体外培养人胎盘滋养层细胞内吞丙型肝炎病毒过程的电镜观察

目的 探讨丙型肝炎病毒（HCV）感染体外分离培养人胎盘滋养层细胞的可能机制，观察HCV感染滋养层细胞后在细胞内的具体定位。方法采用胰蛋白酶消化法及Percoll密度梯度分离法分离培养人胎盘组织中滋养层细胞后，以HCVRNA阳性血清对滋养层细胞进行体外感染实验，不同时间终止实验，制备电镜标本，透射电镜观察。结果HCV感染滋养层细胞的过程中有吞噬小泡形成，形态学上符合被覆小凹的特点；感染后HCV病毒样颗粒多定位于粗面内质网附近。结论HCV可以感染滋养层细胞，其感染过程可能是被覆小凹介导的内吞过程。本研究提供了HCV体外感染人胎盘滋养层细胞具体方式的形态学资料，对HCV宫内传播机制的进一步研究奠定了实验基础。

HCV infection process in the in vitro human cytotrophoblasts under transmission electron microscope

Objective In order to in vitro investigate the possible mechanism of HCV infecting the human cytotrophoblasts cultured in vitro,and to observe the concrete location of HCV after infec- tion.Methods Human placentae were digested with trypsin and centrifuged with percoll density gra- dient to obtain cytotrophoblasts.The cytotrophoblasts was incubated in DMEM-HG medium with HCV-RNA-positive serum.Stop the infection at different phases and prepare specimen for transmis- sion electron microscope(TEM)examination.Results With TEM,an endocytic vesicle surrounding a HCV-like particle was investigated,which accorded with the morphologic characteristics of clathrin- coated pits.HCV-like particles mainly located near rough endoplasmic reticulum.with clear envelope, either round-shaped or oval-shaped.Conclusions Cytotrophoblasts could be infected by HCV,and the process of HCV infection should be internalization via clathrin-coated pits.This study provides morphological evidences to identify that the cytotrophoblasts could be infected by HCV,which is the base of further study on the mechanism of HCV vertical transmission.