稳定表达人乳头瘤病毒(HPV)58型E6E7融合基因的B16细胞系的建立

目的:构建pIRES-neo-HPV58E6E7真核表达载体,稳定转染入小鼠黑色素瘤B16细胞,建立稳定表达HPV58E6E7基因的B16细胞系。方法:采用PCR方法扩增出HPV58E6E7融合基因的全长序列,利用DNA重组技术将其定向插入到真核表达载体pIRES-neo中,并加入酶切位点和6×his标签,构建重组真核表达质粒pIRES-neo-HPV58E6E7。利用阳离子脂质体介导法将其转染入小鼠黑色素瘤B16细胞,经G418加压筛选出稳定转染的阳性克隆。利用Western blot、流式细胞术、免疫荧光等检测方法验证HPV58E6E7融合基因在稳定转染的B16细胞株中的表达。结果:经PCR、限制性内切酶鉴定及测序分析,pIRES-neo-HPV58E6E7重组质粒构建正确,转染B16细胞株后,经过Western blot、流式细胞术和免疫荧光等检测显示B16细胞株能够稳定、高效表达HPV58E6E7融合基因,表明B16-HPV58E6E7稳定转染细胞系构建成功。结论:成功构建了pIRES-neo-HPV58E6E7真核表达载体,建立了可以高效、稳定表达HPV58E6E7融合基因的B16细胞系。该稳定转染细胞系的建立为进一步研究HPV58治疗性基因疫苗的功能提供了良好的靶细胞,为其在肿瘤免疫治疗中的应用奠定了研究基础。     

人乳头状瘤病毒11型E7抗原HLA-A*0201限制性细胞毒性T淋巴细胞表位的功能鉴定

目的 筛选和鉴定人乳头状瘤病毒11型E7抗原(HPVllE7)HLA-A*0201限制性细胞毒性T淋巴细胞(cytotoxic T lymphocyte,CTL)表位.方法 预测HPVllE7抗原HLA-A*0201限制性CTL表位并合成相对应的表位多肽和四聚体(tetramer),即HPVllE7 7-15(TLKDIVLDL)、15-23(LQPPDPVGL)、47-55(PLTQHYQIL)、81-89(DLLLGTLNI)和82-90(LLLGTLNIV).从健康HLA-A*0201成人外周血单一核细胞诱导树突状细胞(DC)并负载上述表位多肽,流式细胞技术检测DC成熟分化标记及ELISA法检测DC分泌的IL-12;成熟DC负载各组多肽后观察DC激活T淋巴细胞的效应,ELISA法检测T细胞分泌的IFN-γ;四聚体检测抗原特异性CD8+ T细胞及乳酸脱氢酶(LDH)释放法评价DC诱导的CTL对靶细胞的特异性体外杀伤效应.结果 预测的5条HPVllE7表位多肽均能诱导DC的成熟分化;E7 7-15、82-90和15-23多肽负载的DC能激活T淋巴细胞分泌高水平IFN-γ;E7 7-15多肽负载的DC能刺激特异性tetramer+CD8+细胞增殖且其诱导的CTL对HPVllE7/293细胞产生高效率的特异性杀伤作用(P<0.05).结论 筛选并鉴定出1条HPVllE7HLA-A*0201限制性CTL表位E7 7-15(TLKDIVLDL),负载该表位肽的DC体外可诱导高效、特异性的CTL效应,抗原性较强,有可能作为HPV感染治疗用肽疫苗的候选表位.     

