HLAⅠ类抗原的基因芯片分型技术研究

目的：采用DNA芯片技术进行汉族人群HLAⅠ类抗原A、B位点的DNA分型研究，并实现将A、B位点的DNA分型集中于一张芯片上，同时完成。方法：根据HLAⅠ类抗原A、B位点不同基因亚型的独特序列设计探针，制成分型芯片；待检测样品经PER反应标记上荧光之后，与探针在芯片上进行杂交，通过对杂交产生的荧光信号值进行分析，确定样品的HLA-A、B基因亚型。将这一方法应用于220份样本的HLAⅠ类DNA分型并将部分样品进行基因测序。结果：所有样本的HLAⅠ类基因芯片分型均获得成功，无假阳性和假阴性出现，80份样本的重复率为100％，总耗时2．5h。分型结果经双盲验证完全符合。可准确分辨出A位点等位基因20个，B位点等位基因41个，实际检出汉族人群A抗原特异性13个、B抗原特异性32个。结论：基因芯片用于HLAⅠ类A、B分型技术可行，其分辨率高、特异性强、重复性好、操作简便快速、结果直观，可以在一张芯片上同时检测HLA-A、B位点，并实现一张芯片多人份，适合于临床应用。     

HLAⅠ、Ⅱ类抗原的组织配型基因芯片的建立及应用

目的应用基因芯片技术进行北方汉族人群HLAⅠ、Ⅱ类抗原中分辨度分型研究,建立稳定的HLA检测芯片。方法采用寡核苷酸芯片分型方法,选择了中国人群基因频率较高的等位基因,同时考虑遗传的连锁不平衡,根据HLA-A、HLA-B、HLA-DR、HLA-DQB、HLA-DQA不同基因亚型的独特序列,完成了探针的设计与筛选,共设计了213条探针(HLA-A 56条,HLA-B 66条,HLA-DQA 22条,HLA-DQB 38条,HLA-DR 31条)制成基因分型芯片。采用带荧光标记的引物,用合适的PCR方法扩增HLAⅠ、Ⅱ类抗原上的多态性区域,产物与芯片上探针杂交。杂交结果经荧光扫描并用特定软件分析判断,以此确定样品基因型。结果所有样本的HLAⅠ、Ⅱ类抗原基因分型均获成功。此中分辨度探针可分出598个Ⅰ类抗原等位基因,511个Ⅰ类抗原等位基因,可检出Ⅰ类抗原特异性57个,Ⅱ类抗原特异性30个。结论基因芯片用于HLAⅠ、Ⅱ类抗原分型可行。其分辨率高、特异性强,可用于HLA基因分型、骨髓移植、器官移植的HLA配型、与HLA有密切关系的遗传性疾病的人群筛查。     

HLA-Ⅰ类抗原的组织配型基因芯片的建立及应用

目的:应用基因芯片技术进行北方汉族人群HLA-Ⅰ类抗原中分辨度分型研究,建立稳定的HLA检测芯片.方法:采用寡核苷酸芯片分型方法,依据第十三届国际组织相容性工作会议报告及相关文献,同时考虑遗传的连锁不平衡,及强脊炎、幼年型糖尿病等与HLA密切相关的遗传病等因素,选择了中国人群基因频率较高的等位基因,根据HLA-Ⅰ类不同基因亚型的独特序列,完成了探针的设计与筛选,最后设计了122条探针(HLA-A56条,HLA-B66条)制成基因分型芯片.采用带荧光标记的引物,用合适的PCR方法扩增HLA-Ⅰ类抗原上的多态性区域,产物与芯片上探针杂交.杂交结果经荧光扫描并用特定软件分析判断阳性探针,以此确定样品基因型.结果:所有样本的HLA-Ⅰ类抗原基因分型均获成功.此中分辨度探针可分出598个Ⅰ类抗原等位基因,可检出Ⅰ类抗原特异性57个.结论:基因芯片用于HLA-Ⅰ类抗原分型可行.其分辨率高,特异性强,可用于HLA基因分型、骨髓移植、器官移植的HLA配型、与HLA有密切关系的遗传性疾病的人群筛查.     

