Molecular Basis for the Immune Regulatory Receptor System

配对免疫球蛋白样受体（配对免疫球蛋白样受体，PIR）-B是一种基于酪氨酸的MHC I类分子抑制基序受体，它可以参与B-1细胞的调节，因为PIR-B在B-1细胞中的表达比在B-2细胞或常规B细胞中高几倍。最近的意外发现指出，PIR-B通过结合髓鞘的三种轴突生长抑制剂（包括Nogo），在神经突再生中发挥了新的抑制作用。因此，确定抑制髓磷脂蛋白和MHCI的作用在pir - b介导的免疫和神经细胞抑制中是共存还是互斥变得很有趣。我们研究了这一主题，并获得了支持Nogo-和mhci介导的抑制共存的数据。我们现在提出了一种新的机制，通过免疫系统细胞中的MHCI和Nogo双重实现pir - b介导的调节。

Paired immunoglobulin-like receptor (PIR)-B, an immunoreceptor tyrosine-based inhibitory motif-harboring receptor for MHC class I molecules, could participate in the regulation of B-1 cells, because PIR-B expression is several times higher in B-1 cells than in B-2 cells or conventional B cells. Recent unexpected findings pointed to a novel inhibitory role of PIR-B in neurite regeneration through binding to three axonal outgrowth inhibitors of myelin including Nogo. Thus, it becomes interesting to determine whether the actions of the inhibitory myelin proteins and MHCI could coexist or be mutually exclusive as to the PIR-B-mediated immune and neural cell inhibition. We studied this subject and obtained data supporting the coexistence of Nogo- and MHCI-mediated inhibition. We now propose a novel mechanism by which PIR-B-mediated regulation is achieved dually via MHCI and Nogo in cells of the immune system.