抗t-PA抗体水平和血栓的相关性研究

目的:研究自身免疫性疾病病人抗t-PA抗体水平和病人血栓形成之间的关系。方法:用酶联免疫吸附法(ELISA)检测原发性抗磷脂综合症和红斑狼疮患者(32例狼疮样抗凝物阳性,32例狼疮样抗凝物阴性)与40例健康对照的IgG类抗t-pA抗体的水平,用Pearson Chi-Square test的方法分析了病人体内IgG类抗t-PA抗体水平和血栓之间的相关性。结果:本试验研究的病人群体中IgG类抗t-PA抗体阳性的有13(20.3%)个,并且我们的研究表明IgG类抗t-PA抗体阳性和血栓病史显著相关(P=0.04)。结论:原发性抗磷脂综合症和红斑狼疮病人群体中有较高的IgG类抗t-PA抗体水平,它们可能和病人体内血栓的发生有关。     

兔抗金黄地鼠酶标抗体的制备及应用

目的 纯化金黄地鼠血清IgG,制备兔抗金黄地鼠酶标抗体(IgG-HRP),开展金黄地鼠仙台病毒的初步检测.方法 采用亲和层析纯化法纯化金黄地鼠IgG,用SDS- PAGE电泳测定IgG纯度并制备兔抗金黄地鼠IgG抗体(second antibody,Ab2);用免疫双扩散法检测抗血清效价后,再用亲和层析纯化抗血清IgG( Ab2);采用改良过碘酸钠标记法制备兔抗金黄地鼠酶标抗体( rabbit anti-hamster IgG-HRP);用直接ELISA和Western-blot法对兔抗金黄地鼠IgG酶标抗体进行工作浓度测定;应用金黄地鼠酶标抗体对金黄地鼠仙台病毒进行酶免检测(IEA).结果 金黄地鼠血清IgG纯度达95％;兔抗金黄地鼠IgG抗体(Ab2)免疫双扩散效价为1(:)64;兔抗金黄地鼠IgG -HRP经直接ELISA和Western-Blot测定工作浓度分别为1∶5000和1∶2000;酶免(IEA)效价为1:2000.结论 高效快速纯化了金黄地鼠IgG,制备了金黄地鼠IgG-HRP,为金黄地鼠病原微生物的血清学检测提供了条件.     

双峰驼血清IgG亚型的分离纯化及多克隆抗体的制备

双峰驼IgG亚型包含IgG1、IgG2和IgG3,其中IgG2和IgG3为重链抗体,在结构上与IgG1存在显著差异。为获取双峰驼血清中的IgG1、IgG2和IgG3,并分析其抗原特异性和抗体特异性,本文交替使用Protein A和Protein G亲和层析柱,对其分离纯化,并通过聚丙烯酰胺凝胶电泳进行鉴定;之后分别制备兔抗双峰驼IgG1、IgG2和IgG3的多克隆抗体,通过ELISA对制备的多克隆抗体的效价进行测定;最后应用Western blot评估这三个亚型多克隆抗体的特异性,进而对双峰驼血清中IgG1、IgG2和IgG3的抗原特异性进行分析。结果表明,应用Protein A和Protein G亲和层析柱成功分离纯化出双峰驼血清中的IgG1、IgG2和IgG3;并制备兔抗双峰驼IgG1、IgG2和IgG3的多克隆抗体效价均在1∶10000以上,并且所获得的多克隆抗体分别与IgG1、IgG2和IgG3之间均存在交叉反应,但兔抗双峰驼IgG1多克隆抗体较其它两个亚型多克隆抗体特异性低。结果证明,双峰驼IgG1、IgG2和IgG3均具有良好的免疫原性,三者结构虽存在显著差异,但其抗原特性类似。     

