Membrane Vesicles Released by Intestinal Epithelial Cells Infected with Rotavirus Inhibit T-Cell Function
Membrane Vesicles Released by Intestinal Epithelial Cells Infected with Rotavirus Inhibit T-Cell Function
复制标题
DOI：
10.1089/vim.2009.0113
复制
发表时间：
2010-12-01
期刊：
影响因子：
2.2
通讯作者：
Angel, Juana
中科院分区：
文献类型：
--
作者：
Barreto, Alfonso;Rodriguez, Luz-Stella;Angel, Juana
轮状病毒（RV）主要在肠上皮细胞（IEC）中复制，这些细胞释放的“危险信号”可以调节病毒免疫。我们最近发现，感染恒河猴RV的人类模型IEC（Caco-2细胞）释放一组非炎症性免疫调节剂，包括热休克蛋白（HSP）和TGF-β 1。在这里，我们表明，这两种蛋白质的释放部分与膜囊泡（MV）从过滤的Caco-2上清液通过超离心浓缩。这些MV表达外泌体的标志物（CD 63和其他），但不表达内质网（ER）或细胞核的标志物。RV感染的细胞比未感染的细胞释放更多的与MV相关的蛋白质。VP 6与这些MV中存在的CD 63共免疫沉淀，并且VP 6与RV感染的细胞中的CD 63共定位，表明这种病毒蛋白与MV相关，并且这种关联发生在细胞内。分析了来自36例RV所致或非RV所致胃肠炎儿童粪便样本的MV制剂中存在的CD 63。在RV感染儿童的3/8粪便样本中，VP 6与CD 63共免疫沉淀，表明这些MV是由RV感染的细胞在体内释放的。此外，含有来自RV感染细胞的MV的组分比来自未感染细胞的组分在更大程度上诱导死亡并抑制CD 4（+）T细胞的增殖。这些作用部分是由于TGF-β，因为它们通过用TGF-β受体抑制剂ALK 5i处理T细胞而逆转。来自RV感染的和未感染的细胞的MV是异质的，具有针对外来体（在1.10和1.18 g/mL之间）描述的形态和典型浮选密度，以及更致密的囊泡（>1.24 g/mL）。来自RV感染细胞的两种类型的MV在抑制T细胞功能方面比来自未感染细胞的MV更有效。我们认为RV感染IEC释放MV调节病毒免疫。
Rotavirus (RV) predominantly replicates in intestinal epithelial cells (IEC), and "danger signals" released by these cells may modulate viral immunity. We have recently shown that human model IEC (Caco-2 cells) infected with rhesus-RV release a non-inflammatory group of immunomodulators that includes heat shock proteins (HSPs) and TGF-beta 1. Here we show that both proteins are released in part in association with membrane vesicles (MV) obtained from filtrated Caco-2 supernatants concentrated by ultracentrifugation. These MV express markers of exosomes (CD63 and others), but not of the endoplasmic reticulum (ER) or nuclei. Larger quantities of proteins associated with MV were released by RV-infected cells than by non-infected cells. VP6 co-immunoprecipitated with CD63 present in these MV, and VP6 co-localized with CD63 in RV-infected cells, suggesting that this viral protein is associated with the MV, and that this association occurs intracellularly. CD63 present in MV preparations from stool samples from 36 children with gastroenteritis due or not due to RV were analyzed. VP6 co-immunoprecipitated with CD63 in 3/8 stool samples from RV-infected children, suggesting that these MV are released by RV-infected cells in vivo. Moreover, fractions that contained MV from RV-infected cells induced death and inhibited proliferation of CD4(+) T cells to a greater extent than fractions from non-infected cells. These effects were in part due to TGF-beta, because they were reversed by treatment of the T cells with the TGF-beta-receptor inhibitor ALK5i. MV from RV-infected and non-infected cells were heterogeneous, with morphologies and typical flotation densities described for exosomes (between 1.10 and 1.18 g/mL), and denser vesicles (>1.24 g/mL). Both types of MV from RV-infected cells were more efficient at inhibiting T-cell function than were those from non-infected cells. We propose that RV infection of IEC releases MV that modulate viral immunity.