HLA-DQB1 基因多态性与广西壮族女性HPV16 感染和宫颈癌易感性的关联研究

目的:探讨HLA-DQB1 等位基因多态性对广西壮族女性HPV16 感染和宫颈癌发生的影响,为寻找广西壮族女性宫颈癌的遗传易感基因或保护基因提供线索。方法:选取广西地区25 ~45 岁宫颈癌确诊的壮族患者、无癌健康壮族女性各171 例作为研究对象(按年龄依3 岁配对),采集研究对象样本并提取HPV 核酸和人基因组DNA,分别应用PCR-SSP 和分子导流杂交技术进行HLA-DQB1 基因型检测和HPV 基因分型检测,最后进行统计学分析。结果:(1)171 例宫颈癌患者中HPV总感染率为91.22%,其中高危型病毒占90.76%, HPV16 型为主要致病亚型(43.58%);(2)广西壮族女性宫颈癌患者组的HLA-DQB1*04 等位基因携带率高于无癌对照组,差异具有统计学意义(P<0.05);等位基因HLA-DQB1*06/09 在宫颈癌患者组中的携带率明显低于无癌组,差异具有统计学意义(P<0.05);而两组间的HLA-DQB1*02/05/07/08 等位基因携带率无显著性差异(P>0.05);(3)HLA-DQB1*04 基因在HPV16 阳性宫颈癌患者中出现的频率明显高于HPV16 阴性患者,差异具有统计学意义(P<0.05)。结论:HLA-DQB1*04 可能是广西壮族女性宫颈癌发生的易感基因,HLA-DQB1*06/09 可能是广西壮族女性宫颈癌的保护基因。而HLA-DQB1*02/05/07/08 等位基因可能与广西壮族女性宫颈癌遗传易感性无关。携带HLA-DQB1*04 等位基因的广西壮族妇女可能更容易感染HPV16 型病毒,从而增加了其患宫颈癌的危险性。     

幽门螺杆菌黏附素HLA-DRB1限制性CD4+T细胞表位的预测与鉴定

目的针对中国汉族高频HLA-DRB1基因型人群,预测与鉴定幽门螺杆菌(Helicobacter pylori,H.pylori)黏附素蛋白A亚单位(neuraminyllactose-binding hemagglutinin,HpaA)CD4+T细胞表位。方法通过Allele Frequency Net数据库分析中国汉族人群HLA-DRB1高频基因型,利用NetMHCIIpan对HpaA蛋白中能被这些高频基因型递呈的CD4+T细胞表位进行预测;通过PCR-SBT法筛选携带有这些高频基因型的H.pylori感染者,利用重组HpaA抗原刺激感染者外周血单个核细胞体外扩增出HpaA抗原特异性T淋巴细胞后利用合成短肽对所预测表位进行鉴定,通过抗体阻断实验对表位的HLA限制性进行分析,利用DC细胞负载重组HpaA蛋白对表位的自然递呈特征进行分析。结果中国汉族人群中HLA-DRB1高频基因型为DRB1*0901(14.4%)、DRB1*1202(13.3%)和DRB1*1501(10.8%),针对上述3种高频基因型预测出24个HpaA蛋白CD4+T细胞表位。其中,4个表位:HpaA39-53(HLA-DRB1*0901)、HpaA42-56(HLA-DRB1*0901)、HpaA89-103(HLA-DRB1*1202)和HpaA87-101(HLA-DRB1*1501)可有效刺激体外扩增的HpaA特异性T细胞产生高水平IFN-γ,且均能被DC细胞自然递呈。结论鉴定得到的4个HLA-DRB1限制性CD4+T细胞表位有可能成为H.pylori表位疫苗设计的候选抗原。     

稳定表达人乳头瘤病毒58型(HPV58)E6E7融合基因的人宫颈癌细胞株C33A的构建及验证

为构建稳定表达人乳头瘤病毒(HPV)58型E6E7融合基因的人宫颈癌C33A细胞系,将实验前期构建好并实现真核表达的重组慢病毒颗粒LV-HPV58E6E7转染入HPV(–)的人宫颈癌C33A细胞,经流式细胞仪分选出稳定转染的阳性克隆,利用四唑盐比色(MTT)法检测转染后细胞的生长情况以及流式细胞术检测细胞周期,并将稳定表达HPV58E6E7融合基因的C33A细胞LV-HPV58E6E7/C33A接种于裸鼠左腋下成瘤,用荧光定量PCR(q RT-PCR)、Western blot检测瘤组织中HPV58型E6E7融合基因的转录和表达。结果显示HPV58E6E7融合基因可促进C33A细胞的增殖;LV-HPV58E6E7/C33A细胞株能在裸鼠体内稳定转录及表达HPV58型E6E7融合基因。这表明我们成功建立了能稳定表达HPV58E6E7融合基因的人宫颈癌C33A细胞系LV-HPV58E6E7/C33A,为HPV58型治疗性疫苗的免疫效果检测提供了抗原细胞来源。     

