乙型肝炎病毒核心区DNA疫苗接种后H-2d小鼠的特异性免疫应答

目的观察乙型肝炎病毒（ＨＢＶ）核心区ＤＮＡ疫苗接种后ＢＡＬＢ／ｃ（－２ｄ）小鼠的特异性免疫应答。方法构建ＨＢＶ核心区ＤＮＡ疫苗（ＰＪＷ４３０３／ＨＢｃ）;用基因枪法和肌肉注射祛将该ＤＮＡ疫苗接种ＢＡＬＢ／ｃ小鼠;ＥＬＩＳＡ法检测小鼠血清抗－ＨＢＣ（ＩｇＧ）及ＩｇＧ亚类（ＩｇＧ１,ＩｇＧ２ａ）;５１铬释放法检测小鼠脾细胞ＨＢｃＡｇ特异性ＣＴＬ活性。结果该ＤＮＡ疫苗在体外转染细胞中可良好表达ＨＢｃＡｇ。血清抗－ＨＢｃ终点滴度在ＤＮＡ疫苗基因枪组和肌肉注射接种组小鼠分别为１：３２８０５０和１：１０９３５０．两组小鼠的抗－ＨＢｃＩｇＧ亚类均以ＩｇＧ２ａ略占优势。两组小鼠的ＨＢＣＡｔｈｅ异性ＣＴＬ杀伤活性分别达到５１．１％和５５．２％。结论ＨＢＶ核心区ＤＮＡ疫苗在小鼠实验中具有良好的细胞免疫和体液免疫原性。     

HBcAg DNA疫苗诱导小鼠（H—2^b）特异性细胞和体液免疫应答

目的 观察ＨＢｃＡｇ ＤＮＡ疫苗（ｐＪＷ４３０３／ＨＢｃ）免疫Ｃ５７ＢＬ／６小鼠（Ｈ－２＾ｂ）的特异性细胞和体液免疫应答。方法 基因枪和肌肉注射两种方法接种ＤＮＡ疫苗;ＥＬＩＳＡ法检测小鼠血清抗－ＨＢｃ（ＩｇＧ）及ＩｇＧ亚类（ＩｇＧ１,ＩｇＧ２ａ）;＾５１铬释放法检测小鼠脾细胞ＨＢｃＡｇ特异性ＣＴＬ活性。结果 该ＤＮＡ疫苗体外可表达ＨＢｃＡｇ;小鼠经基因枪或肌肉注射接种该疫苗后血清抗－ＨＢｃ滴度分     

DNA疫苗诱导小鼠细胞免疫及抗肿瘤免疫研究

目的 观察ＨＢＶＤＮＡ疫苗诱导ＢＡＬＢ／Ｃ小鼠（Ｈ－２＾ｄ）的特异性细胞免疫应答及其对稳定表达ＨＢｓＡｇ的小鼠肥大细胞瘤Ｐ８１５细胞（这５－ＨＢＶ－Ｓ）（Ｈ－２＾ｄ）成瘤性的影响。方法 肌肉注射ＤＮＡ疫苗,背部皮下接种Ｐ８１５－ＨＢＶ－Ｓ细胞,观察成瘤情况,４ｈ＾５１Ｃｒ释放法不细胞细胞毒Ｔ淋细胞（ＣＴＬ）活性。结果 ＤＮＡ疫苗可以降低成瘤率,抑制成长小鼠存活期和提高小鼠存活率。ＣＴＬ细胞杀伤活性     

