甘露聚糖结合凝集素基因启动子区多态性及其意义

甘露聚糖结合凝集素是机体重要的天然免疫防御分子，其血清水平主要受结构基因点突变的影响和启动子区多态性的调控。本文简介其启动子区基因结构、多态性及生物学意义。     

甘露聚糖结合凝集素基因启动子区多态性及其意义

甘露聚糖结合凝集素是机体重要的天然免疫防御分子 ,其血清水平主要受结构基因点突变的影响和启动子区多态性的调控。本文简介其启动子区基因结构、多态性及生物学意义。     

096 甘露聚糖结合凝集素基因启动子区多态性及其意义

甘露聚糖结合凝集素是机体重要的天然免疫防御分子，其血清水平主要受结构基因点突变的影响和启动子区多态性的调控。本文简介其启动子区基因结构、多态性及生物学意义。     

甘露聚糖结合凝集素基因多态性与血清蛋白表达水平的关系

目的了解汉族儿童甘露聚糖结合凝集素(MBL)第一外显子54密码子的基因多态性以及与血清MBL蛋白水平的关系。方法用ELISA方法检测71例儿童血清MBL水平,用聚合酶链反应-限制性内切酶片段长度多态性分析(PCR-RFLP)方法对第一外显子54密码子基因多态性进行分析,比较不同基因型的血清蛋白质表达水平,并测定部分PCR产物的核苷酸序列。结果汉族人群MBL基因第1外显子54密码子3种基因型为GGC/GGC(77.5%)、GGC/GAC(18.3%)、GAC/GAC(4.2%),等位基因GGC(0.87)出现频率较GAC(0.13)高;低MBL水平基因型为GGC/GGC(12.5%)、GGC/GAC(75.0%)、GAC/GAC(12.5%),GGC/GAC基因型及等位基因GAC(0.50)频率较正常MBL组(0.03)高(P<0.005);GGC/GGC基因型的血清MBL的水平比GGC/GAC基因型明显增高[(3.67±2.10)μg/ml,(0.10±0.05)μg/ml,P<0.001],GGC/GGC基因型汉族人群血清水平较巴布亚新几内亚人[Papua NewGuinea,(2.45±0.82)μg/ml]明显增高(P<0.001);发现MBL第一外显子15、21、58、61密码子的突变。结论第一外显子第54密码子表现不同基因多态性分布,并对应不同的血清MBL水平。主要是GGC/GAC导致低血清MBL水平,但可能存在除52、54、57密码子外的第一外显子其他部位的基因多态性导致血清MBL蛋白质表达的种族差异。     

甘露聚糖结合凝集素与妊娠期糖尿病的研究进展

甘露聚糖结合凝集素(mannose binding lectin,MBL)也曾称为甘露聚糖结合蛋白(mannan binding protein)是一种钙离子依赖的(C型)血清凝集素蛋白,也是第一个被发现的具有防御功能的C型凝集素。MBL作一种急性时相蛋白由肝脏合成分泌,是宿主体内非特异免疫最重要的免疫分子。一直以     

