Cytopathogenic mechanisms of Entamoeba histolytica.
Cytopathogenic mechanisms of Entamoeba histolytica.
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DOI：
10.1084/jem.152.2.377
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发表时间：
1980-08-01
期刊：
影响因子：
--
通讯作者：
Guerrant RL
中科院分区：
文献类型：
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作者：
Ravdin JI;Croft BY;Guerrant RL
溶解组织内阿米巴破坏中国仓鼠卵巢(CHO)细胞的电影显微摄影显示，阿米巴的细胞致病作用由两部分组成：接触性细胞致死效应和吞噬作用。没有接触阿米巴的细胞保持完好。应用一击假说定量测定阿米巴对CHO细胞的破坏，证实阿米巴的细胞毒性作用是接触依赖的。111Indioxine标记细胞的研究提供了进一步的证据，证明了溶组织埃希菌对细胞外的杀伤作用，并表明94%的靶细胞在吞噬之前就被杀死了。当我们检测溶组织埃希氏菌的细胞毒素释放时，我们发现阿米巴滤液对CHO细胞没有影响，而阿米巴滤液对细胞圆形和释放的非特异性影响。阿米巴的声学效应是时间剂量依赖的，不会对细胞产生毒性，是可逆的，并且被αII巨球蛋白抑制。细胞松弛素B改变了阿米巴的运动和形态，单层实验证实细胞松弛素A、B或D可抑制组织溶解埃希氏菌对CHO细胞的破坏。细胞松弛素D也能抑制阿米巴对CHO细胞的细胞外杀伤作用，这种抑制作用与阿米巴运动或吞噬作用无关。秋水仙碱和长春花碱单独或与细胞松弛素D合用不能抑制溶组织性肠杆菌的细胞致病性，表明阿米巴杀靶细胞不需要微管功能。
Cinemicrography of Entamoeba histolytica destruction of Chinese hamster ovary (CHO) cells shows that ameba cytopathogenicity consists of separate components: a contact-dependent cytolethal effect, and phagocytosis. Cells not in contact with amebae remain intact. Quantitation of ameba destruction of CHO cells by applying the one-hit hypothesis confirms that the cytoethal effect of amebae is contact dependent. Studies with 111Indium oxine-labeled cells provide further evidence of extracellular killing by E. histolytica and indicate that > 94% of the target cells are killed before phagocytosis. When we examined for a cytotoxin release by E. histolytica, we found no effect on CHO cells with filtrates of amebae, and a nonspecific effect of cell rounding and release with sonicates of amebae. The ameba sonicate effect was time-dose dependent, was not cytolethal, was reversible, and was inhibited by alpha II macroglobulin. Cytochalasin B altered ameba motility and morphology, and monolayer experiments confirmed that cytochalasins A, B, or D inhibited CHO cell destruction by E. histolytica. Cytochalasin D also inhibited extracellular killing of CHO cells by amebae in pellets, apparently independent of effects on ameba motility or phagocytosis. Colchicine and vinblastine, alone or in combination with cytochalasin D, did not inhibit E. histolytica cytopathogenicity, which indicates that microtubule function is not required for target cell killing by amebae.