Nucleic acid vaccines: A taboo broken and prospect for a hepatitis B virus cure

Although a prophylactic vaccine is available,hepatitis B virus(HBV)remains a major cause of liver-related morbidity and mortality.Current treatment options are improving clinical outcomes in chronic hepatitis B;however,true functional cure is currently the exception rather than the rule.Nucleic acid vaccines are among the emerging immunotherapies that aim to restore weakened immune function in chronically infected hosts.DNA vaccines in particular have shown promising results in vivo by reducing viral replication,breaking immune tolerance in a sustained manner,or even decimating the intranuclear covalently closed circular DNA reservoir,the hallmark of HBV treatment.Although DNA vaccines encoding surface antigens administered by conventional injection elicit HBVspecific T cell responses in humans,initial clinical trials failed to demonstrate additional therapeutic benefit when administered with nucleos(t)ide analogs.In an attempt to improve vaccine immunogenicity,several techniques have been used,including codon/promoter optimization,coadministration of cytokine adjuvants,plasmids engineered to express multiple HBV epitopes,or combinations with other immunomodulators.DNA vaccine delivery by electroporation is among the most efficient strategies to enhance the production of plasmid-derived antigens to stimulate a potent cellular and humoral anti-HBV response.Preliminary results suggest that DNA vaccination via electroporation efficiently invigorates both arms of adaptive immunity and suppresses serum HBV DNA.In contrast,the study of mRNA-based vaccines is limited to a few in vitro experiments in this area.Further studies are needed to clarify the prospects of nucleic acid vaccines for HBV cure.

DNA-based vaccination induces humoral and cellular immune responses against hepatitis B virus surface antigen in mice without activation of Cmyc

AIM To develop a safe and effective DNAvaccine for inducing humoral and cellularimmunological responses against hepatitis Bvirus surface antigen(HBsAg).METHODS BALB/c mice were inoculated withNV-HB/s,a recombinant plasmid that had beeninserted S gene of hepatitis B virus genome andcould express HBsAg in eukaryotes.HBsAgexpression was measured by ABC immunohis-tochemical assay,generation of anti-HBs byELISA and cytotoxic T lymphocyte(CTL),byMTT method,existence of vaccine DNA bySouthern blot hybridization and activation ofoncogene C-myc by in situ hybridization,RESULTS With NV-HB/s vaccination byintramuscular injection,anti-HBs was initiallypositive 2 weeks after inoculation while all micetested were HBsAg positive in the muscles.Thetiters and seroconversion rate of anti-HBs weresteadily increasing as time went on and weredose-dependent.All the mice inoculated with100 μg NV-HB/s were anti-HBs positive onemonth after inoculation,the titer was 1:1024 ormore.The humoral immune response was similarinduced by either intramuscular or intradermalinjection.CTL activities were much stronger(45.26%)in NV-HB/s DNA immunized mice as compared with those(only 6%)in plasma-derived HBsAg vaccine immunized mice.Twomonths after inoculation,all muscle sampleswere positive by Southern-blot hybridization forNV.HB/s DNA detection,but decreased to 25%and all were undetectable by in situhybridization after 6 months.No oncogene C-myc activation was found in the muscle ofinoculation site.CONCLUSION NV-HB/s could generatehumoral and cellular immunological responsesagainst HBsAg that had been safely expressed insitu by NV-HB/s vaccination.

Humoral and cellular immunogenecity of DNA vaccine based on hepatitis B core gene in rhesus monkeys

INTRODUCTIONHepatitis B virus (HBV) is the most commonetiologic agent for infectious liver diseases. It isestimated that there are more than 250 millionchronic HBV carriersin the world today and thereis a significant association among persistentinfection, liver cirrhosis and hepatocellularcarcinoma[1-3].