Grave 病与 HLA-DQA1 和 HLA-DQB1等位基因多态性的相关性分析

目的 探索Grave病(Graves'disease,GD)与HLA-DQA1和HLA-DQB1等位基因多态性之间关系.方法 选取就诊于我院的Grave病患者为研究对象.使用PCR-SBT方法对Grave病患者及正常对照组进行测序分析,使用SPSS 19.0统计软件进行分析GD患者组与对照组间差异性.结果 GD患者的HLA-DQAl* 01:01、*01:03、* 03:03、* 05:03的频率显著高于对照组,HLA-DQA1* 02:01、*05:05的基因频率明显低于正常对照组,P均＜0.05,差异具有统计学意义.HLA-DQB1* 04:01、*06:01的频率显著高于对照组,HLA-DQB1 * 02:02、*05:01的基因频率明显低于正常对照组,P均＜0.05,差异具有统计学意义.结论 HLA-DQAl* 01:01、* 01:03、* 03:03、* 05:03和 HLA-DQB1 * 04:01、* 06:01 可能为 GD的危险因素.HLA-DQA1* 02:01、*05:05和 HLA-DQB1 * 02:02、* 05:01 可能为 GD 的保护因素.     

人乳头瘤病毒58型治疗性复合DNA疫苗载体的构建

目的:构建和表达人乳头瘤病毒(Human papilloma virus,HPV)58型相关宫颈癌治疗用PVAX1-HPV58mE6E7Fc-hIL12复合DNA疫苗载体。方法:将HPV58mE6E7融合基因片段插入真核表达载体pCI-Fc-GPI中,构建重组真核表达质粒pCI-sig-HPV58mE6E7-Fc-GPI。再将得到的sig-HPV58mE6E7-Fc-GPI片段插入新型疫苗载体PVAX1-IRES-hIL12中,构建PVAX1-HPV58mE6E7Fc-hIL12复合DNA疫苗载体,流式细胞术、免疫荧光及ELISA分别检测该疫苗载体的表达。结果:经限制性内切酶鉴定及测序分析证实PVAX1-HPV58mE6E7Fc-hIL12复合DNA疫苗载体构建成功。流式细胞术、免疫荧光及ELISA检测表明该疫苗载体中的融合抗原sig-HPV58mE6E7-Fc-GPI及分子佐剂人白介素12(hIL12)能够同时实现真核表达。结论:PVAX1-HPV58mE6E7Fc-hIL12复合DNA疫苗载体可作为治疗HPV58相关肿瘤及其癌前病变的候选疫苗载体。     

单个碱基变异致HLA-DQB1*03新等位基因的鉴定

目的确认1例HLA-DQB1新等位基因的序列,分析新等位基因的遗传学特征。方法应用PCR-序列特异性寡核苷酸探针分型技术(sequence-specific oligonucleotide probe,SSOP)及PCR-直接测序分型法(sequence-based typing,SBT)对1个白血病家系进行HLA常规检测,发现患者母亲及哥哥HLA-DQB1序列组合无完全匹配的基因型。应用二代测序(next generation sequencing,NGS)技术对该基因进行确认。结果PCR-SBT提示患者母亲及哥哥HLA-DQB1序列组合与已知基因型不完全匹配。NGS分析显示,与同源性最高的等位基因DQB1*03:02相比,该等位基因在第2外显子c.233T>G变异,导致46位编码氨基酸由缬氨酸变为甘氨酸(p.Val46Gly)。家系调查显示患者哥哥HLA-DQB1新等位基因来源于母亲。新等位基因序列已递交给GenBank数据库(MK729743)。结论应用NGS鉴定了1个HLA-DQB1新等位基因,该等位基因被世界卫生组织HLA因子命名委员会正式命名为HLA-DQB1*03:362。     

