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1.
目的构建人源抗EV71病毒Fab噬菌体抗体库,筛选具有中和活性的人源单克隆抗体,为EV71感染引起的手足口病临床诊断及治疗奠定基础。方法从成人志愿者抗凝血中分离外周淋巴细胞,提取总RNA并逆转录为cDNA。以cDNA为模板,用人源IgG Fab段基因引物扩增轻链及重链Fd区基因,分步克隆至pComb3载体,构建Fab噬菌体抗体库。以SP70为抗原对Fab噬菌体抗体库进行富集筛选,将获得的重组噬菌体感染XL1-Blue菌并诱导表达,用SP70对诱导表达的菌上清进行筛选。结果共获得3株轻、重链基因组合序列不同的克隆,且这3株Fab抗体可特异性结合SP70多肽。结论成功构建人源抗EV71病毒Fab噬菌体抗体库,并从中筛选出3株针对EV71病毒结构蛋白VP1上中和线性表位SP70的特异性人源Fab抗体,为研发新的手足口病诊断和治疗工具奠定基础。  相似文献   

2.
抗华支睾吸虫噬菌体抗体库的构建   总被引:8,自引:1,他引:7  
目的 构建抗华支睾吸虫噬菌体抗体库 ,以期筛选出抗循环抗原的抗体组合。方法 应用噬菌体表面呈现技术 ,从感染华支睾吸虫病人淋巴细胞中提取总 RNA,逆转录成 c DNA后 ,用相应引物 PCR扩增出重链 Fd和轻链基因 ,经 Xho 和 Spel、Sac 和 Xba 双酶切 ,先后克隆入噬粒载体 p Comb3,再电转化大肠杆菌 XL1- blue菌株 ,辅助噬菌体 VCSM13超感染。结果 从感染华支睾吸虫病人淋巴细胞中扩增出约 70 0 bp重链 γ1 、γ3Fd段和轻链 κ、λ基因 ,分别和 p Com b3连接后成功导入 XL 1- blue,得到滴度为 7.5× 10 1 0 cfu/ ml,库容量为 5 .6× 10 6 噬菌体抗体库。结论 抗华支睾吸虫 Fab段噬菌体抗体库的构建 ,为进一步筛选抗华支睾吸虫循环抗原单克隆抗体奠定了基础。  相似文献   

3.
目的 构建人源性抗大肠癌噬菌体Fab抗体库.方法 术中剥取老年大肠癌患者系膜内转移淋巴结,提取细胞总RNA,逆转录合成cDNA,进行PCR,克隆于pComb3 载体,再经电转化大肠杆菌XLI-Blue菌株,形成噬菌体抗体库,最后通过免疫印记法鉴定初级抗体库中噬菌体上有Fab段的表达.结果 从系膜内转移淋巴结中扩增出650 bp重链Fd和轻链基因产物,轻链基因产物插入测得转化菌数为4.7×10~6,鉴定插入率为70%;重链Fd基因产物测得转化菌数为3.5×10~6,插入率为60%;免疫印迹法鉴定成功建立噬菌体Fab抗体库,库容量达1.4×10~6.结论 筛选大肠癌特异性抗原和相应噬菌体抗体,对大肠癌发病机制的研究以及探讨早期诊断方法有重要意义.  相似文献   

4.
目的利用噬菌体抗体展示技术构建人源性抗日本血吸虫Fab段噬菌体抗体库并进行初步鉴定。方法RT-PCR从对血吸虫感染有一定抗性成年人外周血淋巴细胞中扩增出入IgG轻链和重链Fd段基因片段,将其克隆入PComb3中.构建人源性Fab段噬菌体抗体库。并用限制性内切酶酶切、序列分析、DOT-BLOT以及SDS-PAGE等方法对噬菌体抗体库进行初步鉴定。结果噬菌体抗体库的滴度为6.2×10^11/L。库容量为1.2×10^7。酶切鉴定结果显示噬菌体抗体库轻重链重组率达到66.6%,测序结果表明克隆入PComb3的是人免疫球蛋白轻链和重链基因,DOT-BLOT实验证明该抗体库表达了人源性的抗体,而SDS-PAGE证实了免疫球蛋白Fab段的可溶性表达。结论成功地构建了人源性抗日本血吸虫Fab段噬菌体抗体库,为筛选人源性抗日本血吸虫的抗体、研究这些抗体的特性和功能奠定了基础。  相似文献   

