Determinants of Natural Killer Cell Ly49 Receptor Specificity

自然杀伤（NK）细胞是淋巴细胞，作为抵御病毒和肿瘤的第一道防线，摧毁病理改变的细胞。NK细胞表达对I类（CI）主要组织相容性复合物分子特异性的抑制性受体，其在健康细胞上普遍表达。由于通常在病毒感染的细胞或肿瘤细胞中发生的Cl表达的丧失，NK抑制性受体的参与的缺乏释放NK细胞的抑制，允许它们破坏这种改变的细胞。Ly 49是由小鼠和大鼠NK细胞表达的CI特异性受体的主要类别的大家族，但不是人类。CI与β-2微球蛋白（b2 m）结合，并结合和呈递来自细胞内蛋白水解事件的肽片段。我们和其他人已经发现，CI结合肽的身份可以决定Ly 49对CI的识别。目前尚不清楚的是，健康细胞中调节NK细胞的内源性肽的性质，

Natural killer (NK) cells are lymphocytes that act as a first line of defense against viruses and tumours, destroying pathologically altered cells. NK cells express inhibitory receptors specific for class I (CI) major histocompatiblity complex molecules ubiquitously expressed on healthy cells. Lack of engagement of NK inhibitory receptors, due to loss of CI expression that typically occurs with virus-infected cells or tumour cells, releases inhibition of NK cells, allowing them to destroy such altered cells. Ly49 are large families of major class of CI-specific receptors expressed by mouse and rat NK cells, but not humans. CI associate with beta-2 microglobulin (b2m) and bind and present peptide fragments from intracellular proteolytic events. We, and others, have found that the identity of the CI-bound peptide can determine Ly49 recognition of CI. What is unclear, is the nature of endogenous peptides in healthy cells that regulate NK cells, and the