Killer immunoglobulin-like receptors (KIRs) are molecules expressed on the surface of natural killer (NK) cells, which play an important role in innate immunity. KIR recognition of major histocompatability complex (MHC) class I allotypes represents one component of the complex interactions between NK cells and their targets in determining NK cell reactivity. KIRs are encoded by a gene cluster at human chromosome 19q13.4. Despite their high degree of sequence identity, KIR genes encode proteins that have diverse recognition patterns (specific HLA class I allotypes) and confer opposing signals (activating or inhibitory) to the NK cell. The KIR gene cluster is highly polymorphic, with individual genes exhibiting allelic variability and individual haplotypes differing in gene content. The polymorphism of the KIR locus parallels that of the MHC, facilitating the adaptation of the immune system to a dynamic, challenging environment. This variation is associated with a growing number of human diseases, which is likely to extend to levels observed for the HLA loci. Here we review current progress in understanding KIR biology and genetics.

中文翻译：

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杀手免疫球蛋白样受体基因簇：调整基因组以进行防御。

杀伤免疫球蛋白样受体（KIR）是在自然杀伤（NK）细胞表面表达的分子，在先天免疫中起重要作用。主要的组织相容性复合物（MHC）I类同种异型的KIR识别代表NK细胞与其靶标之间确定NK细胞反应性的复杂相互作用的一个组成部分。KIR由人类染色体19q13.4上的基因簇编码。尽管其高度的序列同一性，KIR基因仍编码具有多种识别模式（特定的HLA I类同种异型）并向NK细胞赋予相反信号（激活或抑制）的蛋白质。KIR基因簇是高度多态的，单个基因表现出等位基因变异性，单个单倍型的基因含量不同。KIR基因座的多态性与MHC类似，促进免疫系统适应动态，充满挑战的环境。这种变化与越来越多的人类疾病有关，很可能会扩展到HLA基因座所观察到的水平。在这里，我们回顾了在了解KIR生物学和遗传学方面的最新进展。