结核分支杆菌Hsp70和Hsp 65 DNA疫苗免疫原性比较研究

分支杆菌热休克蛋白 (Ｈｓｐ)既有增强免疫应答的作用 ,又保持了分支杆菌本身的抗原特性。我们采用分子生物学技术 ,将结核分支杆菌Ｈｓｐ70基因克隆到真核表达质粒ｐｃＤＮＡ3中 ,构成裸露ＤＮＡ疫苗 (ＤＮＡ70 )。采用英国Ｌｏｗｒｉｅ教授赠送的Ｈｓｐ65ＤＮＡ疫苗和本室构建的Ｈｓｐ70ＤＮＡ疫苗免疫ＢＡＬＢ/ｃ小鼠 ,然后观察其对小鼠免疫应答的影响 ,探讨两种疫苗的抗感染机制及比较两种疫苗的免疫原性。材料与方法　雄性ＢＡＬＢ/ｃ小鼠 ,购自本校实验动物学部 ;ＲＰＭＩ 164 0购于美国Ｓｉｇｍａ公司 ;白细胞介素 2 (ＩＬ 2 )和γ干…     

日本血吸虫副肌球蛋白全基因核酸疫苗在小鼠诱生的保护性免疫力

目的： 研究日本血吸虫大陆株副肌球蛋白全基因核酸疫苗免疫Ｃ５７ ＢＬ／６ 及ＢＡＬＢ／ｃ 小鼠诱生的保护性免疫力。方法： 将构建的日本血吸虫大陆株副肌球蛋白全基因核酸疫苗 （ｐＣＭＶ－ＳｊＣ９７） 经后腿胫前肌免疫Ｃ５７ＢＬ／６及ＢＡＬＢ／ｃ小鼠, 共免疫３ 次, 每次间隔３ ｗ ｋ。末次免疫后３ ｗ ｋ 以血吸虫尾蚴攻击感染, ６ ｗｋ 后计数成虫负荷及肝、脾、肠组织虫卵数。设不含ＳｊＣ９７ 编码基因的空载体质粒免疫组为对照组。结果： ｐＣＭＶ－ＳｊＣ９７ 免疫Ｃ５７ ＢＬ／６ 小鼠主要诱生ＩｇＧ２ａ 和ＩｇＧ２ｂ 亚类, 而免疫ＢＡＬＢ／ｃ小鼠除诱生ＩｇＧ２ａ 和ＩｇＧ２ｂ 亚类外, 还诱生ＩｇＧ１。ｐＣＭＶ－ＳｊＣ９７ 免疫Ｃ５７ＢＬ／６ 小鼠诱生较明显的减虫率 （３５．５％ ～４１．１％ ） 和减卵率 （肝、脾及肠组织减卵率分别为４４．５％ ～５９．６％ 、５６．７％ ～８２．４％ 及５７．９％ ）, 而对ＢＡＬＢ／ｃ小鼠未诱生保护性。结论： ｐＣＭＶ－ＳｊＣ９７ 核酸疫苗能对Ｃ５７ＢＬ／６ 小鼠诱生较明显保护性免疫力, 而对ＢＡＬＢ／ｃ 小鼠未诱生免疫保护力     

基因疫苗诱导小鼠抗HBV皮下移植瘤免疫研究

目的　观察 ＨＢＶ ＤＮＡ 疫苗（ｐＣＲ３－１Ｓ） 诱导Ｂａｌｂ／ ｃ 小鼠（ Ｈ２ｄ） 的特异性细胞免疫应答及其对稳定表达ＨＢｓＡｇ 的小鼠肥大细胞瘤Ｐ８１５ 细胞（Ｐ８１５ＨＢＶＳ） （ Ｈ２ｄ） 成瘤性的影响．方法　肌肉注射ＤＮＡ 疫苗,背部皮下接种Ｐ８１５ＨＢＶＳ 细胞,观察成瘤情况,４ ｈ ５１Ｃｒ 释放法检测小鼠脾细胞ＣＴＬ 活性．结果　接种 ＤＮＡ 疫苗后小鼠成瘤率为１２－５ ％ , 对照组为１００ ％ ． 小鼠平均存活期大于３８－２ ｄ ,对照组为２８－４ ｄ ,４０ ｄ 后小鼠存活率为８７－５ ％ ,对照组为０ ％ ． ＣＴＬ 细胞杀伤活性明显增加,ｐＣＲ３－１Ｓ 组５１ ％ ,对照组为２１ ％ （ Ｐ＜ ０－００１） ．结论　ＤＮＡ 疫苗可以诱导细胞免疫应答,对体内ＨＢＶ 感染具有预防及治疗作用．     