中国人MBL cDNA的克隆与序列分析

从中国汉族人胎肝组织提取ＲＮＡ,以ＲＴ－ＰＣＲ方法获得了编码含号顺序的全长甘露聚糖结合凝集素肽链的ｃＤＮＡ片段,将其与ｐＧＥＭ－Ｔ载体连接,转化大肠杆菌ＴＧ１,     

儿童巨细胞病毒感染与甘露聚糖结合凝集素表达相关性研究

目的探讨甘露聚糖结合凝集素（MBL）基因多态性及血浆蛋白水平与儿童巨细胞病毒（HCMV）感染的相关性。方法收集2007年3～11月在浙江大学医学院附属儿童医院诊断为HCMV感染的患儿作为HCMV感染组,选择同期行健康体检的儿童作为对照组。对两组行MBL基因检测和分型,并对HCMV感染组进行随访,分别测定其急性期和恢复期血浆MBL蛋白水平。分别比较两组基因变异频率和血浆MBL蛋白水平。结果HCMV感染组纳入104例,对照组纳入105例;HCMV感染组有50例患儿进行随访,HCMV感染组MBL基因启动子区-550位点的L型变异频率明显高于对照组（56.7%vs34.3%,P=0.001）,野生单体基因型HYPA的频率明显低于对照组（47.6%vs62.8%,P=0.002）,完整基因型中高水平表达基因型（YA/YA）的频率低于对照组（41.3%vs60.0%,P=0.007）,而低水平表达基因型（YA/XA,YA/YB,XA/XA）的频率高于对照组（52.9%vs29.5%,P=0.001）。HCMV感染组急性期和恢复期血浆MBL蛋白水平均低于对照组（P=0.019和0.000）。HCMV感染组急性期血浆MBL蛋白水平高于恢复期（P=0.000）。结论MBL基因多态性导致的血浆MBL蛋白水平低下与儿童HCMV感染相关,提示MBL可能对儿童HCMV感染具有保护作用。     

人血清中甘露聚糖结合凝集素的检测及意义

建立检测甘露聚糖结合凝集素 (MBL )的酶联免疫法 ,检测 2 2 6例不同性别、年龄正常人和 115例病人血清中的MBL水平。结果发现儿童组显著低于成人组。术后、烧 (烫 )伤和支原体肺炎患者的血清MBL水平 ( x±s)分别为 (6 73± 3 2 9)mg/L、 (5 86± 3 37)mg/L和 (5 18± 3 4 3)mg/L ,较正常对照组 (2 6 5± 1 5 6 )mg/L显著增高 ,而慢性肾脏病患者的血清MBL水平 (1 0 4± 0 4 8)mg/L显著降低。结果提示血清MBL水平可作为监测个体天然免疫功能的一项指标     

甘露聚糖结合凝集素缺损与自身免疫性疾病

甘露聚糖结合凝集素(MBL)系胶原凝集素家族成员,是天然免疫系统中的重要分子。血清MBL浓度受其结构基因第一外显子几个点突变的影响和启动子区多态性的调控。MBL基因突变使其血清浓度降低,除导致调理吞噬缺损外,还与自身免疫性疾病如系统性红斑狼疮、类风湿性关节炎、干燥综合征、皮肌炎、克隆病、动脉炎等有关。     

甘露聚糖结合凝集素与临床疾病的研究进展

甘露聚糖结合凝集素(MBL)是天然免疫补体系统中的一员,主要由肝细胞合成,作为急性期反应蛋白分泌入血清。血清MBL的水平主要由MBL2基因启动子区及外显子1区的基因多态性决定。MBL可选择性的与病原微生物(如G+/G-细菌、病毒、真菌、原生物等)、坏死损伤细胞、凋亡细胞以及肿瘤细胞等表面的相应配体结合,通过激活补体系统、调理吞噬、调节炎症反应等保护人体。血清MBL的水平对人体影响较大:当血清MBL缺乏时,机体易患某些疾病,如感染性疾病、自身免疫性疾病;但如果血清MBL水平过高,又会对自身组织造成损伤,如在心肌梗死及器官移植中,引起机体的缺血再灌注损伤;此外,MBL基因型及血清MBL水平与肿瘤的易感性可能也存在一定关系。     

