EB病毒潜伏膜蛋白2多表位的原核表达及其抗原特性分析

目的 对EB病毒(EBV)潜伏膜蛋白2(LMP2)中富含T、B细胞多表位肽段基因进行原核表达,并分析该多表位蛋白的抗原特性.方法 利用计算机在线软件预测EBV LMP2蛋白的CTL表位、Th表位.选取富含CTL表位和Th表位的肽段,兼顾其上下游已预测的B细胞表位,组成含多个T、B细胞表位的EBV LMP2多表位,该多表位基因序列经原核密码子优化后全序列合成,并克隆入原核表达载体pET32a(+)得到pET32a(+)/EBV-LMP2多表位重组质粒,经IPTG诱导在E.coli BL21(DE3)表达并纯化,经SDS-PAGE和Western blot分析鉴定;采用EBV膜蛋白家兔免疫血清和鼻咽癌患者血清进行Western blot分析其抗原特性;并利用EBV-LMP2多表位蛋白免疫BALB/c小鼠,分别采用LDH和ELISA方法检测小鼠脾细胞特异性CTL杀伤效应及血清特异性抗体IgG水平,以分析该表位蛋白的免疫原性.结果 LMP2(aa195-232)和LMP2(aa419-436)肽段富含CTL、Th和B细胞表位,将其串联后作为EBV LMP2多表位,该多表位基因在大肠杆菌中获得了表达.表达产物的相对分子质量(Mr)约27×103,与预期Mr相符;经Western blot证实EBV-LMP2多表位具有抗原特异性,可被EBV膜蛋白家兔免疫血清和鼻咽癌患者血清特异性抗体识别;小鼠免疫结果显示EBVLMP2多表位可诱导机体产生特异性的CTL杀伤效应,随着效靶比(1:5,1:10,1:25)增加,CTL杀伤活性逐渐增强(12.52%±2.59%,21.80%±1.08%,23.68%±3.74%),同时产生了特异性血清IgG抗体反应(A490=0.258±0.040),与对照组比较差异均具有统计学意义(P＜0.05).结论 本研究没计的EBV-LMP2多表位具有良好的抗原性和一定的免疫原性.     

潜伏期膜蛋白1与疾病关系的研究进展

EB病毒(EBV)是一种普遍存在的致癌病毒,是高度相关的淋巴和上皮肿瘤的来源和发展,包括伯基特淋巴瘤和鼻咽癌(NPC)等,EBV基因几乎可以在所有细胞中。EBV感染通常与少数潜伏病毒功能的蛋白质表达,包括潜伏膜蛋白LMP1和LMP2A等和巴尔核抗原1(EBNA1)。LMP1是肿瘤坏死因子受体超家族的成员,被认为是EBV的主要致瘤蛋白。在EB病毒中通过2个C末端结构域编码基因蛋白LMP1信号来驱动细胞生长,存活和转化。LMP1蛋白目前是惟一已被证实的EB病毒的癌基因,LMP1的表达参与了肿瘤的发生与发展,是目前癌症方面研究的重点。     

