Stimulatory killer immunoglobulin-like receptors, NKG2D and stimulatory receptors of the CD94-NKG2 family have duplicity in function. On natural killer (NK) cells, these receptors act as independent and competent recognition units. Stimulatory NK receptors also appear on subsets of effector T cells, particularly those that have replicated extensively. When expressed on T cells, they amplify signals mediated through the T-cell antigen receptor and, thus, function as co-stimulatory, but not direct stimulatory, molecules. One mechanism responsible for this dichotomy is the differential expression of adaptor molecules. This duplicity in function, which is not seen for other co-stimulatory molecules, is responsible for the unique context information provided by the NK receptors, and it could explain their involvement in chronic inflammation and autoimmunity.

中文翻译：

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NK受体的双重寿命：刺激还是共同刺激？

刺激性杀手免疫球蛋白样受体，NKG2D和CD94-NKG2家族的刺激性受体具有双重功能。在自然杀伤（NK）细胞上，这些受体充当独立且有效的识别单位。刺激性NK受体也出现在效应T细胞的亚群上，特别是那些已经大量复制的细胞。当在T细胞上表达时，它们会放大通过T细胞抗原受体介导的信号，因此起共刺激分子的作用，而不是直接刺激分子。造成这种二分法的一种机制是衔接子分子的差异表达。这种功能上的双重性是其他共刺激分子所没有的，它负责NK受体提供的独特背景信息，