing gp55 were generated after cotransfection of the SFFV-TK vectors with murine leukemia virus. The revertant viruses lost both tk sequences and the ability to transduce TK- fibroblasts to a TK+ phenotype. These experiments demonstrate that segregation of the TK and erythroleukemia functions can occur in retrovirus vectors which initially carry both markers.
D000818:Animals; D002472:Cell Transformation, Viral; D002872:Chromosome Deletion; D005622:Friend murine leukemia virus / Q000235:genetics*; D005796:Genes; D005814:Genes, Viral; D005822:Genetic Vectors; D007739:L Cells / Q000201:enzymology; D051379:Mice; D010641:Phenotype; D018139:Simplexvirus / Q000201:enzymology / Q000235:genetics*; D013937:Thymidine Kinase / Q000235:genetics*; D014161:Transduction, Genetic; D014162:Transfection
D013937:Thymidine Kinase