甘露聚糖结合凝集素突变型等位基因与SLE关联的研究

收集系统性红斑狼疮(SLE)患者和普通人群血标本,提取白细胞基因组DNA,以多聚酶链反应扩增目的基因片段,应用荧光探针杂交技术检测甘露聚糖结合凝集素(MBL)基因GGC54GAC、GGA57GAA和CGT52TGT点突变(分别称为等位基因B、C、D,所有突变型统称为O,野生型即A),分析MBL突变型等位基因与SLE及其严重程度的关系。74例SLE患者中,检出等位基因型A/B24例(32.4%)、B/B5例(6.8%)、A/C2例(2.7%)、A/D1例(1.4%)和B/C2例(2.7%),B、C、D的频率为0.250、0.028和0.007,突变型等位基因O的频率为0.285;95例对照组中,检出A/B22例(23.2%)、B/B2例(2.1%)和A/C1例(1.1%),B、C的频率分别为0.137和0.005,O的频率为0.142;两者比较,其突变等位基因的分布有显著差异(P<0.05)。等位基因型O/O纯合子SLE患者肾脏损害的发生率达100%,而A/A或A/O型病人分别为35.0%和37.0%,存在非常显著差异(P<0.01)。因此,MBL突变型等位基因是SLE的易感因素并与肾脏累及有关。     

中国维吾尔族人群MBL基因启动子及第一外显子区SNP及其单倍型与基因型研究

收集新疆维吾尔族自治区维吾尔族一般人群血标本,提取白细胞基因组DNA,以序列特异性引物-多聚酶链反应技术检测其甘露聚糖结合凝集素(MBL)基因启动子区单核苷酸多态性位点-550G/C(称H/L等位基因)、-221C/G(X/Y)、+4C/T(P/Q)和结构基因第一外显子点突变CGT52TGT、GGC54GAC和GGA57GAA(分别称为D、B、C等位基因,野生型即A等位基因),并分析其单倍型与基因型。发现MBL基因启动子区等位基因主要为L、Y、P,第一外显子等位基因只发现B,未检出C和D;检出5种单倍型,其频率分别是HYPA 0.282、LYPA 0.268、LXPA 0.260、LYPB 0.120、LYQA 0.070。检出12种基因型,其频率分别为HYPA/HYPA 0.183、LXPA/LXPA 0.141、LYPA/LYQA 0.113、LYPA/LYPA 0.112、LYPA/LXPA 0.085、HYPA/LYPA 0.085、LXPA/LYPB 0.085、HYPA/LXPA 0.070、HYPA/LYPB 0.042、LYPA/LYPB 0.028、LYPB/LYQA 0.028、YPB/LYPB 0.028。     

Functional polymorphisms in the mannan-binding lectin 2 gene: effect on MBL levels and otitis media

BACKGROUND: Mannan-binding lectin (MBL) can bind to microorganisms, initiating the lectin pathway of complement activation. Aberrant MBL serum levels, caused by MBL2 gene polymorphisms, are a possible risk factor for recurrent infections. Within the 7 common MBL haplotypes, still considerable variation in MBL serum levels exists. OBJECTIVE: To investigate functional MBL levels and MBL2 polymorphisms in a large cohort of children with recurrent acute otitis media. METHODS: Twelve genetic variants in the MBL2 gene and functional MBL serum levels were determined in a cohort of children with recurrent acute otitis media. Haplotypes were constructed and associated with functional MBL serum levels and the number of otitis episodes in the previous year. RESULTS: The 7 common MBL2 haplotypes mainly determine the level of functional MBL in serum. In addition, the 3130G>C single nucleotide polymorphism, located in exon 4, further significantly influenced functional MBL levels within the LXPA haplotype. LXPA carriers with 3130G showed a significantly lower geometric mean functional MBL serum level of 0.19 mug/mL compared with 0.70 mug/mL in 3130C carriers (P = .026). Nonwild-type MBL2 carriers between 12 and 24 months had a significantly increased number of otitis episodes (5.1/y) compared with wild-type MBL2 carriers (4.1/y; P = .027). In older children, this association was not found anymore. CONCLUSION: Additional single nucleotide polymorphisms within the 7 common haplotypes can further explain the observed variation in functional MBL serum levels. MBL seems to be of particular clinical importance during early childhood, when maternally derived antibodies have waned, and protective adaptive immunity is not well developed yet. CLINICAL IMPLICATIONS: Single nucleotide polymorphisms in the promoter region, in exon 1, and in exon 4 of MBL2 contribute to increased risk for otitis media in children younger than 2 years.     