Phase Ⅱb trial of in vivo electroporation mediated dualplasmid hepatitis B virus DNA vaccine in chronic hepatitis B patients under lamivudine therapy

AIM To assess the efficacy and safety of in vivo electroporation(EP)-mediated dual-plasmid hepatitis B virus(HBV) DNA vaccine vs placebo for sequential combination therapy with lamivudine(LAM) in patients with chronic hepatitis B. METHODS Two hundred and twenty-five patients were randomized to receive either LAM + vaccine(vaccine group, n = 109) or LAM + placebo(control group, n = 116). LAM treatment lasted 72 wk. Patients received the DNA vaccine or placebo by intramuscular injection mediated by EP at weeks 12(start of treatment with vaccine or placebo, SOT), 16, 24, and 36(end of treatment with vaccine or placebo, EOT). RESULTS In the modified intent-to-treat population, morepatients had a decrease in HBV DNA > 2 log10 IU/m L in the vaccine group at week 12 after EOT compared with the control group. A trend toward a difference in the number of patients with undetectable HBV DNA at week 28 after EOT was obtained. Adverse events were similar. In the dynamic per-protocol set, which excluded adefovir(ADV) add-on cases at each time point instantly after ADV administration due to LAM antiviral failure, more patients had a decrease in HBV DNA > 2 log10 IU/mL in the vaccine group at week 12 and 28 after EOT compared with the control group. More patients with undetectable HBV DNA at week 28 after EOT in the vaccine group were also observed. Among patients with a viral load < 1000 copies/mL at week 12, more patients achieved HBeA g seroconversion in the vaccine group than among controls at week 36 after EOT, as well as less virological breakthrough and YMDD mutations. CONCLUSION The primary endpoint was not achieved using the HBV DNA vaccine. The HBV DNA vaccine could only be beneficial in subjects that have achieved initial virological response under LAM chemotherapy.

Coimmunization with IL-15 plasmid enhances the longevity of CD8 T cells induced by DNA encoding hepatitis B virus core antigen

瞄准：为了测试交付为改善作为一个 DNA 疫苗的助手编码 IL-15 的一个原生质标志的可行性，有免疫力的回答由肝炎 B 核心基因 DNA 疫苗导致了。方法：我们使用了 RT-PCR 开发 IL-15 表示构造的基于的策略。我们首先证实基因能由于 IL-15 的差的表示在埃希氏杆菌属关口 i 被表示。然后， IL-15 原生质标志表示产品的简历活动被 CTLL-2 增长试金识别。从每 IL-15 的 DNA 的 100 微克真核细胞的表示原生质标志和怀有编码 HBV 核心基因(缩短的 pHBc144 ) 的 N 终点的 144 氨基酸的 DNA 的 recombinant 原生质标志习惯于共同使免疫 C57 BL/6 老鼠。anti-HBcIgG 的效价被 ELISA 检测，抗原特定的 CD8 (+) T 房间(CD8 (+) IFN-gamma (+) T 房间) 被在不同时间点染色的细胞内部的 cytokine 检测。结果：在由 pIL-15 和老鼠的抗原特定的 CD8 (+) 房间逐渐地增加了的 pHBc144 DNA 疫苗的合作免疫以后，有免疫力的反应的第一座山峰出现了 14 d 以后，然后，抗原特定的 CD8 (+) T 房间的数字逐渐地减少了并且在 3 瞬间在稳定的水平维持了。在增加以后，抗原特定的 CD8 (+) T 房间的数字到达了第二座山峰与以后的 10 d 一第一山峰双，然后，抗原特定的 CD8 (+) T 房间的数字慢慢地减少了。一个基因助手没在体液的有免疫力的回答上有重要效果的 IL-15 由肝炎 B 核心基因 DNA 疫苗导致了，但是增加了抗原特定的 CD8 (+) T 房间由肝炎 B 核心基因 DNA 疫苗导致了的记忆。结论：HBc Ag 1-144 氨基酸构造的 DNA 疫苗导致交付 plasmid 的 IL-15 提高的有效房间免疫，和 cytokine CD8 (+) T 房间的长寿。

Novel DNA vaccine based on hepatitis B virus core gene induces specific immune responses in Balb/c mice

