Correa I, Raulet D H
Department of Molecular and Cell Biology, University of California, Berkeley 94720, USA.
Immunity. 1995 Jan;2(1):61-71. doi: 10.1016/1074-7613(95)90079-9.
Class I MHC expression by target cells inhibits lysis mediated by natural killer (NK) cells, often in an allele-specific fashion. It has been proposed that NK cell inhibitory receptors recognize complexes of class I molecules with specific cellular peptides that define self, displacement of which would render cells NK sensitive. By loading the mostly empty Dd class I molecules of cell lines deficient in peptide transporter molecules with synthetic or natural Dd-bound peptides, we have demonstrated specific dose-dependent inhibition of the Ly49+ subset of activated NK cells by class I-peptide complexes. Inhibition occurred with most if not all Dd-binding peptides, suggesting that Ly49+ NK cells recognize class I-peptide complexes largely independently of peptide composition. The results suggest a primary role of NK cells in the destruction of cells that have down-regulated or extinguished cell surface expression of some or all class I molecules.
靶细胞上的I类主要组织相容性复合体（MHC）表达通常以等位基因特异性方式抑制自然杀伤（NK）细胞介导的细胞裂解。有人提出，NK细胞抑制性受体识别I类分子与定义自身的特定细胞肽的复合物，这些肽的置换会使细胞对NK敏感。通过用合成或天然的与Dd结合的肽加载缺乏肽转运分子的细胞系中几乎为空的Dd I类分子，我们证明了I类肽复合物对活化NK细胞的Ly49 +亚群具有特异性剂量依赖性抑制作用。大多数（如果不是全部）与Dd结合的肽都能产生抑制作用，这表明Ly49 + NK细胞识别I类肽复合物在很大程度上与肽的组成无关。结果表明，NK细胞在破坏下调或消除部分或全部I类分子细胞表面表达的细胞中起主要作用。
