HIV DNA疫苗与重组腺病毒伴随病毒联合免疫效果的研究

目的 构建含HIV-1B亚型中国株gagV3基因的DNA疫苗及重组腺病毒伴随病毒(rAAV)疫苗，并研究DNA疫苗和rAAV联合免疫的免疫效果。方法 将HIV-1B亚型中国株gagV3基因克隆入真核表达载体pCI-neo上，构建了含HIV-1 gagV3基因的DNA疫苗pCI-gagV3。采用电击法将pCI-gagV3质粒转染p815细胞，用G418压力筛选，得到转入重组质粒的细胞系p815-gagV3，用免疫酶法检测细胞系中HIV-1基因的表达。用该DNA疫苗进行小鼠免疫实验，检测免疫效果；用该DNA疫苗初次免疫，含同样gagV3基因的重组腺病毒伴随病毒rAAV-gagV3加强免疫，采用免疫酶法检测免疫小鼠血清中HIV-1特异性的抗体水平，用乳酸脱氢酶法检测免疫小鼠的HIV-1特异性CTL水平。结果 pCI-gagV3可以在p815细胞中表达HIV-1的基因，免疫BALB／c小鼠后可以在小鼠体内诱发HIV-1特异性的细胞和体液免疫反应。HIV-1特异性抗体滴度为1：20；效靶比为50：1时，CTL平均杀伤率为41．7％。pCI-gagV3与rAAV-gagV3联合免疫并不能明显提高抗体水平，但可以提高CTL反应，效靶比为50：1时，CTL平均杀伤率为61.3％，高于单独用DNA疫苗或重组AAV疫苗免疫后产生的CTL活性。结论 DNA疫苗与重组腺病毒伴随病毒联合免疫可以提高免疫小鼠产生的HIV-1特异性CTL反应。     

含密码子优化型HIV-1 gp120基因重组腺病毒的构建及其免疫效果研究

目的 构建能表达野生型和密码子优化型人免疫缺陷病毒Ⅰ型(HIV-1)B亚型中国流行株gp120基因的非复制型腺病毒。方法 按哺乳动物细胞偏好的密码子对HIV-1B亚型中国流行株Ch gp42的gp120基因进行优化，合成优化基因。将野生型和密码子优化的gp120基因插入穿梭质粒，再与腺病毒骨架质粒pAdEasy-1共转化E．coli BJ5183，获得重组子，转染293细胞后获得重组病毒。分别以两种重组腺病毒疫苗免疫小鼠，ELISA检测小鼠血清中的特异性抗体，乳酸脱氢酶法检测小鼠细胞毒性T淋巴细胞(CTL)反应。结果 获得两株重组腺病毒rAd-wt．gp120和rAd．mod．gp120，能正确表达Gp120。rAd-mod．gp120比rAd-wt．gp120蛋白表达水平明显提高。重组腺病毒免疫小鼠后能产生HIV-1特异性的抗体及CTL反应，rAd-mod．gp120组明显优于rAd-wt．gp120组。结论 成功构建了表达野生型和密码子优化的HIV-1 gp120基因的重组腺病毒，能诱导HIV-1特异性体液和细胞免疫反应。     

含HIV-1 gag基因的重组腺病毒5型与35型嵌合病毒免疫效果研究

目的探讨含HIV-1 gag基因的重组腺病毒5型与35型嵌合病毒(rAd5/F35)在BALB/c小鼠中的免疫效果。方法PCR,间接免疫荧光鉴定HIV-1gag基因在重组腺病毒(rAd5/F35-mod.gag)的正确插入和体外细胞水平的表达,用rAd5/F35-mod.gag以不同的方式免疫BALB/c小鼠,ELISA检测小鼠血清中的p24特异性抗体,细胞内细胞因子染色法检测小鼠的特异性细胞毒性T淋巴细胞(CTL)应答。结果重组腺病毒rAd5/F35-mod.gag在体外细胞水平可以很好的表达目的基因gag;在小鼠体内重组腺病毒rAd5/F35-mod.gag可诱导特异性的CTL应答和血清IgG抗体反应,用rAd5/F35单独免疫2次,所诱发的CTL和血清IgG反应最强。但Ad5初次感染后,产生的抗Ad5抗体可以抑制rAd5/F35疫苗的特异性免疫反应。结论重组腺病毒rAd5/F35-mod.gag单独免疫可在小鼠体内诱导特异性的CTL应答和血清IgG抗体反应。只改变Ad5纤突蛋白Fiber,不能避免抗Ad5抗体的抑制作用。     