口服丙型肝炎复合多表位DNA减毒鼠伤寒沙门活菌苗的实验研究

目的　利用减毒鼠伤寒沙门菌作为载体,探讨丙型肝炎病毒（ＨＣＶ） 口服ＤＮＡ 疫苗的可行性。方法　把ＨＣＶ 复合多表位抗原基因ＰＣＸ 克隆到真核表达载体ｐｃＤＮＡ３（ＣＭＶ 启动子） ,构建ＨＣＶ 真核表达载体ｐｃＤＮＡ３／ＰＣＸ,转化减毒鼠伤寒沙门菌ＳＬ３２６１ ,获得ＨＣＶ 重组口服ＤＮＡ 活菌苗ＳＬ３２６１ （ｐｃＤＮＡ３／ＰＣＸ） ,免疫小鼠及家兔后,检测特异性免疫应答及安全性。结果　ＳＬ３２６１（ｐｃＤＮＡ３／ＰＣＸ） 在小鼠及家兔中均可诱发低水平的特异性体液免疫及细胞免疫应答,免疫动物未见明显的毒性反应。结论　ＨＣＶ 口服减毒鼠伤寒沙门菌ＤＮＡ 疫苗可诱发特异性的免疫应答,为ＨＣＶ 疫苗的研究提供新的理论及实验依据     

丙型肝炎病毒核心基因免疫诱生细胞免疫应答研究

目的 研究丙型肝炎病毒（ＨＣＶ）核心（Ｃ）基因免疫在诱生特异性细胞免疫应答中的作用。方法 将包含ＨＣＶ Ｃ基因片段的重组真核表达质粒ｐｃＣＮＡ ＨＣＶ Ｃ,在主宰其可以在小鼠骨髓瘤ＳＰ２／０（Ｈ－２^d）中表达之后,注射ＢＡＬＢ／ｃ小鼠股四头肌。ＥＬＩＳＡ法检测血清中抗体水平;^3Ｈ－ＴｄＲ掺入法测定免疫小鼠脾细胞特异性增殖能力;^51Ｃｒ释放法检测免疫小鼠细胞毒性Ｔ淋巴细胞（ＣＴＬｓ）体外杀伤功能。结     

小鼠HCV皮下移植瘤的建立及使用DNA疫苗的治疗作用

建立小鼠丙型肝炎病毒 (ＨＣＶ)皮下移植瘤 ,并以其为ＨＣＶ感染动物模型 ,观察ＨＣＶ核心 (Ｃ)基因ＤＮＡ疫苗 ( ｐｃＤＮＡ ＨＣＶ Ｃ)在体内对ＨＣＶ感染的治疗作用。将 ｐｃＤＮＡ ＨＣＶ Ｃ用脂质体 (Ｌｉｐｏｆｅｃｔａｍｉｎｅ)法转染ＢＡＬＢ/ｃ小鼠骨髓瘤ＳＰ2 /0 (Ｈ 2 ｄ)细胞 ,经Ｇ4 18筛选获稳定表达ＨＣＶＣ抗原之后 ,以 5× 10 5个细胞 /10 0 μｌ注射ＢＡＬＢ/ｃ小鼠右肋皮下 ,3ｄ后 30只试验小鼠分成 3组 ,即 :生理盐水对照组、ｐｃＤＮＡ3对照组和 ｐｃＤＮＡ ＨＣＶ Ｃ治疗组。观察并记录成瘤时间、肿瘤大小及小鼠存活时…     