基因芯片法特异性检测丙型肝炎病毒的基因分型

目的：采用基因芯片特异性检测血清中丙型肝炎病毒（HCV）并进行基因分型。方法：设计HCV基因型特异探针，将其固定在玻璃片上制成微阵列芯片。阳性组血清60份，阴性组血清15份，乙型肝炎血清5份（抗HCV阴性）。经核酸提取，多聚酶链式反应（PCR）扩增，与芯片上的探针杂交，最后分析结果并与测序分型结果比较。结果：阳性组血清全部检测到HCV-RNA，均有基因芯片分型结果。基因芯片分型结果与测序分型结果一致者56例。阴性组血清HCV-RNA全部阴性。乙型肝炎血清全部阴性。结论：基因芯片可准确对HCV感染血清做定性检测并同时检测HCV基因型，简便快捷，特异性好，并且不需荧光标记和昂贵的荧光扫描仪器，与乙型肝炎血清无交叉反应。可替代基因测序分型，适于临床大量样品的检测。     

HLA-DR位点的基因芯片分型与临床应用

目的：建立一种新型的HLA－DR位点的基因分型方法，为HLA－DR的基因分型提供一个较新的思路。方法：利用基因芯片技术HLA不同基因亚型的独特序列设计探讨，制成分型芯片；待检测样品经PCR反应标记上荧光之后，与芯片进行杂交，根据杂交产生的荧光信号值分析确定样品DR位点的基因亚型，将这一方法应用于70份标准DNA和200份医院移植供受者的HLA－DR基因分型并将部分样品进行基因测序。结果：检测结果表明HLA－DR基因分型芯片可准确分辨出DR位点等位基因30大类，耗时3h 。结论：基因芯片用HLA－DR的基因分型，分辨率高，特异性强，重复性好，操作简便，对比常规的PCR－SSP和PCR－SSO方法，HLA－DR基因芯片方法更为直观，并具有集成化优势。可以在一张芯片上同时检测HLAⅠ类的A、B位点，并实现一张芯片多人份，适合于临床应用和骨髓库，脐血库的建立。     

自行构建人类白细胞抗原DQA1位点基因分型寡核苷酸芯片性能评价:100例样本与PCR-SSP法的比较

背景:人类白细胞抗原等位基因分型对器官移植和法医鉴定等有重要意义。目前的分型方法难以实现高通量和集成化,准确性和重复性也不理想。目的:比较自行构建的寡核苷酸芯片与序列特异性引物-聚合酶链反应(polymerase chain reaction with sequence-specific primers,PCR-SSP)两种方法用于人类白细胞抗原DQA1基因分型的结果,以评价寡核苷酸芯片的性能。方法:纳入2006-01/2009-03于中国医科大学附属第一医院血液科门诊就诊的患者100例。分别用等位基因特异的PCR-SSP和自行构建的寡核苷酸芯片对患者的人类白细胞抗原DQA1进行分型。寡核苷酸芯片分型采用荧光标记的组间特异性引物扩增基因组DNA,扩增后的产物与分型芯片的探针杂交,由杂交产生的荧光信号确定人类白细胞抗原DQA1位点基因型。比较两种方法分型所获得的结果,不吻合的样本经第三方测序验证。结果与结论:100例临床样本经寡核苷酸芯片和PCR-SSP分型全部成功。分型结果的吻合率为94%。不吻合样本6例,其中4例PCR-SSP定型为杂合子,芯片分型全部为纯合子。经第三方验证,证实芯片的分型全部正确。另外2例不吻合的样本经测序,证实SSP分型错误1例,芯片分型错误1例。芯片的重复率为95%。说明自行构建的寡核苷酸芯片的特异性和灵敏度都能满足基因分型的需要,且稳定性较好。     

通用型病毒检测芯片在三种人类致病病毒属检测中的应用

目的 研究制备对人类有致病作用的38个属的病毒寡核苷酸（oligo）基因芯片对三种人类致病病毒的检测能力。方法 应用生物信息学软件设计70-mer oligo探针，固定于玻片载体制备成基因芯片。以痘苗病毒天坛株、甲肝病毒、乙肝病毒作为检测样本，提取病毒核酸，经随机引物扩增、荧光标记，用于芯片杂交，清洗和干燥后对芯片进行扫描和数据分析。结果 芯片上oligo探针能与相应病毒的PCR扩增样品杂交，呈现阳性荧光信号。结论 建立的病毒寡核苷酸基因芯片能够检出和区分三种检测病毒，为进行未知病毒的基因芯片筛查方法的建立奠定了基础。     