AIM: To investigate the immunogenicity of a novel DNA vaccine,pSW3891/HBc, based on HBV core gene in Balb/c mice.METHODS: A novel DNA vaccine, pSW3891/HBc, encoding HBV core gene was constructed using a vector plasmid pSW3891. Balb/c mice were immunized with either pSW3891/HBc or empty vector DNA via gene gun. IgG anti-HBc responses in mouse sera were demonstrated by ELISA. Specific cytotoxicity of cytotoxic T lymphocytes (CTLs) of mice was quantitatively measured by lactate dehydrogenase release assay.RESULTS: HBcAg was expressed effectively in 293T cell line transiently transfected with pSW3891/HBc. Strong IgG anti-HBc responses were elicited in mice immunized with pSW3891/HBc. The end-point titers of anti-HBc reached the highest 1:97 200, 4 wk after the third immunization. The specific CTL killing with the highest specific lysis reached 73.25% at effector:target ratio of 20:1 in mice that received pSW3891/HBc DNA vaccine.CONCLUSION: pSW3891/HBc vaccination elicits specific anti-HBc response and induces HBc-specific CTL response in immunized Balb/c mice.

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 classⅠor 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.

Hepatitis B virus S gene enhances immune responses of a multiple-epitope DNA construct of hepatitis C virus in mice

The purpose of this study was to construct an eukaryotic DNA vector encoding a multiple-epitope antigen (MFC) of hepatitis C virus (HCV) and a hepatitis B surface antigen (HBsAg) , and explore the effect of HBsAg gene on the immunity of HCV multiple-epitope DNA construct in vitro and in vivo in mice. An HCV DNA vector (pVAX1-HBs-MFC) was constructed by fusing HBsAg gene to the N-terminal of an HCV multiple-epitope antigen gene. The pVAX1-HBs-MFC was transfected into HEK 293T cells and its expression was measured by ELISA and Western blotting. BALB/c mice were intramuscularly immunized with the pVAX1-HBs-MFC, and an ELISA approach was applied to determine the specific antibody titers and subtypes in the mouse serum. The cross-reactivity of the antibodies was also checked with two synthesized HCV hypervariable region 1 (HVR1) peptides. The IFN-γ production and cell proliferation of the mouse spleen cells were evaluated by ELISA and MTS (3-[4, 5-dimethylthiazol-2-yl]-5-[3-carboxymethoxyphenyl]-2-[4-sulfophenyl] -2H-tetrazolium, inner salt) assays, respectively. The expression of pVAX1-HBs-MFC was detectable in the transfected HEK 293T cells. The serum antibody response was effectively elicited in BALB/c mice injected with pVAX1-HBs-MFC. The highest titer of antibody against HCV (MFC) was 1∶1280, and the ratio of IgG2a/IgG1 was 1.50±0.12 at the fifth week after first immunization. Moreover, the collected mouse serum antibody had the ability to cross-react with the two synthesized HCV HVR1 peptides. The stimulation index of the mouse splenocytes to MFC was 1.79 ±0.07, and the IFN-γ level was 287±6?pg/ml at week 21 after first immunization. The highest titer of the antibody in control BALB/c mice immunized with pVAX1-MFC was 1∶320, and the ratio of IgG2a/IgG1 was 1.33±0.11 at week 5 post-immunization. Furthermore, the stimulation index of the mouse splenocytes cells to MFC was 1.52±0.06, and the IFN-γ level was 225±9.3?pg/ml at week 21 post-immunization. The HBsAg gene can enhance the effects of an HCV multiple-epitope DNA construct on its humoral and cellular immune responses. This HBsAg enhanced HCV multiple-epitope DNA vector may be of potential use in the development of HCV vaccines.

治疗型双质粒HBV DNA疫苗的构建及其鉴定

为构建以人白细胞介素 2 /γ干扰素(hIL 2 /hIFN γ)融合基因为佐剂的治疗型HBVDNA疫苗 ,采用DNA重组技术分别构建含有HBV包膜中蛋白 (preS2 ·S)抗原和hIL 2 /hIFN γ融合蛋白的真核表达质粒即pcDNAS2 ·S和pcDNAIIF ,酶谱和测序分析表明克隆的preS2 ·S和hIL 2 /hIFN γ融合蛋白基因片段的方向、序列与预期相符。用脂质体转染试剂转染COS 7细胞 ,并用ELISA检测转染细胞培养上清中目的基因表达水平。结果显示 ,质粒转染后 4 8h达峰值 ,分别为HBsAg(P/N) =7.6 3、IL 2 =1 0 .35ng/ml、IFN γ =7.90ng/ml。以CTLL 2依赖细胞株/MTT比色法和微量细胞病变抑制法 (WISH VSV)检测pcDNAIIF转染后 4 8h培养上清中IL 2及IFN γ活性 ,结果分别为 998U/ml和 2 4 9U/ml。证明构建的重组质粒pcDNAS2 ·S和pcDNAIIF结构正确 。