表达HIV-1 gag-polΔ和gp140TM蛋白复制缺陷型重组腺病毒的构建及免疫效果研究

目的 构建表达人免疫缺陷病毒Ⅰ型gag-polΔ和gp140TM基因的非复制型重组腺病毒。方法 首先将HIV-1的gag-polΔ和gp140TM基因插入穿梭载体，再与腺病毒骨架质粒pAd Easy-1共转化E．coli BJ5183，获得重组子。转化293细胞后获得重组病毒。重组腺病毒与DNA疫苗联合免疫小鼠，ELISA检测小鼠血清中的抗体。结果 获得两株重组腺病毒vAd-gag-polΔ和vAd-gp140TM，能正确表达Gp140TM、Gag蛋白以及经剪切加工的P24蛋白，与DNA疫苗联合免疫小鼠后能产生高滴度的HIV-1特异性的抗体。结论 成功构建了表达HIV-1结构基因的重组腺病毒，能有效诱导HIV-1特异性抗体。     

HIV-1CN54 DNA疫苗滴鼻免疫小鼠诱发系统和黏膜免疫应答

目的：探讨重组痘苗病毒rVVsyngp120或rVVmCN54gp120候选疫苗是否增强HIV-1CN54合成gp120基因(syngp120)DNA疫苗的免疫原性。方法：第0、7、14、21天用DNA疫苗滴鼻免疫小鼠,第28、35、42天再滴鼻接种rVVsyngp120或rVVmCN54gp120。体外测脾和肠系膜淋巴结(MLN)淋巴细胞增殖应答与CD8^ CTL应答。测血清和黏膜洗液特异的IgG和IgA,并测其是否中和实验室适应株HIV-1SF33。结果：单纯DNA免疫后,脾和MLN淋巴细胞在体外发生增殖应答和CTL应答,且测出血清特异的IgG和黏膜洗液特异的IgA。重组痘苗病毒末次免疫后第2周(第56天),发现rVVmCN54gp120增强MLN淋巴细胞增殖应答和CTL应答,脾CTL应答也增强。rVVsyngp120则增强MLN CTL应答。同时发现：2组重组痘苗病毒免疫的动物其血清中特异IgG抗体滴度均有所增高,但黏膜(粪便和阴道)洗液特异IgA抗体滴度却未增高,未测出血清特异IgA和黏膜洗液特异IgG。免疫血清可中和HIV-1SF33,而阴道洗液却不能。结论：单纯DNA疫苗滴鼻免疫可诱发较弱的系统和黏膜体液免疫与细胞免疫,但维持时间短。重组痘苗病毒主要增强局部黏膜的细胞免疫应答,且稍增强系统体液免疫应答,未增强黏膜的IgA应答。免疫血清有中和作用。     

小鼠对HIV-2 gp105核酸疫苗免疫应答的研究

目的: 探讨HIV- 2gp105基因核酸疫苗在小鼠体内的免疫应答, 为开发HIV- 2核酸疫苗提供实验依据。方法:将HIV- 2外膜蛋白 (gp105 )基因插入真核表达质粒载体pVAX1中, 构建pVAX1 gp105重组表达质粒。将其肌注免疫BALB/c小鼠, 用ELISA法检测小鼠血清抗HIV -2抗体, 用流式细胞仪测定CD4 、CD8 T细胞亚群数, 以乳酸脱氢霉释放法检测脾特异性CTL的杀伤活性。结果: 重组质粒pVAX1 -gp105免疫组小鼠的血清抗体滴度、脾T细胞亚群的数量及特异性CTL的杀伤活性, 均明显高于对照组, 分别为P<0. 01, P<0. 05和P<0. 01。结论: HIV -2gp105核酸疫苗能诱导小鼠产生特异性细胞和体液免疫。     