国产HLA-DRB基因分型检测芯片应用体会

目前,国内HLA基因分型大多采用聚合酶反应一序列特异引物技术(PCR-SSP)或序列特异寡核苷酸探针杂交技术(PCR-SSO）,使用的试剂也大都是进口。国产HLA试剂的开发,将大大降低移植配型技术的成本,给患者带来福音。我们应用上海博星基因芯片有限责任公司研制的国产HLA-DRB基因分型检测芯片,对临床移植配型的患者进行HLA-DRB基因分型。     

胰腺癌相关基因寡核苷酸芯片的制备和初步应用(英文)

目的：研究胰腺癌相关基因寡核苷酸芯片的构建及其在检测胰腺癌基因表达谱方面的应用。方法：有目的地筛选胰腺癌相关基因，采用合成后点样的方法将合成的寡核苷酸探针点于同型双功能偶联剂（APS-PDC）包被的基片上，制成寡核苷酸基因芯片。Trizol法抽提组织总RNA，并用Qiagen Rneasy kit 进一步纯化。在cDNA第1链合成过程中，通过反转录酶将CyDye标记核苷酸直接渗入到cDNA中制备荧光探针，其中用Cy3-dCTP标记胰腺癌组织，Cy5-dCTP标记正常胰腺组织。将荧光标记探针定量后与芯片杂交16-18 h。用Agilent 扫描仪进行扫描，Imagene3.0软件（Biodiscovery,Inc.）图像分析，计算2种荧光Cy3 与Cy5信号强度的比值。挑选差异基因CDC25B和TUSC3进行荧光定量PUR（Sybrgreen方法）验证，以B-actin基因为内参照基因，PCR产物的定量方法采用比较Ct法。结果：芯片杂交扫描图像信号清晰，具有较低的整体背景和较高的信噪比，各阳性质控点信号均匀一致，阴性质控点和空白点信号低。与正常组织相比，胰腺癌组织中差异表达基因24条，占全部基因的25.5%，其中上调基因17条（占18.1%），下调基因7条（占7.4%）。荧光定量PCR验证，CDC25B和TUSC3基因在胰腺癌中的表达分别为上调和下调，其表达趋势与芯片实验的结果一致。结论：制备的胰腺癌相关基因芯片，可同时、并行检测多种胰腺癌相关基因的表达改变，具有一定的特异性和灵敏性。胰腺癌组织与正常胰腺组织相比，基因表达谱具有明显的差异，为进一步研究胰腺癌的发病机理和早期诊断提供了有用的信息。     

3种分型方法在HLA-B分型中的应用分析

在人类白细胞抗原（Human leucocyte antigen，HLA）的多种分型技术中，以血清学方法、序列特异性引物．聚合酶链反应（Polymerase chain reaction sequence—specific primer，PCR-SSP）方法和多聚酶链反应-序列特异寡核苷酸探针（PCR—sequence—specific oligonucleotide probes，PCR—SSOP）杂交配型技术实用性较强。我们采用此3种方法同时对30份标本进行HLA—B位点进行分型和比较，报道如下：     

DNA typing of the HLA-A gene: population study and identification of four new alleles in Japanese

With the use of polymerase chain reaction (PCR) and sequence-specific oligonucleotide probe (SSOP), we established a DNA typing method of the HLA - A locus. A pair of primers to amplify the highly polymorphic region of HLA-A gene including exon 2 and exon 3 was designed and the amplified DNAs were hybridized with 91 types of ³²P labeled SSOPs. This method allowed discrimination of all known HLA-A alleles except for two combinations, A*0201 or A*0209 and A*0207 or A*0215N, which have identical sequences in exon 2 and exon 3. Another pair of primers was designed for amplification of exon 4 and the PCR products were hybridized with 5 SSOPs to distinguish A*0201 and A*0207 from A*0209 and A*0215N, respectively. In this study, 81 B-lymphoblastoid cell lines (BLCL) homozygous for HLA and 553 unrelated healthy Japanese individuals were determined for their HLA-A genotypes. Based on the genotyping results, frequency of HLA-A alleles and linkage disequilibrium between HLA-A and HLA-B in the Japanese population were investigated. In addition, four new HLA-A alleles were identified and their nucleotide sequences in exon 2 and exon 3 were determined to confirm the typing results.     