抗猪鼻支原体单克隆抗体的研制及双抗体夹心ELISA检测法的建立

目的 制备多种抗猪鼻支原体的单克隆抗体,建立双抗体夹心ELISA方法用于该病原体的检测。方法用猪鼻支原体CVCC361免疫BALB／c小鼠,采用杂交瘤技术和酶联免疫吸附实验筛选出抗该病原体的单克隆抗体;运用免疫双向扩散试验、Western blotting确定I异G亚类及针对抗原的相对分子质量;筛选出配对抗体,建立双抗体夹心ELISA的检测方法,并评价其灵敏度和特异性。结果共筛选出17株单克隆抗体,抗体亚类分别为IgG1、IgG2a、IgG2b、IgG3,免疫印迹结果表明单抗ZB1、ZB2及ZB16与相对分子质量为35×103的抗原有特异性结合,而ZB3和ZBIO与相对分子质量为70×10^3的抗原有特异性结合。确定了2个配对抗体（ZB1-ZB1-HRP和ZB1-ZB2-HRP）,可检出最小抗原量为30ns／mL,检出猪鼻支原体活菌8．34×10^2CFU／mL,与人呼吸道常见的致病菌及支原体均无非特异性反应。结论筛选的单克隆抗体具有较高的特异性和敏感性,应用双抗体夹心ELISA方法可用于猪鼻支原体的检测。     

SLE血清中抗-DNA抗体分离和性质的研究

本文用国产高分子树脂(T)接枝小牛胸腺DNA,通过亲合层析从系统性红斑狼疮SLE患者血清中纯化出抗-ds DNA抗体和抗-ss DNA抗体。酶联免疫吸附分析(ELISA)的研究表明:SLE抗-DNA抗体和DNA结合的差异性很大,是高度非均一性的。抗-ss DNA抗体不仅组成成分比抗-ds DNA抗体复杂,ss DNA/抗-ssDNA亲合能力也明显高于ds DNA/抗-ds DNA。纯化的抗-DNA抗体以IgG类抗体占主导,同时也有其它类型抗体存在(例如IgM等)。抗-ds DNA抗体有较抗-ss DNA抗体高的IgG含量(两者的IgG/IgM分别是7.0和4.0),说明IgG抗-DNA抗体更倾向于同dsDNA结合。     

抗GPNMB单克隆抗体的制备及双抗体夹心ELISA方法的建立

目的:制备抗GPNMB单克隆抗体,建立双抗体夹心ELISA检测GPNMB在胶质母细胞瘤中的表达情况.方法:以新鲜胶质母细胞瘤组织为材料,提取总RNA,通过RT-PCR扩增得到GPNMB cDNA序列,经NcoⅠ和XhoⅠ双酶切后,克隆入PET-28a(+)进行原核表达,经蛋白纯化得GPNMB-6× His融合蛋白;以该融合蛋白免疫BALB/c小鼠,淋巴细胞杂交瘤法制备单克隆抗体;采用Western-blot、双抗体夹心ELISA以制备所得的抗GPNMB抗体检测胶质母细胞瘤细胞系U251、U373、SHG44和星形胶质细胞系SVG12中GPNMB的表达.结果:成功构建了GPNMB原核表达载体,获得了GPNMB-6×His重组蛋白;制备得到了G203、F105和M306共3株抗GPNMB的单克隆抗体,腹水ELISA效价分别为1∶8000、1∶8000、1∶5000,抗体亚类分别为IgG2、IgG1和IgG1,进一步实验证实单克隆抗体G203和M306可用于双抗体夹心ELISA检测不同胶质细胞瘤细胞系中GPNMB的表达.结论:成功制备出抗GPNMB单克隆抗体,效价及特异性良好,并证实GPNMB在胶质母细胞瘤细胞系中高表达,为进一步研究GPNMB在胶质母细胞瘤中的作用奠定了基础.     

