皖籍汉族正常人群TAP等位基因多态性分析

抗原处理相关转运蛋白体 (transporter associated with antigen processing, TAP)基因位于HLAⅡ类区域的DQB1和DPB1位点之间, 包括TAP1和TAP2,相距约70 kb.TAP基因产物是内质网膜上的跨膜二聚体,功能是将与胞浆内的蛋白酶体(proteosome)结合后并降解的内源性抗原转运至内质网腔,与HLAⅠ类分子结合,形成稳定的HLA-Ag复合物,然后才能表达于细胞表面并提呈给T细胞. Colonna M等[1]通过基因测序获得TAP全基因序列,证实该基因具有高度多态性和变异性.TAP的多态性可使不同的肽转运至内质网,因此,不同个体的MHCⅠ类分子对同一大分子提呈的抗原片段不同,从而使不同机体对同一抗原的免疫应答表现出个体差异[2].本研究对皖籍汉族正常人群进行TAP等位基因分型,并与不同种族、不同地区的资料进行比较,为进一步研究TAP关联疾病的发病机制奠定基础.     

HBV抗原基因修饰树突状细胞疫苗体外抗HBV的研究

慢性乙型肝炎产生免疫耐受的原因之一是患者体内抗原提呈细胞不正常,尤其是树突状细胞（DCs）数量减少和功能存在缺陷,不能将抗原信号有效提呈给机体的免疫系统而发挥免疫清除效应.本研究利用整合HBV基因组的HepG2 22.1.5为细胞模型,通过携带编码HBV抗原基因的重组腺病毒载体的介导,探讨腺病毒介导的HBV抗原基因修饰的DCs能否诱导产生特异性抗感染免疫反应,为慢性乙型肝炎的治疗探索一种新的免疫治疗措施.     

导入TAP基因上调其在肺腺癌细胞系的表达

目的克隆TAP1及TAP2基因，分别转染TAP1及TAP2表达下调的人肺腺癌细胞系Anip973，以提高其表达水平，从而增强肿瘤细胞的抗原提呈能力。方法采用RT-PCR方法自EBV刺激的B-LCLs克隆TAP1及TAP2基因，与pcDNA3．1／V5-His-TOPO TA Expression vector连接，构建真核细胞表达载体，脂质体法(Lipofectamine^TM2000)转染人肺腺癌细胞系Anip973，经G418筛选4-6周，通过RT-RCR检测TAP1及TAP2的表达。结果经测序确认已成功克隆人TAP1及TAP2基因，建立稳定表达TAP1或TAP2的细胞系，经RT-PCR分析，Anip973细胞TAP1、TAP2的mRNA表达明显增加。结论基因转染可恢复肿瘤细胞TAP1及TAP2的表达，为增强MHCⅠ类分子提呈肿瘤抗原奠定了基础。     

导入TAP基因上调其在肺腺癌细胞系的表达

目的　克隆TAP1及TAP2基因 ,分别转染TAP1及TAP2表达下调的人肺腺癌细胞系Anip973,以提高其表达水平 ,从而增强肿瘤细胞的抗原提呈能力。方法　采用RT PCR方法自EBV刺激的B LCLs克隆TAP1及TAP2基因 ,与pcDNA3.1 V5 His TOPOTAExpressionvector连接 ,构建真核细胞表达载体 ,脂质体法 (LipofectamineTM2 0 0 0 )转染人肺腺癌细胞系Anip973,经G4 1 8筛选 4～ 6周 ,通过RT PCR检测TAP1及TAP2的表达。结果　经测序确认已成功克隆人TAP1及TAP2基因 ,建立稳定表达TAP1或TAP2的细胞系 ,经RT PCR分析 ,Anip973细胞TAP1、TAP2的mRNA表达明显增加。结论　基因转染可恢复肿瘤细胞TAP1及TAP2的表达 ,为增强MHCⅠ类分子提呈肿瘤抗原奠定了基础     

TAP的研究进展

抗原处理相关转运体蛋白(transporter associated with antigen processing,TAP)在内源性抗原提呈过程中有重要作用,负责内源性抗原从胞浆到内质网(ER)腔的转运。TAP异二聚体由TAP1和TAP2蛋白组成,每个亚基各有一个核酸结合区(NBD)和一个跨膜区(TMD)。TAP对抗原肽的转运可分为不依赖ATP的TAP与抗原肽的结合和ATP依赖性的抗原肽到内质网的转运两个基本步骤。人类TAP1和TAP2等位基因在不同种族和地区有不同的分布。TAP与一些自身免疫性疾病、肿瘤和病毒感染性疾病的发生有一定的相关性。     