5.
甲型肝炎     
从噬菌体抗体库筛选获得中和性人源抗甲型肝炎病毒Fab抗体——曹经瑷等(北京中国预防医学科学院病毒学研究所肝炎研究室100052);《中华实验和临床病毒学杂志》。2000,14(4):313-316[目的:研制人源抗甲型肝炎病毒基因工程抗体,为预防甲型肝炎病毒感染提供有效的方法。方法:采用噬菌体表面展示技术,从一名甲型肝炎恢复期病人的抗凝血中分离淋巴细胞,提取总RNA逆转录后,用一组人IgG Fab特异性引物扩增。结果:克隆和表达了8株人源抗甲型肝炎病毒抗体Fab段基因,经ELISA检测为特异性人抗甲型肝炎病毒Fab段抗体。  相似文献   

6.
目的:获得人源性抗HBsAg抗体Fab片段。方法:用预包被HBsAg的ELISA板,从构建的人全套抗体库中筛选出针对HBsAg的噬菌体抗体。并转入大肠杆菌中表达。破裂细胞后,获得可溶性Fab片段。以羊抗人Fab抗体偶联HiTrap柱,用  相似文献   

7.
目的 通过大肠癌组织及体外培养的大肠癌细胞抗原对人源性大肠癌Fab段噬菌体抗体原始库的反复筛选 ,鉴定抗体库的特性并检测其与人大肠癌相关抗原的结合活性。方法 PCR鉴定阳性重组菌xL1 B1ue中人大肠癌相关抗体Fab段的插入率 ,构建人大肠癌Fab段原始库 ,提取 3例用于构建原始抗体库的致敏大肠癌组织抗原 ,13例非致敏大肠癌组织抗原及 3种体外培养的大肠癌细胞株Lovo、HT 2 9、LS 174T的抗原各自等体积混合 ,利用 3组混合抗原分别对原始抗体库进行 3轮筛选 ,将筛选后的三个三级库等体积混和后通过ELISA法鉴定其与人大肠癌组织及体外培养的大肠癌细胞的结合活性 ,取胃癌、食管癌及正常肠粘膜组织和体外培养的胃癌、肝癌细胞进行对照研究。结果 N片段及κ链的插入率分别为 40 %和 70 % ,Fd片段及κ链均插入质粒Pcomb3的重组率为 2 8% ,Fab段基因库库容为 2 .1× 10 6,3组大肠癌混合抗原分别对原始抗体库进行 3轮筛选后 ,抗体库均得到了不同程度的富集 ,ELISA显示富集后的Fab段抗体库对大肠癌组织及体外培养的大肠癌细胞均有较特异性的结合活性。结论 利用噬菌体抗体库技术筛选出了相关抗大肠癌Fab段抗体 ,且筛选后的抗体片段与人大肠癌相关抗原有较特异性的结合活性  相似文献   

8.
目的制备人源性抗肿瘤坏死因子(TNF)-α蛋白的可溶性Fab抗体。方法用固相化的TNF-α蛋白从人天然Fab噬菌体抗体库中筛选出表达抗TNF-α蛋白Fab抗体的阳性克隆,经酶切及连接反应构建可溶性表达噬菌粒并转化至大肠杆菌BL21(DE3)pLysS中,IPTG高效可溶性表达,SDS-PAGE及Western blot分析鉴定抗体表达情况,ELISA鉴定其抗原结合活性和特异性。结果筛选并表达了人源性抗TNF-α蛋白的Fab抗体,在非还原SDS-PAGE中形成相对分子质量47 kD的条带;Western blot分析证实表达的蛋白即Fab抗体;ELISA筛选出的2株抗体(TA-04、TA-13)具有良好的抗原特异性和抗原结合活性,与小牛血清白蛋白无交叉反应。结论成功制备并鉴定了人源性抗TNF-α蛋白的可溶性Fab抗体。  相似文献   