人锌转运蛋白8的HLA-A~*0201限制性CTL表位的预测及初步验证

目的预测和初步鉴定1型糖尿病(T1DM)主要自身抗原锌转运蛋白8(ZnT8)的HLA-A*0201限制性细胞毒性T淋巴细胞(cytotoxic T lymphocytes,CTL)表位,为基于ZnT8抗原表位的特异性免疫治疗奠定基础。方法选取BIMAS预测工具预测该抗原HLA-A*0201限制性结合肽,人工合成待测表位肽,利用T2细胞株测定各肽与HLA-A*0201分子的结合力。利用酶联免疫斑点检测(enzyme-linked immunospotassay,ELISPOT)方法检测候选肽刺激T1DM患者外周血单个核细胞分泌IFN-γ和IL-2的能力,利用标准51Cr释放试验检测特异性CTL诱导活性。结果在所筛选的5个候选CTL表位中,ZnT8(107-115)、ZnT8(115-123)及ZnT8(145-153)与HLA-A*0201分子具有较高的结合荧光强度,可在体外有效诱导抗原特异性CTL的产生,刺激T1DM患者PBMC分泌IFN-γ和IL-2,并对抗原肽负载的T2细胞具有明显的杀伤效应。结论 ZnT8(107-115)、ZnT8(115-123)及ZnT8(145-153)可能是HLA-A*0201限制性CTL表位,为基于人ZnT8抗原表位的特异性免疫治疗奠定理论基础。     

E7多肽的抗原表位特性与多肽反应阳性结核患者的HLA-DR等位基因分析

目的:分析结核分枝杆菌(Mycobacterium tuberculosis,MTB)E7多肽的T细胞抗原表位特性,克隆及分析E7多肽反应阳性的结核患者HLA-DR等位基因。方法:应用从结核患者末梢血分离的单个核细胞(PBMC),以IFN-γ-ELISPOT和细胞内细胞因子染色分析MTB E7多肽的T细胞抗原表位特性;从E7-ELISPOT阳性反应的PBMC或胸水细胞中扩增、克隆和分析HLA-DRα和β链等位基因。结果:311例患者IFN-γ-E7-ELISPOT检测显示233例阳性(阳性率75%),阳性结果的平均SFC为210个斑点/106细胞,E7和另一多肽(E6多肽)混合检测529例患者则显示492例阳性(阳性率93%),平均SFC为572个斑点/106细胞;E7多肽刺激后,19例患者的PBMC经细胞内细胞因子染色结果显示能产生IFN-γ的CD4+T细胞百分率为0.63±1.30,而5例健康对照者为0.05±0.056,两者有显著性差异(P<0.004);扩增、克隆出了共有的HLA-DRA*0101和15种HLA-DRB1等位基因。结论:E7是一种理想的广谱HLA-DR限制性CD4+T细胞反应性多肽,为深入研究结核患者的HLA-DRB等位基因的分布特点以及制备相应四聚体建立了基础。     