A method for typing polymorphism at the HLA-A locus using PCR amplification and immobilized oligonucleotide probes

Abstract: We have developed a simple and rapid method for DNA typing of the HLA-A locus using PCR amplification and hybridization of the PCR product, labeled with biotinylated primers, to an array of immobilized oligonucleotide probes in a single hybridization reaction (reverse dot or line blot). A single primer set (RAP1007 and DB337) is used to specifically amplify a 990-bp fragment containing the HLA-A locus exons 1, 2, and 3 from genomic DNA. This primer set is locus-specific and amplifies all HLA-A alleles. A set of 51 sequence-specific oligonucleotide (SSO) probes, 25 for exon 2 and 26 for exon 3, was immobilized to a nylon membrane by UV-crosslinking oligonucleotide probes containing a poly-thymidine "tail" added with terminal transferase. In the line blot format, all 50 SSO probes plus a control probe are immobilized on a single nylon membrane strip. The probe array was used for typing in a hybridization reaction with DNA amplified from a variety of samples. These probes can identify 37 homozygous HLA-A alleles. In the analysis of heterozygous samples, 604 heterozygous types out of 633 (95.4%) possible heterozygous probe patterns can be detected as a unique probe reactivity pattern. A simple computer program has been developed to assign the alleles and genotypes based on the probe hybridization pattern.     

Complete HLA-A DNA typing using the PCR-RFLP method combined with allele group- and sequence-specific amplification

We have established a practical method of complete high-resolution typing for all HLA-A alleles using the polymerase chain reaction (PCR)-restriction fragment-length polymorphism (RFLP) technique combined with allele group- and sequence-specific amplification. The second and third exons of the HLA-A gene, in which most allelic variations are observed, were separately amplified by PCRs with 3 and 4 group-specific primer pairs, respectively. Each PCR-amplified product was digested by allele-specific restriction endonucleases and then subjected to electrophoresis on a 10% polyacrylamide gel. In this way, 62 out of 79 HLA-A alleles could be discriminated by the RFLP patterns derived from the genetic polymorphism in the exon 2 and 3 domains. The remaining 17 alleles could be defined unequivocally by either PCR-RFLP analysis after exon 4 amplification or PCR analysis with sequence-specific primers (SSP). By this method, complete HLA-A genotyping for all homozygous and heterozygous combinations can be accomplished, establishing technically simple, economical and practical routine typing of the HLA-A gene, especially for small samples.     

Characterization of the HLA-A polymorphism by locus-specific polymerase chain reaction amplification and oligonucleotide hybridization

This report describes a PCR-based typing protocol for the HLA-A polymorphism. Locus-specific primers selectively amplified HLA-A sequences from exon 1 to exon 3 in a single PCR that avoided co-amplification of other classical and nonclassical class I genes. The allelic variation in exons 2 and 3 of the HLA-A gene was examined with a set of 44 oligonucleotide probes. According to the recognized HLA-A sequences the protocol is potentially able to distinguish all known HLA-A alleles with unique nucleotide sequences in this gene region. The related HLA-A genotypes can also be identified in both homozygous and heterozygous individuals. Thus the protocol provides the highest resolution for HLA-A typing. The PCR-SSO typing technique is accurate, reliable, and particularly suitable for a large number of samples. The DNA typing results from 42 Tenth IHWS B-cell lines are compatible with the serologic and IEF definitions. Sixty-six unrelated donors from a northern Chinese population were also tested, with 16 HLA-A alleles detected. Four subtypes of HLA-A2 were found in this population. The distribution of HLA-A subtypes in the population indicated that 40% of donor-recipient pairs thought to be matched for HLA-A by serology would be mismatched. Two novel HLA-A alleles were identified by unusual oligonucleotide hybridization patterns.     

Two-step high resolution sequence-based HLA-DRB typing of exon 2 DNA with taxonomy-based sequence analysis allele assignment.