人类白细胞抗原-Ⅱ类等位基因多态性与HBV慢性感染相关性研究进展

乙型肝炎病毒（hepatitis B virus,HBV）感染仍是我国一个重大的疾病负担.HBV感染后可表现为隐性感染、急性感染或慢性持续感染,后者可进展为肝硬化（liver cirrhosis,LC）、肝细胞癌（hepatocellular carcinoma,HCC）;这些不同的疾病转归和患者对治疗应答的个体差异,不仅与HBV本身有关,也与宿主的遗传背景密切相关.人类白细胞抗原（human leukocyte antigen,HLA）复合物是首个被发现的与疾病有明确关系的遗传系统,其通过参与免疫应答与抗原提呈过程影响机体免疫功能,其中HLA-Ⅱ类分子可决定抗原结合槽的构象、结合及提呈抗原肽给T细胞的效率,其基因多态性影响不同个体对HBV的易感性和感染结局以及治疗应答[1,2].现将相关进展综述如下.     

上海人群中TAP、LMP和HLA-DM基因多态性研究

调查上海人群中抗原处理相关基因TAP、LMP和HLA-DM的分布情况,并探索这些基因与自身免疫病类风湿关节炎(RA)、IgA肾炎(IgAN)和多发性硬化症(MS)的可能关联。应用PCR-SSO或PCR-RFLP技术对80名无血缘关系的上海地区正常人及156名RA患者、60名IgAN患者和21名MS患者作了TAP1、TAP2、LMP2、HLA-DMA和HLA-DMB基因分型。并作了两位点连锁不平衡分析。在该群体中,(1)共观察到4个TAP1、6个TAP2、2个LMP2、4个HLA-DMA和4个HLA-DMB等位基因;(2)在TAP1B-TAP2A、TAP1B-LMP2H和TAP2D-DMA*0101存在连锁不平衡(Pc<0.05);(3)本人群中IgAN和MS的遗传易感性与抗原处理相关基因无关,而RA患者中DMB*0101基因频率降低(P<0.01),TAP1C和DMB*0104等位基因频率显著升高(P<0.01)。比较分析表明,上海人群中抗原处理相关基因多态性与国外其他人种中的报道相似,本人群中IgAN和MS与抗原处理相关基因不关联,而TAP1C和DMB*0104等位基因可能是RA的遗传易感基因。     

抗原处理相关转运体结构与功能的研究进展

内源性抗原通过MHCⅠ类分子提呈给细胞毒性T细胞 (CTL)是机体细胞免疫识别的重要阶段。抗原处理相关转运体 (transporterassociatedwithantigenprocessing ,TAP)负责抗原肽从胞浆到内质网的转运 ,在MHCⅠ类分子的抗原处理及提呈过程中发挥重要作用。TAP结构和功能障碍将导致细胞表面MHCⅠ类分子表达缺陷 ,这成为肿瘤细胞、病毒感染细胞逃逸免疫监视的重要机制。     

057 抗原处理相关转运体结构与功能的研究进展

内源性抗原通过MHCⅠ类分子提呈给细胞毒性T细胞(CTL)是机体细胞免疫识别的重要阶段.抗原处理相关转运体(transporter associated with antigen processing,TAP)负责抗原肽从胞浆到内质网的转运,在MHCⅠ类分子的抗原处理及提呈过程中发挥重要作用.TAP结构和功能障碍将导致细胞表面MHC Ⅰ类分子表达缺陷,这成为肿瘤细胞、病毒感染细胞逃逸免疫监视的重要机制.     

