Suk W A, Long C W
Ann N Y Acad Sci. 1983;419:75-86. doi: 10.1111/j.1749-6632.1983.tb37093.x.
The exposure of a high-passage clone of Kirsten sarcoma virus transformed Balb/c (K-Balb) mouse cells to tuftsin (Thr-Lys-Pro-Arg) enhanced the expression of endogenous xenotropic retrovirus. The tetrapeptide increased the expression of virus that was infectious for rat, but not mouse, cells in a concentration-dependent fashion (0.001-1000 micrograms/ml). Increased virus expression could be achieved during short-term incubations (3-4 hr), with maximum enhancement occurring over longer time periods (16-18 hr). The enhancement of virus expression by tuftsin was proportional to the spontaneous release of virus. The infectivity of the enhanced virus was neutralized by goat anti-RLV gp 70 serum. Actinomycin D inhibited the induction of virus, suggesting that enhanced expression required de novo RNA synthesis. Tuftsin stimulated DNA, RNA, and protein synthesis in K-Balb cells during 16-hr incubations. Increased cellular proliferation was also seen at various time periods. The effects observed using K-Balb cells offer an opportunity to study the modulation of gene expression by tuftsin in a fibroblast culture system.
将 Kirsten 肉瘤病毒转化的 Balb/c（K-Balb）小鼠细胞的高传代克隆暴露于促吞噬素（苏氨酸-赖氨酸-脯氨酸-精氨酸）可增强内源性异嗜性逆转录病毒的表达。该四肽以浓度依赖方式（0.001 - 1000 微克/毫升）增加了对大鼠而非小鼠细胞具有感染性的病毒的表达。在短期孵育（3 - 4 小时）期间即可实现病毒表达增加，在较长时间段（16 - 18 小时）出现最大增强。促吞噬素对病毒表达的增强与病毒的自发释放成比例。增强病毒的感染性可被山羊抗 RLV gp 70 血清中和。放线菌素 D 抑制病毒诱导，表明增强表达需要从头合成 RNA。在 16 小时孵育期间，促吞噬素刺激 K-Balb 细胞中的 DNA、RNA 和蛋白质合成。在不同时间段也观察到细胞增殖增加。使用 K-Balb 细胞观察到的这些效应为在成纤维细胞培养系统中研究促吞噬素对基因表达的调节提供了机会。
