热休克蛋白70-HBcAg(18～27)蛋白复合物对乙型肝炎病毒转基因小鼠的免疫研究

目的研究结核杆菌热休克蛋白(HSP)70-HBcAg(18～27))蛋白复合物对HBV转基因小鼠免疫应答的影响。方法体外构建HSP70-HBcAg(18～27)蛋白复合物,以HBV转基因小鼠为实验对象,进行体内免疫学功能研究。结果HSP70-HBcAg(18～27)蛋白复合物使HBV转基因小鼠外周血及脾中CD4~ T淋巴细胞和CD8~ T淋巴细胞大量增殖,诱导较强的抗原特异性CTL应答,并活化自然杀伤细胞、树突状细胞参与应答反应。结论HSP70-HBcAg(18～27)蛋白复合物具有免疫原性,能够增强转基因鼠细胞免疫应答能力,有望作为蛋白疫苗用于慢性乙型肝炎的免疫治疗。     

外周血前列腺素2及CD69水平对慢性乙型肝炎感染者免疫状态的影响

乙型肝炎病毒（HBV）感染早期,特异性免疫应答产生之前自然杀伤（NK）细胞可溶解被病毒感染的细胞.已知前列腺素（PGE）2在体外对细胞和体液免疫反应有明显的抑制作用.在特异性免疫方面，已有证据表明HBV携带者体内存在免疫紊乱，CD4^＋T／CD8^＋T细胞比例下降，而CD69是T淋巴细胞激活后最早表达的表面抗原，当其表达后，可作为共刺激信号促进T细胞进一步活化和增殖。     

结核杆菌热休克蛋白70-乙型肝炎表面抗原诱导特异性免疫反应

目的 研究体外构建结核杆菌热休克蛋白和乙型肝炎表面抗原复合物(HSP70-HBsAg)诱导针对乙型肝炎表面抗原特异性免疫反应能力,为该复合物的临床应用奠定基础。 方法 考察体外构建HSP70-HBsAg复合物是否能引起小鼠的体液和细胞免疫;将复合物负载树突状细咆(D C),D C激活同源的T淋巴细胞产生细胞毒性T淋巴细胞(CTL),检测其杀伤HepG2-S细胞的能力。 结果 HSP70-HBsAg复合物能引起小鼠的体液免疫和细胞免疫;HSP70-HBsAg和HBsAg均可诱导CD 81 T淋巴细胞的特异性CTL,而前者的诱导效果更强。 结论 体外构建的HSP70-HBsAg蛋白复合物具有免疫原性,HSP70可以增强抗原蛋白诱导特异性免疫反应的能力,HSP70～HBsAg有望作为蛋白疫苗用于临床慢性乙型肝炎的免疫治疗。     

结核杆菌抗原Ag85A HLA-A*0201限制性CD8+ CTL表位的预测和鉴定

目的预测结核杆菌（Mtb）抗原Ag85A的HLA-A＊0201限制性CD8^＋细胞毒性T细胞（CTL）表位,并对其进行鉴定。方法应用数据库SYFPEITHI预测可能存在的HLA—A＊0201的限制性CD8^＋CTL表位,并经流式细胞术分析抗原肽与HLA-A＊0201的亲合力,经时间荧光分辨法检测结核（TB）患者外周血单个核细胞（PB-MC）对抗原肽的增殖反应,再通过细胞毒实验研究抗原肽诱导的T细胞毒杀伤活性,逐步鉴定Ag85A的HLA—A＊0201限制性CD8^＋CTL表位。结果位于Ag85A氨基酸序列7（48-56aa）和5（242-250aa）的表位与HLA—A＊0201分子具有较高的亲和力,并能刺激HLA-A＊0201阳性结核患者PBMC增殖,诱导产生具有特异性杀伤活性的CTL。结论肽7GLPVEYLQV（48—56aa）和肽5KLIANNTRV（242—250aa）是Mtb抗原Ag85A的HLA—A＊0201限制性CD8^＋CTL表位。     