9.
人源性大肠癌自然致敏噬菌体抗体Fab呈现库的构建与筛选   总被引:1,自引:0,他引:1  
目的构建大肠癌病人自然致敏淋巴结抗体 Fab 段噬菌体呈现库,初步筛选相关抗大肠癌抗体。方法取大肠癌病人转移淋巴结,提取淋巴结总 RNA,逆转录 PCR 扩增重链 Fd 和 k 轻链 cDNA。依次将 PCR 产物插入载体 pComb3的相应部位,构建人源性大肠癌噬菌体 Fab 基因库,并应用噬菌体表面呈现技术对该抗体库进行淘选及鉴定。结果所选2种 Ig 亚类的重链 Fd 片段、2种 k 轻链 cDNA 得到扩增。Fd 片段和 k 轻链均插入 pComb3的重组率为40%,Fab 噬菌体表达库容达1.48×10~6。经3轮淘选,抗体库得到约120倍的富集。3轮抗体库的点印记免疫染色均显示有 Fab 表达:酶联免疫吸附实验显示其与大肠癌抗原有结合活性。结论成功构建了大肠癌病人自然致敏淋巴结抗体 Fab 段噬菌体呈现库,利用噬菌体抗体库技术,可筛选相关抗大肠癌抗体。  相似文献   

10.
大肠癌噬菌体抗体库的构建及初步鉴定   总被引:2,自引:0,他引:2  
目的 构建及初步鉴定大肠癌噬菌体抗体Fab呈现库.方法 分离大肠癌患者外周血淋巴细胞,提取淋巴细胞总RNA,逆转录成cDNA.用相应引物进行PCR,扩增出轻链和重链Fd段基因,经酶切后分别和噬粒载体pComb3连接,再经电穿孔转化大肠杆菌XLl-Blue菌株.将轻链和重链Fd基因先后克隆人pComb3中.结果 从分离出的淋巴细胞中提取到高质量RNA,RT-PCR分别扩增出约680 bp大小的κ、λ和Fd基因.PCR 产物和载体经纯化、双酶切后进行连接转化,成功地构建了人源性Fab抗体基因库,库容量达2.1×107,轻链K、κ、λ和重链Fd基因均插入pComb3的重组率为50%.结论 构建了大肠癌患者自然致敏抗体Fab段噬菌体呈现库,为筛选大肠癌相关抗体打下基础.  相似文献   

11.
目的为避免因输血传播疾病引起医疗纠纷和防止职业感染。方法采用酶联免疫吸附试验对2010-01~2011-03 11 606例就医患者进行输血前人类免疫缺陷病毒(HIV)抗体、丙型肝炎病毒(HCV)抗体、梅毒螺旋体(TP)抗体三项指标筛查。结果共检出阳性例数856例。结论患者输血前进行三项感染性指标检测,对诊断和预防医患交叉感染、减少医疗纠纷的发生具有重要意义。  相似文献   

12.
Pooled serum aliquots obtained from sensitized potential renal allograft recipients on chronic hemodialysis were evaluated for their lymphocytotoxicity titers against the lymphocytes and then for alloantibodies against the platelets of 7 random donors by 5 methods. Platelet donor specific lymphocytotoxicity was present in 93% of 42 combinations. Of the positive combinations, 57% had a positive test for antiplatelet activity by the 14C serotonin release assay, 16% by the platelet aggregation method, and 19% as judged by acid phosphatase availability on the platelet membrane. No serum tested released beta-glucoronidase or lactic dehydrogenase. No correlation of the height of the titer of antiplatelet activity with that for lymphocytoxicity was detected. Thus, even in sera demonstrating significant activity against donor lymphocyte antigens, detection of associated platelet antibody activity is not uniform. Thus, a positive lymphocytoxic titer does not necessarily predict detectable antiplatelet activity. Therefore, additional tests for detection of antiplatelet activity should also be considered. This study shows that of the tests evaluated, the 14C serotonin release assay is the most sensitive for detection of antiplatelet antibodies.  相似文献   

