禽流感病毒单克隆抗体的制备及其抗蛋白抗原的分析

以纯化的H9N2亚型禽流感病毒为抗原，免疫BALB／c小鼠，细胞融合后，经间接ELISA和血凝抑制试验（HI）筛选，获得了8株能稳定分泌抗禽流感病毒单克隆抗体的杂交瘤细胞株。特异性试验证明，8株杂交瘤细胞株诱生小鼠腹水的特异ELISA抗体效价可达113．2×10^3～1：5．1×10^4，其中2株HI效价达2^12。8株单抗与H5亚型血凝素分型抗原不发生血凝，与减蛋综合征（EDS-76）病毒、传染性支气管炎病毒（IBV）、新城疫病毒（NDV）均不反应。亚类鉴定证实，除1C7单抗为IgG2b外，其他7株均为IgG1亚类。Western blotting试验分析初步表明。8株单抗至少针对纯化病毒粒子3种不同的蛋白抗原，其中3株针对核蛋白（NP）．2株针对基质蛋白M1，2株针对血凝紊HA／HA1。对感染细胞的Western blotting分析结果与纯化病毒结果基本一致，其中1株朱明显沉淀纯化病毒粒子蛋白的单抗可以与感染细胞的M2蛋白多肽反应。

肿瘤相关糖蛋白-72抗原在原发性胆囊癌中的表达及其临床意义

目的探讨抗肿瘤相关糖蛋白-72（TAG-72）抗原的表达及其与原发性胆囊癌（PGC）病理特征的关系。方法用原核表达获得抗TAG-72单链抗体，并用聚丙烯酰胺凝胶电泳（SDS—PAGE）和Western blot得以验证；用免疫组化方法检测TAG-72抗原在PGC的表达。结果通过原核表达获取大小为31kDa的抗TAG-72单链抗体并得以证实。TAG-72抗原在胆囊良、恶性组织阳性率分别为59．6％、6．7％（P〈0．05）。高分化PGC的TAG-72抗原表达显著低于中低分化PGC（P〈0．05）；肿瘤直径≤2cm者TAG-72表达显著低于〉2cm者（P〈0．05）；在PGC Nevin临床分期Ⅰ～Ⅲ期与Ⅳ～Ⅴ期间则无显著性差异（P〉0．05）。结论获得了抗TAC-72单链抗体的原核表达方法。TAG-72抗原可以作为一个肿瘤标志物在临床中应用，为抗TAG-72单链抗体在PGC诊治中的应用奠定实验基础。

亲和层析微柱在抗肌红蛋白抗体纯化中的应用

为寻找一种操作简便、效率高、纯度好的纯化 Mb抗体的方法 ,用溴化氢活化的琼脂糖珠 4B与肌红蛋白 (Mb)交联建立了亲和层析微柱 ,用于纯化 Mb抗体。纯化过程简单、迅速 ,抗血清可直接上柱 ,用 PAGE方法鉴定显示一条带。柱体积小 ,得率高 ,整个过程可在

国产抗乙型肝炎病毒核心抗原抗体免疫球蛋白M检测试剂的比较

目的为中国急性乙型病毒性肝炎(乙肝)监测,筛选合适的抗乙肝病毒核心抗原抗体免疫球蛋白M(Immunoglobulin M Antibody to Hepatitis B Virus Core Antigen,Anti-HBc-IgM)检测试剂。方法选择市场销量较大的三种酶联免疫吸附试验Anti-HBc-IgM检测试剂,平行检测参比系统各3次,比较各试剂的组内相关系数(Intraclass Correlation Coefficient,ICC)、变异系数,以评价试剂的可靠性,绘制受试者工作特征曲线(Receiver Operating Characteristic,ROC),计算ROC下面积(Area Under Curve,AUC)、部分(Partial)AUC(pAUC)、固定特异度下灵敏度[Sensitivity at a Fix Specificity,Se(FPR=e)],以评价试剂的真实性。结果三种试剂的ICC均接近于1,一致性均好,两两比较中A试剂稳定性最好,变异性最小(Bootstrap法,P<0.05)。B试剂ROC位于最上方,AUC中位数最大,和A、C比较均有统计学意义(Bootstrap法,P<0.05);B和C、A试剂的pAUC中位数和Se(FPR=0.05)中位数差异无统计学意义。结论符合国家标准的三种试剂,以雅培试剂作为参照相比,综合评价结果,B试剂较好。

