艰难梭菌A毒素的细胞致死活性研究

本文报道艰难梭菌Ａ毒素对４种培养细胞的细胞致死活性的探讨。４种培养细胞为Ｖｅｒｏ（非洲绿猴肾细胞）细胞、ＴＰＣ─１（人甲状腺肿瘤细胞）细胞、ＮＩＨ３Ｔ３细胞（小鼠成纤维细胞）及将ｒａｓ癌基因转基因于ＮＩＨ３Ｔ３细胞的ＮＩＨ３Ｔ３ｒａｓ细胞。应用台酚蓝排除能试验、噻唑蓝（ＭＴＳ）比色、细胞膜损害测定试验、荧光显微术观察细胞核的形态变化等测定Ａ毒素细胞致死活性。实验表明：４种培养细胞系对Ａ毒素细胞圆缩化作用的敏感性依次为ＮＩＨ３Ｔ３ｒａｓ，ＴＰＣ─１，Ｖｅｒｏ，ＮＩＨ３Ｔ３细胞。而对Ａ毒素细胞致死活性的敏感性依次为ＴＰＣ─１，ＮＩＨ３Ｔ３，Ｖｅｒｏ，ＮＩＨ３Ｔ３ｒａｓ细胞。从而得知Ａ毒素的细胞致死活性不但依细胞种类不同而不同，而且也不一定与Ａ毒素的细胞圆缩化作用有关。肿瘤细胞ＴＰＣ─１细胞对Ａ毒素致死活性有特殊敏感性。以上结果对探索抗癌新药的研制具有重要意义。

The Cell Killing Activity of Toxin A of Clostridium Difficile

This paper described the cell killing activity of toxin A of Clostridium difficile on four cell lines which were Vero(Africa green monkey kidney),TPC-1 (human thyroid papillary carcinoma),NIH 3T3 (mouse fibroblast)and NIH 3T3 ras (NIH 3T3 cell transfected with ras oncogene)cell line. The methods to assess the cell killing activity including trypan blue exclusion test,MTS calorimetric assay, membrane damage test and fluorescence micrographs (morphology of cell nuclei)were performed on the four cell lines. The results showed the order of sensitivity of rounding of cells of four cell lines to toxin A as follows: NIH 3T3 ras,TPC-1,Vero,NIH 3T3.However, the order of sensitivity of cell killing activity of four cell lines to toxin A as follows TPC -1,NIH 3T3, Vero,NIH 3T3 ras. The results indicated the cell killing activity of toxin A on the four cell lines are not identified and not related to cell rounding of toxin A. Under the same dose of cell rounding of toxin A,the dose of cell killing activity of toxin A and the time-course of cell death were very different on the four cell lines. TPC-1 cell line is most sensitive to cell killing activity of toxin A. The dates suggest that the toxin A may have potential therapeutic value in the treatment of some cancers.