以人乳头瘤病毒16 L1为载体的流感通用疫苗初步研究

目的 构建以人乳头瘤病毒(human papillomavirus,HPV)16 L1为载体的甲型流感病毒M2基因胞外区(M2e)通用疫苗杆粒,利用昆虫细胞杆状病毒表达系统,进行初步的蛋白表达.方法 利用PCR技术将甲型流感病毒M2e基因序列与HPVl6 L1相连.经酶切、酶联将融合基因插入pFastBacHTA载体,在DH10Bac细胞中进行同源重组,经测序鉴定后构建M2e-HPV16 L1杆粒,脂质体转染sf9昆虫细胞,收获并扩增含有M2e-HPV16 L1的杆状病毒,经扩增后获得高效价的重组杆状病毒,用SDS-PAGE、免疫荧光法和电镜检测目的蛋白的表达.结果 构建了以HPV16 L1为载体的M2e通用疫苗杆粒,通过转染sf9昆虫细胞得到初步M2e-HPV16 L1融合蛋白表达.结论 成功构建了HPV16 L1与甲型流感病毒M2e融合蛋白的病毒样颗粒,为流感通用疫苗的研制奠定了基础.     

昆虫细胞偏爱密码子优化的HPV16L1基因在昆虫和哺乳动物细胞中的表达

目的获得有效表达人乳头瘤病毒16型（HPV16）L1基因的重组杆状病毒和腺病毒，为研究HPV的免疫保护机制提供材料。方法按照昆虫细胞密码子偏爱优化并合成HPV16LI基因，利用Bac—to-Bac昆虫表达系统获得表达HPV16L1基因的重组杆状病毒，利用AdEasy腺病毒载体系统获得表达HPV16L1基因的重组腺病毒载体。通过间接免疫荧光和Westernblot对HPV16L1基因表达进行鉴定，利用负染电子显微镜观察病毒样颗粒（VLP）的形成。结果获得了稳定表达HPV16L1蛋白的重组杆状病毒和重组腺病毒载体，在Sf9细胞和293细胞中可有效表达能被抗HPV16L1单克隆抗体识别的L1蛋白，分子质量单位为56ku，在Sf9细胞中可观察到VLP的形成。结论按照昆虫细胞密码子偏爱进行优化的HPV16L1基因，在昆虫细胞和哺乳动物细胞内均可有效表达。     

制备HPV L1 VLP的基因工程技术应用进展

人乳头瘤病毒（HPV）感染与宫颈癌的发生密切相关。研究发现，HPV的主要衣壳蛋白L1能够单独或与次要蛋白L2共同在体外自行组装成病毒样颗粒（VLP），该颗粒具有与成熟HPV相同的形态学和免疫学特征，且具有型内高度保守性和型间高度同源性，又有与天然病毒颗粒相似的能诱生中和抗体的抗原表位，且不含病毒DNA，因而成为HPV预防性疫苗研究的重要靶抗原。近年来通过基因工程技术在真核和原核细胞中成功表达了多种型别的HPVL1蛋白，且均可在相应宿主细胞内组装成VLP。现将制备HPV L1 VLP预防疫苗的基因工程技术的应用进展情况综述如下。     

汉滩病毒核蛋白部分片段与囊膜糖蛋白G1在昆虫细胞中的融合表达

目的　应用Bac -to -Bac杆状病毒表达系统融合表达汉滩病毒囊膜糖蛋白G1与核蛋白部分片段。方法　构建含有汉滩病毒G1S0 7嵌合基因的杆状病毒表达载体 pFBD -G1S0 7,转化DH10Bac致敏菌 ,利用其含有的细菌Tn7转座系统将嵌合基因重组至穿梭质粒Bacmid上 ,快速筛选出含有G1S0 7嵌合基因的重组杆状病毒 ,在昆虫细胞中表达该融合蛋白 ,利用间接免疫荧光、ELISA和免疫印迹对表达产物进行检测。结果　构建的含G1S0 7嵌合基因之重组杆状病毒可在昆虫细胞中表达出融合蛋白 ,该蛋白可被抗汉滩病毒核蛋白及糖蛋白G1特异性单抗所识别 ,表达产物主要集中在细胞内。结论　在昆虫细胞中表达出具有生物学活性的G1S0 7融合蛋白 ,为进一步研究其免疫学特性奠定了基础     