表达HIV-1 gag-pol△和gp 140 TM蛋白复制缺陷型重组腺病毒的构建及免疫效果研究

目的构建表达人免疫缺陷病毒Ⅰ型gag-pol△和gp140TM基因的非复制型重组腺病毒.方法首先将HIV-1的gag-pol△和gp140TM基因插入穿梭载体,再与腺病毒骨架质粒pAdEasy-1共转化E.coli BJ5183,获得重组子.转化293细胞后获得重组病毒.重组腺病毒与DNA疫苗联合免疫小鼠,ELISA检测小鼠血清中的抗体.结果获得两株重组腺病毒vAd-gag-pol△和vAd-gp140TM,能正确表达Gp140TM、Gag蛋白以及经剪切加工的P24蛋白,与DNA疫苗联合免疫小鼠后能产生高滴度的HIV-1特异性的抗体.结论成功构建了表达HIV-1结构基因的重组腺病毒,能有效诱导HIV-1特异性抗体.     

IL-12、IL-18基因对HIV-1外膜蛋白基因疫苗诱导的免疫应答的影响

目的 研究IL-12、IL-18基因对HIV-1外膜蛋白基因疫苗诱导免疫应答的影响，以探求HIV-1核酸疫苗的新策略。方法 pVAX1GP120联合IL-12、IL-18基因或者pVAX1GP120单独免疫BALB／c小鼠，采用ELISA检测免疫小鼠的特异性抗体和IFN-γ水平，以NIT比色法检测免疫小鼠脾淋巴细脯增殖，用乳酸脱氢酶（LDH）试验检测小鼠特异性细胞毒性T淋巴细胞（CIL）的应答。结果 与pVAX1GP120免疫组比较，pVAX1GP120联合IL-12、IL-18基因免疫组小鼠血清的抗HIV-1 gp120抗体滴度升高，IFN-γ升高，小鼠的脾淋巴细胞增殖实验刺激指数（SI）以及特异性CTL活性均高，差异均有统计学意义（P〈0．01）。结论 IL-12、IL-18基因联合HIV-1核酸疫苗免疫小鼠，有可能增强特异性TH1细胞和CTL反应，IL-12、IL-18基因对体液免疫可能有抑制作用。因此，IL-12、IL-18基因对于治疗性HIV-1核酸疫苗可能是具有较好应用前景的免疫佐剂。     

HIV-2 gag rFPV与rDNA疫苗的联合免疫研究

目的 探讨HIV-2核心蛋白基因gag重组DNA疫苗与重组鸡痘病毒进行联合免疫引起小鼠的免疫应答，为研究HIV-2基因重组疫苗的免疫策略提供实验基础。方法 大量制备并纯化HIV-2 gag重组DNA疫苗和重组鸡痘病毒，以肌肉注射的方式免疫BALB／c小鼠，ELISA法检测小鼠血清HIV-2抗体，流式细胞仪测定CD4^＋、CD8^＋T淋巴细胞亚类数量，乳酸脱氢酶（LDH）释放法检测脾CTL对HIV-2靶细胞的杀伤活性。结果 重组DNA疫苗和重组鸡痘病毒单独免疫及二者联合免疫均刺激小鼠产生HIV-2特异性抗体，脾T细胞亚类数量增加，并产生针对HIV-2靶细胞的特异性CTL杀伤活性，但联合免疫组在各项指标上均高于单独免疫组。结论 以HIV-2gag重组DNA疫苗进行基础免疫、以HIV-2gag重组鸡痘病毒进行加强免疫能诱导小鼠产生更强的特异性细胞和体液免疫应答。     

表达HIV-1 gag基因的重组AAV2/1和Ad5疫苗免疫原性比较

目的 在小鼠体内比较表达HIT-1 gag基因的重组AAV2/1和Ad5疫苗的免疫原性.方法 分别用rAAV2/1-gag或rAd5-gag单独免疫BALB/c小鼠一次或两次,于免疫后不同时间点用CFSE染色法和胞内细胞因子染色法检测Gag特异性细胞免疫应答,用ELISA方法检测Gag特异性抗体反应.结果 单次免疫结果显示,在所有检测点rAd5-gag所诱导的Gag特异性CTL应答都比rAAV2/1-gag强,抗体反应在免疫后4周无明显差异.两次免疫后4周的检测结果表明,rAd5-gag所诱导的Gag特异性CTL应答比rAAV2/1-gag强,但抗体反应比rAAV2/1-gag组弱.结论 rAd5-gag诱导了很好的HIV-1特异性细胞和抗体反应,而rAAV2/1-gag诱导的HIV-1特异性抗体反应很强,但细胞免疫应答较弱.     