抗Dysbindin-1多肽双抗夹心ELISA的建立及在肝癌中的应用

目的:制备抗人Dysbindin-1特异性单克隆抗体,建立DAS-ELISA检测体系,并初步应用于肝癌血清的检测。方法:采用合成免疫原免疫BALB/c小鼠,通过杂交瘤技术制备抗Dysbindin-1单克隆抗体,用HRP标记单克隆抗体,ELISA和SDS-PAGE电泳法检测抗体的亚类、滴度;采用DAS-ELISA技术制备Dysbindin-1检测试剂盒,检测正常、肝硬化及肝癌患者各30例血清并比较其差异。结果:细胞融合后获得了4株稳定产生抗Dysbindin-1单克隆抗体的杂交瘤细胞株(1C6A11、1E8H3、2D1C11、5B6D4),抗体亚类分别为IgG2b,IgG2b,IgG1和IgG2a,杂交瘤细胞诱生的腹水抗体效价达106以上,通过抗体配对实验筛选确定2D1C11作为包被抗体,1E8H3作为酶标抗体。该ELISA方法线性范围为62.5-1000ng/mL,检测限为62.5ng/mL;应用该方法检测显示正常组与肝硬化组及肝癌组间差异显著(P0.001),Dysbindin-1诊断肝癌的敏感性和特异性分别为90%和93.3%。结论:Dysbindin-1可以成为新的候选的肝癌血清标志物,抗Dysbindin-1多肽双抗夹心ELISA体系可以初步应用于肝癌的早期诊断。     

抗t-PA单克隆抗体的制备及初步应用

用猪心t-PA和人黑色素瘤细胞分泌的t-PA作抗原,经腹腔及脾内免疫Bal b/c小鼠。用细胞融合技术制备杂交瘤细胞,细胞融合串达85％,获得4株抗t-PA杂交瘤细胞株,鼠腹水抗体效价达1∶10~5;Western Blot结果表明该单抗所结合的抗原分子量与t-PA相符,证明所获得的单抗为特异的抗t-PA单抗;对t-PA的纤溶活性中和抑制试验结果表明,4株单抗中的1株能完全抑制st-PA的纤溶活性,另外3株表现出程度不等的抑制;其中1株亚类为IgG,另外3株为IgM。杂交瘤细胞株无支原体污染;染色体数目正常。对该抗体进行初步纯化后,将其应用于rt-PA的研究中。     

抗CPV-2a单克隆抗体的制备及双抗体夹心ELISA检测方法的建立

犬细小病毒病是危害养犬业的重要传染病之一,患病犬难以治愈.单克隆抗体治疗此病效果明显,本文介绍了制备抗CPV-2a单克隆抗体的方法.用纯化的犬细小病毒(canine parvovirus,CPV) 2a型分离株免疫新西兰大白兔和Balb/c小鼠制备抗CPV-2a多克隆抗体及单克隆抗体.经亚克隆得到1H9、2B5、2B7和2C7共4株单抗,Western blotting鉴定单抗的免疫反应性;间接ELISA方法检测单抗的特异性.为了快速对犬细小病毒病作出诊断,建立了CPV-2a双抗夹心ELISA方法.兔多抗作为捕获抗体,鼠单抗作为示踪抗体,辣根过氧化物酶标记羊抗鼠IgG作为检测系统;捕获抗体和示踪抗体最佳稀释度分别为1:800和1:2 000;检测系统最佳稀释度为1:4 000.结果表明:所得4株单抗与pET-32a-VP2蛋白发生特异性反应,且与狂犬病毒(RV)、犬温热病毒(CDV)不交叉反应;建立的双抗夹心ELISA方法对病毒的最低检出量为4.375 μg/mL,与美国RB试剂盒相比,符合率为95%.单抗制备为犬细小病毒病的治疗奠定了基础;双抗夹心ELISA方法的建立为疑似粪便样本提供了简单、快速和可靠的检测手段.     

天然属性抗LDL 及oxLDL IgM 亚类抗体的制备与鉴定

目的:制备天然属性抗低密度脂蛋白(LDL)及抗氧化低密度脂蛋白(oxLDL)IgM亚类抗体。方法:给予Babl/c小鼠高胆固醇饮食,4周后取脾细胞直接与SP2/0细胞融合,以纯化的LDL及oxLDL为抗原,对阳性杂交瘤细胞生长孔进行间接ELISA筛选。鉴定杂交瘤上清的免疫球蛋白亚类,进而采用免疫沉淀和免疫印迹法对获得的抗体进行免疫学反应性鉴定。结果:杂交瘤细胞分泌的抗LDL及抗oxLDL的天然抗体通过ELISA法被筛选出来,可以与LDL或oxLDL发生高亲和力结合,经过4次克隆化,最终获得2株稳定分泌天然抗LDL的抗体,命名为5G8和2H7,及1株稳定抗oxLDL的抗体,命名为3A6,3株抗体均属于IgM亚类,无交叉反应,可以满足免疫印迹、免疫沉淀等实验要求。结论:成功制备了抗LDL及抗oxLDL IgM亚类抗体,为研究天然抗体在体内脂质代谢和相关心脑血管疾病如动脉粥样硬化等发生发展中的作用提供了重要的研究工具。     