重型肝炎患者乙型肝炎病毒特异性细胞毒性T淋巴细胞应答功能研究

目的 用主要组织相容性复合物（MHC）抗原肽四聚体（Tetramer）流式细胞技术，分析乙型重型肝炎患者外周血中特异性细胞毒性T淋巴细胞（CTL）应答状况，并探讨其临床意义。方法 采用Tetramer流式细胞技术检测乙型重型肝炎患者外周血中受人类白细胞抗原Ⅰ类分子限制的三类特异性CD8^＋CTL细胞数量；采用酶联免疫吸附斑点试验技术，测定经特异性乙型肝炎病毒（HBV）肽段诱导培养的特异性CTL表达膜内细胞因子IFNγ、TNFα、IL-4和IL—10等的水平；采用Promega CytoTox96非放射性细胞毒试验技术，测定经特异性HBV肽段诱导培养的特异性CTL杀伤靶细胞能力。结果 急性乙型重型肝炎组外周血中针对HBVcore18-27表位的特异性CTL数量高于慢性乙型重型肝炎组（P〈0．05），而低于急性乙型肝炎组（P〈0．05）；急性乙型重型肝炎组表达干扰素γ和肿瘤坏死因子α较慢性乙型重型肝炎组高（P值均〈0．05）；急性乙型重型肝炎组HBVcore18—27特异性CTL裂解靶细胞能力高于慢性乙型重型肝炎组（P〈0．05）。结论 急性乙型重型肝炎患者特异性CTL应答作用增强，而慢性乙型重型肝炎患者特异性CTI。应答缺乏。急性乙型重型肝炎患者外周血特异性CTL持续存在，可能与促进病毒清除等相关。     

恶性疟原虫复合抗原DNA疫苗诱导小鼠的细胞免疫及体液免疫应答

目的 观察用恶性疟原虫复合抗原基因HGFSP构建的DNA疫苗pc-HGFSP免疫小鼠诱导的细胞及体液免疫应答。方法 用pc-HGFSP肌注免疫C57BL／6小鼠并加强免疫2次，取小鼠脾淋巴细胞及血清测定；脾淋巴细胞增殖活性（MTT）法，NK细胞活性和CTL活性（LDH）；脾脏CD4^ 及CD8^ T细胞亚群（免疫荧光法）：血清pc-HGFSP批原特异性抗体（ELISA法）及一氧化氮（NO）含量。结果 与pcDNA3对照比较，pc-HGFSP免疫小鼠脾淋巴细胞增殖活性增高24％－37％；NK细胞活性增高38％－90％；CTL活性增高65％－153％；CD8^ T细胞亚群增加。免疫血清产生HGFSP抗原特异性IgG抗体；NO含量也有所增高。结论 恶性疟DNA疫 pc-HGFSP有一定的诱导小鼠细胞免疫和体液免疫应答的作用。     

聚乙二醇干扰素对慢性丙型肝炎患者淋巴细胞亚群的影响

目的：研究聚乙二醇干扰素α-2b治疗慢性丙型肝炎（CHC）的疗效与机体免疫状态的关系。方法：采用流式细胞仪检测聚乙二醇干扰素α-2b治疗前后CHC患者T淋巴细胞亚群CD3＋、CD4＋、CD8＋T淋巴细胞及NK（自然杀伤细胞）、CTL（细胞毒性T淋巴细胞）的变化。结果：应答组患者血清CD3＋、CD4＋T淋巴细胞、NK细胞、CD4＋/CD8＋比值的上升程度及CD8＋、CTL细胞的下降程度明显高于无应答组,而持续应答组又相应优于复发组。结论：聚乙二醇干扰素α-2b治疗后患者的细胞免疫状态明显增强,检测患者T淋巴细胞亚群、NK、CTL细胞的变化,可以预测患者干扰素治疗的疗效。     

树突状细胞负载甲胎蛋白、细胞毒性T细胞表位肽后的免疫应答

目的 用负载hAFP 218-226位LLNQHACAV九肽的树突状细胞（dendritic cells,DC)诱导自身淋巴细胞，使之活化为肝细胞癌（HCC）特异性细胞毒性T细胞（cytotoxic T lymphocyte,CTL)，并特异性杀伤HCC细胞。方法 在体外用GM-CSF和IL-4诱导HLA-A2^ 健康志愿者外周血单核细胞，使其分化为高纯度DC。用负载hAFP 218-226位LLNQHACAV九肽的DC诱导自身淋巴细胞，使之成为HCC特异性CTL。结果 诱导的DC分泌较高水平的IL-12（17.6-21.5pg/ml)，其中以第7天为最高（21.5pg/ml)，经DC和DC负载AFP表位肽后活化的淋巴细胞培养上清液中TNF水平均比在IL-2条件下培养的未活化淋巴细胞高。L929细胞死亡百分率分别为80.65和11.6%；经DC和DC负载AFP表位肽后活化的淋巴细胞培养上清液中IL-12水平分别为20.5pg/ml和46.9pg/ml，经DC活化后淋巴细胞增殖指数大于3。活化后的淋巴细胞不但特异性杀伤HLA-A2^ 的HCC细胞HepG2和负载AFP表位肽的T2细胞，而且还不同程度杀伤HLA-A3^ HCC细胞Alexander和其它表型HCC细胞，对NK细胞敏感的靶细胞慢性髓原白血病细胞K562也有较强的杀伤作用。结论 负载hAFPHLA-A2限制性CTL九肽的DC对表达AFP HCC的研究和治疗有潜在应用价值。     