人乳头状瘤病毒16型伪病毒载体对肝癌细胞系HepG2细胞的杀伤研究

目的 构建基于人乳头状瘤病毒（HPV）16型的伪病毒载体,并检测其对肝癌细胞系HepG2细胞的杀伤活性。方法利用昆虫什状病毒表达系统表达病毒蛋白,在体外将病毒蛋白包装白喉毒（DT）A链表达型质粒,形成伪病毒。透射电镜观察病毒样颗粒（VLP）的结构,并转染肝癌细胞系HepG2。乳酸脱氢酶释放法检测对肝癌细胞系HepG2的杀伤能力。结果透射电镜观察显示病毒蛋白可自我组装成VLP,在转染肝癌细胞系HepG2后,乳酸脱氢酶释放法成功检测到伪病毒埘肝癌细胞系HepG2的杀伤作用。结论基于HPV16的新型伪病毒载体能成功转染肝癌细胞系HepG2,并产生杀伤活性,为肝癌的基因治疗提供了一种可选择的方法。     

犬细小病毒VP2蛋白在家蚕/昆虫细胞中表达

目的犬细小病毒(canine parvovirus,CPV)能够引起犬急性出血性肠炎,在幼犬中的死亡率很高,为我国养犬业和经济动物养殖业带来巨大的经济损失。因而,寻找一种新型、安全、高效的疫苗为细小病毒性肠炎的防控具有重要意义。方法本研究利用Bac-to-Bac表达系统构建了表达CPV VP2蛋白的重组杆状病毒rBV-D-VP2。该重组病毒感染昆虫细胞和家蚕后,表达CPV VP2蛋白。体外表达的VP2蛋白自动装配成病毒样粒子。随后用蚕蛹中大量组装成的病毒样粒子分别通过口服和肌注两种途径免疫豚鼠。结果经电镜检测,观察到直径为25nm大小的球形病毒样粒子,表明重组杆状病毒表达的VP2能形成病毒样粒子,且在大小、形态上与天然病毒相似。间接免疫荧光检测表明成功构建了表达VP2的病毒样粒子。口服和肌注两种途径免疫豚鼠,均产生了血凝抑制效价。结论本研究为CPV新型亚单位疫苗的研究提供了依据。     

丙型肝炎

慢性丙型肝炎患HLA—DRB等位基因表达频率分析及其与抗病毒治疗应答关系的比较，具有蛋白酶及解旋酶活性的HCV—NS3重组蛋白的纯化及活性分析，丙型肝炎病毒NS2蛋白在Huh-7细胞中抑制NF-kB活性，丙型肝炎病毒样颗粒疫苗的研究现状(综述)，丙型肝炎病毒核心蛋白结合蛋白6的反式调节基因研究，HCV结构蛋白在昆虫细胞中的表达及病毒样颗粒的组装。     

人乳头瘤病毒E2蛋白生物学活性及疫苗研究进展

人乳头瘤病毒(human papilloma virus,HPV)能感染皮肤和粘膜的基底层上皮细胞,尤其与生殖系统感染相关密切。乳头瘤的形成与HPV E2蛋白密不可分,该蛋白质与细胞增殖及病毒的有丝分裂等有关。近年来,学者们利用E2蛋白的特性研制出各种E2蛋白相关的疫苗,有助于清除与HPV感染有关的早期病变,有效降低宫颈癌的发生。     

携带HPV11型基因组细胞三维培养模型的建立及其衣壳蛋白L1的表达

目的用携带人乳头瘤病毒11型(HPV11)基因组的角质形成细胞(HPV11.HaCaT细胞),在体外建立皮肤类似培养物三维模型,观察HPV11衣壳蛋白L1是否表达,为进一步建立体外病毒复制系统和药效筛选模型奠定基础。方法用人成纤维细胞和I型鼠尾胶原制备真皮类似物凝胶,接种HPV11.HaCaT细胞进行三维培养。同时以正常HaCaT细胞作对照。15天时取皮肤类似物进行冰冻切片,HE染色进行组织结构检查,免疫组化法检查角蛋白10、泛角蛋白以及HPV11L1蛋白表达。结果HE染色显示,HPV11.HaCaT细胞和正常HaCaT细胞的层数明显增多。免疫组化显示,两种细胞的皮肤类似物角蛋白10、泛角蛋白表达全部阳性。HPV11.HaCaT细胞表达L1蛋白阳性,而正常HaCaT表达L1蛋白阴性。结论三维培养方式可诱导HPV11.HaCaT细胞分化,皮肤类似培养物出现细胞分化标志,并且表达HPV11型衣壳蛋白L1。     