HBV包膜-核心蛋白融合基因DNA疫苗诱导小鼠持久的细胞免疫应答

构建编码HBV包膜 核心蛋白融合基因的DNA疫苗pSC、pSS1S2C和编码HBV包膜蛋白或核心蛋白基因的DNA疫苗 pHBs、pHBc ,分别肌肉注射免疫BALB/c小鼠 ,检测小鼠的血清抗体、T细胞增殖和细胞毒性T淋巴细胞反应 ,比较融合基因DNA疫苗与单基因DNA疫苗诱生免疫应答的强度 ,发现融合基因DNA疫苗诱生抗体的效率明显不及单基因DNA疫苗 ,但其能诱导更强、更持久的细胞免疫应答 ,表明HBV包膜 核心蛋白融合基因DNA疫苗对于治疗慢性乙型肝炎可能比单基因DNA疫苗更为有效 .

电脉冲肌注法增强治疗型HBV DNA疫苗免疫效果的实验研究

为提高细胞内质粒DNA的导入率并增强DNA疫苗诱导的免疫效果 ,采用在体电脉冲肌注法接种治疗型HBVDNA疫苗。结果接受电脉冲(2 0 0V/cm)肌注的 8只BALB/c小鼠局部肌肉组织荧光素酶活性为 1 6 1 70± 1 2 5 33RLU ,未加电脉冲对照组为 8 0 2±8 0 0RLU ,相差 4个数量级 ,差异具非常显著性 (P <0 0 0 5 ,t=3 6 74 )。新西兰兔电脉冲肌注法接种后第 2、4周 ,双质粒 (pS2 ·S +pFP)大剂量组 (5 0 +5 0 μg/只 )血清抗 HBs阳性动物数明显较同期未加电脉冲对照组 (大剂量 :1 0 0 0 +1 0 0 0 μg/只 )高 ,差异具显著性意义 (P <0 0 5 ) ;第 1 3周时 ,电脉冲免疫大 (5 0 +5 0 μg/只 )、中 (2 5 +2 5 μg/只 )、小 (5 +5 μg/只 )剂量组均有血清抗 HBs阳性鼠出现 ,分别为 5、4和 4 只 ,组间阳性动物数并无显著性差异 (P >0 0 5 ) ,但均较同期的对照组高 ,并具有显著性意义 (P <0 0 5 )。恒河猴电脉冲肌注法接种后 8周血清抗 HBs阳性动物数为大剂量 (1 0 0 0 +1 0 0 0 μg/只)组 3/ 3只 ,中剂量 (5 0 0 +5 0 0 μg/只 )组 2 / 3只 ,小剂量 (1 0 0 +1 0 0 μg/只 )组 0 / 3只 ,大剂量组与小剂量组及非电脉冲对照组之间比较差异具有显著性意义 (P <0 0 5 ) ;至免疫第 1 3周时 ,电脉冲免疫的大、中、小

HBV与HCV融合DNA疫苗的构建及其体液免疫应答

目的构建含乙型肝炎病毒(HBV)表面抗原基因(S区基因)与丙型肝炎病毒(HCV)核心抗原基因(C区基因)的嵌合真核表达载体,观察preS1和preS2基因对HBV表面抗原及HCV核心抗原体液免疫的影响。方法用PCR方法,分别扩增HBVS区基因和HCVC区基因。将S区基因克隆入真核表达载体pcDNA3.1,酶切鉴定后,再将C区基因克隆至S区基因的下游。测序正确后,大量提取质粒并免疫Balb/c小鼠,用ELISA法检测抗HBs和抗HCV抗体。结果成功地扩增出目的基因片段,克隆后酶切鉴定结果正确,序列分析与文献报道相一致。免疫后检测到抗HBs和抗HCV抗体。preS1与preS2基因对构建的融合DNA疫苗的体液免疫应答有一定的抑制作用。抗HBs抗体的产生低于只含S基因的真核表达载体;preS1基因对抗HCV抗体的产生具有抑制作用,而preS2无影响。结论不同长度的HBVS区基因可影响抗HBs和抗HCV抗体的产生。