HBV基因疫苗联合抗原蛋白免疫小鼠的研究

目的构建乙肝病毒（ＨＢＶ）基因疫苗,观察其与ＨＢＶ表面抗原蛋白（ＨＢｓＡｇ）联合免疫小鼠诱导的免疫应答．方法构建重组真核表达质粒ｐＣＲ３１Ｓ作为ＨＢＶ基因疫苗,联合应用纯ＨＢｓＡｇ蛋白免疫Ｂａｌｂ／ｃ小鼠,以单用基因疫苗ｐＣＲ３１Ｓ或纯蛋白ＨＢｓＡｇ免疫小鼠作为对照组．采用ＥＬＩＳＡ法检测免疫小鼠血清抗ＨＢｓ,另取免疫小鼠脾细胞,用３ＨＴｄＲ掺入法测定各组免疫小鼠的淋巴细胞增殖活性．结果２,４ｗｋ时联合免疫组抗ＨＢｓ效价低于纯蛋白免疫组,高于基因疫苗免疫组;６ｗｋ后基因疫苗免疫组抗ＨＢｓ效价升至最高,联合免疫组次之．３ＨＴｄＲ掺入法测定显示,各组免疫小鼠的淋巴细胞增殖反应差异不显著．结论乙肝病毒基因疫苗与表面抗原蛋白联合免疫无优势．     

乙型及丙型肝炎DNA疫苗联合重复接种小鼠的免疫应答

目的 :观察由编码 HBs Ag与 HCV- CE2 抗原的两种重组真核细胞表达质粒制备的 DNA疫苗重复联合接种 BAL B/c小鼠后 ,其诱生的特异性免疫应答反应。方法 :应用上述两种 NDA疫苗重复联合免疫小鼠 ,动态观察血中特异性抗体水平、特异性细胞毒性 T淋巴细胞 (CTL )体外杀伤活性 ,并进行 CTL杀伤活性活体诱生实验。结果 :两种 DNA疫苗联合重复免疫小鼠 ,能够诱生机体特异性体液免疫及细胞免疫完全应答。其小鼠荷瘤表达目的抗原的靶细胞后 ,生存率明显高于未免疫鼠 (P <0 .0 5 )。结论 :乙型及丙型肝炎联合 DNA疫苗的重复接种 ,可有效地诱生小鼠机体特异性免疫应答反应。 DNA疫苗诱生的 CTL应答可与体液免疫应答分离存在 ,可能是 DNA疫苗免疫保护的更重要方面。     

HBV主蛋白、HCV-CE2真核细胞表达质粒在小鼠肌细胞内的共表达

目的:比较真核细胞表达质粒混合与单独接种对各自表达的影响。方法:在小鼠肌组织内单独或混合接种编码HBV主蛋白、HCV-CE2抗原的两种真核细胞表达质粒,取不同时间肌组织进行免疫组化检测,进行比较分析。结果:混合接种后相应蛋白均能够表达,但表达强度及持续时间明显不及单独免疫。结论:两种真核表达质粒可以在小鼠肌细胞内表达,但其程度较弱,可能与相对较弱的体液免疫应答有关。     

体内外检测乙型肝炎DNA疫苗诱生小鼠特异性CTL活性的比较研究

目的：了解体内外两种方法检测乙型肝炎DNA疫苗诱生BALB／c小鼠特异性细胞毒性T淋巴细胞（CTL）活性的特点，比较其异同，建立与体外法互为补充，且更加直观、简便的活体CTL活性检测模型。方法：用HBV-S真核表达质粒pVAX1／S对SP2／0细胞进行转染，经鉴定后作为目的靶细胞（稳定转染并表达HBV主蛋白，命名为SP2／0-S细胞）；对照靶细胞为稳定转染pVAX1空载质粒的细胞（命名为SP2／0-P细胞）备用。活体诱生实验：用目的或对照靶细胞分别使小鼠荷瘤，观察免疫及非免疫小鼠在各靶细胞负荷下的生存时间与肿瘤的生长情况，设置不同组合做同期对照观察，小鼠生存率的差异可以提示体内特异性CTL是否存在。体外诱生实验：采用经典CTL活性检测方法，LDH释放法成品药盒。SP2／0-S细胞与SP2／0-P细胞作为靶细胞，免疫鼠与非免疫鼠的脾细胞为效应细胞，按照不同效／靶比共孵育后以酶标仪检测LDH的释放活性。结果：活体诱生实验：免疫小鼠存活时间明显长于对照小鼠（P〈0．05）。体外诱生实验：免疫鼠CTL活性在彬靶比为50／1时出现最大杀伤活性，为36．9％，明显优于对照组（P〈0．05）。结论：体内外两种方法均能够检测到乙型肝炎DNA疫苗诱生BALB／c小鼠特异性CTL活性，实验中发现体外LDH释放法CTL活性并不高，但是总体上仍然能够反映CTL活性。而活体诱生实验操作相对简便，表现更为直观，可望成为与经典方法相互补充的新型实验模型。     