鼻咽癌中EB病毒BamHI"f"变异和潜伏膜蛋白1基因XhoI缺失型的分析

目的 检测鼻咽癌组织中EB病毒BamHI“f”和LMP1。XhoI—loss基因变异并探讨其意义。方法 采用聚合酶链反应(PCR)、巢式PCR和限制性酶切分析检测40例鼻咽癌组织中EB病毒BamHI“f”和LMP1 XhoI—loss基因变异。对48例健康成人外周血单个核细胞进行了EB病毒LMP1 XhoI—loss变异的检测。对3例具有代表性的PCR产物进行了基因序列分析。结果 40例鼻咽癌中EB病毒BamHI“f”变异型30例(75％),BamHI F型10例(25%)。40例鼻咽癌组织中39例同时进行了EB病毒LMP1 XhoI—loss的检测,30例(76．9%)为LMP1 XhoI—loss;7例(18．0％)为LMP1 Wt—XhoI;2例为LMP1 Wt-XhoI和XhoI-loss并存。97．4％(38／39)鼻咽癌中至少出现一种类型：EB病毒基因变异。仅1例鼻咽癌为EB病毒LMP1 Wt—XhoI／BamHI F,基因序列分析(LMP1第3外显子)发现也有7个碱基替换(其中5个为错义突变和2个为同义突变)。48例健康成人外周血单个核细胞有10例(20．8%,10／48)成功扩增出EB病毒LMP1片段,10例均为LMP1 Wf—XhoI。结论 与B95—8细胞株中EB病毒基因比较,鼻咽癌组织中EB病毒几乎均存在基因变异。健康成人携带的均为EB病毒LMP1 Wt—XhoI,而鼻咽癌细胞中主要为LMP1 XhoI—loss。因而,EB病毒基因变异可能与鼻咽癌的发生发展过程有关。     

EBV编码的BART microRNA在鼻咽癌中的表达及对患者免疫功能的影响

目的探究EB病毒(EBV)编码的BART微小RNA(miRNA)在鼻咽癌中的表达及对患者免疫功能的影响。方法选择我院2015年6月至2018年3月耳鼻咽喉头颈外科收治的鼻咽癌患者57例作为研究组,另选择同期来院治疗的慢性鼻窦炎鼻息肉患者42例作为对照组。分别采用RT-PCR法与Western blot法检测鼻咽癌组织与鼻息肉组织中EBV BART miRNA表达水平与Fas、CD44s与CD44变异体6(CD44v6)蛋白表达水平;采用酶联免疫吸附法与细胞分析仪分别检测研究组放疗前后及对照组血清中EB病毒衣壳抗原免疫球蛋白-A(VCA-IgA)、早期抗原免疫球蛋白-A(EA-IgA)、CD8~+、CD4~+T细胞水平;分析鼻咽癌组织中EBV BART miRNA表达水平与Fas、CD44s与CD44v6蛋白表达水平的相关性。结果鼻咽癌组织中EBV BART miRNA表达水平较鼻息肉组织明显提高(P0.05);研究组患者VCA-IgA与EA-IgA、CD8~+T细胞、CD8~+/CD4~+水平较对照组受试者明显提高,CD4~+T细胞水平较对照组受试者明显降低(P0.05);鼻咽癌患者放疗前VCA-IgA与EA-IgA、CD8~+T细胞、CD8~+/CD4~+水平均明显大于放疗后,CD4~+T细胞水平明显小于化疗后(P0.05);鼻咽癌组织中Fas蛋白相对表达水平明显低于鼻息肉组织(P0.05);且鼻咽癌组织中CD44s与CD44v6蛋白相对表达水平明显高于鼻息肉组织(P0.05);鼻咽癌组织中EBV BART miRNA表达水平与Fas蛋白相对表达水平、CD4~+T细胞水平呈明显负相关(P0.05);鼻咽癌组织中EBV BART miRNA表达水平与CD44s和CD44v蛋白相对表达水平、CD8~+T细胞水平呈明显正相关(P0.05)。结论 EBV BART miRNA在鼻咽癌组织中呈高表达;EBV相关抗体在鼻咽癌患者血清中呈高表达;EBV BART miRNA可能通过影响免疫来介导鼻咽癌的发生发展。     

EB病毒潜伏膜蛋白1对鼻咽癌细胞P53蛋白表达的影响

目的:研究EB病毒潜伏膜蛋白1(LMP1)对鼻咽癌细胞P53蛋白表达的影响。方法:将LMP1基因真核表达质粒转染至鼻咽癌CNE1细胞,脂质体介导端粒酶反义核酸处理转染细胞,MTT法检测细胞增殖能力,免疫组化法检测LMP1和P53蛋白表达,原位杂交技术检测端粒酶逆转录酶(hTERT)mRNA表达。 结果:对照组,转染并表达LMP1基因的细胞的增殖能力、P53蛋白和hTERT mRNA表达水平均显著高于未转染细胞和转染空载质粒的细胞。端粒酶反义核酸作用组,LMP1基因转染细胞的LMP1蛋白表达水平显著低于对照组(P＜0.01);LMP1基因转染细胞与未转染细胞和转染空载质粒的细胞的增殖能力、P53蛋白和hTERT mRNA表达水平均显著低于对照组(P＜0.01),但LMP1基因转染细胞的增殖能力和P53蛋白表达水平仍显著高于未转染细胞和转染空载质粒的细胞(P＜0.01)。 结论:EB病毒LMP1可促进鼻咽癌细胞P53蛋白的表达。     

