HLA-G多态性研究进展

HL A- G是非经典的 HL A- I类分子 ,限制性地表达在母胎界面的组织细胞上 ,对它在妊娠过程中所发挥的作用已引起广泛的兴趣 ,在肿瘤细胞的免疫逃逸方面的功能也日益受到重视 ,虽有各种假说 ,但具体的作用机制仍不清楚。 HL A- G多态性研究是探讨其作用机制的一条重要途径 ,近年来许多学者在这方面做了大量的工作 ,力求通过 HL A- G基因水平的研究进一步阐明 HL A - G的功能及作用机理。本文就 HL A - G基因结构、基因多态性及其与疾病相关性等方面作简要阐述     

HLA-G在妊娠中的研究进展

人类白细胞抗原G（HLA-G）属于非经典人类主要组织相容性复合体（MHC-Ib）类分子,具有低度多态性和限制性分布的特点,可以通过抑制自然杀伤（NK）细胞、细胞毒性T细胞等效应细胞在妊娠母胎界面免疫中发挥着重要的作用,本文对HLA-G的功能及在试管婴儿和病理妊娠中的研究进展进行了综述。     

HLA-G基因多态性与疾病关联的研究进展

HLA-G是一种非经典的HLA-I类抗原,作为免疫耐受分子之一,它可通过多种机制参与机体免疫耐受的诱导与维持。大量的研究显示,HLA-G除表达于母胎界面外,在病理条件下HLA-G在周边组织也表达,例如病毒性感染、恶性肿瘤、自身免疫病和器官移植等。影响HLA-G表达的因素包括外源的(LPS、IL-10、IFN-γ等)和内源性(基因多态性等)。本文阐述的重点是HLA-G基因多态性与疾病的关联。     

HLA-G非编码区单核苷酸多态性在复发性流产患者中的表达及对影响多因素Logistic分析研究

目的探讨HLA-G非编码区单核苷酸多态性在复发性流产患者中的表达及对影响多因素Logistic分析研究。方法选择2016年6月-2018年12月我院正常妊娠且无流产史患者作为对照组,选择期间复发性流产患者(URSA)作为观察组其中对照组30例,观察组20例。采用聚合酶链反应(PCR)检测HLA-G非编码区14bp基因多态性和逆转录-聚合酶链反应(RT-PCR),比较两组人群绒毛组织HLA-G 14bp插入/缺失基因型及绒毛组织中HLA-G mRNA的相对表达量及对多因素Logistic分析的影响。结果观察组-14bp/+14bp的杂合子基因频率为65.00%,对照组-14bp/+14bp的杂合子基因频率为43.33%,观察组高于对照组,差异有统计学意义(P<0.05);插入纯合子基因频率为+14bp/+14bp为10%。对照组基因频率为26.67%,与对照组比较有统计学意义(P<0.05);观察组HLA-G mRNA水平显着高于对照组(t=9.658,P=0.000)(P<0.05);HLA-G 蛋白在观察组里呈强表达,在对照组里呈弱表达,差异有统计学意义(P<0.05);HLA-G非编码区单核苷酸多态性也是导致患者复发性流产的一个重要因素,对于复发性流产多因素Logistic分析研究提供一个新的研究方向。结论 HLA-G非编码区-14bp/+14bp的杂合子基因大大增加了复发性流产患者的发病几率,同时复发性流产影响HLA-G mRNA及HLA-G 蛋白的正常表达。对复发性流产多因素Logistic分析提供一个新的研究方向。     

染色体多态性与ART妊娠结局的临床分析

目的分析染色体多态性对生育功能的影响,探讨其与ART妊娠结局的关系。方法回顾性调查分析珠海市妇幼保健院2009年至2010年生殖中心行IVF-ET共1607例患者的染色体核型及其临床资料,研究其ART妊娠情况。结果 1607例生殖异常患者中,检出染色体正常核型1563例(97.3%),ART妊娠877例,妊娠率为56.1%,流产113例,流产率为12.9%;检出染色体多态性核型37例(2.3%),ART临床妊娠20例,妊娠率为54.1%,流产2例,流产率为10.0%。结论染色体正常组与染色体多态性组ART的妊娠率及流产率的差异无显著性统计学意义,染色体多态性患者不影响ART妊娠结局。     

人类白细胞抗原G(HLA-G)与非小细胞肺癌的研究进展

人类白细胞抗原G(HLA-G)属于非经典主要组织相容性复合体Ⅰb(MHCⅠb)类分子,包括膜结合型和可溶性HLA-G两种形式,通过相应受体调节多种免疫细胞的功能,是形成母胎耐受、肿瘤免疫逃逸的重要免疫学机制之一。非小细胞肺癌(NSCLC)在肺癌中占比最高且预后差,研究发现HLA-G的基因多态性及表达水平与NSCLC发生发展密切相关,提示HLA-G可作为NSCLC早期诊断、亚型区分、治疗及预后等潜在的生物标志物,具有辅助诊断依据的临床价值,对其机制的深入研究更可能提供NSCLC诊疗的新策略。     