抗乙型肝炎病毒核心抗原抗体免疫球蛋白M诊断试剂区分急慢性乙型肝炎患者方法的初步探讨

目的调整抗乙型肝炎(乙肝)病毒核心抗原抗体免疫球蛋白M(Immunoglobulin M Antibody to Hepatitis B Virus Core Antigen,Anti-HBc-Ig M)诊断试剂临界值,使该指标能够区分急性乙肝(Acute Hepatitis B,AHB)和慢性乙肝(Chronic Hepatitis B,CHB)急性期患者。方法选择A公司国产和美国雅培(Abbott)公司Anti-HBc-Ig M检测试剂,平行检测2658份疑似AHB患者血清标本。利用R语言程序软件(R Programming Software,R)的VGAM程序包,通过最大似然法求得各自的分布参数和估计的阳性率,采用最大似然法、最大准确率法和固定特异度法,以及试剂说明书提供方法求得两种检测试剂的临界值、估计阳性率、灵敏度及特异度指标进行比较。结果采用最大似然法确定临界值,临界值调整前后A公司试剂阳性率为51.58%、12.23%,雅培试剂为28.37%、10.27%。两种试剂受试者工作特征曲线(Receiver Operating Characteristics Curve,ROC)的曲线下面积(Area Under Curve,AUC)均接近于1,都有较高的灵敏度和特异度。最大似然法、最大准确率法和固定特异度法与试剂说明书参考值比较,前三种方法得到的阳性率较为接近,灵敏度、特异度较高,试剂说明书参考值法,灵敏度均较低,假阳性率过高。结论本研究中调整Anti-HBc-Ig M检测试剂临界值的方法,可以使Anti-HBc-Ig M区分AHB和CHB急性期患者的能力更可靠。

类风关标志物检测的临床意义及相关性分析

目的:探讨抗环瓜氨酸肽抗体(anti-CCP)、葡萄糖-6-磷酸异构酶抗原(GPI)、抗角蛋白抗体(AKA)、类风湿因子(RF)四项指标联合检测在类风湿关节炎(RA)诊断中的价值。方法:对78例RA、56例非RA其他风湿病患者、40例健康志愿者的anti-CCP、GPI、AKA、RF进行检测。结果:1 78例RA患者中anti-CCP、GPI、AKA及RF的灵敏度分51.2%、42.3%、29.5%和58.9%;特异性分别为98.2%、98.8%、98.2%和81.9%。56例非RA其他风湿病患者anti-CCP、GPI、AKA及RF的阳性率分别为1.79%、3.57%、3.57%和33.9%;40例正常对照组中检测到1例抗CCP弱阳性,1例RF阳性,其余指标均为阴。2相关性分析显示:anti-CCP、GPI、RF与疾病活动性指标hs-CRP、α1-AGP、ESR、PLT呈显著正相关(P<0.05或P<0.01)。结论:anti-CCP、GPI、AKA对RA诊断灵敏度不高,但均是RA的特异性诊断指标,三者与RF可相互补充,适当联合检测有助于提高诊断的特异性;且三者与疾病活动性项指标高度相关。

Soluble forms of extracellular cytokeratin 18 may differentiate simple steatosis from nonalcoholic steatohepatitis