人肺癌TAP1功能缺陷基因致1型MHC抗原提呈的丢失

目前认为肺癌表达有多种新的表位，它相当于潜在的免疫靶标，因而临床上明显的肿瘤能有效躲避免疫识别和剔除。抗原提呈相关的转运蛋白（TAP）是将细胞内肽运入内质网并合成1型MHC复合物，尔后由细胞毒T淋巴细胞识别。据证实人小细胞肺癌（SCLC）细胞系H1436中邻近TAP结合部有一种新JIW序（R659Q），该细胞系为这个等位基因的杂合子，但仅有R659Q等位基因被转录为RNA。即使R659Q蛋白质表达，上述细胞似乎仍由结合TAP缺陷起作用，而抗原提呈则在功能性TAPI等位基因转染后得以恢复，这表明在人类实体瘤中有自然产生的蛋白结构异…     

TAP1 and TAP2 polymorphisms and their linkage disequilibrium with HLA-DR, -DP, and -DQ in an eastern Andalusian population

Transporter associated with antigen processing (TAP) molecules are involved in the processing of endogenous peptides that bind to major histocompatibility complex (MHC) class I molecules. The possible functional significance of TAP polymorphisms for antigenic peptide transport is an unresolved issue. Population genetics is a tool for investigating the evolutionary and functional significance of genetic polymorphisms. We studied 105 unrelated individuals from Eastern Andalusia in Southern Spain for TAP1 and TAP2 polymorphisms and to detect linkage disequilibrium between TAP1 and TAP2 and between TAP1/TAP2 and human lymphocyte antigen (HLA) DR, DP, and DQ genes. HLA-DR, -DQ, -DP, and TAP1 loci were genotyped with the polymerase chain reaction (PCR)-sequence-specific oligonucleotide method, and TAP2 genes were typed by using the amplification-refractory mutation system-PCR technique. The alleles TAP1*D (3.3%), TAP2*D (2.4%), and TAP2*E (2.9%) were present in the Eastern Andalusian population but not in the general Spanish population. No evidence of linkage disequilibrium was found between TAP1 and TAP2 or between the TAP genes and HLA-DR, -DP, and -DQ in the Eastern Andalusian population. These results are consistent with the absence of coevolution between TAP and MHC class II genes and the hypothesis of selective neutrality.     

Significance of Transporter Associated with Antigen Processing 2 (<Emphasis Type="Italic">TAP2</Emphasis>) Gene Polymorphisms in Susceptibility to Dengue Viral Infection

Background and Aims The polymorphic transporter associated with antigen processing (TAP)1 and TAP2 genes encode subunits of the transporter that delivers peptides to the human leukocyte antigen class I molecules. Because the polymorphism of the TAP genes has been shown to affect peptide transport, it has been suggested that TAP genes are potential regulators of the immune response. We recently reported that TAP1 gene polymorphism is associated with severe dengue infection. This study was carried out to elucidate whether TAP2 polymorphisms are involved in diverse pathogenesis of dengue infection. Materials and Methods This study included 100 controls and 197 dengue-infected patients who were further categorized into 90 dengue fever (DF) cases, 75 dengue hemorrhagic fever cases (DHF), and 32 dengue shock syndrome (DSS) cases as per WHO grading system. TAP2 gene polymorphisms were determined by amplification refraction mutation system-polymerase chain reaction. Results The frequency of isoleucine at TAP2 379 (34.5%) was increased among DHF in comparison to controls (21%, P = 0.014). DHF cases were more likely to be heterozygous at TAP2 379 (50.7%) than controls [24%, odds ratio (OR) = 2.11, P = 0.001]. Significantly high proportion of DHF was found to have TAP2 665 threonine/alanine (THR/ALA) genotypes (30.7%) when compared with DF (13.3%, OR = 2.3, P = 0.006) cases. There was no difference in the genotypes studied between DSS and controls or DF or DHF. Conclusion This first report on TAP 2 gene polymorphism in dengue suggested that heterozygous pattern at TAP2 379 locus confers susceptibility to DHF, and TAP2 665 THR/ALA genotype was found to be a risk factor for development of DHF.     

Presentation of viral antigens restricted by H-2Kb,Db or Kd in proteasome subunit LMP2-and LMP7-deficient cells

