Navas Maria-Cristina, Fuchs Anne, Schvoerer Evelyne, Bohbot Alain, Aubertin Anne-Marie, Stoll-Keller Françoise
Institut de Virologie, U544 INSERM, Strasbourg, France.
J Med Virol. 2002 Jun;67(2):152-61. doi: 10.1002/jmv.2204.
In vitro infection of human monocyte-derived dendritic cells was carried out to study their susceptibility to hepatitis C virus (HCV) infection. Immature dendritic cells and mature dendritic cells were incubated overnight at 37 degrees C with HCV-positive (genotype 1) serum samples; the presence of the viral genome associated with the production of its replicative intermediate was used as evidence of infection. In immature dendritic cells, HCV RNA was detectable from days 1-10 post-infection (p.i.), and de novo synthesis of negative-strand HCV RNA could be demonstrated by a strand-specific rTth reverse transcription-polymerase chain reaction at day 2. In mature dendritic cells, the positive-strand form was detectable from days 1-5 p.i., while the negative-strand HCV RNA appeared at days 1 and 2 p.i. Quasispecies present in the inoculum and 6 days p.i. were analyzed by sequencing hypervariable region 1 of the E2 protein. Only two of seven HVR variants present in the inoculum were found in HCV-infected immature dendritic cells. Another two HVR variants not found in the inoculum were recovered from infected immature dendritic cells, suggesting serum minor variants selection or virus evolution during in vitro replication. Analysis by single-strand conformation polymorphism assay of 5' untranslated region of HCV sequences showed that the patterns obtained from the inoculum and infected immature dendritic cells and mature dendritic cells differed slightly. These findings indicate that both immature dendritic cells and mature dendritic cells are susceptible to HCV genotype 1 infection, supporting at least HCV RNA replication. This model should be a valuable tool for the study of modulation of dendritic cell functions in HCV infection.
为了研究人单核细胞衍生的树突状细胞对丙型肝炎病毒（HCV）感染的易感性，进行了体外感染实验。将未成熟树突状细胞和成熟树突状细胞与HCV阳性（1型基因型）血清样本在37℃下孵育过夜；将与病毒复制中间体产生相关的病毒基因组的存在作为感染的证据。在未成熟树突状细胞中，感染后第1 - 10天可检测到HCV RNA，并且在第2天通过链特异性rTth逆转录 - 聚合酶链反应可证明负链HCV RNA的从头合成。在成熟树突状细胞中，感染后第1 - 5天可检测到正链形式，而负链HCV RNA在感染后第1天和第2天出现。对接种物和感染后6天存在的准种通过对E2蛋白高变区1进行测序分析。在接种物中存在的七个HVR变体中，只有两个在HCV感染的未成熟树突状细胞中被发现。从未感染的未成熟树突状细胞中回收了另外两个在接种物中未发现的HVR变体，这表明在体外复制过程中存在血清次要变体选择或病毒进化。通过单链构象多态性分析对接种物、感染的未成熟树突状细胞和成熟树突状细胞的HCV序列5'非翻译区进行分析，结果显示所获得的图谱略有不同。这些发现表明，未成熟树突状细胞和成熟树突状细胞均易受HCV 1型基因型感染，至少支持HCV RNA复制。该模型应是研究HCV感染中树突状细胞功能调节的有价值工具。
