KIR2DL4(杀伤细胞免疫球蛋白样受体2DL4)是杀伤细胞免疫球蛋白样受体(KIR)基因家族的重要成员,主要表达于自然杀伤(NK)细胞表面。该基因位于人类19号染色体上,属于KIR基因家族,该家族由多个高度多态性的基因组成,编码的受体可识别主要组织相容性复合体(MHC)I类分子,在免疫调节中发挥关键作用。KIR2DL4的独特之处在于它既能作为抑制性受体(通过胞内ITIM结构域传递抑制信号),又能作为激活受体(通过结合FcRγ链传递激活信号)。其主要配体是非经典MHC I类分子HLA-G,这种相互作用在母胎耐受和免疫逃逸中至关重要。KIR2DL4在妊娠期间调节NK细胞对胎盘的侵袭,维持母胎界面免疫平衡。该基因突变可能导致功能异常,与反复流产、子痫前期等妊娠并发症相关,也可能影响肿瘤免疫监视。KIR2DL4过表达可能增强NK细胞对HLA-G阳性细胞的识别(如某些肿瘤细胞),但过度激活可能导致自身免疫风险;而表达降低则可能削弱母胎耐受,增加流产风险或降低抗肿瘤免疫力。KIR基因家族的共同特征是都编码细胞表面受体,具有免疫球蛋白样结构域,参与NK细胞功能调控,且多数具有多态性,在个体间呈现高度多样性。KIR2DL4因其双重信号特性在家族中较为特殊,其表达水平受表观遗传调控,在不同NK细胞亚群中表达差异显著。该基因还与某些病毒感染(如HIV)的疾病进展相关,可能影响病毒免疫逃逸机制。
Killer cell immunoglobulin-like receptors (KIRs) are transmembrane glycoproteins expressed by natural killer cells and subsets of T cells. The KIR genes are polymorphic and highly homologous and they are found in a cluster on chromosome 19q13.4 within the 1 Mb leukocyte receptor complex (LRC). The gene content of the KIR gene cluster varies among haplotypes, although several "framework" genes are found in all haplotypes (KIR3DL3, KIR3DP1, KIR3DL4, KIR3DL2). The KIR proteins are classified by the number of extracellular immunoglobulin domains (2D or 3D) and by whether they have a long (L) or short (S) cytoplasmic domain. KIR proteins with the long cytoplasmic domain transduce inhibitory signals upon ligand binding via an immune tyrosine-based inhibitory motif (ITIM), while KIR proteins with the short cytoplasmic domain lack the ITIM motif and instead associate with the TYRO protein tyrosine kinase binding protein to transduce activating signals. The ligands for several KIR proteins are subsets of HLA class I molecules; thus, KIR proteins are thought to play an important role in regulation of the immune response. This gene is one of the "framework" loci that is present on all haplotypes. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2008]
杀伤细胞免疫球蛋白样受体(的KIRs)是通过自然杀伤细胞和T细胞亚群表达跨膜糖蛋白。的KIR基因多态和高度同源的并且它们中的1兆白细胞受体复合物(LRC)内染色体19q13.4群集找到。的KIR基因簇的基因含量的单倍型的不同而不同,虽然有几个“框架”的基因在所有的单倍型(KIR3DL3,KIR3DP1,KIR3DL4,KIR3DL2)找到。的KIR蛋白由细胞外免疫球蛋白结构域(2D或3D)的数目和由划分他们是否具有长(L)或短(S) - 胞质域。与长的胞质域的KIR蛋白质在配体经由一个基于免疫受体酪氨酸的抑制基序(ITIM)结合转导抑制性信号,同时与短胞质域KIR蛋白缺乏ITIM基序,而是与TYRO蛋白酪氨酸激酶关联结合蛋白转导激活信号。数KIR蛋白配体是HLA I类分子的子集;因而,KIR蛋白被认为在免疫应答的调节中发挥着重要作用。这个基因就是“框架”的位点是存在于所有的单倍型中的一个。选择性剪接结果在多个抄本变形。 [由RefSeq的,2008年7月提供]
KIR2DL4基因(以及对应的蛋白质)的细胞分布位置:
KIR2DL4基因的本体(GO)信息:
名称 |
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4650 Natural killer cell mediated cytotoxicity [PATH:hsa04650] |
4612 Antigen processing and presentation [PATH:hsa04612] |
名称 |
---|
Adaptive Immune System |
Immune System |
Immunoregulatory interactions between a Lymphoid and a non-Lymphoid cell |
疾病名称 | 关系值 | NofPmids | NofSnps | 来源 |
Diabetes Mellitus, Insulin-Dependent | 0.007372538 | 4 | 0 | BeFree_GAD |
Graft-vs-Host Disease | 0.007101096 | 3 | 0 | GAD |
leukemia | 0.007101096 | 3 | 0 | GAD |
HIV Infections | 0.00554839 | 5 | 0 | BeFree_GAD |
Multiple Sclerosis | 0.005276948 | 3 | 0 | BeFree_GAD |
Autoimmune Diseases | 0.005005506 | 3 | 0 | BeFree_GAD |
Lupus Erythematosus, Systemic | 0.005005506 | 3 | 0 | BeFree_GAD |
Pregnancy loss | 0.004734064 | 2 | 0 | GAD |
Cervix carcinoma | 0.004734064 | 2 | 0 | GAD |
Uveomeningoencephalitic Syndrome | 0.004734064 | 2 | 0 | GAD |
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