结核分枝杆菌Rv0440 CTL表位肽的免疫原性研究

目的 体外鉴定结核分枝杆菌（Mycobacterium tuberculosis,Mtb）Rv0440蛋白序列中表位肽362 370 aa和369-377 aa的HLA A＊0201限制性CD8＋ CTL表位的免疫原性,为基于表位的结核疫苗研究提供实验依据.方法 根据T2细胞HLA-A＊ 0201分子与多肽结合力分析实验结果,选取结核分枝杆菌Rv0440蛋白质氨基酸序列中对HLA-A＊ 0201分子高亲合力的Rv0440 1（362-370 aa,KLQERLAKL）和Rv0440-2（369 377 aa,KLAGGVAVI）作为候选表位肽.用候选表位肽刺激PPD（＋＋＋）健康志愿者外周血单个核细胞（peripheral blood mononuclear cells,PBMC）检测细胞分泌IFN γ的水平.用候选表位肽诱导特异性CTL细胞,检测特异性CTL细胞对负载表位肽的T2细胞的杀伤活性,观察Rv0440-1和Rv0440 2的HLA-A＊ 0201限制性CD8＋ CTL表位的免疫原性.结果 ELISPOT实验结果显示,表位肽Rv0440-1能够明显诱导HLA-A＊ 0201（＋）、PPD（＋＋＋）健康志愿者PBMC分泌IFN γ（P＜0.05）;且表位肽Rv0440-1负载DC诱导的CTL在效靶比为10：1时对负载相应表位肽的T2细胞的特异性杀伤活性高于对照组（P＜0.05）;与对照组相比,表位肽Rv0440 2没有诱导能力.结论 表位肽Rv0440-1（362-370 aa,KLQERLAKL）具有良好的免疫原性,是有效的结核分枝杆菌的HLA-A＊0201限制性CTL表位.     

慢性乙型肝炎患者PB MC中H BV特异性IL-21表达及其对CD8^＋T淋巴细胞功能的影响

目的：探讨慢性乙型肝炎患者外周血单个核细胞（PBMC）中 HBV特异性IL-21的表达及其对CD8＋T淋巴细胞功能的调节作用。方法以 HBVc18-27（10μg/mL）多肽刺激46例不同临床类型慢性乙型肝炎患者PBMC。ELISA检测上清液IL-21水平。在 HBVc18-27（10μg/mL）多肽和IL-21（50 U/mL）或IL-2（100 ng/mL）培养条件下,应用 MHC-肽五聚体结合流式细胞术检测PBMC中 HBV特异性CTL细胞频数变化;免疫磁珠分离纯化免疫耐受期和免疫激活期慢性乙型肝炎患者PBMC中CD8＋T淋巴细胞,以 HBcAg（10μg/mL）预刺激CD8-PBMC 5 h后,采用Transwell 小室共培养技术,在阻断IL-21通路条件下,应用实时PCR检测CD8^＋T淋巴细胞IFN-γmRNA的表达。结果 HBV特异性IL-21在免疫控制期和免疫激活期慢性乙型肝炎患者P B MC中表达水平显著高于免疫耐受期患者,而在免疫控制期和免疫激活期两组之间无显著差异。与 PBS 对照组相比,IL-21组 HBV 特异性 CTL 细胞频数明显增高,差异有统计学意义（P＜0．01）,而与IL-2组相比差异无统计学意义。以IL-21抗体阻断IL-21通路后,CD8^＋T 淋巴细胞IFN-γmRNA 表达水平显著下降,差异有统计学意义。结论免疫控制期和免疫激活期慢性乙型肝炎患者PBMC 均可生成一定水平的 HBV 特异性IL-21,并能增强外周CD8＋T淋巴细胞的增殖和IFN-γ表达水平。     

