Antisense inhibition of amoebapore expression in Entamoeba histolytica causes a decrease in amoebic virulence
Antisense inhibition of amoebapore expression in Entamoeba histolytica causes a decrease in amoebic virulence
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DOI：
10.1046/j.1365-2958.1999.01607.x
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发表时间：
1999-11-01
影响因子：
3.6
通讯作者：
Mirelman, D
中科院分区：
文献类型：
--
作者：
Bracha, R;Nuchamowitz, Y;Mirelman, D
阿米巴孔被认为是原生动物寄生虫溶组织内阿米巴的主要致病因子，它负责杀死靶细胞。这些77个氨基酸残基是猪和人细胞毒性淋巴细胞NK-裂解素和颗粒裂解素的结构和功能类似物，在含有Neo抗性基因和编码阿米巴阿米巴A基因(包括其5‘和3’非翻译区(UTR)序列的基因)的杂交质粒构建体(Pap-R2)下，在一个启动子(G34)的作用下，从溶组性肠杆菌核糖体蛋白(RP-L21)基因拷贝中反向导入阿米巴阿米巴蛋白基因表达。强毒E的转化子HM-1：IMSS对阿米巴基因表达的抑制率接近60%，致病性显著降低。活的滋养体对哺乳动物有核细胞的细胞病变和细胞溶解活性以及对红细胞的裂解明显受到抑制。此外，与对照相比，Pap-R2转基因细胞的滋养体提取物显示出较低的成孔活性和较弱的抑制细菌生长的能力。值得注意的是，转导Pap-R2基因的仓鼠肝脓肿形成显著受损。这些结果首次证明阿米巴孔虫是溶组织埃希氏菌滋养体发挥显著的细胞溶解和组织破坏活性的致病因子之一。
Amoebapores have been proposed to be a major pathogenicity factor of the protozoan parasite Entamoeba histolytica, which is responsible for the killing of target cells. These 77-residue peptides are structural and functional analogues of NK-lysin and granulysin of porcine and human cytotoxic lymphocytes, Inhibition of amoebapore gene expression in amoebae was obtained following transfection with a hybrid plasmid construct (pAP-R2) containing the Neo resistance gene and the gene coding for amoebapore a, including its 5' and 3' untranslated region (UTR) sequences, in reverse orientation under a promoter (g34)taken from one of the E. histolytica ribosomal protein (RP-L21) gene copies. Transfectants of Virulent E, histolytica strain HM-1:IMSS, in which the expression of amoebapore was inhibited by similar to 60%, were significantly less pathogenic. Cytopathic and cytolytic activities of viable trophozoites against mammalian nucleated cells, as well as lysis of red blood cells, were markedly inhibited. Moreover, trophozoite extracts of pAP-R2 transfectant displayed lower pore-forming activity and were less potent in inhibiting: bacterial growth compared with controls. Notably, liver abscess formation in hamsters by the pAP-R2 transfectant was substantially impaired. These results demonstrate for the first time that amoebapore is one of the pathogenicity factors by which trophozoites of E, histolytica exert their remarkable cytolytic and tissue destructive activity.