Dupont B, Selvakumar A, Steffens U
Immunology Program, Sloan-Kettering Institute for Cancer Research, Memorial Sloan-Kettering Cancer Center, New York, New York, USA.
Tissue Antigens. 1997 Jun;49(6):557-63. doi: 10.1111/j.1399-0039.1997.tb02802.x.
Multiple genes encoding type I transmembrane molecules and belonging to the immunoglobulin superfamily have recently been localized to human chromosome 19q13.4. These include a family of genes encoding killer cell inhibitory receptors (KIR) expressed on natural killer (NK) cells and subsets of T-lymphocytes, immunoglobulin-like transcripts (ILT-1, -2 and 3) expressed on myeloid cells and subsets of lymphoid cells, the gp49 family of receptors expressed on mast cells and NK cells and the gene encoding human myeloid immunoglobulin A Fc receptor (CD89). The receptors have one to four extracellular immunoglobulin domains, and the ligands are known for some of these molecules. This includes the Fc alpha R and KIRs of the p58/p50 and p70/p70 delta, but the ligands for many others are unknown. Except for CD89, each subfamily of receptors exist, in two forms, of which one has a long cytoplasmic domain containing one to four immunoreceptor tyrosine-based inhibitory motifs (ITIM) and another form with a short cytoplasmic tail without ITIMs. ITIM-containing receptors can recruit cytoplasmic tyrosine phosphatases and provide inhibitory signals for cell activation, whereas receptors with a "short" tail induce activating signals. The 19q13.4 chromosomal region is therefore now emerging as the immunoglobulin superfamily linkage group of genes differentially expressed on hematopoietic cell lineages and encoding pairs of receptors with opposing effects on signal transduction pathways and effector functions in hematopoietic cells.
最近，多个编码I型跨膜分子且属于免疫球蛋白超家族的基因已被定位到人类染色体19q13.4。这些基因包括一个编码杀伤细胞抑制受体（KIR）的基因家族，该受体表达于自然杀伤（NK）细胞和T淋巴细胞亚群；免疫球蛋白样转录物（ILT-1、-2和3），表达于髓样细胞和淋巴样细胞亚群；gp49受体家族，表达于肥大细胞和NK细胞；以及编码人类髓样免疫球蛋白A Fc受体（CD89）的基因。这些受体具有1至4个细胞外免疫球蛋白结构域，其中一些分子的配体是已知的。这包括FcαR以及p58/p50和p70/p70δ的KIR，但许多其他受体的配体尚不清楚。除CD89外，每个受体亚家族都以两种形式存在，其中一种具有长细胞质结构域，包含1至4个基于免疫受体酪氨酸的抑制基序（ITIM），另一种形式具有短细胞质尾巴，不含ITIM。含ITIM的受体可募集细胞质酪氨酸磷酸酶，并为细胞活化提供抑制信号，而具有“短”尾巴的受体则诱导活化信号。因此，19q13.4染色体区域正逐渐成为免疫球蛋白超家族基因连锁群，这些基因在造血细胞谱系上差异表达，编码对造血细胞信号转导途径和效应功能具有相反作用的受体对。
