@article{mbs:/content/journal/jgv/10.1099/0022-1317-72-3-609, author = "Heitman, Catherine Krebs and Innes, Cynthia L. and Jetten, Anton M. and Boone, Lawrence R.", title = "Analysis of Fv-1 restriction in two murine embryonal carcinoma cell lines and a series of differentiated derivatives", journal= "Journal of General Virology", year = "1991", volume = "72", number = "3", pages = "609-616", doi = "https://doi.org/10.1099/0022-1317-72-3-609", url = "https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-72-3-609", publisher = "Microbiology Society", issn = "1465-2099", type = "Journal Article", abstract = "We have used antibiotic-resistant retrovirus vectors rescued by Fv-1-sensitive murine leukaemia viruses (MuLV) to examine the Fv-1 phenotype of two undifferentiated embryonal carcinoma (EC) cell lines derived from teratocarcinomas of mouse strain 129. In addition, a set of EC cell-derived differentiated cell lines was analysed. Restriction of both B-tropic and endogenous N-tropic virus is characteristic of the Nr-type restriction reported in mouse strain 129. However, results indicate that Fv-1 restriction is not expressed in the PCC4.aza1R EC cell line. In contrast, the F9 EC cell line showed a strong restriction of the B-tropic pseudotyped vector but failed to restrict endogenous N-tropic pseudotypes. The Fv-1 gene thus seems to be differentially expressed in two EC cell lines derived from the same mouse strain. Furthermore, the selective restriction of B-tropic but not endogenous N-tropic MuLV in F9 cells suggests that these activities function independently of each other. Analysis of PCC4.aza1R-derived differentiated cell lines revealed that three fibroblast cell lines derived by retinoic acid-induced differentiation were also phenotypically silent for Fv-1. However, a pre-adipocyte line established following simultaneous exposure to retinoic acid and 5-azacytidine showed strong restriction of both B-tropic and endogenous N-tropic MuLV. Although additional data suggest that there is no correlation between the differentiated pre-adipocyte phenotype and Fv-1 expression, our results nonetheless show that Nr restriction can be observed in some derivatives of PCC4.aza1R cells, presumably by activating expression of the Fv-1 gene.", }