微流控技术在辅助生殖领域应用的研究进展

辅助生殖技术(ART)领域进展迅速,由于临床实践中操作步骤繁琐,如分选精子,卵母细胞的选择,体外受精,胚胎培养,胚胎的监测等,所以在效率和临床决策方面仍有进一步改进的需求.微流控技术既是技术手段也是一门科学,它是在亚微升水平研究流体的行为特征.其检测系统管道及检测终端具有极大灵活性,可适用于不同的检测目的,其检测精度高...     

人类单核苷酸多态性及其在医学领域的研究进展

单核苷酸多态性(SNPs)作为第3代遗传标记,在人类基因组中广泛存在,已广泛应用于人类遗传学、基础医学、临床医学、药物基因组学等多学科研究.在此,主要介绍SNPs的分类及特点、常用检测技术、在医学领域的研究进展以及其存在的问题和发展前景.     

HLA多态性与疾病机制关联的研究进展

人类白细胞抗原(HLA)是人类最复杂、最具多态性的遗传系统,其功能涉及到机体免疫应答和调节的各个方面.大量研究表明,HLA基因多态性与炎症、病毒感染、肿瘤等相关.本文就HLA的多态性与各个系统的的多种疾病机制关联的研究进展进行简要综述.     

PAI-1水平及基因多态性与妊娠合并症关系的研究进展

妊娠合并症包括早产、流产、死产、宫内发育迟缓、胎盘早剥等 ,其病因除感染、染色体、解剖、自身免疫性疾病和内分泌方面的异常外 ,遗传性或获得性抗凝血因子或纤溶活性缺陷导致胎盘部位的血栓形成亦是其重要发病因素。本文就近年来 PAI- 1及基因多态性与妊娠合并症关系的研究作一综述     

HLA-G polymorphism and in vitro fertilization failure in a Polish population

To investigate whether human leukocyte antigen-G ( HLA-G ) gene polymorphism is associated with in vitro fertilization (IVF) failure, we sequenced exons 2–4 of the HLA-G gene in 50 couples with three or more IVFs (including 10 couples with five or more IVFs) and 58 control fertile couples from a Polish population. Of the 10 different HLA-G alleles identified in our study subjects, neither allele was found to be associated with IVF. We also genotyped 50 couples with IVF and 71 control couples for the −725C>G variant in the promoter region and the 14 bp insertion or deletion polymorphism in the 3' untranslated region of the HLA-G gene. The frequency of −725GG or GC genotype in women with IVF and in control fertile women was similar [26% vs 25.3%; odds ratio (OR) = 1.0; P  = 1.0]. The 14 bp ins/ins or ins/del genotype was more common in women with IVF than in control women (76.9% vs 59.1%; OR 2.4; P  = 0.03), but the difference was not significant after Bonferroni correction for multiple comparisons. The frequency of the ins/ins or ins/del genotype was particularly high (90%) in women who experienced five or more IVFs (OR = 6.2; P  = 0.08), but again, the excess was not statistically significant, possibly because of small sample sizes. These results are in line with functional studies that show lower levels of HLA-G mRNA and protein related to the HLA-G allele including the 14 bp sequence and suggest that the insertion allele may be associated with an increased risk of IVF.     

Association of the maternal 14-bp insertion polymorphism in the HLA-G gene in women with recurrent spontaneous abortions

Human leukocyte antigen (HLA)-G has been postulated as an important immunotolerant molecule in maintaining fetal-maternal relationship. Recent reports indicated that the 14-bp deletion/insertion polymorphism in exon 8 of HLA-G gene influences HLA-G mRNA stability and isoform splicing patterns, thus modulating the levels of HLA-G expression. This might play an immunomodulatory role of HLA-G during implantation and pregnancy. In the present study, 109 unrelated fertile control women and 79 women who had experienced recurrent spontaneous abortion (RSA) were genotyped for the 14-bp insertion/deletion polymorphism. No significant difference was observed in the distribution of 14-bp insertion/deletion genotype between controls and the RSA group. However, a greater number of 14-bp insertion alleles exist in the RSA group than in the controls.     

HLA-G polymorphism in a Polish population and reproductive failure.

