Obom K M, Popple S W, Holland J G, Pogo B G, Friend C
Virus Res. 1986 Aug;5(2-3):221-34. doi: 10.1016/0168-1702(86)90020-1.
FL vac cell lines are Friend erythroleukemia cells persistently infected with vaccinia virus. These cells produce attenuated leukemia virus, virulent poxvirus, resist superinfection with vaccinia, and show high levels of spontaneous erythrodifferentiation and decreased tumorigenicity in syngeneic hosts (Pogo, G.T. and Friend, C. (1982) Proc. Natl. Acad. Sci. USA 79, 4805-4809). To determine whether resistance to superinfection was associated with the presence of vaccinia DNA in the nucleus, DNA from cells at different passage levels was hybridized to a vaccinia DNA probe. Vaccinia DNA sequences were detected in the nucleus of cells of lines that were productively infected with vaccinia. No such sequences were detected in productively infected with vaccinia. No such sequences were detected in productively infected L cells nor in persistently infected cell lines that no longer produced infectious particles but were resistant to superinfection. Although no evidence of integration of vaccinia DNA was observed, differences in the restriction patterns were detected at some passage levels. The presence of vaccinia virus DNA sequences in the nucleus apparently did not affect the size of the provirus, the integration pattern or the expression of the leukemia virus.
FL vac细胞系是持续感染痘苗病毒的弗氏红白血病细胞。这些细胞产生减毒的白血病病毒、强毒痘病毒，对痘苗病毒的再次感染具有抗性，并且在同基因宿主中表现出高水平的自发红细胞分化以及降低的致瘤性（波戈，G.T.和弗赖恩德，C.（1982年）《美国国家科学院院刊》79卷，4805 - 4809页）。为了确定对再次感染的抗性是否与细胞核中痘苗病毒DNA的存在有关，将不同传代水平细胞的DNA与痘苗病毒DNA探针进行杂交。在被痘苗病毒有效感染的细胞系的细胞核中检测到了痘苗病毒DNA序列。在被痘苗病毒有效感染的细胞中未检测到此类序列。在被有效感染的L细胞中以及在不再产生感染性颗粒但对再次感染具有抗性的持续感染细胞系中也未检测到此类序列。尽管未观察到痘苗病毒DNA整合的证据，但在某些传代水平检测到了限制性图谱的差异。细胞核中痘苗病毒DNA序列的存在显然不影响前病毒的大小、整合模式或白血病病毒的表达。