A two-step high resolution sequence-based DRB typing method was developed. The system needs only one polymerase chain reaction (PCR) to type all functional DRB alleles of a given individual. It uses a pair of generic PCR primers to amplify exon 2 DNA of all functional DRB genes and a first-step taxonomy-based sequence analysis (FSTBSA) method to assign allele groups after sequencing the PCR products with a generic primer. In the second step, group-specific primers are used to sequence the same PCR products and a taxonomy-based sequence analysis (TBSA) is used to assign alleles. Thus, both low and high resolution DRB typing can be done with PCR amplified exon 2 DNA from a single PCR reaction. Correct allele group assignment by FSTBSA was confirmed by sequencing the PCR products with group-specific primers and correctly assigned all 158 DNA samples including 34 samples pre-typed by PCR-sequence-specific primer or PCR-sequence-specific oligonucleotide probe. FSTBSA correctly assigned 116 heterozygous combinations of 81 DRB1-DRB3/4/5 haplotypes. Sixty-seven DRB1, 6 DRB3, 1 DRB4, and 3 DRB5 alleles were identified in this study. TBSA successfully resolved all heterozygous allele combinations including 31 heterozygous combinations of 33 alleles of DRB1*03, 08, 11, 12, 13, and 14 allele groups, and six heterozygous combinations of six DRB3 alleles.     

A simplified PCR-SSP method for HLA-A2 subtype in a population of Wuhan, China

HLA-A2 is the most frequent HLA-A allele in all ethnic populations, and an important restriction element for peptide presentation to T cells in infectious disease and cancer. However, the HLA-A2 supertype consisting of up to 75 subtypes, mutation studies and analyses using cytotoxic T lymphocytes suggest the functional relevance of subtype-specific differences in HLA-A2 molecules for peptide binding and T-cell recognition. Therefore, it is necessary for T-cell response study to discriminate the HLA-A2 subtypes and to understand the profile of HLA-A2 allellc distribution in a given population. In this study, we developed a simple, robust approach based on the nested polymerase chain reaction using sequence-specific primers （PCR-SSP） to discriminate 17 HLA-A2 subtypes which cover the most HLA-A2 alleles （〉 99% allele frequency） reported in Chinese, using 15 combinations of 19 allelic specific primers. In the first round of PCR, 3 combinations of 5 primers were used to determine whether the tested sample was HLA-A2 positive, meanwhile the subtypes of HLA-A＊0209 and HLA-A＊0215N were determined for the variant position of these two subtypes is in exon 4 instead of exon 2, 3. Samples of HLA-A2 positive were subtyped in the second round of PCR, using PCR products of the first round as templates. This strategy was applied to test the samples of 78 random HLA-A2 positive individuals for their HLA-A2 subtypes. Those samples were screened for HLA-A2 positive by the first round PCR-SSP from 154 healthy blood donors in Wuhan, China. The subtyping results were verified by using flow cytometric analysis （FCM） with HLA-A2 specific monoclonal antibody BB7.2 and DNA sequencing. The typing results of the samples show 50.7% random individuals in the population carry HLA-A2, HLA-A＊0201 ranks the first （allele frequency = 15.5%）, followed by A＊0207 （5.8%）, A＊0206 （4.7%）, A＊0203 （2.6%）, A＊0210 （0.7%）, and these 5 alleles account for 99.0% HLA-A2 subtypes of allele frequency. Our study indicates that the developed typing method is simple and reliable for HLA-A2 subtyping in Chinese, and the profile of allelic distribution of HLA-A2 subtypes is revealed in the population of Wuhan, China.     

Molecular typing of HLA-A, -B, and DRB using a high throughput micro array format

The goal of this study was to develop a DNA micro array procedure for molecular human leukocyte antigen (HLA) typing of a large number of samples. DNA was isolated from peripheral blood samples and polymerase chain reaction (PCR) amplified for HLA-A, -B, and -DRB. Amplified DNA samples were spotted on silane-treated glass slides using a micro array spotter. The spotter was capable of spotting multiple slides with up to 9216 samples per slide or 2304 samples in quadruplicate. The allele specific oligo nucleotide probes for HLA-A, -B, and -DRB were labeled with the fluorescent dye Cy3, while a control probe, to quantitate the total amount of PCR product in a sample, was labeled with Cy5. Each slide was hybridized with a mixture of an allele specific Cy3 probe plus the control Cy5 probe. Following hybridization and wash, the amount of probe hybridizing to each DNA sample on the slide was measured with a micro array scanner. A computer program was used for image analysis, to calculate the average Cy3/Cy5 ratios and to identify the positive and negative samples. In turn, this information was used to determine the HLA phenotype of each sample. There was very good concordance between the results obtained for all three loci using Cy-labeled probes as compared with those previously obtained by chemiluminescent detection of alkaline phosphatase labeled probes. This methodology has the potential of greatly simplifying HLA molecular typing of large number of samples.     

