Lowy D R
Proc Natl Acad Sci U S A. 1978 Nov;75(11):5539-43. doi: 10.1073/pnas.75.11.5539.
DNA from virus-negative AKR mouse embryo cells is infectious for NIH 3T3 cells if the transfected cells are treated with 5-iododeoxyuridine (IdUrd) either before or after addition of the DNA. The virus isolated after transfection of the AKR DNA is an ecotropic murine leukemia virus (MuLV) indistinguishable from endogenous AKR MuLV. The AKR DNA is not infectious in the absence of IdUrd treatment of the recipient cells. DNA from AKR cells treated with IdUrd before DNA isolation is not infectious unless the recipient cells have been treated with IdUrd. Transfected DNA from NIH mouse cells is not infectious even when the recipient cells have been treated with IdUrd. DNA from cells chronically infected with AKR MuLV or Rauscher MuLV is infectious with or without IdUrd treatment of the recipient cells, but the infectivity is not enhanced by IdUrd. The results indicate that the endogenous AKR MuLV DNA genome is potentially infectious. The data are consistent with an IdUrd-sensitive restriction in the recipient NIH 3T3 cells that prevents viral replication from endogenous AKR MuLV DNA but does not prevent viral replication from MuLV DNA of productively infected cells.
如果在添加DNA之前或之后用5-碘脱氧尿苷（IdUrd）处理转染的细胞，来自病毒阴性AKR小鼠胚胎细胞的DNA对NIH 3T3细胞具有感染性。转染AKR DNA后分离出的病毒是一种嗜亲性鼠白血病病毒（MuLV），与内源性AKR MuLV无法区分。在未对受体细胞进行IdUrd处理的情况下，AKR DNA没有感染性。在DNA分离前用IdUrd处理的AKR细胞的DNA没有感染性，除非受体细胞已用IdUrd处理。来自NIH小鼠细胞的转染DNA即使在受体细胞已用IdUrd处理的情况下也没有感染性。来自长期感染AKR MuLV或劳舍尔MuLV的细胞的DNA，无论受体细胞是否用IdUrd处理都具有感染性，但IdUrd不会增强其感染性。结果表明，内源性AKR MuLV DNA基因组具有潜在感染性。这些数据与受体NIH 3T3细胞中对IdUrd敏感的限制一致，该限制可阻止内源性AKR MuLV DNA的病毒复制，但不会阻止来自生产性感染细胞的MuLV DNA的病毒复制。