In the class II region of the major histocompatibility complex (MHC), four genes implicated in MHC class I-mediated antigen processing have been described. Two genes (TAP 1 and TAP 2) code for multimembrane-spanning ATP-binding transporter proteins and two genes (LMP 2 and LMP 7) code for subunits of the proteasome. While TAP 1 and TAP 2 have been shown to transport antigenic peptides from the cytosol into the endoplasmic reticulum, where the peptides associate with MHC class I molecules, the role of LMP 2/7 in antigen presentation is less clear. Using antigen processing mutant T2 cells that lack TAP 1/2 and LMP 2/7 genes, it was recently shown that expression of TAP 1/2 alone was sufficient for processing and presentation of the influenza matrix protein M1 as well as the minor histocompatibility antigen HA-2 by HLA-A2. To understand if presentation of a broader range of viral antigens occurs in the absence of LMP 2/7, we transfected T2 cells with TAP 1, TAP 2 and either of the H-2K^b, D^b or K^d genes and tested their ability to present vesicular stomatitis vires and influenza virus antigens to virus-specific cytotoxic T lymphocytes. We found that T2 cells, expressing TAP 1/2 gene products, presented all tested viral antigens restricted through either the H-2K^b, D^b or K^d class I molecules. We conclude that the proteasome subunits LMP 2/7 as well as other gene products in the MHC class II region, except from TAP 1/2, are not generally necessary for presentation of a broader panel of viral antigens to cytotoxic T cells. However, the present results do not exclude that LMP 2/7 in a more subtle way may, or in rare cases completely, affect processing of antigen for presentation by MHC class I molecules.     

广东汉族人群LMP和TAP基因多态性及与变应性鼻炎的相关性

目的对广东地区汉族变应性鼻炎患者作抗原处理相关肽(TAP)和低分子量多肽(LMP)分型,探讨这些基因与广东人群中变应性鼻炎遗传易感性的可能关系。方法采用PCR扩增阻碍突变系统(PCR-ARMS)法和PCR-RFLP法对62名无亲缘关系的变应性鼻炎病人和95名无血缘关系的广东籍健康汉族人作TAP、LMP分型。结果TAPl-333、637位等位基因基因型在广东汉族变应性鼻炎组及正常对照组中均以I和D为主,TAP2-379、565、665等位基因基因型分别为V-A-T。TAP1和TAP2各等位基因基因型频率在变应性鼻炎组和正常人组间差异无显著性(P>0.05)。变应性鼻炎患者LMP7A/A频率占8.70%,低于正常对照组的21.35%,有显著差异(P<0.05),其余各型与正常对照组无明显差异(P>0.05)。变应性鼻炎病人中LMP7等位基因A的频率占36.23%,B的频率占63.77%,与正常对照组的A为47.09%、B为52.91%有显著差异(P<0.05)。结论提示LMP7等位基因A与AR的发病呈负关联,B与AR的发病呈正关联。变应性鼻炎与TAP基因可能无相关性.     

Association of TAP1 and TAP2 gene polymorphisms with systemic sclerosis in Korean patients

We sought to determine whether transporter associated with antigen processing (TAP) gene polymorphism is associated with susceptibility to systemic sclerosis (SSc). TAP1 and TAP2 gene polymorphisms were analyzed in 61 Korean patients with SSc and 100 ethnically matched healthy Koreans by polymerase chain reaction-restriction fragment length polymorphism. Human leukocyte antigen (HLA)-DRB1 genotyping data of the patients from our previous study was used for the assessment of independent role of TAP genes to SSc susceptibility. Patients were stratified according to anti-topoisomerase I (anti-topo I) antibody status and clinical subsets of diffuse and limited cutaneous SSc (dcSSc and lcSSc). TAP1 and TAP2 gene polymorphisms were associated with different subsets of SSc: TAP1*A/A genotype with anti-topo I-positive dcSSc (p = 0.01, p corrected = 0.04), TAP2*A1/C genotype with anti-topo I-positive lcSSc (p < 0.05), TAP2*Bky2 and *C alleles with anti-topo I-negative dcSSc (both p < 0.05), and TAP2*B/E genotype with anti-topo I-negative lcSSc (p = 0.004). Although TAP gene associations were generally weak, some associations (TAP2*A1/C, TAP2*C, and TAP2*B/E) with different subsets of SSc were independent of HLA-DR associations, revealing even stronger associations (TAP2*A1/C and TAP2*C) among individuals not possessing the risk HLA-DR alleles. These results suggest the possible role of TAP gene polymorphisms in the genetic susceptibility to SSc.     

