Functional analysis of MHC class I molecules in the neuronal cells of central nervous

为了阐明MHC分子在中枢神经系统（CNS）中的作用，我们用RT-PCR和免疫组织化学方法检测了经典和非经典I类分子在C57 BL/6小鼠CNS中的表达。在I类分子中，虽然通过RT PCR分析发现了H2-K和H2-D转录物，但通过使用抗I类抗体的免疫组织化学研究，这些蛋白质主要定位于内皮细胞和脉络丛细胞中。神经元细胞的染色较淡或较弱，且在神经元细胞中不识别I类MHC分子的特征性分布。与此相反，非经典的I类蛋白主要定位于神经元细胞。H2-Qa 1蛋白在大脑皮质第5、6层、海马和结节核的神经细胞中呈强阳性染色。提示非经典MHC Ⅰ类分子在中枢神经系统神经细胞中可能具有特殊的作用。据报道， ...更多信息 在小鼠中编码非经典I类分子的基因有10多个，但其确切数目和基因结构尚未确定。从小鼠基因组草图序列中估计出17个非经典I类基因，并对大脑皮层、下丘脑、小脑、胸腺、小肠、肝、肾和脾的总RNA进行RT-PCR分析。在大脑皮层、下丘脑和小脑中观察到8个非经典MHC I类转录物，尽管8个基因中的7个在迄今为止检查的所有组织中表达。H2-M5基因特异性表达于CNS。八种非经典的MHC I类分子的表达可能表明这些分子在神经细胞连接的重塑和可塑性中或在CNS中的一些免疫反应中起重要作用。为了确定非经典MHC I类分子的确切作用，目前正在进行H2-M5基因靶向小鼠和H2-Qa 1过表达小鼠的生产。少

In order to elucidate a role of MHC molecules in the central nervous system (CNS), we have examined the expression of classical and non-classical class I molecules in the CNS of C57BL/6 mice by using RT-PCR and immuno-histochemistry. In class I molecules, although H2-K and H2-D transcripts were found by RT PCR analysis, these proteins were mainly localized in endothelial cells and choroids plexus cells by immuno-histochemical study using an anti-class I antibody. The staining of neuronal cells was faint or weak, and the characteristic distribution of class I MHC molecules was not recognized in neuronal cells. In contrast, non-classical class I proteins were localized mainly in the neuronal cells. The strong staining of H2-Qa 1 protein was observed In the nerve cells localized in the 5th and 6th layer of cerebral cortex, hippocampus and the tuberal nucleus. These data suggested that non-classical MHC class I molecules may have special roles in nerve cells of CNS. It was reported that th … More ere are over 10 genes coding the non-classical class I molecules in mouse, however, the exact number or gene structures had not been determined. We estimated the 17 non-classical class I genes from the draft sequence of mouse genome by computerr analysis, and RT-PCR analysis was performed on total RNAs extracted from cerebral cortex, hypothalamus, cerebellum, thymus, small intestine, liver, kidney and spleen. Eight non-classical MHC class I transcripts were observed in cerebral cortex, hypothalamus and cerebellum, although the seven among eight genes were expressed in all the tissues so far examined. The H2-M5 gene is expressed specifically for CNS. The expression of eight non-classical MHC class I molecules may suggest an important role of these molecules in the remodeling and plasticity of connection of nerve cells or in some immune responses in the CNS. To determine exact roles of non-classical MHC class I molecules, the production of the H2-M5 gene targeting mouse and the H2-Qa1 overexpressing mouse are now in progress. Less