广州地区EB病毒相关胃癌的临床病理特征及相关分子表达

目的 观察鼻咽癌高发区广州地区EB病毒相关胃癌的构成比、临床病理特征、EB病毒的潜伏类型,并初步探讨DNMT1、p16和cyclin D1在发病过程中的作用.方法 对676例胃癌采用组织芯片和EBER1原位杂交的方法筛选EB病毒相关胃癌,并用免疫组织化学EnVision法检测EB病毒潜伏期膜蛋白(LMP)和DNMT1、p16和cyclin D1的表达.结果 在676例胃癌中,45例EB病毒阳性(6.7%),EB病毒相关胃癌以男性为主,主要发生在胃的中上2/3,以弥漫型多见(P＜0.05).EBNA1和LMP2A的阳性例数分别为42例(93.3%)和24例(53.3%),EBNA2、LMP1和ZEBRA均未见表达.DNMT1、p16和cyclin D1在45例EB病毒相关胃癌的阳性例数分别为35例(77.8%)、10例(22.2%)和29例(64.4%),在40例EB病毒阴性胃癌的阳性例数分别为20例(50.0%)、25例(62.5%)和12例(30.0%),3个分子在两组胃癌的表达率差异均具有统计学意义(P＜0.05).p16与肿瘤的浸润深度有关(P＜0.05).LMP2A与DNMT1、DNMT1与p16、p16与cyclin D1存在相关关系(P＜0.05).结论 广州地区EB病毒相关胃癌占胃癌构成比的6.7%(45/676),EB病毒的潜伏类型部分为Ⅰ型,部分介于Ⅰ型和Ⅱ型之间.LMP2A、DNMT1、p16和cyclin D1的相互作用在EB病毒相关胃癌发生过程中起着重要的作用.     

鼻咽癌中EB病毒编码的潜伏膜蛋白1对β-catenin转录活性及表达的影响

目的 观察鼻咽癌细胞潜伏膜蛋白1(LMP1)表达对β-catenin的转录活性及蛋白表达的影响,探讨LMP1与Wnt/β-catenin信号通路在鼻咽癌发生发展中的作用.方法应用免疫组织化学EnVision法检测75例鼻咽癌组织中LMP1和β-catenin的表达.构建pHA2-LMP1重组质粒,应用细胞免疫荧光、双荧光素酶报告分析、Western blot方法研究LMP1在鼻咽癌细胞株CNE1和CNE2中对β-catenin转录活性及表达的影响.结果 (1)鼻咽癌组织中β-catenin的异常表达率为50.7%(38/75),LMP1的阳性表达率为50.7%(38/75).鼻咽癌组织中β-catenin异常表达与LMP1表达存在正相关(相关系数为x2=7.048,P=0.008).(2)LMP1表达明显提高鼻咽癌细胞株CNE1和CNE2中β-catenin的核表达,且β-catenin的核表达在低分化鼻咽癌细胞株CNE2明显高于高分化鼻咽癌细胞株CNE1.(3)LMP1可明显上调CNE1和CNE2中β-catenin的转录活性,且呈时间依赖性.另外,β-catenin的转录活性在低分化鼻咽癌细胞株CNE2高于高分化鼻咽癌细胞株CNE1.(4)LMP1对鼻咽癌细胞株β3-catenin的总蛋白表达水平无明显影响.结论 EB病毒编码的LMP1可能通过β-catenin信号通路参与鼻咽癌的发生发展.     