人巨细胞病毒 pp65基因重组蛋白在昆虫细胞中的表达与分析

目的为了制备人巨细胞病毒(HCMV)pp65基因疫苗,应用BacToBac系统对HCMVpp65基因进行表达,并对重组蛋白质的特异性及生物活性进行确定。方法通过脂质体法用HCMVpp65基因重组病毒感染Sf9昆虫细胞,并在感染的不同时期收集细胞,用特异性的HCMVpp65MAb对重组蛋白进行Westernblot,并选择HCMVIgG阳性及阴性的孕妇血清与重组蛋白进行免疫印迹反应。结果重组Bacmid大分子DNA直接转染昆虫细胞可得到100%的阳性重组病毒,病毒滴度为3×107pfu/ml,重组病毒组在感染后48h开始出现一相对分子质量为65000大小的特异带,感染后72h量明显增加,持续至感染后96h,在野生型AcNPV感染细胞及正常昆虫细胞的空白对照中未见该蛋白带。Westernblot显示目的蛋白条带与HCMVpp65MAb发生特异反应。6例阳性血清中有5例与重组pp65发生特异性反应,而阴性对照组未见特异性反应带。结论HCMVpp65基因可在Sf9昆虫细胞中有效表达,且所表达的重组蛋白pp65与人体中感染的野生型HCMVpp65具有相同的抗原性。因此有望为疫苗的制备打下基础。     

HPV16 L1在整合型重组毕赤酵母中的表达及病毒样颗粒的纯化

目的 构建可稳定表达HPV16 L1的整合型重组毕赤酵母,并纯化自主组装成的HPV16 L1病毒样颗粒（VLPs）.方法 根据酵母密码子偏爱性优化HPV16 L1基因并克隆到pPIC3.5K表达载体,构建pPIC3.5K/HPV16 L1重组质粒;重组质粒经Bgl Ⅱ酶切线性化后,电转化至GS115菌株中,筛选HPV16 L1重组毕赤酵母.阳性整合菌株甲醇诱导后,以HPV16 L1单克隆抗体检测目的蛋白表达;采用肝素亲和层析法纯化HPV16 L1VLPs并进行透射电镜观察.结果 PCR、酶切和测序分析表明成功构建了pPIC3.5K/HPV16 L1重组质粒.成功构建的HPV16 L1重组毕赤酵母甲醇诱导后,Western blot证实重组酵母菌裂解产物存在HPV16 L1目的蛋白.肝素亲和纯化后,透射电镜观察到了直径大约55 nm的VLPs,其形态与HPV16天然病毒颗粒相似.结论 利用整合型重组毕赤酵母表达系统成功表达了HPV16L1蛋白,并用肝素亲和纯化可快速获得结构完整的HPV16 L1VLPs,为HPV16预防性疫苗的研制奠定基础.     

Papillomavirus L1 major capsid protein self-assembles into virus-like particles that are highly immunogenic.

Infection by certain human papillomavirus types is regarded as the major risk factor in the development of cervical cancer, one of the most common cancers of women worldwide. Analysis of the immunogenic and structural features of papillomavirus virions has been hampered by the inability to efficiently propagate the viruses in cultured cells. For instance, it has not been established whether the major capsid protein L1 alone is sufficient for virus particle assembly. In addition, it is not known whether L1, L2 (the minor capsid protein), or both present the immunodominant epitopes required for induction of high-titer neutralizing antibodies. We have expressed the L1 major capsid proteins of bovine papillomavirus type 1 and human papillomavirus type 16 in insect cells via a baculovirus vector and analyzed their conformation and immunogenicity. The L1 proteins were expressed at high levels and assembled into structures that closely resembled papillomavirus virions. The self-assembled bovine papillomavirus L1, in contrast to L1 extracted from recombinant bacteria or denatured virions, also mimicked intact bovine papillomavirus virions in being able to induce high-titer neutralizing rabbit antisera. These results indicate that L1 protein has the intrinsic capacity to assemble into empty capsid-like structures whose immunogenicity is similar to infectious virions. This type of L1 preparation might be considered as a candidate for a serological test to measure antibodies to conformational virion epitopes and for a vaccine to prevent papillomavirus infection.     