应用斑点金免疫渗滤试验快速同步检测抗HIV-1，HIV-2 IgG抗体

应用斑点金免疫渗滤试验(dotimmunogoldfiltrationassay,DIGFA)建立了一种同步快速检测四种抗HIV-1/2IgG抗体的HIV诊断试纸。通过基因工程技术在大肠杆菌中表达了5种HIV抗原蛋白片段(P24,GP41,GP36,GP120V3,GP120C)。这5种抗原蛋白首先被固定在硝酸纤维素膜上,然后滴加待测血清,其中的病毒抗体通过免疫反应与抗原结合,再加胶体金标记的葡萄球菌蛋白A(SPA),待其渗过膜片后,洗涤,即可形成肉眼可见的红色斑点。用已确证的21份HIV阳性血清(其中包括1份HIV-1标准阳性血清和1份HIV-2标准阳性血清)和30份阴性血清进行了试验,结果表明该快速检测方法与ELISA方法无显著差异。该检测方法不需任何仪器,仅凭肉眼即可判定结果,整个检测过程不超过5分钟。与传统的的ELISA法相比,具有方便快速,成本低廉,应用范围广等优点。同时,此HIV快速诊断试纸可以同步检测并区分针对HIV-1和HIV-2感染的不同检测标志物(抗P24、GP41、GP120和GP36抗体),这对提高快速检测的灵敏度和准确性,以及对判断HIV感染者是否临近或已进入AIDS期有着较高的应用价值。     

Increased Levels of IgG Antibodies against Human HSP60 in Patients with Spondyloarthritis

Spondyloarthritis (SpA) comprises a heterogeneous group of inflammatory diseases, with strong association to human leukocyte antigen (HLA)-B27. A triggering bacterial infection has been considered as the cause of SpA, and bacterial heat shock protein (HSP) seems to be a strong T cell antigen. Since bacterial and human HSP60, also named HSPD1, are highly homologous, cross-reactivity has been suggested in disease initiation. In this study, levels of antibodies against bacterial and human HSP60 were analysed in SpA patients and healthy controls, and the association between such antibodies and disease severity in relation to HLA-B27 was evaluated.Serum samples from 82 patients and 50 controls were analysed by enzyme-linked immunosorbent assay (ELISA) for immunoglobulin (Ig)G1, IgG2, IgG3 and IgG4 antibodies against human HSP60 and HSP60 from Chlamydia trachomatis, Salmonella enteritidis and Campylobacter jejuni. Disease severity was assessed by the clinical scorings Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI) and Bath Ankylosing Spondylitis Metrology Index (BASMI).Levels of IgG1 and IgG3 antibodies against human HSP60, but not antibodies against bacterial HSP60, were elevated in the SpA group compared with the control group. Association between IgG3 antibodies against human HSP60 and BASMI was shown in HLA-B27⁺ patients. Only weak correlation between antibodies against bacterial and human HSP60 was seen, and there was no indication of cross-reaction.These results suggest that antibodies against human HSP60 is associated with SpA, however, the theory that antibodies against human HSP60 is a specific part of the aetiology, through cross-reaction to bacterial HSP60, cannot be supported by results from this study. We suggest that the association between elevated levels of antibodies against human HSP60 and disease may reflect a general activation of the immune system and an increased expression of human HSP60 in the synovium of patients with SpA.     