鼻咽癌组织中DNA损伤与EB病毒感染的相关性研究

目的分析鼻咽癌(NPC)组织磷酸化组蛋白H2AX(γ-H2AX)的表达水平和EB病毒(EBV)的感染情况,探寻二者的相关性。并用细胞实验进行验证,以阐明EBV诱导DNA损伤应答进而促进NPC发生发展的可能机制。方法选取NPC标本50例和鼻咽炎(NPI)20例,采用免疫组化法检测γ-H2AX及EB病毒潜伏膜蛋白1(LMP1)的表达,对LMP1阴性标本采用原位杂交方法检测EB病毒编码的RNA(EBER);采用Western blot法检测EBV感染鼻咽癌细胞CNE1后γ-H2AX表达的变化。结果NPC组γ-H2AX的阳性率达94%,显著高于NPI组的40%;EBV阳性率为94%,显著高于NPI组的30%;97.9%EBV感染的NPC组织γ-H2AX阳性,二者表达有相关性(P0.05)。通过Western blot法检测进一步验证,EBV感染可使CNE1中γ-H2AX的表达量增高。结论γ-H2AX表达和EB病毒感染有密切关联性,EBV感染可能是通过诱导细胞DNA损伤,造成基因组不稳定从而促进NPC的发生发展。     

鼻咽癌组织中EB病毒潜伏相关基因的表达

目的： 通过检测鼻咽癌组织中EB病毒的潜伏膜蛋白LMP1的序列以及LMP1、EBNA1、EBNA2的mRNA表达来探讨EB病毒的感染状态及其表达产物与鼻咽癌的关系。方法: 应用PCR法检测鼻咽癌组织中LMP1 DNA的存在，并对鼻咽癌来源的LMP1和EB病毒永生化狨猴B淋巴细胞系B95-8来源的LMP1进行测序，比较序列的差异。利用巢式RT-PCR检测鼻咽癌组织中LMP1、EBNA1、EBNA2的mRNA表达。结果: 47例鼻咽癌组织均含有LMP1 DNA，所有鼻咽癌来源的LMP1 DNA与B95-8来源的LMP1 DNA序列比较均存在着多个单核苷酸变异，最明显的是XhoⅠ酶切位点的丢失。测序后显示鼻咽癌来源的LMP1 DNA有30个核苷酸的丢失。巢式RT-PCR显示LMP1、EBNA1、EBNA2在鼻咽癌中的mRNA表达率分别为76.6％、80.0％和74.5％。其中EBNA1的表达是由Qp启动的，而B95-8细胞中EBNA1的表达是由Cp启动的。结论: 鼻咽癌中EB病毒的作用途径比较复杂，LMP1、EBNA1、EBNA2等潜伏期基因还有早期裂解基因BARF1均可能参与鼻咽癌的发生发展过程。     

EBV-LMP2蛋白的表达和初步纯化

目的 应用杆状病毒表达载体表达并纯化EB病毒LMP2蛋白.方法 利用杆状病毒Bac-to-Bae杆状病毒表达系统,将EBV-LMP2基因插入到质粒pFastBacTMHT B中,获得携带EBV-LMP2基因的重组杆状病毒Bac-LMP2.重组病毒感染Sf-9细胞,表达N端携带6个组氨酸(6 X His)的LMP2融合蛋白His-LMP2.经镍离子亲和层析纯化,获得纯化蛋白.结果 SDS-PAGE及Western-Blot检测表达的蛋白相对分子质量大小与预计结果一致.HPLC分析纯化后蛋白的纯度可达86%.结论 利用杆状病毒表达系统表达EB病毒LMP2基因并经过初步纯化后,可以获得较好纯度的LMP2蛋白.     