Soluble HLA-G in rheumatoid arthritis

We investigated potential correlations between soluble HLA-G (sHLA-G) and soluble HLA class I (sHLA-I) levels, respectively, and parameters of disease activity or genetic factors determined by HLA-DRB1 and HLA-DQB1 in patients with rheumatoid arthritis (RA). SHLA-G plasma concentrations from 106 RA patients (mean age 59.8 years, 80 women) were assessed by a sensitive enzyme-linked immunosorbent assay format. The mean sHLA-G levels were lower and sHLA-I levels higher in the RA patients than in healthy controls. Correlation coefficients of 0.248 to 0.344 (p < 0.01) between sHLA-G and rheumatoid factor, CRP, and EULAR joint swelling score were found. Patients with disease-associated HLA epitopes had higher sHLA-G levels than those without. Significantly lower sHLA-G was observed in groups of patients having HLA-DRB1*03 or HLA-DQB1*02 compared to groups without these genotypes. In contrast, HLA-DQB1*03 or disease-associated epitopes combined with HLA-DQB1*03 were associated with higher sHLA-G levels, whereas the inverse was observed in the combined presence of HLA-DRB1*03 and HLA-DQB1*02. SHLA-G as a percentage of sHLA-I was lower in patients positive for HLA-DQB1*02 and higher in patients positive for HLA-DQB1*03 and in its combined presence with disease-associated epitopes or with HLA-DRB1*07. As especially sHLA-G strongly inhibits T and natural killer (NK) cell functions, low sHLA-G suggests that T and NK cell activities are not efficiently restricted by sHLA-G molecules in rheumatoid arthritis. The sHLA-G levels, however, increase in correlation with parameters of disease activity and appear to be affected by the presence of disease-predisposing epitopes and other HLA-DRB1, DQB1 genotypes.     

HPV58 E6体外降解p53蛋白作用的研究

通过PCR方法从有乳头瘤病毒58型（HPV58）全基因克隆中扩增出HPV58E6基因片段，克隆至真核表达质粒pcDNA3的T7启动子下游，并在体外转录成mRNA后，在源自网织红细胞的翻译缓冲液中成功表达了含有生物素标记的HPV58E6蛋白，并在体外成功发现HPV58E6能够降解p53蛋白，从而推断结合并降解p53蛋白是其致癌作用的关键环节，这为日后在细胞内对其致癌机理行进一步研究以及针对其进行治疗奠定下坚实的基础。     

Memory T cells specific for novel human papillomavirus type 16 (HPV16) E6 epitopes in women whose HPV16 infection has become undetectable

Human papillomavirus (HPV)-specific T-cell response to the HPV type 16 (HPV16) E6 protein has been shown to be associated with successful viral clearance. The patterns of CD8 T-cell epitopes within HPV16 E6 protein were previously studied in two women with HPV16 clearance. The goal of this study was to characterize these epitopes in terms of their minimal and optimal amino acid sequences and the human leukocyte antigen (HLA) restriction molecules. The presence of the epitope-specific memory T cells after viral clearance was also examined. In subject A, the dominant epitope was characterized to be E6 75-83 (KFYSKISEY), restricted by the HLA-B62 molecule, while that of subject B was E6 133-142 (HNIRGRWTGR), restricted by the HLA-A6801 molecule. Homologous epitopes were identified in five other high-risk HPV types for both of these epitopes, but they were not recognized by respective T-cell clone cells. An enzyme-linked immunospot assay or tetramer analysis was performed on peripheral blood mononuclear cells from blood samples collected after viral clearance but prior to isolation of the T-cell clones. The presence of epitope-specific memory T cells was demonstrated. These data suggest that HPV-specific memory T cells were generated in vivo and that they may remain in circulation many months, if not years, after viral clearance. Our findings broaden the spectrum of the CD8 T-cell epitopes of the HPV16 E6 protein. The characterization of novel T-cell epitopes and long-lasting epitope-specific memory T cells may be useful for the development of a potential epitope-based vaccine.     

