Ghosh P C, Wellner R B, Wu H C
Mol Cell Biol. 1984 Jul;4(7):1320-5. doi: 10.1128/mcb.4.7.1320-1325.1984.
By osmotic lysis of pinocytic vesicles we were able to inject ricin or ricin A chain directly into the cytosol of Chinese hamster ovary cells. The lag time of 1 to 2 h before the onset of the inhibition of protein synthesis by ricin in intact cells was reduced to 15 to 30 min by this method. Preincubation of cells with a low concentration of nigericin, which was shown earlier to enhance the cytotoxicity of ricin, had no effect under this condition. Direct transfer of either intact ricin or the ricin A subunit by osmotic lysis of pinocytic vesicles into the cytosol of the ricin-resistant CHO mutant cell line 4-10 rendered the mutant 4-10 cells as sensitive to ricin as the CHO pro wild-type cells. Both the lag time and the rate of inhibition of protein synthesis in the wild-type and mutant cell lines after the introduction of ricin by osmotic lysis of pinocytic vesicles were the same. These results indicate that injection of ricin into the cytosol by osmotic lysis of pinosomes bypasses the internalization defect in the mutant cell line.
通过对胞饮小泡进行渗透裂解，我们能够将蓖麻毒素或蓖麻毒素A链直接注入中国仓鼠卵巢细胞的胞质溶胶中。完整细胞中蓖麻毒素抑制蛋白质合成开始前1至2小时的延迟时间，通过这种方法缩短至15至30分钟。用低浓度尼日利亚菌素预孵育细胞（之前已证明该物质可增强蓖麻毒素的细胞毒性），在此条件下并无效果。通过胞饮小泡的渗透裂解将完整的蓖麻毒素或蓖麻毒素A亚基直接转移到对蓖麻毒素具有抗性的CHO突变细胞系4 - 10的胞质溶胶中，使突变的细胞系4 - 10细胞对蓖麻毒素的敏感性与CHO野生型细胞相同。通过胞饮小泡的渗透裂解引入蓖麻毒素后，野生型和突变细胞系中蛋白质合成的延迟时间和抑制速率均相同。这些结果表明，通过胞饮小体的渗透裂解将蓖麻毒素注入胞质溶胶可绕过突变细胞系中的内化缺陷。