HLA-Cw基因全长序列分子克隆及测序方法的建立

目的 建立可靠的HLA-Cw基因全长序列的分子克隆和测序技术.方法 设计合成HLA-Cw基因全长序列PCR引物和探索PCR反应体系,采用长距离PCR技术,扩增HLA-Cw基因非翻泽区(untranslated region,5'-UTR)区、8个外显子、7个内含子和3'-UTR区,全长约4.5 kb.PCR产物纯化后进行分子克隆,筛选阳性克隆,提取质粒DNA,采用自行设计的测序引物进行全长双向测序.12份已经AlleleSEQR HLA-Cw测序分型试剂盒进行PCR产物直接测序、基因型已知的样本,分别用TaKaRa LATaq酶和Stratagene Pfu Taq DNA聚合酶进行HLA-Cw基因全长扩增,以及PCR产物分子克隆和序列测定,克隆测序结果分别与PCR产物直接测序结果进行对比分析.结果 PCR扩增获得了特异性目的 片段,测序获得了HLA-Cw基因-962～3576位碱基全长序列.克隆测序结果的对比表明,Pfu酶保真性高于LA Taq酶.比较本文测定的Cw*010201与Cw*07020101等位基因序列,在5'上游-962～-284位碱基区域存在11个单核苷酸多态(single nucleotide polymorphisms,SNPs)和2个插入(或)缺失多态性位点;3'-UTR下游3067～3576位碱基区域存在11个SNPs和1个插入(或)缺失.结论 建立了HLA-Cw基因全长序列分子克隆及测序方法,在HLA-Cw基因全长序列分子多态性及表达调控等研究领域,具有广泛应用前景.     

MBL对树突状细胞体外分化成熟的影响

目的: 探讨甘露聚糖结合凝集素 (MBL)对人外周血单核细胞来源的树突状细胞 (MoDC)分化成熟的影响。方法: 以天然人MBL刺激MoDC, 在倒置显微镜下观察DC的形态; 用FACS分析DC的表型; 用 3H- TdR掺入法测定DC刺激同种异体T细胞增殖的能力; 以酵母多糖颗粒吞噬试验评估DC的抗原摄取能力; 用ELISA检测DC培养上清中IL- 12和TNF- α的含量。结果: MBL刺激的DC表面分子CD1a、CD83、CD40、CD80、CD86和MHC DR的表达均上调,摄取酵母多糖颗粒的能力降低, 激发初始T细胞增殖的能力加强, 分泌的IL- 12增多但几乎不分泌TNF- α。结论: MBL能诱导DC分化成熟, 提示其可能通过调节DC的功能而参与获得性免疫应答。     

抗溶藻弧菌独特型单克隆抗体可变区基因的克隆和序列分析

目的: 克隆并分析抗溶藻弧菌独特型单克隆抗体(mAb)VH及VL基因。方法: 从分泌抗溶藻弧菌独特型mAb的杂交瘤细胞株 (AL1 )中提取总RNA。利用RT- PCR技术,克隆抗溶藻弧菌独特型mAbVH 和VL基因, 并将其重组入PMD18 Tvector中进行测序分析。结果: VH基因序列全长为369bp, 编码 123个氨基酸; VL基因序列全长为 339bp, 编码113个氨基酸。通过国际联机检索及Kabat库分析, 二者均符合小鼠IgGV区基因的特征, 含有 4个框架区 (FR), 3个抗原互补决定区 (CDR)及两个抗体特征性的半胱氨酸残基。结论: 抗溶藻弧菌独特型mAb的VH和VL基因的克隆成功,为抗溶藻弧菌独特型mAb基因工程疫苗的构建奠定了基础。     

The significance of IgG subclasses and mannan-binding lectin (MBL) for susceptibility to infection in apparently healthy adults with IgA deficiency.