Polymorphisms of the TAP 1 and 2 gene may influence clinical outcome of primary dengue viral infection

Antigen peptides are actively transported across the endoplasmic reticulum by the transporters associated with antigen presentation (TAP). TAP genes polymorphism could influence the selection process that determines which antigen peptides play a role in the pathogenesis of dengue infection. The aim of this study was to investigate the association of TAP genes polymorphism in diverse pathogenesis of dengue infection. This study included 197 dengue-infected patients who were further categorized into 64, 23 and 11 primary dengue fever (DF), dengue hemorrhagic fever (DHF), dengue shock syndrome (DSS) cases, respectively and 26, 52, and 21 secondary DF, DHF and DSS cases, respectively as per WHO grading system. TAP1 and 2 gene polymorphisms were performed by the amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). Analysis of TAP1 gene polymorphism demonstrated decreased frequency of Ile/Ile genotype at TAP1(333) in primary DHF cases (39.1%) when compared with primary DF (64.1%, P < 0.034, OR = 0.611). The genotype frequency of Val/Val at TAP2(379) locus was significantly decreased among primary DHF (43.5%) in comparison to primary DF (71.9%, P = 0.015, OR = 0.605). Significant low proportion of primary DSS were found to have TAP1(637) Asp/Asp genotypes (54.5%) when compared with primary DF (70.3%, P = 0.043). Asp/Asp genotype at TAP1(637) was found to reduce the risk by 0.643 times for primary DSS. There was no significant difference in the genotypes studied between primary and secondary infection and also within secondary dengue infection in all three clinical groups. This report on TAP gene polymorphisms in dengue suggested that among the primary-infected individuals, homozygous patterns for Ile at TAP1(333) Val at TAP2(379) loci and Asp at TAP1(637) were found to be a protective factor against development of DHF and DSS, respectively.     

Association of TAP Gene Polymorphisms and Risk of Cervical Intraepithelial Neoplasia

Background. Transporter associated with antigen processing (TAP) is responsible for peptide loading onto class I major histocompatibility complex (MHC-I) molecules. TAP seems to facilitate the detection of HPV by MHC-I molecules and contributes to successful eradication of HPV. TAP polymorphisms could have an important impact on the course of HPV infection. Objective. The aim of this study is to evaluate the association between five TAP gene polymorphisms and the risk of CIN. Methods. This case-control study investigated five common TAP polymorphisms in TAP1 (1341 and 2254) and TAP2 (1135, 1693, and 1993) in 616 women with CIN and 206 controls. Associations between gene polymorphisms and risk of CIN were analysed by univariate and multivariable models. The combined effect of the five TAP gene polymorphisms on the risk for CIN was investigated by haplotype analysis. Results. No significant difference in genotype distribution of the five TAP polymorphisms was observed in women with CIN and controls. Haplotype analysis revealed that women with haplotype mut-wt-wt-wt-wt (TAP polymorphisms t1135-t1341-t1693-t1993-t2254) had a significantly lower risk for CIN, compared to women with the haplotype wt-wt-wt-wt-wt (P = 0.006; OR 0.5 [0.35–0.84]). Conclusion. Identification of this haplotype combination could be used to identify women, less susceptible for development of CIN following HPV infection.     

Analysis of IL1B, TAP1, TAP2 and IKBL polymorphisms on susceptibility to tuberculosis

Genetic determinants of human susceptibility to tuberculosis (TB) have not been completely elucidated. Interleukin-1 beta (IL-1beta) and the inhibitor of kB-like (IkBL) are important molecules that participate in the inflammatory response required for the immunological control of a broad spectrum of infectious agents. The transporter associated with antigen processing (TAP) is involved in the antigen processing via major histocompatibility complex class I molecules and in turn might regulate the T-cell response against Mycobacterium tuberculosis. To better characterize the host genetic factors determining the susceptibility to TB, we evaluated the influence of functional polymorphisms in IL1B, TAP and IKBL genes on the risk of developing pulmonary TB in a Northwestern Colombian population, an endemic area of M. tuberculosis infection. A total of 122 TB patients and 166 healthy controls (N = 166) negative for human immunodeficiency virus infection were examined for IL1B-511 and +3,953, TAP1 and TAP2 and IKBL+738 polymorphisms. Univariate analysis disclosed significant differences between patients and controls for IL1B+3,953 polymorphism. After unconditional logistic regression analysis, a strong protection conferred by IL1B+3,953 T-allele-carrying genotypes was observed. A trend between TAP2*0201 allele and disease was observed. Association between IL1B-511, TAP1 or IKBL polymorphisms and TB disease was not found. These results indicate that a functional polymorphism in the IL1B gene influences the susceptibility to TB and suggest a role for IL-1beta in the pathogenesis of mycobacterial infection.