Bottino C, Biassoni R, Millo R, Moretta L, Moretta A
Istituto Nazionale per la Ricerca sul Cancro, Genova, Italy.
Hum Immunol. 2000 Jan;61(1):1-6. doi: 10.1016/s0198-8859(99)00162-7.
The cytolytic activity mediated by human natural killer (NK) cells is the result of a balance between signals delivered by inhibitory and activating receptors. The inhibitory receptors are represented by different families of HLA-specific receptors characterized by immunoreceptor tyrosine-based inhibiting motif(ITIM) sequences in their cytoplasmic portion. The function and the specificity of the inhibitory receptors imply the existence of triggering receptors specific for non-HLA ligands that are responsible for the induction of the cytolytic activity against HLA class I-deficient target cells. These receptors have remained elusive until recently when three distinct NK-specific molecules, termed natural cytotoxicity receptors (NCR), were identified and cloned. The different members of this novel family of receptors play a complementary role in the recognition and lysis of target cells. The NCR family is composed by a heterogeneous group of molecules belonging to the Ig superfamily that associate to different immunoreceptor tyrosine-based activating motif (ITAM)-containing signal transducing polypeptides.
人类自然杀伤（NK）细胞介导的细胞溶解活性是抑制性受体和激活受体传递的信号之间平衡的结果。抑制性受体由不同家族的HLA特异性受体代表，其细胞质部分具有基于免疫受体酪氨酸的抑制基序（ITIM）序列。抑制性受体的功能和特异性意味着存在针对非HLA配体的触发受体，这些受体负责诱导针对HLA I类缺陷靶细胞的细胞溶解活性。直到最近，当三种不同的NK特异性分子，即自然细胞毒性受体（NCR）被鉴定和克隆时，这些受体才得以明确。这个新的受体家族的不同成员在靶细胞的识别和裂解中发挥互补作用。NCR家族由属于Ig超家族的一组异质分子组成，这些分子与不同的含有基于免疫受体酪氨酸的激活基序（ITAM）的信号转导多肽相关联。