Hepatitis B virus precore protein augments genetic immunizations of the truncated hepatitis C virus core in BALB/c mice

DNA immunization has been used to induce either humoral or cellular immune responses against many antigens, including hepatitis C virus (HCV). In addition, DNA immunizations can be enhanced or modulated at the nucleotide level. Genetic immunizations were examined in BALB/c mice through the use of plasmids and chimeric DNA constructs encoding HCV core proteins and hepatitis B virus (HBV) precore (preC) regions. Plasmids encoding the truncated HCV core induced potent humoral and cellular responses to HCV; pcDNA3.0A-C154 produced a stronger antibody response than pcDNA3.0A-C191 (P < 0.01) and pcDNA3.0A-C69 (P < 0.05). HBV preC enhanced the humoral and cellular immune responses of BALB/c mice to HCV; however, pcDNA3.0A-C69preC resulted in a weak cytotoxic T lymphocyte (CTL) response. In addition, the humoral and cellular immune responses to HCV of groups immunized with pcDNA3.0A-C154preC and pcDNA3.0A-C191preC plasmids were higher than those of groups immunized with pcDNA3.0A-C154 and pcDNA3.0A-C191. In vivo CTL responses verified that mice immunized with preC core fused DNAs showed significantly high specific lysis compared with mice immunized with HCV cores only (P < 0.01). In our study, pcDNA3.0A-C154preC led to the highest immune response among all DNA constructs. Conclusion: DNA that encodes truncated HCV core proteins may lead to increased immune responses in vivo, and these responses may be enhanced by HBV preC.     

乙型肝炎病毒复制调控元件对HBV DNA疫苗诱导的免疫应答

目的研究乙型肝炎病毒（HBV）复制调控元件增强子Ⅰ（ENHⅠ）及前S2（Pre-S2）抗原基因对HBV DNA疫苗诱导的免疫应答的影响。方法采用常规聚合酶链反应（PCR）从HBV adr亚型全基因DNA序列中分别扩增HBsAg、PreS2-HBsAg、HBsAg-ENHI和PreS2-HBsAg-ENHⅠ基因片段，重组到VR1012载体中，构建4种HBV DNA疫苗，转染HepG2细胞并免疫Balb／C小鼠。通过细胞免疫化学、酶联免疫分析（ELISA）、酶联免疫斑点试验（ELISPOT）等方法检测其在HepG2细胞内的表达及小鼠的体液及细胞免疫应答。结果转染的HepG2细胞表达相应的目的蛋白．ENHⅠ及Pre-S2抗原基因均可增强HBV DNA疫苗转染HepG2细胞表达HBsAg；免疫接种小鼠后第2周产生抗-HBs及HBsAg特异性细胞毒T淋巴细胞（CTL），Pre—S2抗原基因可增强HBV DNA疫苗免疫Balb／C小鼠诱导的抗-HBs及HBsAg特异性CTL的产生，ENHⅠ基因对免疫应答无影响。结论ENHI及Pre—s2抗原基因均可增强HBVDNA疫苗转染HepG2细胞表达HBsAg．Pre-S2抗原基因可增强HBVDNA疫苗免疫Balb／C小鼠引起的免疫应答。     