Genital human papillomavirus infection.

Genital human papillomavirus (HPV) infection is a common sexually transmitted disease that at the present time is not effectively controlled or treated. Many infections are inapparent and transient. However, some HPV infections result in persistent lesions that in some cases undergo carcinogenic progression. A subset of genital HPVs, designated high-risk types, are preferentially associated with high-grade dysplasias and carcinomas. About 90% of cervical cancers contain high-risk HPV DNA, most often HPV16. Development of a subunit vaccine against high-risk genital HPVs is a desirable and, it appears, an increasingly feasible long-term goal. The viral E6 and E7 oncoproteins are selectively maintained and expressed in progressed HPV tumors and could potentially be targets for therapeutic vaccines. The L1 major virion structural proteins have recently been shown to self-assemble into virus-like particles when expressed in insect cells. These particles might serve as the basis for a prophylactic vaccine to prevent genital HPV infection.     

人乳头瘤病毒16型L1的表达、病毒样颗粒组装及其免疫原性研究

目的 在原核表达系统中表达HPV16 L1蛋白,纯化后在体外自组装成VLPs并鉴定。方法 优化GenBank中HPV16 L1基因序列并截短C末端25个氨基酸,构建至原核表达载体pET-28a上,获得重组表达载体pET28a-16L1△C25。采用镍亲和层析法纯化超声上清,于体外解组装-重组装HPV16 VLPs,采用动态光散射和透射电镜进行形貌分析,纯化后于第0、2和4周免疫小鼠,假病毒中和试验检测HPV16 VLPs免疫后血清中和抗体。结果 双酶切和测序结果表明成功构建pET28a-16L1△C25重组质粒,诱导表达后,经SDS-PAGE和Western blotting分析显示表达的L1蛋白大部分以可溶性形式存在,纯化后的蛋白样品于体外重新组装,动态光散射和透射电镜能够观察到形态与天然病毒颗粒相似的VLPs,第6周小鼠血清中和抗体滴度Log10平均值达到4.43。结论 利用原核表达系统成功表达了截短型HPV16 L1蛋白,并于体外组装成结构完整的VLPs,且具有较好的免疫原性,为低成本HPV预防性疫苗的研发奠定基础。     

Evidence for Chlamydia trachomatis as a human papillomavirus cofactor in the etiology of invasive cervical cancer in Brazil and the Philippines.

Chlamydia trachomatis infection was examined as a cause of invasive cervical cancer (ICC) among women with human papillomavirus (HPV) infection. In total, 499 women with incident ICC (ICC patients) and 539 control patients from S?o Paulo, Brazil, and Manila, the Philippines, were included. C. trachomatis antibodies were detected by microimmunofluorescence assay. Presence of HPV DNA in cervical specimens was determined by a polymerase chain reaction-based assay. C. trachomatis seropositivity was associated with sexual behavior but not with HPV infection. C. trachomatis increased the risk of squamous cervical cancer among HPV-positive women (odds ratio, 2.1; 95% confidence interval, 1.1-4.0). Results were similar in both countries. There was a suggestion of increasing squamous cancer risk with increasing C. trachomatis antibody titers. This large study examined C. trachomatis and cervical cancer, taking into account the central role of HPV infection. C. trachomatis infection was found to be a possible cofactor of HPV in the etiology of squamous cervical cancer, and its effect may be mediated by chronic inflammation.     

Coinfection of Chlamydia trachomatis, Ureaplasma urealyticum and human papillomavirus among patients attending STD clinics in Estonia

Women visiting Estonian STD clinics were subjected to PCR assay for human papillomavirus (HPV), Chlamydia trachomatis and Ureaplasma urealyticum biovar 2. The overall prevalence of coinfection was 8%. The chlamydial infection was found to be associated with HPV, especially with high-risk HPV (OR=2.5, p<0.005) and most significantly in women over 41 y of age. C. trachomatis infection also occurred more frequently in U. urealyticum-infected than in U. urealyticum-free patients (OR=2.6, p=0.02). U. urealyticum infection did not associate with HPV status. The clinical significance of the association between C. trachomatis and U. urelyticum infection remains to be elucidated.