Identification and characterization of novel B-cell epitopes within EBV latent membrane protein 2 (LMP2)

The purpose of this study was to screen and identify the linear B-cell epitopes of Epstein-Barr virus (EBV) latent membrane protein 2 (LMP2). The secondary structure and surface properties of EBV LMP2A protein were analyzed. In combination with hydrophilicity, accessibility, flexibility, and antigenicity analysis, and average antigenicity index (AI) of epitope peptide investigation, three peptides were selected as potential candidates of linear B-cell epitopes. The peptides were 199-209 (RIEDPPFNSLL), 318-322 (TLNLT), and 381-391 (KSLSSTEFIPN). The fragments encoding potential B-cell epitopes were cloned and overexpressed in an E. coli system. The immune sera of these fusion proteins were collected from BALB/c mice by subcutaneously immunizing them three times. Western blotting results showed that these epitope recombinant proteins could be recognized by the serum antibodies against the whole LMP2 from nasopharyngeal carcinoma (NPC). Indirect ELISA measuring individual sera from 196 NPC patients, 44 infectious mononucleosis (IM) patients, 253 healthy adults, and 61 healthy children, indicated that NPC patients had significantly higher reactivity to these epitope-fused proteins compared with IM and healthy individuals (p?相似文献   

Nipah virus glycoprotein: production in baculovirus and application in diagnosis

A method for serological diagnosis of Nipah virus (NiV) is described. DNA encoding truncated G protein of NiV was cloned into the pFastBac HT vector, and the fusion protein to His-tag was expressed in insect cells by recombinant baculovirus. The resulting His-G recombinant fusion protein was purified by affinity chromatography and used as the coating antigen for serological testing by indirect enzyme-linked immunosorbant assay (ELISA). When tested against a panel of swine serum samples, the recombinant G protein-based ELISA successfully discriminated all 40 samples previously determined to be serum neutralizing test (SNT) positive from 11 SNT negatives samples. The data show that the recombinant G protein exhibits the antigenic epitopes and conformation necessary for specific antigen-antibody recognition. The main advantage of the recombinant G protein-based NiV ELISA compared to an ELISA using whole virus antigen is the use of a single antigenic protein instead of inactivated whole virus which is required to be prepared under high risk and cost. This test is suitable for routine diagnosis of NiV and also for epidemiological surveys as it allows highly reliable testing of a large number of sera rapidly.     

Native early antigen of Epstein-Barr virus, a promising antigen for diagnosis of nasopharyngeal carcinoma

The Epstein-Barr virus (EBV) early antigen (EA) complex consists of multiple proteins with relevance for diagnosis of acute, chronic and malignant EBV related diseases, including nasopharyngeal carcinoma (NPC). In a recent study, it was found that the molecular diversity of EBV-specific IgG and IgA antibody responses in NPC patients and demonstrated that these reflect independent B-cell triggering leading to distinct EBV antigen-recognition profiles. The fine-specificity of NPC-related IgG and IgA responses was explored further against defined recombinant and synthetic EBV-EA antigens using immunofluorescence, immunoblot and ELISA techniques and determined their diagnostic value in a large panel of sera from NPC (n = 154), non-NPC tumor patients (n = 133), acute mononucleosis patients (n = 70) and healthy EBV carriers (n = 259). Individual recombinant EBV-EA markers yielded sensitivity/specificity values not exceeding 86%, whereas selected EA-specific peptide epitopes were rather poorly recognized by IgG and IgA antibodies in NPC sera. Surprisingly, we found that a "low salt" native EA-protein extract reproducibly prepared from purified nuclei of EA-induced HH514 cells, and containing characteristic EA(D)-polypeptides, such as p47-54 (BMRF1), p138 (BALF2), p55-DNAse (BGLF5), and p65-TK (BXLF1), but without viral capsid (VCA) or nuclear antigen (EBNA) reactivity, gave highest sensitivity (90.4%) and specificity (95.5%) values for NPC diagnosis in both IgG and IgA ELISA. The data support further the notion that EBV-EA reactive IgG and IgA antibodies in NPC patients are directed against distinct conformational and-in part-linear epitopes on EBV-specific proteins, barely recognized in other EBV-related syndromes. The use of a defined native EBV EA-specific antigen opens the way to further improve serological diagnosis of NPC.     