13.
Human cytomegalovirus (HCMV) can cause serious morbidity/mortality in transplant patients, and congenital HCMV infection can lead to birth defects. Developing an effective HCMV vaccine is a high medical priority. One of the challenges to the efforts has been our limited understanding of the viral antigens important for protective antibodies. Receptor-mediated viral entry to endothelial/epithelial cells requires a glycoprotein H (gH) complex comprising five viral proteins (gH, gL, UL128, UL130, and UL131). This gH complex is notably missing from HCMV laboratory strains as well as HCMV vaccines previously evaluated in the clinic. To support a unique vaccine concept based on the pentameric gH complex, we established a panel of 45 monoclonal antibodies (mAbs) from a rabbit immunized with an experimental vaccine virus in which the expression of the pentameric gH complex was restored. Over one-half (25 of 45) of the mAbs have neutralizing activity. Interestingly, affinity for an antibody to bind virions was not correlated with its ability to neutralize the virus. Genetic analysis of the 45 mAbs based on their heavy- and light-chain sequences identified at least 26 B-cell linage groups characterized by distinct binding or neutralizing properties. Moreover, neutralizing antibodies possessed longer complementarity-determining region 3 for both heavy and light chains than those with no neutralizing activity. Importantly, potent neutralizing mAbs reacted to the pentameric gH complex but not to gB. Thus, the pentameric gH complex is the primary target for antiviral antibodies by vaccination.Human cytomegalovirus (HCMV) is an important pathogen in transplant patients (15), and its infection can lead to invasive end-organ diseases, such as pneumonitis and hepatitis, as well as vascular pathology contributing to graft failure (4, 6, 7). HCMV is also the most common cause of in utero viral infections in North America and Europe, affecting 0.5–2% of newborns annually (810). Congenital HCMV infection can lead to symptomatic diseases at birth and also cause developmental disabilities in children (10, 11). Maternal seropositivity before conception protects against congenital transmission (12, 13), and both maternal humoral and cellular immunity are likely to contribute to the protection (1416). Antibodies in particular are important for preventing congenital infection, serving as the first line of defense against maternal infection. It may also play a role in preventing transmission to the fetus, supported by the results of a small, nonrandomized study in pregnant women with primary HCMV infection, in which the passive immunity of monthly infusions of HCMV hyperimmune human IgG (HCMV-HIG) (200 mg/kg maternal weight) was ∼60% effective in protecting against congenital HCMV infection (17, 18). These studies suggest that it is feasible to develop a vaccine for preventing congenital HCMV infection and its sequelae. However, despite the fact that the Institute of Medicine has identified development of an effective vaccine for prevention of congenital HCMV as a top priority since 1999 (19), progress toward this goal has only been incremental (8, 20, 21). One of the hurdles to the efforts is our limited understanding of component of natural immunity associated with protection against HCMV infection.HCMV is a large, complex virus, with a genome capable of encoding >150 proteins (2226). Because of the strict species specificity, options of animal models for HCMV research are limited (27). Thus, the functions of most HCMV antigens in viral infection in vivo and their roles as targets for host immunity are poorly understood. Furthermore, culture systems of single cell types have limitations for studying HCMV pathogenesis. Immunohistochemistry studies showed that HCMV can infect varieties of cells in vivo, including endothelial, epithelial cells, fibroblasts, and leukocytes (2836). Many HCMV end-organ diseases, such as pneumonitis and gastroenteritis, are due to infection of the epithelial/endothelial cells in the affected organ (3539). However, common laboratory strains, such as AD169 and Towne, were culture-adapted in fibroblast cells, with genomic mutations (22, 24, 40) and, more importantly, have lost their tropism to endothelial and epithelial cells, in contrast to pathogenic clinical isolates (32, 33, 41, 42).Loss of viral tropism to endothelial and epithelial cells was mapped to various mutations in the viral UL131-128 locus, and these mutations abrogated the expression of the pentameric glycoprotein H (gH) complex, composed of gH, gL, UL128, UL130, and UL131 proteins, a determinant for viral tropism to endothelial and epithelial cells (4244). Because the pentameric gH complex is missing in common laboratory strains (42, 43), its importance in viral tropism, viral pathogenesis, and vaccine design was not fully appreciated until recently (42, 45). With this understanding, it is not surprising that Towne virus and recombinant glycoprotein B (gB) vaccines, although with ∼50% efficacy against primary infection in the clinic (4649), induced poor neutralizing titers against viral infection of epithelial cells, in contrast to immune sera from HCMV-seropositive donors (50, 51). Thus, missing the pentameric gH complex is likely a deficiency in antigen composition for both vaccines (50). Studies of monoclonal antibodies (mAbs) isolated from HCMV-seropositive donors or polyclonal IgG enriched for antigen specificity supported the hypothesis that the pentameric gH complex, not gB, appears to be important for neutralizing activity in human subjects with natural infection (52).We recently described an experimental vaccine virus in which expression of the pentameric gH complex was restored (53). Unlike the parental AD169 virus and the recombinant gB vaccine, this virus can elicit high levels of neutralizing antibodies in rabbits and rhesus macaques (53). To support clinical development of this vaccine centered its concept on the pentameric gH complex, we established a comprehensive panel of 45 mAbs from a single rabbit that received vaccination. Of the 45 mAbs, 25 had neutralizing activity against viral entry in epithelial cells, including 11 elite neutralizers with ≥10-fold greater potency than HCMV-HIG. Biochemical analysis demonstrated that all elite neutralizers preferentially bound to the virus expressing the pentameric gH complex, and the majority of elite neutralizers (8 of 11) specifically recognized a recombinant form of the pentameric gH complex. Interestingly, binding affinity for intact virions was not correlated with neutralizing activity. Moreover, genetic analysis of the 45 mAbs based on their heavy- and light-chain sequences identified at least 26 B-cell linage groups characterized by distinct binding or neutralizing properties. In addition, neutralizing antibodies had longer complementarity-determining region 3 (CDR3) for both heavy and light chains than those of antibodies with no neutralizing activity. These data establish the importance of the pentameric gH complex as the primary target for potent neutralizing antibodies by vaccination, and support development of an experimental HCMV vaccine featuring the pentameric gH complex.  相似文献   