急性乙型肝炎HBcAg特异性CTL克隆建立及初步分析

目的建立急性乙型肝炎（乙肝）患者的HBcAg特异性CD8^＋T细胞克隆。方法一例急性乙肝患者经用序列特异引物聚合酶链反应分型技术,测得其人类白细胞抗原（human leukocyte antigen,HLA）-A基因型为1101,其外周血单个核细胞采用重组HHBcAg和合成的HLA—A＊1101限制性表位肽（HBV croe88—96）刺激,并以有限稀释法对活化的T细胞进行克隆化,建立HBcAg特异性的CD8^＋T细胞克隆。用免疫荧光染色、流式细胞术以及乳酸脱氢酶释放实验鉴定所获克隆。结果获得13株HBcAg＋特异性CD8^＋咖胞克隆（6侏为Tc1,3株为Tc2,4株为Tc0）。其中12株具有明显的特异性细胞毒沂陛（37．5％-85．5％,效／靶比为2．5：1）,1株（A10株,Tc0）细胞毒活性仅为10．2％。结论应用HLA—A＊1101限制性表位肽（HBV croe88—96）刺激急性乙肝患者的外周血单个核细胞,建立了13株肽表位特异性的CD8^＋T细胞克隆,为进一步研究打下基础。     

慢性乙型肝炎患者外周血树突状细胞诱导特异性T淋巴细胞应答

目的 探讨慢性乙型肝炎患者外周血树突状细胞(Dc)是否诱导特异性T细胞应答。方法(1)将研究对象分为慢性乙型肝炎患者组、急性乙型肝炎痊愈组、健康志愿者组,分离各组研究对象的外周血单个核细胞(PBMC),细胞内细胞因子染色方法检测其对细胞毒性T淋巴细胞(CTL)特异表位多肽乙型肝炎病毒核心抗原(HBcAg)18-27的记忆性免疫应答;(2)培养慢性乙型肝炎患者DC,将负载有乙型肝炎抗原表位多肽的DC诱导特异的T细胞应答。采用细胞内细胞因子染色方法检测诱导的T细胞分泌的细胞因子,乳酸脱氢酶释放法测定诱导的T细胞杀伤活性。结果(1)急性乙型肝炎患者PBMC对HBcAg 18-27 CTL特异表位多肽存在记忆的免疫应答,其分泌干扰素-γ的CD8+T细胞占CD8+T细胞总数的(4.3±2.5)％,分泌白细胞介素-2的占总细胞数的(4.8±2.2)％,分泌肿瘤坏死因子-α占总细胞数的(4.6±2.3)％。而慢性乙型肝炎患者和健康志愿者对其记忆应答很低,与急性乙型肝炎患者比较差异有显著性,t值为2.508-3.305,P<0.05。(2)用多肽共孵育过的慢性乙型肝炎患者DC多次诱导的T细胞慢性乙型肝炎患者组,加肽孵育的靶细胞比例为30:1、10:1、3:1时,其杀伤率分别为(57.0±20.3)％、(49.5±20.2)％、(21.8±12.9)％,均高于对照组,表明慢性乙型肝炎患者DC可以诱导特异的T     

呼吸道合胞病毒M2:81-95与热休克蛋白70L1融合蛋白的制备及其免疫原性

目的 构建呼吸道合胞病毒(RSV)CTL表位M2:81-95与热休克蛋白(HSP)70L1融合蛋白的重组质粒,原核表达后初步研究其免疫原性.方法 从SMMC7721细胞中克隆HSP70L1基因.PCR扩增M2:81-95基因片段,鉴定后构建质粒pET-HSP70L1-M2:81-95(pET-HSP70L1-M2).经PCR和酶切鉴定,转化E.coli BL21(DE3).用异丙基-β-D-硫代半乳糖苷(IPTG)诱导表达HSP70L1-M2:81-95(HSP70L1-M2),Ni-螫合亲合层析纯化,梯度透析复性.用该蛋白免疫10只BAlB/c小鼠,ELISA榆测IgG抗体及其亚型.噻唑蓝(MTT)法榆测CTL杀伤活性.结果 成功构建重组质粒pET-HSP70L1-M2,并在E.coli中表达重组蛋白HSP70L1-M2,该蛋白诱导RSV及表位特异性的CTL活性,还诱导蛋白抗原特异性的IgG,为4.87±0.35、IgGl为5.53±0.28、IgG2a为4.40±0.21.且IgG1/IgG2a(1.26)的比例平衡,与PBS对照组的IgG,为0.33±0.17、IgG1为0.51±0.21、IgG2a为0比较,差异有统计学意义(t=3.512,3.681,5.856;P<0.05).结论 成功构建原核表达质粒pET-HSP70L1-M2,斤表达纯化获得重组蛋白,免疫小鼠后诱导RSV及表位特异性的CTL活性和辅助性T淋巴细胞(Th)1/Th2混合型应答.     