原核表达和制备EB 病毒GST/BFRF3融合蛋白用于鼻咽癌的诊断筛查

 目的：构建表达EB病毒衣壳抗原BFRF3基因的原核细胞表达载体并探讨其在鼻咽癌血清学诊断中的应用。方法：以EB病毒 DNA为模版,采用PCR法扩增目的基因BFRF3,与原核表达载体PGEX-5X-1连接,构建PGEX-5X- BFRF3重组质粒,转化大肠杆菌BL21（DE3）,IPTG诱导表达GST/BFRF3融合蛋白。表达产物经SDS-PAGE和免疫印迹法鉴定后,纯化目的蛋白作为包被抗原,制备ELISA试剂检测鼻咽癌患者和正常人群BFRF3-IgA抗体。结果：在大肠杆菌中成功地表达了GST/BFRF3融合蛋白,相对分子质量为44 kD,免疫印迹证实目的蛋白带有免疫原性,目的蛋白经纯化后作为包被抗原检测鼻咽癌患者的灵敏度和特异度分别为65％和87％。结论：采用原核表达系统成功构建并表达了GST/BFRF3融合蛋白,其在鼻咽癌血清筛选中具有诊断价值。     

Design and construction of a new recombinant fusion protein (2b2t+EPC1) and its assessment for serodiagnosis of cystic echinococcosis

The immunodiagnostic tests for cystic echinococcosis (CE) are mostly serological tests based on ELISA that use hydatid cyst antigens for primary screening because of its simple preparation and availability. The challenge to develop new serological methods (as compared to those based on the hydatid cyst fluid antigens) to meet the gold standard remains. Appropriate sources of antigenic material are necessary for application to improve the efficacy of immunodiagnostic tests at a population level. In the current study, a fusion protein containing the coding sequence of antigen B2t and two sequences of EPC1 antigen with some modifications was reconstructed. Using bioinformatics tools, these sequences were joined together by applying the sequence of a rigid α‐helix‐forming linker to obtain an appropriate structure of a fusion protein. Synthetic recombinant fusion protein was expressed using pET28a as a vector and evaluated by indirect ELISA test for sera from patients with hepatic CE and other parasitic infections. The sensitivity of the fusion protein was lower (88.46%) than the available ELISA kit (96.15%). However, the differences in sensitivity were not statistically significant as compared to the recombinant fusion peptide with the commercial kit (p = 0.269). The specificity of the recombinant fusion protein (95.45%) was not significantly lower than the commercial kit (96.59%; p = 1.000). Moreover, surprisingly there was no difference in the cross‐reactivity values of performance between the recombinant‐ELISA and commercial kit. The positive and negative predictive values of the recombinant antigen were achieved as 92% and 93.33%, respectively, while for the commercial kit, they were obtained as 94.33% and 97.70%, respectively. In conclusion, as an early evaluation of these antigens the performance of our recombinant fusion protein in ELISA is relatively promising. Although, it seemed that this peptide with specific antigenic epitopes might be more appropriate for the serological evaluation of CE by use of bioinformatics tools, our findings showed that cross‐reactions and a negative reaction could occur in clinical performance. This fusion protein may have utility for diagnosis in humans, but further evaluation is needed using the WHO ultrasound classification for CE.     

Computational Prediction and Identification of Epstein-Barr Virus Latent Membrane Protein 2A Antigen-Specific CD8^＋ T-Cell Epitopes