治疗型HBV DNA疫苗在小鼠组织中的分布和长期毒性研究

为研究治疗型HBVDNA疫苗使用的安全性 ,观察质粒在小鼠组织中的分布和其长期毒性 ,采取给小鼠肌注 电转染治疗型HBVDNA疫苗 1 0 μg和 5 0 μg后 ,用PCR法检测外源基因在小鼠组织的分布和存留时间 ;另用小鼠肌注 电转染治疗型HBVDNA疫苗30、6 0和 1 2 0 μg,每周 2次 ,连续 4周 ,共 8次 ,于末次给药后 4 8h,各组活杀 1 / 2 ,留下 1 / 2继续观察 4周 ,进行血液学、血生化、病理组织学及抗核抗体检查。结果单次肌注 电转染疫苗后 ,质粒DNA主要分布于注射部位肌肉组织 ,可存留 8周 ,其他组织也有散在低水平分布 ,但持续时间较短 ;未发现动物有异常表现 ,血液学、血生化和病理组织学检查未见异常 ;未观察到抗核抗体的产生和自身免疫病理损害。上述结果表明 。

治疗性双质粒HBV DNA疫苗的体外转染表达与鉴定

目的:探讨治疗性双质粒HBVDNA疫苗转染COS-7细胞后目的基因的表达情况。方法:以脂质体转染试剂LipofectamineTM2000介导,将带有preS2+S基因的重组疫苗质粒pS2.S和带有hIL2+hIFNγ融合基因的重组佐剂质粒pFP分别转染COS-7细胞,同时设立空质粒转染和未转染细胞为对照组,于转染后24,48,72,96h采用ELISA法检测细胞培养上清的HBsAg、融合蛋白白细胞介素(IL-2)及干扰素(IFN-γ)的表达,并测定融合蛋白的IL-2、IFN-γ活性,采用ECLWesternblotting分析和鉴定目的蛋白preS2+S、IL-2及IFN-γ的分子质量大小。结果:双质粒在转染COS-7细胞后不同时间均可进行分泌表达,且48h时目的蛋白的表达量达峰值,其中表达的融合蛋白具有较高的IL-2和IFN-γ的生物学活性,pS2.S和pFP的转染上清分别在30.6ku和110ku处有特异性阳性反应条带。结论:HBVDNA疫苗质粒pS2.S和佐剂质粒pFP在COS-7细胞的最佳表达时间是转染后48h,并鉴定双质粒表达产物的分子质量大小分别为30.6ku和110ku。

治疗型HBV DNA疫苗肌注电转染法免疫恒河猴的效果及安全性观察

为观察肌注 电转染法接种治疗型HBVDNA疫苗对恒河猴的免疫效果 ,对健康恒河猴采用肌注 电转染法接种治疗型HBVDNA疫苗 ,剂量分别为 0 2mg/只、1mg/只和 2mg/只 ;前 3次给药时间间隔 1个月 ,主要观察免疫效果 ;此后 6次给药为每天 1次 ,观察重复给药的安全性。结果显示肌注 电转染法接种疫苗后 ,不同剂量组均可有效诱导恒河猴产生HBsAg特异性抗体 (抗 HBs) ;重复给药未见明显的各系统毒副反应及血液学和血生化异常 ,血清抗核抗体 (ANA)阴性。表明治疗型HBVDNA疫苗用肌注 电转染法免疫可显著增强恒河猴的免疫效果 ;多次重复接种该疫苗未见恒河猴的毒性反应 。

