Esclatine A, Bellon A, Michelson S, Servin A L, Quéro A M, Géniteau-Legendre M
Institut National de la Santé et de la Recherche Médicale, Unité 510, Pathogènes et Fonctions des Cellules Epithéliales Polarisées, Faculté de Pharmacie, Université Paris XI, 92296 Châtenay-Malabry Cedex, France.
Virology. 2001 Oct 10;289(1):23-33. doi: 10.1006/viro.2001.1122.
Human cytomegalovirus (HCMV) causes a broad spectrum of clinical manifestations in immunocompromised patients, including infection of the gastrointestinal tract. To investigate the role of epithelial cells in the gastrointestinal HCMV disease, we used the intestinal epithelial cell line Caco-2, which is permissive for HCMV replication. In differentiated Caco-2 cells, we showed previously that HCMV infection proceeds preferentially from the basolateral membrane, suggesting that receptors for HCMV may be contained predominantly in the basolateral membrane (A. Esclatine et al., 2000, J. Virol. 74, 513-517). Therefore, we examined expression and localization in Caco-2 cells of heparan sulfate (HS) proteoglycan and annexin II, previously implicated in initial events of HCMV infection. We observed that annexin II is expressed in Caco-2 cells, but is not essential for entry of HCMV. We showed that, during the differentiation process, HS, initially present on the entire surface of the membrane of undifferentiated cells, ultimately became sequestered at the basolateral cell surface of fully differentiated cells. We established by biochemical assays that membrane-associated HS proteoglycan mediates both viral attachment to, and subsequent infection of, Caco-2 cells, regardless of the cell differentiation state. Thus, the redistribution of HS is implicated in the basolateral entry of HCMV into differentiated Caco-2 cells.
人巨细胞病毒（HCMV）在免疫功能低下的患者中会引发广泛的临床表现，包括胃肠道感染。为了研究上皮细胞在胃肠道HCMV疾病中的作用，我们使用了对HCMV复制具有易感性的肠上皮细胞系Caco-2。在分化的Caco-2细胞中，我们之前已表明HCMV感染优先从基底外侧膜开始，这表明HCMV的受体可能主要存在于基底外侧膜中（A. Esclatine等人，2000年，《病毒学杂志》74卷，513 - 517页）。因此，我们检测了硫酸乙酰肝素（HS）蛋白聚糖和膜联蛋白II在Caco-2细胞中的表达及定位，它们之前被认为与HCMV感染的起始事件有关。我们观察到膜联蛋白II在Caco-2细胞中表达，但对HCMV的进入并非必需。我们发现，在分化过程中，最初存在于未分化细胞整个膜表面的HS，最终在完全分化细胞的基底外侧细胞表面聚集。我们通过生化分析确定，膜相关的HS蛋白聚糖介导了病毒与Caco-2细胞的附着以及随后的感染，而与细胞分化状态无关。因此，HS的重新分布与HCMV向分化的Caco-2细胞的基底外侧进入有关。
