Chang K S
Zhonghua Min Guo Wei Sheng Wu Xue Za Zhi. 1975 Jun;8(2):82-92.
Although the doses of X-ray (312-2,500 R) used for irradiation of cells caused impairment of DNA synthesis and cell replication, co-cultivation of X-irradiated MuLV- carrier cells with un-irradiated nonproducer cells of MSV-induced tumour resulted in as much as 20-fold increase in MSV retrieval compared with the un-irradiated control. The enhancement was apparent also as a 3-fold increase in the number of cells producing MSV (infectious centers) in the co-cultivation plate. This suggested that the MSV genome rescue efficiency in terms of MSV per cell, as well as the number of cells producing MSV, increased markedly. By uridine-3H-labeling and focus assay experiments, evidence was presented which suggested that an increase in MSV/MuLV ratio in the culture fluid of co-cultivation plates was obtained when the MuLV-carrier cells were pre-irradiated. By contrast, X-irradiation of the nonproducer cells prior to co-cultivation caused only reductions of MSV genome rescue efficiency. However, use of X-irradiated MuLV-carrier cells for co-cultivation with X-irradiated nonproducer cells restored this efficiency to some extent. The dose-survival curve of the nonproducer cells was not much different from those of the MuLV-carrier cells after X-irradiation. It was suggested that the viability of nonproducer cells was required for replication of MuLV transferred from the carrier cells and for subsequent MSV genome rescue.
尽管用于细胞照射的X射线剂量（312 - 2500伦琴）会导致DNA合成和细胞复制受损，但将经X射线照射的MuLV载体细胞与未照射的MSV诱导肿瘤的非生产细胞共同培养，与未照射的对照组相比，MSV的回收量增加了多达20倍。在共同培养平板中，产生MSV的细胞（感染中心）数量增加了3倍，这种增强也很明显。这表明，就每个细胞中的MSV而言，MSV基因组拯救效率以及产生MSV的细胞数量都显著增加。通过尿苷-3H标记和焦点分析实验，有证据表明，当MuLV载体细胞预先照射时，共同培养平板培养液中的MSV/MuLV比率会增加。相比之下，在共同培养前对非生产细胞进行X射线照射只会降低MSV基因组拯救效率。然而，使用经X射线照射的MuLV载体细胞与经X射线照射的非生产细胞共同培养在一定程度上恢复了这种效率。X射线照射后，非生产细胞的剂量存活曲线与MuLV载体细胞的剂量存活曲线没有太大差异。这表明非生产细胞的活力对于从载体细胞转移的MuLV的复制以及随后的MSV基因组拯救是必需的。