Epstein-Barr virus （EBV） associated nasopharyngeal carcinoma （NPC） is a high incidence tumor in Southeast Asia. Among EBV encoded proteins, latent membrane protein 2A （LMP2A） is an important antigen for T cell therapy of EBV. In this study, we predicted six HLA-A2 restricted CTL candidate epitopes of LMP2A by SYFPEITHI, NetMHC and MHCPred methods combined with the polynomial method. Subsequently, biological functions of these peptides were tested by experiments in vitro. In ELISPOT assay, the positive response of the LMP2A specific CTL stimulated by three （LMP2A264.272, LMP2A426-434 and LMP2A3s6.364） of six peptides respectively showed that the numbers of spots forming cells （SFC） ranged from 55.7 to 80.6 SFC/5 x 104 CO8^＋ T cells and the responding index （RI） ranged from 5.4 to 7. These three epitope-specific CTLs could effectively kill specific HLA-A2- expressing target cells. As a result, LMP2A264.272 （QLSPLLGAV）, LMP2A426.434 （CLGGLLTMV） and LMP2A356.364 （FLYALALLL） were identified as LMP2A-specific CD8^＋ T-cell epitopes. It would be useful to clarify immune response toward EBV and to develop a vaccine against EBV-correlative NPC.     

用点突变的方法组建巨细胞病毒抗原决定簇基因的表达克隆

研究资料表明，人巨细胞病毒（ＨＣＭｖ）单一蛋白的单一抗原决定簇只能被部分患者阳性血清识别。组建在血清学诊断中能够替代全病毒抗原的基因工程抗原，需要含有病毒多种主要抗原蛋白的抗原决定簇。为搞清在表达载体中重复插入某一抗原决定簇基因是否能表达出更高抗原效价的融会蛋白，我们用点突变的方法，在表达载体中分别插入了人ＨＣＭｖ的ｐｐＵＬ３２蛋白羧基端一个抗原决定簇基因的１个、２个和３个拷贝。在免疫转印检测中，这些克隆表达的融合蛋白与特异性阳性血清的反应性差别不明显。这表明，插入表达载体中目的基因的多寡对表达蛋白的抗原效价没有显著影响。     

T7 phage displaying latent membrane protein 1 of Epstein-Barr virus elicits humoral and cellular immune responses in rats

The latent membrane protein 1 (LMP1) encoded by Epstein-Barr virus (EBV) has become a potential target in EBV-associated tumor prevention and treatment due to its multiple biological effects. In this study, the recombinant T7 phage displaying full-length LMP1 protein was cloned and used as an immunogen to immunize rats. Results of flow cytometry, Western blot analysis, and ELISA confirmed that both humoral and cellular immune responses were elicited in the immunized rats. Our data suggested that T7 phage was an efficient antigen carrier. The recombinant T7-LMP1 phage reconstitutes the antigenic and immunogenic properties of LMP1 and can serve as a vaccine against EBV.     

Antibody against the Epstein-Barr virus BHRF1 protein,a homologue of Bcl-2, in patients with nasopharyngeal carcinoma

The Epstein-Barr virus (EBV) open reading frame BHRF1, a homologue of the oncogene bcl-2, was cloned from a patient with nasopharyngeal carcinoma (NPC) and overexpressed in Escherichia coli. The resulting recombinant BHRF1 fusion protein, with an apparent molecular weight of 35 KD, was used as antigen in an immunoblotting assay for IgG antibody in human sera. Anti-BHRF1 antibody was detected in 57 (61.3%) of 93 patients with NPC, 5 (5.7%) of 87 patients with nonmalignant diseases of the nasopharynx, and in 1 (1.3%) of 78 healthy blood donors. The positivity rate in these nonmalignant patients was 4.4 times that of the normal controls. Negative results were observed in four patients with infectious mononucleosis and patients with other cancers, including 4 with esophageal cancer, 11 with lung cancer, 10 with lymphoma, 13 with gastric carcinoma, 10 with cervical carcinoma, and 10 with other head and neck cancers. Antibody neutralizing EBV DNase and IgA antibody to viral capsid antigen (VCA) were assayed in parallel. The results showed that 7.5% of the NPC patients were negative for anti-DNase and anti-VCA antibodies and EBV infection could be detected by the anti-BHRF1 antibody alone. The demonstration of anti-BHRF1 antibody in most NPC sera strongly supports the hypothesis that the EBV BHRF1 protein is expressed in most NPC patients and its specific antibody can be a useful marker for the diagnosis of NPC. J. Med. Virol. 56:179–185, 1998. © 1998 Wiley-Liss, Inc.