Limitations of HLA-transgenic mice in presentation of HLA-restricted cytotoxic T-cell epitopes from endogenously processed human papillomavirus type 16 E7 protein

We investigated the use of mice transgenic for human leucocyte antigen (HLA) A*0201 antigen-binding domains to test vaccines composed of defined HLA A*0201-restricted cytotoxic T-lymphocyte (CTL) epitopes of human papillomavirus (HPV) type 16 E7 oncoprotein. HPV is detected in >90% of cervical carcinomas. HPV16 E7 oncoprotein transforms cells of the uterine cervix and functions as a tumour-associated antigen to which immunotherapeutic strategies may be directed. We report that although the HLA A*0201 E7 epitope peptides function both to prime for E7 CTL responses, and to sensitize target cells for E7-directed CTL killing in situations where antigen processing is not required, the epitopes are not processed out of either endogenously expressed or immunization-introduced E7, by the mouse antigen-processing and presentation machinery. Thus (1) CTL induced by HLA A*0201 peptide immunization killed E7 peptide-pulsed target cells, but did not kill target cells expressing whole E7; (2) immunization with whole E7 protein did not elicit CTL directed to HLA A*0201-restricted E7 CTL epitopes; (3) HLA A*0201-restricted CTL epitopes expressed in the context of a DNA polytope vaccine did not activate E7-specific T cells either in 'conventional' HLA A*0201 transgenic (A2.1Kb) mice, or in HHD transgenic mice in which expression of endogenous H-2 class 1 is precluded; and (4) HLA A*0201 E7 peptide epitope immunization was incapable of preventing the growth of an HLA A*0201- and E7-expressing tumour. There are generic implications for the universal applicability of HLA-class 1 transgenic mice for studies of human CTL epitope presentation in murine models of human infectious disease where recognition of endogenously processed antigen is necessary. There are also specific implications for the use of HLA A2 transgenic mice for the development of E7-based therapeutic vaccines for cervical cancer.     

人乳头瘤病毒16型L1/E7融合蛋白在原核细胞中的表达及免疫效果观察

目的构建能表达L1E7融合蛋白的原核表达菌株,纯化蛋白,并观察其免疫效果。方法用PCR方法分别扩增出C末端部分缺失的HPV16L1基因和HPV16E7编码基因N端部分序列。将上述基因连接,构建融合基因L1ΔCE7N并将其插到原核表达载体pGEX-2T中进行融合蛋白表达纯化,然后观察其免疫效果。结果L1ΔCE7N融合基因测序结果表明,序列与设计相符,读码框架正确。将其插入原核表达质粒在大肠埃希菌中获得高效表达;经Wester-Blot鉴定在相对分子质量约85×103处有特异性表达带,与预期相符。用亲和层析和分子筛可纯化L1ΔCE7N融合蛋白,将其免疫C57BL/6小鼠,结果表明融合蛋白能诱发高滴度L1、E7抗体,并能保护小鼠免受TC-1肿瘤细胞的攻击。结论本实验在原核系统中高效表达并纯化了L1ΔCE7N融合蛋白,该蛋白可作为预防和治疗HPV16感染以及相关肿瘤的候选疫苗株。为研制HPV16预防治疗性疫苗探索一条经济、易普及的途径。     

HPV16 L1基因的原核表达及免疫反应性鉴定

目的：在大肠杆菌中表达人乳头瘤病毒16型(HPV16)主要衣壳蛋白L1，并鉴定其免疫反应性。方法：将HPV-16L1基因克隆人原核表达载体pThioHisC中，构建重组表达载体。以重组载体分别转化大肠杆菌Top10和DH5α，在IPTG诱导下表达外源基因，用SDS—PAGE和Western blot对表达产物进行鉴定和分析。结果：构建了HPV—16L1基因的原核表达质粒pThioHisC／HPV—16L1，并在大肠杆菌中表达出相对分子质量(Mr)约为70800的蛋白。表达的蛋白能与抗HPV—16L1抗体发生特异性反应。结论：在原核细胞中成功地表达HPV—16L1基因，为HPV—16L1疫苗的研制提供了必要的基础。     

DR3-restricted T cells from different HLA-DR3-positive individuals recognize the same peptide (amino acids 2-12) of the mycobacterial 65-kDa heat-shock protein