The aim of this study was to investigate the significance of IgG subclasses and MBL for susceptibility to infection in association with IgA deficiency. The study population consisted of 139 apparently healthy adult blood donors with IgA deficiency and normal serum levels of IgG and IgM, and an increased susceptibility to infection demonstrated at a population level. Additionally, 216 controls matched for age and sex were investigated. IgG4 deficiency was more common and the mean level of IgG4 lower in persons with IgA deficiency than in the controls. No significant associations could be demonstrated between overt IgG subclass deficiencies and increased susceptibility to infection. However, when the mean concentrations of IgG subclasses were analysed with regard to medical history, that of IgG1 was lower in persons who reported recurrent viral respiratory infections, that of IgG3 in persons who had episodes of severe infection in their history, and that of IgG4 in persons who had recurrent mild respiratory infections, compared with those who had no particular history of infections. In contrast, MBL deficiency-alone or combined with that of the IgG subclass-was not associated with increased susceptibility to infection in persons with IgA deficiency. The results indicate that the proneness to infections observed in a population of otherwise healthy persons with IgA deficiency can only for a small part be accounted for by concomitant deficiencies of IgG subclasses. Contrary to expectations, no synergism between the deficiencies of IgA and MBL could be demonstrated.     

中国汉族、维吾尔族人群甘露聚糖结合凝素基因多态性的检测

分别收集广东省汉族和新疆维吾尔族自治区维吾尔族一般人群血标本,提取白细胞基因组DNA,以多聚酶链反应扩增目的基因片段,应用荧光探针杂交可视技术检测其甘露聚糖结合凝集素(MBL)基因54位密码点突变(GGC54GAC)。从138份汉族样本中检出GGC54GAC突变型纯合子4例,占2.9%,杂合子30例,占21.74%;120份维吾尔族标本中,检出突变型纯合子3例,占2.5%,杂合子34例,占28.33%。因此,汉族和维吾尔族人群MBL基因GGC54GAC突变的频率分别为0.138和0.167,两民族间无明显差异。     

Mannan-binding lectin is a determinant of survival in infective endocarditis

Mannan-binding lectin (MBL) is a collectin plasma protein activating the lectin pathway of the complement system, enhancing opsonophagocytosis and modulating the cytokine response to inflammation. Deficiency of MBL, caused by structural mutations or promoter polymorphisms in the MBL2 gene, has been associated with increased susceptibility to infection and autoimmune disease. Thus, as infective endocarditis remains a severe disease requiring intensive and long-term treatment with antibiotics, we examined whether there was an association between MBL and clinical outcome in 39 well-characterized patients with infective endocarditis. Five patients (13%) had MBL concentrations < 100 microg/l and were considered MBL-deficient. This proportion was similar to that in a healthy control group of blood donors. Mortality 3 months after diagnosis was 20% in patients with MBL-deficiency and 9% in patients with normal MBL. The 5-year mortality was 80% and 25%, respectively. MBL-deficiency was on univariate survival statistics associated with significantly higher mortality on follow-up (P=0 x 03). In conclusion, this is the first report of an association between MBL-deficiency and survival in infective endocarditis. The present observation is important, as replacement therapy in MBL-deficient patients is possible. For certain high-risk subgroups, it opens new perspectives for improvement of treatment and outcome in infective endocarditis.     

广东地区汉族人MBL基因GGC54GAC点突变的初步筛查

目的对广东地区汉族人群的甘露聚糖结合凝集素结构基因第一外显子第54位密码点突变(GGC54GAC)进行初步筛查.方法提取外周血白细胞DNA进行相应片段的PCR扩增,再对产物进行单链构象多态性分析.结果在166人中查出野生型纯合子147例,占88.55%,GGC54GAC突变杂合子19例,占11.45%,未发现GGC54GAC突变纯合子.结论广东地区汉族人群MBL基因GGC54GAC突变频率为0.057.