AIM: To investigate whether serum levels of two soluble forms of extracellular cytokeratin 18 (M30-antigen and M65-antigen) may differentiate nonalcoholic steatohepatitis (NASH) from simple steatosis in patients with nonalcoholic fatty liver disease (NAFLD). METHODS: A total of 83 patients with suspected NAFLD and 49 healthy volunteers were investigated. Patients with suspected NAFLD were classified according to their liver histology into four groups: definitive NASH (n = 45), borderline NASH (n = 24), simple fatty liver (n = 9), and normal tissue (n = 5). Serum levels of caspase-3 generated cytokeratin-18 fragments (M30-antigen) and total cytokeratin-18 (M65-antigen) were determined by ELISA. RESULTS: Levels of M30-antigen and M65-antigen were significantly higher in patients with definitive NASH compared to the other groups. An abnormal value (> 121.60 IU/L) of M30-antigen yielded a 60.0% sensitivity and a 97.4% specificity for the diagnosis of NASH. Sensitivity and specificity of an abnormal M65-antigen level (> 243.82 IU/L) for the diagnosis of NASH were 68.9% and 81.6%, respectively. Among patients with NAFLD, M30-antigen and M65-antigen levels distinguished between advanced fibrosis and early-stage fibrosis with a sensitivity of 64.7% and 70.6%, and a specificity of 77.3% and 71.2%, respectively. CONCLUSION: Serum levels of M30-antigen and M65-antigen may be of clinical usefulness to identify patients with NASH. Further studies are mandatory to better assess the role of these apoptonecrotic biomarkers in NAFLD pathophysiology.

Indirect ELISA with Recombinant GP5 for Detecting Antibodies to Porcine Reproductive and Respiratory Syndrome Virus

Porcine reproductive and respiratory syndrome is caused by the PRRS virus (PRRSV),which has six structural proteins (GP2,GP3,GP4,GP5,M and N). GP5 and N protein are important targets for serological detection by enzyme-linked immunosorbent assay (ELISA) and other methods. Toward this goal,we developed an indirect ELISA with recombinant GP5 antigens and this method was validated by comparison to the LSI PRRSV-Ab ELISA kit. The results indicated that the optimal concentration of coated recombinant antigen was 0.2 μg/well for a serum dilution of 1:40. The rate of agreement with the LSI PRRSV-Ab kit was 88.7% (266/300). These results support the potential use of recombinant GP5 as an antigen for indirect ELISA to detect PRRSV antibodies in pigs.

Current prophylactic strategies against hepatitis B virus recurrence after liver transplantation

Prophylactic strategies against hepatitis B virus(HBV) recurrence after liver transplantation(LT) are essential for patients with HBV-related disease.Before LT, lamivudine(LAM) was proposed to be down-graded from first-to second-line therapy.In contrast, adefovir dipivoxil(ADV) has been approved not only as first-line therapy but also as rescue therapy for patients with LAM resistance.Furthermore, combination of ADV and LAM may result in lower risk of ADV resistance than ADV monotherapy.Other new drugs such as entecavir, telbivudine and tenofovir, are probably candidates for the treatment of hepatitis-B-surface-antigen-positive patients awaiting LT.After LT, low-dose intramuscular hepatitis B immunoglobulin(HBIG), in combination with LAM, has been regarded as the most cost-effective regimen for the prevention of post-transplant HBV recurrence in recipients without pretransplant LAM resistance and rapidly accepted in many transplant centers.With the introduction of new antiviral drugs, new hepatitis B vaccine and its new adjuvants, post-transplant HBIG-free therapeutic regimens with new oral antiviral drug combinations or active HBV vaccination combined with adjuvants will be promising, particularly in those patients with low risk of HBV recurrence.

E2 GLYCOPROTEIN OF GENOTYPE Ⅲ CHINESE ISOLATES OF HEPATITIS C VIRUS EXPRESSED IN MAMMALIAN CELL AS ANTIGEN FOR ANTI-E2 ANTIBODY DETECTION

Expression vector inserted with E2/NS1 gene derived from genotype Ⅲ Chinese isolates of HCV was transfected into mammalian cells to express E2 glycoprotein. Expressed protein was used as antigen for an- ti-E2 antibody detection in 19 cases of hepatitis C patients by Western blot. It was first to express E2 gly- coprotein of genotype Ⅲ Chinese hepatitis C virus isolates. For anti-E2 detection, 14 cases of patients were positive of antibodies against E2(73. 7 % ). These results indicated that E2 glycoprotein expressed in mam-malian cells had good immunogenicity and cross reactivity to serum infected with genotype Ⅱ Chinese hep-atitis C virus isolates.