腺病毒介导的白细胞介素-12表达对丙型肝炎病毒包膜2基因免疫的调节

目的 观察腺病毒介导表达白细胞介素-12(IL-12)对调节丙型肝炎病毒(HCV)包膜基因2(E2)诱导免疫应答的影响。方法 以NIH 3T3细胞表达HCVE2糖蛋白，纯化后用于酶免疫分析法检测抗E2抗体；以表达HCVE2糖蛋白的SP2／0细胞^3Cr释放法检测细胞毒性T淋巴细胞(CTL)应答；以293细胞繁殖表达重组IL-12亚单位p35和p40的腺病毒ADIL12。6～8周龄BALB／C鼠右后肢股四头肌注射表达HCVE2的质粒，同时经腹腔注射ADIL12。分别于2、3、4周尾静脉采血检测抗E2抗体，4周处死动物分离脾细胞检测CTL应答。结果 表达HCVE2的基因免疫可有效诱导特异性抗E2体液免疫应答。腹腔注射后，外源性IL-12微量表达。微量表达的外源性白细胞介素-12不影响特异性抗E2体液免疫应答。同时，显著增强特异性CTL应答的作用。结论 腺病毒微量表达的IL12对HCV E2基因免疫诱导的特异性CTL应答具有调节作用。     

Induction of hepatitis C virus-specific cytotoxic T and B cell responses by dendritic cells expressing a modified antigen targeting receptor

AIM: To find a novel antigen (Ag) presentation strategy to improve the immune responses induced by dendritic cell (DC) vaccine expressing hepatitis C virus (HCV) core antigen (pcDNA3HCV C-Fc) in Balb/c mice (H-2d). METHODS: pcDNA3HCV C-Fc plasmid and eukaryotic expression vector pcDNA3 were injected into mice sc. Immune responses to pcDNA3HCV C-Fc were studied. Meanwhile the effect of pcDNA3HCV C-Fc on anti-translated subcutaneous tumor of SP2/0 cells stably expressing HCV C Ag (SP2/0-HCV C-FC) was also studied. Anti-HCV C in serum was detected by enzyme-linked immunoadsordent assay (ELISA) and HCV specific cytotoxic T lymphocyte (CTL) activity was measured by LDH release assay. After 3 wk of DNA immunization, the cells of SP2/0-HCV C-FC were inoculated into mice subcutaneously and tumor growth was measured every 5 d. The survival rate and living time of mice were also calculated. RESULTS: After 4 wk of DC immunization, the A450 nm values of sera in mice immunized with pcDNA3HCV C-Fc-DC and pcDNA3-DC were 0.56±0.17 and 0.12±0.03 respectively. The antibody titres in mice codeliveried with pcDNA3HCV C-Fc with DC were significantly higher than those of mice injected with pcDNA3-DC. The HCV specific CTL activities in mice coinjected with DC and pcDNA3HCV C-Fc or empty expression vectors were(73.2±3.1) % and (24.4±8.8) % , which were significantly higher than those of mice injected with water. The DC vaccine could evidently inhibit tumor growth, prolong the survival time of mice and improve the survival rate of mice and these effects could be improved by HCV C-Fc (pcDNA3HCV C-Fc) gene codelivered. CONCLUSION: DC vaccine has a strong antigenicity in humoral and cellular immunities, which can be promoted by transduced pcDNA3HCV C-Fc expressing HCV C or Fc. Thus, pcDNA3HCV C-Fc-transduced DCs may be a promising candidate for a CTL-based vaccine against HCV.     

旋毛虫DNA疫苗诱导小鼠免疫应答的研究

目的　观察旋毛虫DNA疫苗在小鼠体内诱导的免疫应答。方法　将旋毛虫肌幼虫编码 31kDa抗原结构基因真核表达质粒pcDNA3-TspE1分别用肌肉注射和基因枪免疫BALB/c小鼠 ,免疫血清用旋毛虫肌幼虫冰冻切片及石蜡切片抗原进行IFAT检测 ,并用旋毛虫肌幼虫可溶性抗原进行Westernblot分析。结果　IFAT表明 pcDNA3-TspE1接种BALB/c小鼠后产生的免疫血清与旋毛虫肌幼虫可产生阳性反应 ,在肌幼虫冰冻及石蜡切片上均显示黄绿色荧光。Westernblot检测结果显示 ,pcDNA3-TspE1接种小鼠后产生的免疫血清只能识别旋毛虫肌幼虫可溶性抗原中的 31kDa抗原组分 ,而 pcDNA3质粒接种小鼠后的血清不能与旋毛虫肌幼虫可溶性抗原发生免疫反应。结论　旋毛虫DNA疫苗 pcDNA3-TspE1能够诱导小鼠产生特异性体液免疫应答。     