Therapeutic polypeptides based on HBV core 18-27 epitope can induce CD8^＋ CTL-mediated cytotoxicity in HLA-A2^＋ human PBMCs

AIM: To explore how to improve the immunogenicity of HBcAg CTL epitope based polypeptides and to trigger an HBV-specific HLA I-restricted CD8^+ T cell response in vitro.METHODS: A new panel of mimetic therapeutic peptides based on the immunodominant B cell epitope of HBV PreS2 18-24 region, the CTL epitope of HBcAg18-27 and the universal T helper epitope of tetanus toxoid (TT) 830-843 was designed using computerized molecular design method and synthesized by Merrifield‘s solid-phase peptide synthesis.Their immunological properties of stimulating activation and proliferation of lymphocytes, of inducing TN1 polarization,CD8^+ T cell magnification and HBV-specific CD8^+ CTL mediated cytotoxicity were investigated in vitro using HLA-A2^+ human peripheral blood mononuclear cells (PBMCs) from healthy donors and chronic hepatitis B patients.RESULTS: Results demonstrated that the therapeutic polypeptides based on immunodominant HBcAg18-27 CTL,PreS2 B- and universal TN epitopes could stimulate the activation and proliferation of lymphocytes, induce specifically and effectively CD8+ T cell expansion and vigorous HBVspecific CTL-mediated cytotoxicity in human PBMCs.CONCLUSION: It indicated that the introduction of immunodominant T helper plus B-epitopes with short and flexible linkers could dramatically improve the immunogenicity of short CTL epitopes in vitro.     

Dendritic cells from chronic hepatitis B patients can induce HBV antigen-specific T cell responses

AIM: To determine whether dendritic cells (DCs) from chronic hepatitis B patients could induce HBV antigen-specific T cell responses or not. METHODS: DCs were generated from peripheral blood mononuclear cells of patients with chronic hepatitis B (CHB) infection and healthy donors. We compared the phenotypes of these DCs and their ability to secrete cytokines and to participate in mixed lymphocyte reactions. In addition, autologous lymphocytes were cultured with DCs loaded with HBV core region peptide HBcAg8-27, an epitope recognized by cytotoxic T lymphocytes (CTL), and bearing human leucocyte antigen (HLA)-A2 for 10 d. Cytokine secretion and lytic activity against peptide-pulsed target cells were assessed. RESULTS: DCs with typical morphology were generated successfully by culturing peripheral blood mononuclear cells (PBMCs) from CHB patients with AIM-V containing GM-CSF and IL-4. Compared with DCs from normal donors, the level of CD80 expressed in DCs from CHB patients was lower, and DCs from patients had lower capacity of stimulate T cell proliferation. When PBMCs isolated from patients with chronic or acute hepatitis B infection and from normal donors were cocultured with HBcAg18-27 peptide, the antigen-specific memory response of PBMCs from acute hepatitis B patients was stronger than that of PBMCs from chronic hepatitis B patients or normal donors. PBMCs cocultured with DCs treated with HBcAg18-27 CTL epitope peptide induced an antigen-specific T cell reaction, in which the level of secreted cytokines and lytic activity were higher than those produced by memory T cells. CONCLUSION: DCs from patients with CHB can induce HBV antigen-specific T cell reactions, including secretion of cytokines essential for HBV clearance and for killing cells infected with HBV.     