Staphylococcal opsonization and anti-Staphylococcus aureus IgG subclass antibodies in patients with severe or recurrent S. aureus infections

Abstract Opsonization of Staphylococcus aureus (Oxford strain) and specific IgG subclass antibodies against formalised staphylococci were meausred in plamas from 27 patients with significant S. aureus infections and 35 healty adults and 15 children. There were no statistically significant differences in the IgG2 and IgG4 levels between two groups and IgG3 was not detected, but the median plasma IgG1 level was significantly higher in patients with staphylococcal infections ( P < 0.00003). The concentration of IgG2 anti- S. aureus antibodies was 25–47 times greater than that of IgG1. If plasmas were decomplemented, the raised IgG1 levels were associated with increased opsonophagocytosis by normal neutrophils ( P < 0.0002).     

Production and characteristics of human tissue plasminogen-activator antibodies with region-oriented synthetic peptides.

We selected six peptide sequences as belonging to potential epitopes of tissue plasminogen activator (tPA) using, as the main criterion for their choice, the location of the peptide sequences on the surface of the protein molecule. The six peptides (corresponding to amino acids 4-8, 11-16, 96-101, 272-277, 371-376 and 514-519) were synthesized, coupled to carrier proteins and injected into rabbits. All of these peptides elicited antibodies and 15-75% binding of the corresponding iodinated peptide was obtained with a 1:100 dilution of antiserum. Only two anti-(peptide) sera [anti-(tPA96-101) and anti-(tPA272-277)] reacted with intact tPA and its heavy chain in Western immunoblotting analysis. These two peptides sequences and fragment tPA11-16 appear to be involved in the structure of native antigenic epitopes of tPA, since they were recognized and antibodies present in antisera raised against native tPA. There was no interaction between anti-(tPA4-8) and anti-(tPA371-376) sera with intact one-chain or two-chain tPA. In the case of anti-(tPA4-8) cleavage of one-chain tPA to two-chain tPA and reduction of disulfide bonds exposed this epitope.     

Differentiation-dependent localisation of tissue-type plasminogen activator in human bladder urothelium

Human bladder urothelium is able to secrete tissue-type plasminogen activator (tPA). The aim of our study was to analyse localisation of tPA antigen in comparison to differentiation state of cells in samples of histologically normal urothelium and non-invasive tumours of the human urinary bladder. Twenty-five samples of normal urothelium and 31 non-invasive papillary tumours from 36 patients were examined. The presence of tPA antigen was evaluated immunohistochemically. Differentiation of superficial cells was assessed by the presence of urothelial cell differentiation markers, uroplakins (UPs; immunohistochemistry) and cell's apical surface architecture (scanning electron microscopy). All tissue samples stained anti-tPA positive. In normal urothelium, the intensity of anti-tPA staining was the strongest in superficial cells, which were well-differentiated. In tumours, all cell layers stained anti-tPA positive. The intensity of anti-tPA positive reaction in the upper cell layer correlated with the percentage of anti-UP positive superficial cells. Superficial cells showed various differentiation states. The localisation of tPA antigen in human in vivo tissue is not confined to the well-differentiated superficial cells. Our results suggest a positive correlation between tPA secretion and cell differentiation.     

A Rapid Method to Characterize Mouse IgG Antibodies and Isolate Native Antigen Binding IgG B Cell Hybridomas

B cell hybridomas are an important source of monoclonal antibodies. In this paper, we developed a high-throughput method to characterize mouse IgG antibodies using surface plasmon resonance technology. This assay rapidly determines their sub-isotypes, whether they bind native antigen and their approximate affinities for the antigen using only 50 μl of hybridoma cell culture supernatant. Moreover, we found that mouse hybridomas secreting IgG antibodies also have membrane form IgG expression without Igα. Based on this surface IgG, we used flow cytometry to isolate rare γ2a isotype switched variants from a γ2b antibody secreting hybridoma cell line. Also, we used fluorescent antigen to single cell sort antigen binding hybridoma cells from bulk mixture of fused hybridoma cells instead of the traditional multi-microwell plate screening and limiting dilution sub-cloning thus saving time and labor. The IgG monoclonal antibodies specific for the native antigen identified with these methods are suitable for in vivo therapeutic uses, but also for sandwich ELISA assays, histology, flow cytometry, immune precipitation and x-ray crystallography.     