Studies in experimental animals have demonstrated that the T cell response to immunogenic proteins is limited to one or a few epitopes on such proteins and that the MHC haplotype of the responder is an important factor in determining which epitope is recognized (immune response gene effect). However, if and to what extent MHC genes control the immune response to pathogens in man is virtually unknown. We have studied the human T cell response to the mycobacterial 65-kDa heat-shock protein, a major immunogen of Mycobacterium leprae and M. tuberculosis, the causative agents of leprosy and tuberculosis, respectively, in relation to HLA-DR phenotype. In a large panel of short-term cultured polyclonal anti-mycobacterial T cell lines, from 45 different individuals representing all DR-restriction specificities, only DR1 and DR3-restricted T cell lines proliferated to the 65-kDa protein. The DR1-restricted T cell lines responded to three new epitopes on the mycobacterial 65-kDa protein, one of which is specific for the M. tuberculosis complex. Altogether nine T cell epitope-containing regions have now been mapped on the 65-kDa protein and the response to each of them was exclusively restricted via one HLA-DR allele. Most importantly, all six 65-kDa-responsive DR3-restricted T cell lines from different individuals recognized an epitope on the same peptide, representing amino acids 2-12 of the 65-kDa protein, that was previously mapped using DR3-restricted T cell clones. From these data we conclude that the human T cell response to both the whole mycobacterial 65-kDa heat-shock protein and to defined epitopes on this protein is controlled by HLA-DR genes. The mycobacterial 65-kDa protein has been implicated in the design of subunit vaccines against tuberculosis and leprosy as well as the induction of immunopathology. In both instances the Ir gene control of the T cell response to this protein may have to be taken into account.     

人乳头瘤病毒6b L1/16E7嵌合蛋白的基因克隆和表达

目的 研究HPV6bL1/16E7嵌合蛋白的基因克隆及其在昆虫细胞的表达,为防治尖锐湿疣和宫颈癌的基因工程疫苗研究作准备。方法 用PCR扩增出HPV6bL1/16E7嵌合蛋白基因,将其克隆到杆状病毒转移载体pVL1393,制备重组杆状病毒并感染昆虫细胞表达HPV6bL1/16E7嵌合蛋白。结果 HPV6bL1/16E7嵌合蛋白基因在昆虫细胞中得到了表达,并可自组装形成病毒样颗粒。结果 昆虫细胞表达的HPV6bL1/16E7嵌合病毒样颗粒可进一步用于HPV感染的免疫机理及基因工程疫苗研究。     

Effective induction of type 1 cytotoxic T cell responses in mice with DNA vaccine encoding two hepatitis C virus cytotoxic T lymphocyte epitopes

The aims of this study were to explain whether a multiple cytotoxic T lymphocyte (CTL) epitope-based anti-hepatitis C virus (HCV) DNA vaccine can induce specific CTL responses to each HCV CTL epitope independently and long-term CD8(+) T cell memory responses, and to determine the cytokine secretion pattern and subtype of epitope-specific cytotoxic T cells. A multi-CTL epitope gene, which consists of two epitopes of HCV (H-2(d)-restricted HCV core(133142) and E1(315322)), was cloned into the eukaryotic expression vector pcDNA3.1. BALB/c mice (H-2(d) restricted) were vaccinated intramuscularly with this multi-CTL epitope-based DNA vaccine. The epitope-specific CTLs against target cells (P815,H-2(d) restricted) pulsed with various CTL epitope peptides were detected by lactate dehydrogenase release assay, and the precursor frequency of epitope-specific CTLs was determined by limiting dilution analysis. Cytokines (interleukin [IL]-2, IL-4, and interferon-) in culture supernatants were determined by enzyme-linked immunosorbent assay. The multi-CTL epitope-based DNA vaccine directed against two HCV CTL epitopes could induce specific CTL responses to each of the two CTL epitopes independently and long-term CD8(+) T cell memory responses. The epitope-specific cytotoxic T cells produced helper T cell type 1 cytokines. This work demonstrated that multiepitope DNA vaccination is a potential strategy to control HCV infection.