Preclinical development of an adjuvant-free peptide vaccine with activity against CMV pp65 in HLA transgenic mice

Epitope vaccines have shown promise for inducing cellular immune responses in animal models of infectious disease. In cases where cellular immunity was augmented, peptide vaccines composed of covalently linked minimal cytotoxic T-lymphocyte (CTL) and T-helper (T(H)) epitopes generally showed the most efficacy. To address a clinical vaccine strategy for cytomegalovirus (CMV) in the context of HCT (hematopoietic cell transplantation), we observed that linking the synthetically derived pan-DR epitope peptide (PADRE) or one of several tetanus T(H) epitopes to the immunodominant human leukocyte antigen (HLA) A*0201-restricted CTL epitope from CMV-pp65 to create a fusion peptide caused robust cytotoxic cellular immune responses in HLA A*0201/K(b) transgenic mice. Significantly, the fusion peptides are immunogenic when administered in saline solution by either subcutaneous or intranasal routes. CpG-containing single-stranded DNA (ss-oligodeoxynucleotide [ODN]) added to the fusion peptides dramatically up-regulated immune recognition by either route. Notably, target cells that either expressed full-length pp65 protein from vaccinia viruses or were sensitized with the CTL epitope encoded in the vaccine were recognized by splenic effectors from immunized animals. Visualization of murine peptide-specific CTL by flow cytometry was accomplished using an HLA A*0201 tetramer complexed with the pp65(495-503) CTL epitope. T(H)-CTL epitope fusion peptides in combination with CpG ss-ODN represent a new strategy for parenteral or mucosal delivery of vaccines in a safe and effective manner that has applicability for control or prophylaxis of infectious disease, especially in situations such as vaccination of donors or recipients of HCT, where highly inflammatory adjuvants are not desired.     

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.     

Stimulation of HIV gp120-specific cytolytic T lymphocyte responses in vitro and in vivo using a detoxified pertussis toxin vector.

CD8+ cytolytic T lymphocytes (CTL) are almost certainly an important component of a potentially protective immune response to HIV. To test the ability of pertussis toxin (PT) to deliver an HIV-derived major histocompatibility complex (MHC) class I peptide for CTL stimulation, we constructed a fusion of the gp120 P18-I10 CTL epitope with a genetically detoxified derivative of PT (PT9K/129G) and assayed this fusion for its ability to stimulate a gp120-specific CTL response in vitro and in vivo. Antigen-presenting cells incubated with this fusion protein were lysed by P18-I10-specific CTL in vitro and this activity was shown to be MHC class I restricted. The activity was inhibited by brefeldin A but was not inhibited by proteasome inhibitors, possibly because PT undergoes retrograde intracellular transport through the Golgi apparatus to the endoplasmic reticulum and delivers epitopes directly to nascent class I molecules. Mice immunized intraperitoneally with a single dose of the fusion protein without adjuvant raised a strong gp120-specific CTL response in the spleen. This CTL response was dependent on (1) the dose of fusion administered, (2) the fusion of the epitope with the toxin (since coadministration of peptide and toxin gave no response), and (3) the activity of CD8+ cells. These data demonstrate that this detoxified derivative to PT, which is already a component of a licensed vaccine for humans, could represent a useful vaccine vector molecule for stimulation of HIV-specific CTL responses.     

日本血吸虫热休克蛋白40 kDa免疫学功能研究

目的探索日本血吸虫热休克蛋白40 k Da(Sj HSP40)免疫学功能。方法采用生物信息学方法分析Sj HSP40蛋白序列同源性,并预测其B细胞及T细胞表位。应用PCR技术扩增全长Sj HSP40基因,将其克隆入原核表达质粒p GEX-6P-1,再转入大肠埃希菌BL21中;以异丙基-β-D-硫代半乳糖苷(IPTG)诱导表达,再经亲和柱分离纯化获得谷胱甘肽巯基转移酶(GST)-Sj HSP40融合蛋白,分别采用十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)及Western blotting进行鉴定。以GST-Sj HSP40免疫BALB/c小鼠后,以酶联免疫吸附试验(ELISA)检测小鼠血清中抗Sj HSP40特异性Ig G抗体及其亚型Ig G1、Ig G2a抗体,采用流式检测术观察Sj HSP40对CD4+T细胞亚群分化的影响。结果 Sj HSP40含有7个潜在B细胞表位及多个T细胞表位(CTL表位和Th表位)。成功构建了原核表达重组质粒p GEX-6P-1-Sj HSP40,并通过诱导表达和蛋白纯化获得GST-Sj HSP40融合蛋白。与其他组相比,GST-Sj HSP40免疫小鼠血清中抗Sj HSP40特异性Ig G抗体及其亚型Ig G1和Ig G2a水平均显著升高,但Sj HSP40对CD4+T淋巴细胞分化无显著影响。结论 Sj HSP40可诱导小鼠产生特异性体液免疫应答,但不影响小鼠体内各类Th免疫反应平衡,可作为潜在疫苗候选分子。