To investigate whether human leukocyte antigen (HLA)-G gene polymorphism is associated with reproductive failure in a Polish population, we sequenced exons 2-4 of the HLA-G gene in 58 couples with three recurrent spontaneous abortions (RSAs) in the first trimester of pregnancy and 58 fertile control couples. We identified 12 different HLA-G alleles. Neither allele was found to be associated with an increased risk of RSA in the population. HLA-G allele sharing was similar in couples with RSA and in control fertile couples. All cases and controls were also genotyped for the -725C>G polymorphisms in the promoter region and the 14-bp insertion deletion in the 3' untranslated region of the HLA-G gene. The frequencies of both variants in RSA women and control fertile women were similar. These results suggest that HLA-G gene polymorphism does not influence the risk of RSA in the Polish population, but further studies are needed in this regard.     

Embryonic soluble HLA-G as a marker of developmental potential in embryos

BACKGROUND: In human reproduction, embryo implantation is complex and poorly understood. At present, no single markers are used in routine treatment to assay biochemical functions of the human embryo. Soluble human leukocyte antigen-G (sHLA-G) could be considered a possible marker of embryo developmental potential. It is localized primarily on the extravillous trophoblast, making this antigen a potential mediator of immune interaction at the maternal-fetal interface during gestation. METHODS: Soluble-HLA-G levels were evaluated by an enzyme-linked immunosorbent assay (ELISA) employing monoclonal antibody MEM-G9. It was evaluated in 318 media of single embryo cultures. We correlated the presence of sHLA-G with embryo morphology and the pregnancy obtained in that treatment cycle. RESULTS: No correlation was found between embryo morphology and sHLA-G levels. Pregnancy was observed only when the medium of at least one transferred embryo contained sHLA-G. In 26 out of 66 patients, none of the obtained embryos showed any detectable sHLA-G molecules and no pregnancy occurred. CONCLUSIONS: From our results, we propose sHLA-G as a potential marker of embryo development: the sHLA-G ELISA can be a useful biochemical assay in addition to embryo morphology in embryo selection for transfer in IVF treatment if there are other embryos with the same morphology.     

Maternal human leukocyte antigen-G polymorphism is not associated with pre-eclampsia in a Chinese Han population

Pre-eclampsia is a multisystem disorder of pregnancy and remains the leading cause of both maternal and fetal morbidity and mortality in many countries. Despite extensive studies, the underlying mechanisms still remain unknown. Besides its restricted expression in the tissues of placenta and its function in regulating immune suppression and in ensuring successful invasion of placental tissues into maternal deciduas, it has been postulated that HLA-G may play a role in modulation of immune tolerance at the fetal-maternal interface. Aberrant HLA-G expression may result in pregnancy disorders that are associated with poor invasion of extravillous cytotrophoblast into maternal spiral arteries, such as pre-eclampsia. Studies have shown that pre-eclampsia is largely under genetic control, but genetic mechanisms underlying the disorder have yet to be determined. In the current study, we focus on the potential role of HLA-G polymorphism in the pathogenesis of pre-eclampsia. Samples were obtained from Chinese Han primiparous women with pre-eclampsia and irrelative normal women, and case-matched placentas were genotyped for the HLA-G polymorphism in the exons 2, 3, and 4, and the 14-base-pair (bp) insertion/deletion polymorphism in the 3'-untranslated region of exon 8 was analyzed separately. The frequency of HLA-G polymorphism in these samples was not significantly different from those of normal controls, indicating that maternal HLA-G polymorphism is not associated with the risk for pre-eclampsia in this Chinese Han population. However, the maternal 14-bp insertion/deletion polymorphism is ethnically different.     

Down-regulation of HLA-G1 cell surface expression in human cytomegalovirus infected cells

PROBLEM: Down-modulation of human leukocyte antigen (HLA)-G1 cell surface expression by human cytomegalovirus (HCMV) has only been studied in cellular models expressing independent unique short (US) recombinant proteins, but not in the context of viral infection. To explore the level of HLA-G1 cell surface expression after HCMV infection and to investigate the influence of US viral proteins, we infected HLA-G1 expressing cells by HCMV laboratory strains. METHOD OF STUDY: Human U373-MG astrocytoma cells were transfected with HLA-G1 cDNA. Following HCMV infection, HLA-G1 cell surface expression of these transfectants was evaluated by flow cytometry and confocal microscopy, using an HLA-G specific monoclonal antibody, and compared with that of uninfected cells. US-deleted viruses were then used to evaluate the implication of US proteins. RESULTS: Using flow cytometry, it was found that HCMV infection of U373-G1 cells decreased HLA-G1 cell surface expression. Similar results were obtained with two different HCMV strains, namely Towne and AD169. Two color confocal microscopy staining further confirmed such HLA-G down-modulation in HCMV-infected cells stained for immediate early (IE1/2) nuclear proteins expression. Infection of U373-G1 cells with US-deleted HCMV strain had no effect on the level of cell surface HLA-G1 expression, thus demonstrating the US dependency of the HCMV-mediated down-regulation of HLA-G1. CONCLUSION: HCMV infection down-modulates HLA-G1 expression at the cell surface. This is likely to have functional consequences in case of HCMV uterine infection during pregnancy.     

