Gaulton G N, Stein M E, Safko B, Stadecker M J
Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia 19104.
J Immunol. 1989 Jun 1;142(11):3821-5.
The ability of thyroid follicular epithelial cells (TFEC) to act as APC is linked to the expression of class II (Ia) molecules of the MHC. The cloned murine thyroid-derived epithelial cell line M.5 was used to demonstrate the potential effects of virus in the direct induction of Ia molecules on TFEC. Membrane binding and replication of reovirus type 1 in TFEC was demonstrated using fluorescein-labeled antireovirus antibody and fluorescence microscopy. One consequence of the interaction between reovirus and M.5 cells was the induction of Ia Ag and augmented class I molecule expression in M.5 cells. The levels of Ia expression at three days after reovirus binding were amplified 17.3-fold over controls and were 2-fold less than that seen upon treatment of M.5 cells with IFN-gamma. Supernatant transfer experiments showed that the induction of Ia expression was directly linked to the binding of virus to M.5 cells, and was not dependent upon virus replication or the presence of IFN. These results indicate that early events of reovirus binding or receptor internalization on TFEC initiate a signaling process which results in the induction of class II and augmentation of class I MHC protein levels on the cell surface.
甲状腺滤泡上皮细胞（TFEC）作为抗原呈递细胞（APC）的能力与主要组织相容性复合体（MHC）Ⅱ类（Ia）分子的表达有关。克隆的鼠源甲状腺衍生上皮细胞系M.5被用于证明病毒在直接诱导TFEC上Ia分子表达方面的潜在作用。使用荧光素标记的抗呼肠孤病毒抗体和荧光显微镜证实了呼肠孤病毒1型在TFEC中的膜结合和复制。呼肠孤病毒与M.5细胞相互作用的一个结果是在M.5细胞中诱导了Ia抗原并增强了Ⅰ类分子的表达。呼肠孤病毒结合三天后Ia表达水平比对照扩增了17.3倍，并且比用γ干扰素处理M.5细胞时观察到的水平低2倍。上清液转移实验表明，Ia表达的诱导与病毒与M.5细胞的结合直接相关，并且不依赖于病毒复制或干扰素的存在。这些结果表明，TFEC上呼肠孤病毒结合或受体内化的早期事件启动了一个信号传导过程，该过程导致细胞表面Ⅱ类分子的诱导和Ⅰ类MHC蛋白水平的增加。