表达HIV-1 B亚型env基因的质粒DNA及腺病毒载体疫苗的免疫原性研究

目的 构建表达中国B亚型HIV-1流行株env基因的DNA及重组腺病毒载体疫苗,将其用于预防或治疗HIV感染.方法 构建质粒DNA疫苗pVR-gp160及重组腺病毒载体疫苗rAdV-gp160.将这两种疫苗以不同的方式免疫BALB/c小鼠,分别采用ELISPOT方法 和ELISA方法 检测免疫小鼠中HIV-1 Gp120特异性细胞免疫反应及抗体反应.结果 DNA疫苗单独免疫及DNA疫苗初免/腺病毒疫苗加强免疫的联合免疫方案皆可诱导较高水平的Gp120特异性细胞免疫反应;而在体液免疫方面,各实验组产生的Gp120特异性抗体水平都较低.结论 所构建的DNA疫苗及rAdV疫苗能有效表达Gp160蛋白,并可有效激活机体的细胞免疫反应.     

不同HBsAg疫苗联合免疫后诱导小鼠细胞和体液免疫应答的研究

目的：了解HBsAg的蛋白疫苗（P）、痘苗病毒疫苗（V）、DNA疫苗（D）联合免疫小鼠诱导的特异性体液和细胞免疫应答。方法：以P、V或D疫苗中的一种疫苗初次免疫BALB／c小鼠后，于第2、5、8、11周再用另一种疫苗加强，共产生9种免疫组合：即PP、PV、PD、VP、VV、VD、DP、DV及DD。于初免后第2、5、8、11周采血检测血清中抗HBsAgIgG的总滴度及其IgG1和IgG2a亚类，并于每次加强免疫后第7天，检Nd,鼠脾脏的CTL对P815S细胞的特异性杀伤率。结果：在P、V、D3种疫苗中，V疫苗诱导产生抗HBsAg抗体的速度最快，P疫苗诱导的体液免疫回忆反应最强，D疫苗诱导产生的抗体最弱。除PP疫苗组合诱导的抗体明显倾向于IgG1外，其他均无明显的倾向性。各种免疫组合中，VD和DV疫苗组诱导的CTL应答最强，对P815S的特异性杀伤率分别为71％和64％。结论：在各种联合免疫组合中，PV、PD、VP和VD疫苗组的抗体应答较好；而DV和VD疫苗组诱导的CTL杀伤效应最强。     

Construction and characterization of recombinant fowlpox virus coexpressing HIV-1(CN) gp120 and IL-2

The acquired immunodeficiency syndrome (AIDS) has now become one of the most serious infectious disease in the world, the safe and effective AIDS vaccines would be the best tools to control the disease. Fowlpox virus has been studied recently as a potential vector for the delivery of heterologous vaccine antigen. In this study, a recombinant fowlpox virus coexpressing gp120 of Chinese prevalent HIV-1 strain and IL-2 was constructed and the cellular immune responses against HIV-1 gp120 in BALB/c mice were evaluated. Chinese vaccine strain 282E4 of fowlpox virus was used as the vector to construct the recombinant fowlpox virus (rFPV) coexpressing HIV-1 gp120 and IL-2 via homologous recombination, and the recombinant virus was identified by PCR and Western blotting. The specific DNA fragment was amplified by PCR from the genomes of rFPV. Western blotting analysis showed that HIV-1 gp120 and IL-2 was expressed not only in chicken embryo fibroblast (CEF) cells infected by rFPV, but also in mammalian cells infected by rFPV. After the recombinant fowlpox virus was inoculated into BALB/c mice, specific CTL activities in the immunized mice were detected in the spleen. The results demonstrated that rFPV had good immunogenicity and could induce BALB/c mice to produce specific cellular immunity. IL-2 played a role of immunoadjuvant and enhanced the cellular immune response. The study provides the basis for the preparation of a Chinese vaccine candidate against HIV-1.     

