Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK.
Immunogenetics. 2014 Feb;66(2):73-83. doi: 10.1007/s00251-013-0742-5. Epub 2013 Nov 21.
Leukocyte immunoglobulin-like receptors (LILR) are cell surface molecules that regulate the activities of myelomonocytic cells through the balance of inhibitory and activation signals. LILR genes are located within the leukocyte receptor complex (LRC) on chromosome 19q13.4 adjacent to KIR genes, which are subject to allelic and copy number variation (CNV). LILRB3 (ILT5) and LILRA6 (ILT8) are highly polymorphic receptors with similar extracellular domains. LILRB3 contains inhibitory ITIM motifs and LILRA6 is coupled to an adaptor with activating ITAM motifs. We analysed the sequences of the extracellular immunoglobulin domain-encoding regions of LILRB3 and LILRA6 in 20 individuals, and determined the copy number of these receptors, in addition to those of other members of the LILR family. We found 41 polymorphic sites within the extracellular domains of LILRB3 and LILRA6. Twenty-four of these sites were common to both receptors. LILRA6, but not LILRB3, exhibited CNV. In 20 out of 48 human cell lines from the International Histocompatibility Working Group, LILRA6 was deleted or duplicated. The only other LILR gene exhibiting genomic aberration was LILRA3, in this case due to a partial deletion.
白细胞免疫球蛋白样受体（LILR）是细胞表面分子，通过抑制和激活信号的平衡来调节髓样细胞的活性。LILR 基因位于染色体 19q13.4 上的白细胞受体复合物（LRC）内，紧邻 KIR 基因，这些基因受到等位基因和拷贝数变异（CNV）的影响。LILRB3（ILT5）和 LILRA6（ILT8）是高度多态性的受体，具有相似的细胞外结构域。LILRB3 含有抑制性 ITIM 基序，而 LILRA6 与具有激活 ITAM 基序的衔接子相连。我们分析了 20 个人的 LILRB3 和 LILRA6 细胞外免疫球蛋白结构域编码区的序列，并确定了这些受体以及 LILR 家族其他成员的拷贝数。我们在 LILRB3 和 LILRA6 的细胞外结构域中发现了 41 个多态性位点。其中 24 个位点在两个受体中都存在。LILRA6 而不是 LILRB3 存在 CNV。在国际组织相容性工作组的 48 个人类细胞系中，有 20 个细胞系缺失或重复了 LILRA6。唯一另一个表现出基因组异常的 LILR 基因是 LILRA3，在这种情况下是由于部分缺失。