14.
Antibody discovery platforms have become an important source of both therapeutic biomolecules and research reagents. Massively parallel DNA sequencing can be used to assist antibody selection by comprehensively monitoring libraries during selection, thus greatly expanding the power of these systems. We have therefore constructed a rationally designed, fully defined single-chain variable fragment (scFv) library and analysis platform optimized for analysis with short-read deep sequencing. Sequence-defined oligonucleotide libraries encoding three complementarity-determining regions (L3 from the light chain, H2 and H3 from the heavy chain) were synthesized on a programmable microarray and combinatorially cloned into a single scFv framework for molecular display. Our unique complementarity-determining region sequence design optimizes for protein binding by utilizing a hidden Markov model that was trained on all antibody-antigen cocrystal structures in the Protein Data Bank. The resultant ∼1012-member library was produced in ribosome-display format, and comprehensively analyzed over four rounds of antigen selections by multiplex paired-end Illumina sequencing. The hidden Markov model scFv library generated multiple binders against an emerging cancer antigen and is the basis for a next-generation antibody production platform.  相似文献   

15.
自身免疫性肝炎患者自身抗体的测定及意义   总被引:3,自引:1,他引:2  
目的:探讨自身抗体测定对诊断自身免疫性肝炎的临床意义.方法:采用间接免疫荧光法(IIF)检测47例自身免疫性肝炎患者、158例非自身免疫性肝炎患者及40例健康体检者体内抗核抗体(ANA)、抗平滑肌抗体(SMA)、抗中性粒细胞胞质抗体(ANCA)、抗线粒体抗体(AMA)等自身抗体,ELISA法检测抗MPO抗体,并对结果进行回顾性分析.结果:ANA、SMA及ANCA检出率的比较,结果显示AIH中阳性率最高为SMA(66.0%, 31/47),而非AIH中则为6.3%(10/158),两组差异有非常显著性意义(P<0.01).经X2检验, SMA、AMA和MPO抗体检测在AIH与PBC中,均有非常显著性意义(P<0.01).AIH各型自身抗体检测结果表明,AIH-Ⅰ与ANA、SMA和ANCA相关,AIH-Ⅱ与LKM相关,而AIH=Ⅲ与SLA和ANCA相关.结论:血清自身抗体的检测对诊断、治疗和阻止自身免疫性肝炎的发展有着十分重要作用,对提高AIH在临床上同其他肝病鉴别诊断和治疗有着非常重要的意义.  相似文献   