Parallel genotyping of human SNPs using generic high-density oligonucleotide tag arrays

Large scale human genetic studies require technologies for generating millions of genotypes with relative ease but also at a reasonable cost and with high accuracy. We describe a highly parallel method for genotyping single nucleotide polymorphisms (SNPs), using generic high-density oligonucleotide arrays that contain thousands of preselected 20-mer oligonucleotide tags. First, marker-specific primers are used in PCR amplifications of genomic regions containing SNPs. Second, the amplification products are used as templates in single base extension (SBE) reactions using chimeric primers with 3' complementarity to the specific SNP loci and 5' complementarity to specific probes, or tags, synthesized on the array. The SBE primers, terminating one base before the polymorphic site, are extended in the presence of labeled dideoxy NTPs, using a different label for each of the two SNP alleles, and hybridized to the tag array. Third, genotypes are deduced from the fluorescence intensity ratio of the two colors. This approach takes advantage of multiplexed sample preparation, hybridization, and analysis at each stage. We illustrate and test this method by genotyping 44 individuals for 142 human SNPs identified previously in 62 candidate hypertension genes. Because the hybridization results are quantitative, this method can also be used for allele-frequency estimation in pooled DNA samples.     

A Generic Sequencing Based Typing Approach for the Identification of HLA-A Diversity

ABSTRACT: Sequencing Based Typing (SBT) is a generic approach for the identification of HLA-A polymorphism. This approach includes the high resolution typing of the HLA-A broad reacting groups, HLA-A subtypes and will identify new alleles directly. The SBT approach described here uses a locus specific amplification of DNA from exon 1 to exon 5. The resulting 2,022 bp PCR product serves as a template for the subsequent sequencing reactions. Amplification is followed by direct sequencing of exons 2, 3 and 4 in both orientations with fluorescently labeled primers to define all polymorphic positions leading to a high resolution typing result. In this study the sequence of exons 2 and 3 of a panel of 49 cell lines was determined. In addition, the exon 4 region of 35 cell lines was also sequenced to evaluate the exon 4 polymorphism. The HLA-A type of most of the cells could be identified by sequencing only exons 2 and 3. However, the sequence of exon 4 was required to discriminate A*0201 from A*0209 and A*0207 from A*0215N. In this panel, an identical new “HLA-A*0103” was identified in two Caucasian samples.     

Complete subtyping of the HLA-A locus by sequence-specific amplification followed by direct sequencing or single-strand conformation polymorphism analysis

Abstract: A variety of reasons related to the HLA class I system has complicated the application of molecular approaches to HLA class I typing. Here we present a PCR-based HLA-A typing strategy considering the sequence variations of the two most polymorphic exons which allows complete subtyping of the HLA-A locus. The method is based on a sequence-specific amplification identifying the serologically defined HLA-A specificities. The PCR products generated by these group-specific primers bear the sequence information necessary for a postamplification specificity step. The primer pairs are located within one exon, either exon 2 or exon 3, which avoids amplification of polymorphic intron sequences allowing subsequent single-strand conformation polymorphism analysis and facilitating direct sequencing. Using this method we investigated 48 cell lines and 153 clinical samples. 23 PCR reactions are performed per individual for the assignment of the serological specificities A1-A80. The reproducibility was 100% in all cell lines and 85 clinical samples typed on two separate occasions. With the exception of 13 out of 231 possible serological combinations all homozygous and heterozygous combinations of A1-A80 can be distinguished by specific amplification patterns. Comparing the PCR based typing results with those of serology in 12% a discrepancy was found. Solid-phase sequencing or SSCP analysis of the group-specific PCR fragments allowed complete subtyping of the HLA-A locus. This strategy can identify all 48 HLA-A alleles based on the sequence variations of the 2nd and 3rd exon. 1128 homozygous and heterozygous allele combinations are possible for the HLA-A locus. Only 4 out of these 1128 allele combinations remained unresolved.