绿脓杆菌外毒素A的细胞毒性和细胞表面受体密度

Cytotoxicity and cellular surface receptor density of Pseudomonas aeruginosa exotoxin A

用微量细胞法观察了肝癌细胞SMMC-7721,成纤维细胞L929。肺癌细胞A549及中国地鼠卵巢细胞CHOk1等4株传代细胞对绿脓杆菌外毒素A细胞毒作用的敏感性,结果SMMC-7721最敏感,L929次之,A549次于前两者,CHOk1最次,用ELISA法显示各细胞株表面绿脓杆菌外毒素A受体,且用图像分析比较受体密度,结果与细胞毒作用一致,以SMMC-7721为最高,显示了细胞毒敏感程度与受体量呈正相关。

The cytotoxic activities ofPseudomonas aeruginosa exotoxin A (PEA) were determined in 4 strains of cultured cell lines, i.e. human hepatoma cell SMMC-7721, mouse fibroblast L929, human lung carcinoma A549 and CHOkl, and the cytotoxic concentration of PEA to the cell lines were 0.1, 0.5, 0.5, and 10 ng·ml-1, respectively. The receptors of PEA on these cells were demonstrated by ELISA and measured by picture analyser. The results show that the receptor density of SMMC-7721 is thehighest. The differences in the density of receptors among the four different cell lines appear to account for the differences in their cytotoxic sensitivities. The results suggest that the SMMC-7721 could be a useful cell line in the study of the pathogenesis of Pseudomonas aeruginosa exotoxin A.