16.
The endothelial hybridoma (EAhy926) cell line was employed to clarify whether antiphospholipid antibodies (aPA) [lupus anticoagulant (LA), antiprothrombin antibody (aPT) and/or anticardiolipin antibody (aCL)] and anti-endothelial cell antibodies (AECA) are identical, and establish whether β2-glycoprotein I (β2-GPI) is needed for reactivity of aPA to endothelial cells. Ig-G AECA was positive in 9/30 SLE patients with aPA (30.0%) and 10/22 SLE patients negative for aPA (45.5%). Ig-M AECA was positive in one SLE patient with aPA and one SLE patient without aPA. AECA-positivity was not significantly different among unfixed, TNF-stimulated and fixed EAhy926. The influence of β2-GPI on the reactivity of serum to EAhy926 was minimal, and absorption experiments of serum with cardiolipin-liposome/β2-GPI or phosphatidylserine-liposome/prothrombin gave little evidence of cross-reactivity of aPA and AECA. The results of our study suggest that aPA and AECA may have partially cross-reacted, but were different antibodies. However, further study is needed to clarify the clinico-pathological significance of AECA.  相似文献   

17.
The prothrombotic mechanisms associated with antiphospholipid antibodies remain incompletely defined. Antibody binding to endothelial cells in vitro is a feature of antiphospholipid antibody-positive sera. We hypothesised that impairment of endothelium-dependent fibrinolysis by antiphospholipid/anti-endothelial antibodies is a contributory factor in the pathogenesis of thrombosis. We also aimed to confirm the displacement of annexin-V from endothelial cells and enhanced fibrin formation. Binding of immunoglobulin (Ig) from antiphospholipid antibody-positive sera to endothelial cells was examined using a cell-based enzyme-linked immunosorbent assay. Effects on fibrin formation and lysis were examined on cultured endothelial cell monolayers. Plasminogen activator inhibitor-1 (PAI-1) was assayed in supernatants. We confirmed antibody binding to endothelial cells. With four of 14 antiphospholipid antibody-positive sera there was some prolongation of fibrin clot lysis time, consistent with impairment of endothelial fibrinolytic activity. Secretion of PAI-1 was significantly correlated with clot lysis time on endothelial cell monolayers incubated with antiphospholipid/anti-endothelial antibody-positive sera, but not with control sera. IgG from antiphospholipid antibody-positive sera had little effect on endothelial cell surface annexin-V expression. We conclude that impaired endothelial fibrinolysis is a potential prothrombotic mechanism in subjects with antiphospholipid antibodies. We were unable to confirm enhanced displacement of annexin-V from endothelium by antiphospholipid antibodies.  相似文献   

18.
类风湿关节炎血清学早期诊断   总被引:46,自引:13,他引:33  
目的 探索抗核周因子(APF)、抗角蛋白抗体(AKA)、抗Sa抗体及抗RA33/36抗体检测对RA的早期诊断价值。方法 对未肯定诊断的关节痛/关节炎病人116例进行上述四种抗体检测并随访观察。APF和AKA用间接免疫荧光法进行检测。抗Sa抗体和抗RA33/36抗体用免疫印迹法检测。结果 对116例未肯定诊断的关节痛/关节患者随访4 ̄18个月。APF阳性的29例中,最后确诊为RA20(69%);AK  相似文献   

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本研究用单克隆抗独特型抗体NP30与日本血吸虫肠相关抗原(GAA)和可溶性虫卵抗原(SEA)检测了702份不同病期及正常人群中的血清抗体,结果显示,在急性感染时,NP30抗体的检出率为98%,与GAA(94%)和SEA(98%)的无差别。在慢性感染时NP30抗体的检出率为87%,与GAA(86%)的无差别,但低于SEA(98%)的。在正常人群中,上述3种的抗体假阳性率均为3%左右,无差别。NP30的抗体滴度几何均数在急性血吸虫感染时高于GAA的,低于SEA的,在慢性感染时低于后两者,提示NP30的抗体在血吸虫感染期间出现比较早,消退较快。上述结果提示,NP30可以替代虫源性抗原,用于日本血吸虫病诊断。  相似文献   

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