携带HBV包膜大蛋白DNA疫苗的减毒沙门菌在小鼠诱导免疫应答

探索一种简便、有效的乙型肝炎病毒DNA疫苗免疫方法。将编码绿色荧光蛋白的真核表达质粒pEGFPN1转化到减毒鼠伤寒沙门菌SL72 0 7,灌胃饲服BALB c小鼠 ,流式细胞术检测出小鼠脾细胞内表达的绿色荧光蛋白 ;构建编码HBV包膜大蛋白的DNA疫苗pCI S1S2S ,分别以SL72 0 7为载体的口服途径或直接肌肉注射途径免疫BALB c小鼠 ,检测小鼠的血清抗体、T细胞增殖和细胞毒性T淋巴细胞反应 ,结果表明两种免疫途径均能在小鼠体内诱生细胞和体液免疫应答 ,但口服途径诱导免疫应答的强度明显强于肌肉注射途径。口服携带HBVDNA疫苗的减毒伤寒沙门菌可能代表一种简便。

超抗原SEA增强小鼠对HBV DNA疫苗的免疫反应

观察超抗原SEA(D227A)的真核表达载体(pmSEA),对HBVDNA疫苗诱导Balbc小鼠(H2d)免疫应答的调节作用。肌内注射空载体pcDNA3、HBVDNA疫苗加pmSEA佐剂(pHBVS2S+pmSEA)或不加佐剂(pHBVS2S);ELISA法测定血清抗HBs;ELISPOT检测分泌IFNγ的脾淋巴细胞;4h51Cr释放法检测小鼠脾细胞CTL活性。HBVDNA佐剂组免疫小鼠抗HBsAg抗体滴度明显高于不加佐剂组,其IgG1IgG2a的比例不同于多肽免疫组,二者分别为0.282与10。HBVDNA佐剂组均能增强IgG1和IgG2a的产生,是不加佐剂组的1.36、1.73倍。佐剂组小鼠脾淋巴细胞IFNγ的分泌量是不加佐剂组2～3倍。CTL细胞杀伤活性(E:T=100)佐剂组与不加佐剂组分别为:69.77%±7.5%、42.81%±7.7%,差异显著(P<0.05)。HBVDNA疫苗具有较强的免疫原性,能够诱导机体产生特异性的抗体及CTL反应;pmSEA佐剂能够提高小鼠对DNA疫苗的免疫应答,有望成为DNA疫苗的免疫佐剂。

白细胞介素—12和白细胞介素—18质粒对HBcAg DNA疫苗诱导小鼠（H—2^d）体液免疫应答的影响

目的:观察编码鼠白细胞介素(IL)-12和IL-18的真核表达载体犤pcDNA3.1/IL-12(以下简称IL-12质粒)和pcDNA3.1/IL-18(以下简称IL-18质粒)犦对HBcAgDNA疫苗(pJW4303/HBc)诱导Balb/c(H-2d)小鼠免疫应答的影响。方法:肌肉注射接种IL-12质粒、IL-18质粒和HBcAgDNA疫苗,ELISA法检测小鼠血清抗HBcIgG亚类(IgG1、IgG2a)水平。结果:免疫6周后,联合注射IL-12、IL-18和IL-12+IL-18组小鼠血清的抗HBc终点滴度均明显高于单纯注射HBcAgDNA疫苗组小鼠(P<0.05),抗HBcIgG亚类以IgG2a占优。结论:IL-12、IL-18以及IL-12+IL-18联合HBcAgDNA疫苗注射能够提高小鼠血清中抗HBc水平。

白细胞介素2提高HBV-SDNA疫苗的免疫效应

目的 :观察IL -2真核表达载体对HBV SDNA疫苗诱导BALB/c小鼠的特异性免疫应答的影响。方法 :肌肉注射基因疫苗及IL -2真核表达载体 ,ELISA法检测小鼠血清抗HBs,4h5 1Cr释放法检测小鼠脾细胞CTL活性。结果 :免疫 8周后 ,单纯注射pCR3 .1 -S及共注射IL -2真核表达载体的小鼠血清 4 50nmA值分别为 1 .2 4± 0 .1 0及 1 .98± 0 .1 7。CTL细胞杀伤活性分别为 ( 50 .5± 6.4 ) %及 ( 61 .9± 7.1 ) % ,两组均有明显差异 (P <0 .0 1 )。结论 :IL -2的真核表达载体能够提高小鼠对DNA疫苗的免疫应答。基因疫苗可能用于预防及治疗HBV感染。