IgG Avidity Antibodies against Toxoplasma gondii in High Risk Females of Reproductive Age Group in India

Toxoplasma gondii is an obligate intracellular protozoan that is distributed worldwide. Recently, several tests for avidity of Toxoplasma IgG antibodies have been introduced to help discriminate between recently acquired and distant infections. The study was conducted in Jawaharlal Nehru Medical College and Hospital, India from February 2011 to September 2012. Serum specimens were subjected to Toxoplasma IgM ELISA and IgG avidity ELISA test. Out of 48 patients with abortions, 17 (35.4%) were positive for IgM ELISA, and 8 (16.6%) had low IgG avidity antibodies. Out of 48 patients with other obstetric problems, 23 (47.9%) were positive for IgM ELISA, and 17 (35.4%) had low IgG avidity antibodies. Combining both groups on avidity test, only 25 of 40 (62.5%) IgM-positive women had low-avidity IgG antibodies suggesting a recent T. gondii infection in these women. More importantly, 15 (37.5%) of the IgM-positive women had high-avidity antibodies suggesting that the infection was acquired before gestation The relation of IgM seropositivity with the following risk factors was not found to be statistically significant; contact with cats (0.13), non-vegetarian food habits (0.05), and low socio-economic status (0.49). While, for IgG avidity ELISA, only contact with cats (0.01) was significantly associated with seropositivity. All other risk factors have P-values of >0.05 (not significant). IgG avidity test when used in combination with IgM test was a valuable assay for diagnosis of ongoing or recently acquired T. gondii infection in India.     

Determinant analysis and interaction studies on monoclonal antibodies to bovine IgG1 and IgG2.

Two mouse monoclonal antibodies SKb1 and SKb6 were prepared by fusion of myeloma cells with spleen cells of female Balb/c mouse immunized with a mixture of bovine IgG1 and IgG2. In radioimmunoassay, SKb1 bound specifically to IgG2 but SKb6 reacted with both IgG1 and IgG2 molecules. In the competition experiments, heavy chain isolated from bovine IgG could inhibit the binding of 125I-IgG1 and 125I-IgG2 to SKb6, while it failed to inhibit the binding of 125I-IgG2 to SKb1. The epitope reacting with SKb1 was found to be present not only on bovine IgG2 but also on goat IgG and was not present on IgG molecules isolated from the serum of rabbit, rat, sheep, horse, human and monkey. Similarly, the epitope reacting to SKb6 was found to be present on bovine IgG1 and IgG2 and also on IgG molecules isolated from goat and sheep serum but was absent in the IgG molecules isolated from the serum of rabbit, rat, horse, human and monkey. The association constants of the interactions of SKb1 with 125I-IgG2 and of SKb6 with 125I-IgG1 and 125I-IgG2, determined by Scatchard analysis, Steward-Petty plot and Sips plot, were found to be in the order of 10(8)-10(10) L/M. The association constants were determined at varying temperatures to obtain the thermodynamic parameters. The enthalpy (delta H0) and entropy (delta S0) values for the above antigen-antibody interactions were in the range of 9.15-15.96 kcal/mole and 36.96-41.15 eu/mole respectively. The heterogeneity indices for similar interactions determined by Sips equation were consistent with the expected values for binding of monoclonal antibodies with homogeneous protein determinants.     

Is there an association between antiphospholipid antibodies and psoriasis?

Ever increasing evidence supports the association between psoriasis and cardiovascular risk. Antiphospholipid antibodies (APAs), which can occur in many autoimmune diseases, are considered prothrombotic and have been associated with atherosclerosis. The aim of this study is to evaluate the prevalence and levels of APAs in psoriasis patients. Fifty patients with moderate to severe plaque psoriasis and 48 healthy subjects were investigated for lupus anticoagulant (LAC) by screening and confirmatory coagulation tests, as well as for antibodies against cardiolipin or beta2-glycoprotein I. Levels of APAs and LAC-related parameters were similar for patients with psoriasis and normal controls (p>0.05). APAs were found in only one psoriatic patient (2%) and in none of the controls. LAC was detected in 2 patients (4%) and in one subject of the control group (2.1%). These results suggest that the prevalence of APAs is not increased in plaque psoriasis as compared to the control group. The increased cardiovascular risk observed in psoriatic patients is therefore likely to be correlated to factors different from APAs.