Targeting hepatitis B virus antigens to dendritic cells by heat shock protein to improve DNA vaccine potency

AIM： To investigate a novel DNA vaccination based upon expression of the HBV e antigen fused to a heat shock protein （HSP） as a strategy to enhance DNA vaccine potency.
METHODS： A pCMV-HBeAg-HSP DNA vaccine and a control DNA vaccine were generated. Mice were immunized with these different construct. Immune responses were measured 2 wk after a second immunization by a T cell response assay, CTL cytotoxicity assay, and an antibody assay in C57BL/6 and BALB/c mice. CT26-HBeAg tumor cell challenge test in vivo was Performed in BALB/c mice to monitor anti-tumor immune responses.
RESULTS： In the mice immunized with pCMV-HBe-HSP DNA, superior CTL activity to target HBV-positive target cells was observed in comparison with mice immunized with pCMV-HBeAg （44% ± 5% vs 30% ± 6% in E： T 〉 50：1, P 〈 0,05）, ELISPOT assays showed a stronger T-cell response from mice immunized with pCMV-HBe- HSP than that from pCMV-HBeAg immunized animals when stimulated either with MHC class I or class Ⅱ epitopes derived from HBeAg （74% ± 9% vs 31% ± 6%, P 〈 0.01）. ELISA assays revealed an enhanced HBeAg antibody response from mice immunized with pCMV- HBe-HSP than from those immunized with pCMV-HBeAg. The lowest tumor incidence and the slowest tumor growth were observed in mice immunized with pCMV- HBe-HSP when challenged with CT26-HBeAg.
CONCLUSION： The results of this study demonstrate a broad enhancement of antigen-specific CD4^＋ helper,CD8^＋ cytotoxic T-cell, and B-cell responses by a novel DNA vaccination strategy. They also proved a stronger antigen-specific immune memory, which may be superior to currently described HBV DNA vaccination strategies for the treatment of chronic HBV infection.     

Costimulatory protein B7-1 enhances the cytotoxic T cell response and antibody response to hepatitis B surface antigen.

There is a need for more effective therapy for chronic virus infections. A principle natural mechanism for elimination of virus-infected host cells is activation of viral antigen-specific cytotoxic T lymphocytes (CTL). In an effort to develop methods of inducing virus-specific CTL responses that might be utilized in therapy of virus infections, we have investigated the effect of B7, a costimulatory factor for T-cell activation. In this study we show that delivery of genes encoding human B7-1 and a viral antigen in the same recombinant viral vector to cells of mice induces a greater viral antigen-specific CTL response than does similar delivery of the viral antigen gene alone. Two recombinant adenovirus vectors were constructed with the foreign genes inserted in the early region 3. One of them (Ad1312) directed expression of the surface antigen gene of hepatitis B virus (HBS); the other (Ad1310) directed coexpression of HBS and human B7-1 (CD80) by means of an internal ribosomal entry site placed between the two coding sequences. When inoculated into BALB/c mice, both vectors induced a viral surface antigen-specific CTL response. The response induced by Ad1310 was stronger than that by Adl312 as measured by a chromium release assay for CTL activity and limiting dilution analysis for CTL precursor frequency, indicating that the B7-1 gene co-delivered with the HBS gene had an enhancing effect on the CTL response against surface antigen. Ad1310 also induced a higher titer of antibody against surface antigen than did Ad1312. This result suggests that expression of a costimulatory protein and a viral antigen in the same cells in vivo induces stronger immune responses than expression of the antigen alone. This could be a novel strategy for development of both preventive and therapeutic vaccines against infectious agents.