In vitro Induction of primary antibody responses to particulate and soluble protein antigens in T cell-replaced murine spleen cell cultures

Specific antibody responses could be induced in serumfree condition.Specific anti-SRBC or anti-SRBC ghost antibody were induced from anti-Thy treated (T-depleted) murine spleen cells in serum-free culture in the presence of Con A conditioned medium.This induction system may facilitate the study of lymphokine functions on antigen triggered B cells. In T cell-replaced cultures,the antibody responses of B cells could be successfully induced when soluble SRBC membrane proteins were used as antigens.It thus indicates that antigen together with lymphokines are sufficient to drive B cells to become antibody secreting cells in the absence of T cells.The T cell-replaced system provides a more stable way for in vitro immunization and may be applied to monoclonal antibody production when in vivo immunization is difficult to be carried out.

Prediction of antigenic determinants of trichosanthin by molecular modeling

The antigenic determinants of trichosanthin were predicted by molecular modeling. First, the threedimensional structure model of the antigen-binding fragment of anti-trichosanthin immunoglobulin E was built on the basis of its amino-acid sequence and the known three-dimensional structure of an antibody with similar sequence. Secondly, the preferable antigen-antibody interactions were obtained based on the known three-dimensional structure of trichosanthin and of the hypervariable regions of anti-trichosanthin immunoglobulin E. Two regions in the molecular surface of trichosanthin were found to form extensive interactions with the hypervariable regions of the antibody and have been predicted to be the possible antigenic determinants: one is composed of two polypeptide segments, Ile201-Glu210 and Ile225-Asp229, which are close to each other in the three-dimensional structure; and the other is the segment Lys173-Thr178. The former region seems to be the more reasonable antigenic determinant than the latter one.

Antigenic analysis of grass carp reovirus using single-chain variable fragment antibody against IgM from Ctenopharyngodon idella

Grass carp （Ctenopharyngodon idella） is an important species of freshwater aquaculture fish in China. However, grass carp reovirus （GCRV） can cause fatal hemorrhagic disease in yearling populations. Until now, a strategy to define the antigenic ca- pacity of the virus＇s structural proteins for preparing an effective vaccine has not been available. In this study, some sin- gle-chain variable fragment antibodies （scFv）, which could specifically recognize grass carp IgM, were selected from a con- structed mouse naive antibody phage display cDNA library. The identified scFv C1B3 clone was shown to possess relatively higher specific binding activity to grass carp IgM. Furthermore, ELISA analysis indicated that the IgM level in serum from vi- rus-infected grass carp was more than two times higher than that of the control group at 5-7 days post infection. Moreover, Western blot analysis demonstrated that the outer capsid protein VP7 has a specific immuno-binding-reaction with the serum IgM from virus-infected grass carp. Our results suggest that VP7 can induce a stronger immune response in grass carp than the other GCRV structural proteins, which implies that VP7 protein could be used as a preferred immunogen for vaccine design.

Antigenically dominant proteins within the human liver mitochondrial proteome identified by monoclonal antibodies

Analysis of the mitochondrial proteome would provide valuable insight into the function of this important organelle, which plays key roles in energy metabolism, apoptosis, free radical production, thermogenesis, and calcium signaling. It could also increase our understanding about the mechanisms that promote mitochondrial disease. To identify proteins that are antigenically dominant in human liver mitochondria, we generated >240 hybridoma cell lines from native mitochondrial proteins after cell fusion, screening, and cloning. Antibodies that recognized mitochondrial proteins were identified by screening human liver cDNA expression libraries. In this study, we identified 6 major antigens that were recognized by at least 2 different monoclonal antibodies (mAbs). The proteins that were antigenically dominant were: acetyl-Coenzyme A acyltransferase 2 (mitochondrial 3-oxoacyl-Coenzyme A thiolase), aldehyde dehydrogenase 1 family member A1, carbamoyl phosphate synthetase 1, dihydrolipoamide S-acetyltransferase (E2 component of pyruvate dehydrogenase complex), enoyl coenzyme A hydratase 1, and hydroxysteroid (11-beta) dehydrogenase 1. We also determined the subcellular localizations of these enzymes within the mitochondria using immunohistocytochemistry. We believe that these well-characterized antibodies will provide a valuable resource for the Human Liver Proteome Project (HLPP), and will make studies aimed at investigating liver mitochondrial function far easier to perform in future. Our results provide strong evidence that, (i) depletion of dominant proteins from liver mitochondrial samples is possible and, (ii) the approaches adopted in this study can be used to explore or validate protein-protein interactions in this important organelle.