HLA-G polymorphisms in couples with recurrent spontaneous abortions

The etiology of a fraction of recurrent spontaneous abortions (RSA) may involve immunological mechanisms. Aberrant profiles of Th1 and Th2 cytokines have been observed which are not present in uncomplicated pregnancies. Studies of classical HLA class I and II antigens in relation to RSA have not been conclusive. Furthermore, these antigens are not expressed in the placenta with the exception of HLA-C. However, HLA-G is expressed on especially invasive cytotrophoblasts and exists in both membrane and soluble forms. HLA-G may be involved in materno-fetal tolerance. Therefore, 61 RSA couples (with three or more spontaneous abortions) and 47 fertile control couples were HLA-G genotyped by direct DNA sequencing and analyzed for specific polymorphisms. No statistically significant differences were observed in the distribution of HLA-G alleles between controls and RSA couples, however, 15% of the RSA women carried the HLA-G*0106 allele compared to 2% of the control women. The 14 bp deletion polymorphism in exon 8 was investigated separately. There were a greater number of heterozygotes for the 14 bp polymorphism in the group of fertile control women than expected, according to Hardy-Weinberg equilibrium. Furthermore, the HLA-G alleles without the 14 bp sequence were prominent in the RSA males in contrast to the RSA women in whom alleles including the 14 bp sequence were frequently observed, especially as homozygotes. These results are discussed in relation to two hypotheses concerning HLA-G and RSA. A hypothesis of HLA-G histo-incompatibility between fetus/placenta and the mother was not supported by the data. Another hypothesis concerned certain HLA-G alleles associated with an altered expression profile of HLA-G isoforms or reduced expression of certain HLA-G isoforms.     

Extended embryo culture in human assisted reproduction treatments

In order to evaluate the niche of extended embryo culture in an IVF programme, retrospective analysis of non-selected IVF patients, who underwent ovarian stimulation from April 1998 to June 1999 in a single private practice assisted reproductive technology centre, was performed. Embryos were cultured for 48 h in S1/G1.2 medium followed by 48 to 72 h of culture in S2/G2.2 to day 5 or day 6. Only fertilized oocytes exhibiting two pronuclei from donor and non-donor IVF and intracytoplasmic sperm injection (ICSI) cases were examined to determine the relationship between embryo cell number on day 3 and subsequent rate of blastocyst formation. Results indicated that a proportional relationship existed between the number of blastomeres present in day 3 embryos and the rate of blastocyst formation. Fifty-four per cent of embryos that had six cells on day 3 formed blastocysts, while 76% of those embryos with eight cells formed blastocysts. Blastocyst development did not increase further when embryos had more than eight cells on day 3, indicating that embryos with greater cell numbers on day 3 are not always predictive of a greater likelihood of blastocyst formation. Fertilized oocytes exhibiting two pronuclei from donors produced significantly more blastocysts (67%) than those from IVF patients (52%; P < 0.01), and had a significantly higher implantation rate (54%) compared with IVF patients (30%; P < 0.01). Furthermore, blastocyst cryopreservation resulted in significantly higher implantation rates than cryopreserved cleavage stage embryos (P < 0.001).     

14 bp deletion polymorphism in the HLA-G gene is a risk factor for idiopathic dilated cardiomyopathy in a Chinese Han population

Human leukocyte antigen (HLA) has been reported to be associated with the pathogenesis of autoimmune-associated idiopathic dilated cardiomyopathy (IDC). However, the HLA-G in this context is limited. In the current study, a total of 117 IDC patients and age and sex matched 401 unrelated healthy controls in a Chinese Han population were HLA-G genotyped for the 14 bp insertion and deletion polymorphism. IDC patients showed markedly increased frequencies of -14 bp/-14 bp genotype [Pc = 0.00049, odds ratio (OR) = 2.17] and -14 bp alleles (Pc = 4.1 x 10(-5), OR = 1.97) when compared with healthy controls. Whereas the frequencies of +14 bp/+14 bp genotype (Pc = 0.0036, OR = 0.35) and +14 bp alleles (Pc = 4.1 x 10(-5), OR = 0.51) were significantly lower in IDC. These data, for the first time, indicated that 14 bp insertion/deletion polymorphism in HLA-G gene could be a genetic risk factor for the susceptibility to IDC.