Humoral immune response elicited by highly attenuated variants of vaccinia virus and by an attenuated recombinant expressing HIV-1 envelope protein

Attenuated variants of vaccinia virus have excellent potential for the construction of safe recombinant live vaccines. In this investigation, highly attenuated variants of vaccinia virus with several genetic markers and a variant recombinant were tested in Balb/c mice for their ability to induce humoral immune response. Mice primed with variants that had an 8-MDa deletion at the left end of the viral genome induced similar levels of circulating anti-vaccinia antibodies as the wild-type virus. However, mice primed with variants that had several genetic lesions (deletions and point mutations) induced lower levels of circulating anti-vaccinia antibodies. Mice primed and boosted with a recombinant variant with several genetic lesions, and containing the complete envelope gene of the human immunodeficiency virus (HIV) and the bacterial beta-galactosidase (beta-gal) gene, induced significant antibody response to gp 160 and beta-gal. The antibody response to gp 160 was markedly increased by successive inoculations with the recombinant variant. Our findings provide evidence that the extent of activation of the immune system by vaccinia variants can be modulated by the nature of the virus genetic lesion. In addition, when these variants are used as recombinant vaccines, it is possible to induce low levels of circulating anti-vaccinia antibodies after priming and yet achieve significant antibody response to virus-expressed foreign antigens, even after repeated boosters. Such variants could be useful in the design of live recombinant viruses as safe vaccines.     

Long-term humoral and cellular immunity induced by a single immunization with replication-defective adenovirus recombinant vector

This study examines the suitability of replication-defective adenovirus vectors for engineering recombinant vaccines. The immunological abilities and limitations of E1-deleted adenoviruses containing the lac Z gene (Ad-β-gal) were investigated by examining the humoral and cellular immune responses to the β-galactosidase protein. BALB/c mice (H-2^d) were given in a single injection of recombinant adenovirus. The cytotoxic T lymphocyte (CTL) response of spleen cells was evaluated. Recognized target cells were H-2^d-derived tumor cells transfected by the lac Z gene, or incubated with the 876–884 β-galactosidase peptide known to be restricted by the L^d molecule of the major histocompatibility complex. A long-lasting β-galactosidase-specific cytotoxic T cell response was obtained. By contrast, CTL from mice immunized with the L^d-restricted peptide were less specific for the endogenous epitope presented by the transfectants expressing β-galactosidase. Ad-β-gal-immunized mice were also protected against an intra-cerebral challenge with a recombinant vaccinia virus expressing the lac-Z gene. These results suggest that Ad-β-gal-induced CTL have protective abilities in vivo. The induction of β-galactosidase-specific T helper lymphocytes and humoral IgG responses were also examined. A proliferative response occurred only late after immunization and the primed T lymphocytes produced interleukin-2, but no interleukin-4. A humoral IgG response to the β-galactosidase protein was detected 15–30 days after a single immunization and remained stable for 6 months without boosting. Lastly, we followed the evolution of the immune response over the course of successive immunizations. The magnitude and kinetics of the cellular and humoral responses were similar to those obtained after a single immunization. Consistent with these observations, an adenovirus-specific neutralizing antibody response was detected as early as the second immunization. Thus, a single immunization with a replication-defective adenovirus recombinant vector induces long-lasting humoral and cellular immune responses specific to the transgene product.     

含HPV16L1基因重组腺病毒和1型重组AAV载体联合免疫效果的研究

目的 对表达HPV16L1抗原的重组腺病毒及1型重组AAV载体联合免疫效果进行研究.方法 分别构建含密码子优化型HPVl6LI基因重组腺病毒rAd-mod.HPV16L1及1型重组从V载体rAAV1-mod-HPV 16L1,将纯化的重组AAV病毒载体以肌注及滴鼻途径单独及联合免疫C57BL/6小鼠,使用体外中和实验检测各组小鼠血清中特异性中和抗体.结果 rAAV1-med-HPV16L1单独及与rAd-mod-HPV16L1联合肌注可诱导高滴度的血清中和抗体,在初免后第16周抗体滴度显著高于其他免疫组,联合肌注组诱导的抗体滴度高于单独肌注组;重组病毒联合滴鼻虽能产生一定的免疫加强作用,但抗体滴度仍显著低于rAAV1-mod-HPV16L1单独及联合肌注组.结论 型重组从V载体联合重组腺病毒以初免.加强模式肌注可诱导更高滴度的血清中和抗体.