Frequencies and Characterization of HBV-specific Cytotoxic T Lymphocytes in Self-limited and Chronic Hepatitis B Viral Infection in China

Hepatitis B virus （HBV）-specific cytotoxic T lymphocytes （CTLs） are believed to play a major role in viral clearance and disease pathogenesis during HBV infection. To clarify the differences in host immune responses between self-limited and chronic HBV infections, we constructed three HLA-A＊0201/HBV tetramers with immunodominant epitopes of core18-27, polymerase 575-583 and envelope 335-343, and analyzed the HBV-specific CTLs in peripheral blood mononuclear cells （PBMCs） from patients infected with HBV. The frequencies and expansion ability of HBV-specific CD8＋T cells in most self-limited HBV infected individuals were higher than those in chronic HBV-infected patients. HBV-specific CD8＋T cells could be induced by in vitro peptide stimulation from chronic patients with a low level of serum HBV-DNA but not from those with a high level of serum HBV-DNA. In chronic infection, no significant correlation was found either between the frequencies of HBV-specific CD8^＋ T cells and the viral load, or between the frequencies and the levels of alanine transaminase. Our results suggested that the frequencies of HBV-specific CTLs are not the main determinant of immune-mediated protection in chronic HBV infection and immunotherapeutic approaches should be aimed at not only boosting a HBV-specific CD8^＋T response but also improving its function.

Enhancement of CTLs induced by DCs loaded with ubiquitinated hepatitis B virus core antigen

AIM： To investigate whether hepatitis B virus （HBV） could induce a hepatitis B virus core antigen （HBcAg）specific cytotoxic T lymphocyte （CTL） response in vitro by dendritic cells （DCs） transduced with lentiviral vector-encoding ubiquitinated hepatitis B virus core antigen （LV-Ub-HBcAg）.METHODS： Recombinant LV-Ub-HBcAg were transfected into highly susceptible 293 T cells to obtain high virus titres, Bone marrow-derived DCs isolated from BALB/c mice were cultured with recombinant granulocyte-macrophage colony-stimulating factor and recombinant interleukin （IL）-4. LV-Ub-HBcAg, lentiviral vector-encoding hepatitis B virus core antigen （LV-HBcAg）, lentiviral vector （LV） or lipopolysaccharide were added to induce DC maturation, and the DC phenotypes were analyzed by flow cytometry. The level of IL-12 in the supernatant was detected by enzyme-linked immunosorbent assay （ELISA）. T lymphocytes were proliferated using Cell Counting Kit-8. DCs were cultured and induced to mature using different LVs, and co-cultured with allogeneic T cells to detect the secretion levels of IL-2, IL-4, IL-10and interferon-γ in the supernatants of T cells by ELISA. Intracellular cytokines of proliferative T cells were analyzed by flow cytometry, and specific CTL activity was measured by a lactate dehydrogenase release assay.RESULTS： LV-Ub-HBcAg-induced DCs secreted more IL-12 and upregulated the expression of CD80, CD86 and major histocompatibility class ]I, DCs sensitised by different LVs effectively promoted cytokine secretion; the levels of IL-2 and interferon-y induced by LV-Ub- HBcAg were higher than those induced by LV-HBcAg, Compared with LV-HBcAg-transduced DCs, LV-Ub- HBcAg-transduced DCs more efficiently stimulated the proliferation of T lymphocytes and generated HBcAgspecific cytotoxic T lymphocytes.CONCLUSION： LV-Ub-HBcAg effectively induced DC maturation. The mature DCs efficiently induced T cell polarisation to Thl and generated HBcAg-specific CTLs.

Identification of the epitopes on HCV core protein recognized by HLA-A2 restricted cytotoxic T lymphocytes

AIM: To identify hepatitis C virus(HCV) core protein epitopes recognized by HLA-A2 restricted cytotoxic T lymphocyte (CTL). METHODS: Utilizing the method of computer prediction followed by a 4h(51)Cr release assay confirmation. RESULTS: The results showed that peripheral blood mononuclear cells (PBMC) obtained from two HLA-A2 positive donors who were infected with HCV could lyse autologous target cells labeled with peptide "ALAHGVRAL (core 150-158)". The rates of specific lysis of the cells from the two donors were 37.5% and 15.8%, respectively. Blocking of the CTL response with anti-CD4 mAb caused no significant decrease of the specific lysis. But blocking of CTL response with anti-CD8 mAb could abolish the lysis. CONCLUSION: The peptide (core 150-158) is the candidate epitope recognized by HLAA2 restricted CTL.

Peripheral T-lymphocyte subpopulations in different clinical stages of chronic HBV infection correlate with HBV load

AIM： To characterize the peripheral T-cell subpopulation profiles and their correlation with hepatitis B virus （HBV） replication in different dinical stages of chronic HBV infection. METHODS： A total of 422 patients with chronic HBV infection were enrolled in this study. The patients were divided into three stages： immune-tolerant stage, immune active stage, and immune-inactive carrier stage. Composition of peripheral T-cell subpopulations was determined by flow cytometry. HBV markers were detected by enzyme-linked immunosorbent assay. Serum HBV DNA load was assessed by quantitative real-time poiymerase chain reaction.RESULTS： CD8^＋ T-cells were significantly higher in patients at the immune-tolerant stage than in patients at the immune-active and -inactive carrier stages （36.87 ± 7.58 vs 34.37 ± 9.07, 36.87 ± 7.58 vs 28.09 ± 5.64, P 〈 0.001）. The peripheral blood in patients at the immune-tolerant and immune active stages contained more CD8^＋ T-cells than CD4^＋ T-cells （36.87 ± 7.58 vs 30.23 ± 6.35, 34.37 ± 9.07 vs 30.92 ± 7.40, P 〈 0.01）, whereas the peripheral blood in patients at the immune- inactive carrier stage and in normal controls contained less CD8^＋ T-cells than CD4^＋ T-cells （28.09 ± 5.64 vs 36.85 ±6.06, 24.02 ± 4.35 vs 38.94 ± 3.39, P 〈 0.01）. ANOVA linear trend test showed that CD8^＋ T-cells were significantly increased in patients with a high viral load （39.41 ± 7.36, 33.83 ± 7.50, 31.81 ± 5.95 and 26.89 ± 5.71, P 〈 0.001）, while CD4^＋ T-cells were significantly increased in patients with a low HBV DNA load （37.45 ± 6.24, 33.33 ± 5.61, 31.58 ± 6.99 and 27.56 ± 5.49, P 〈 0.001）. Nultiple regression analysis displayed that log copies of HBV DNA still maintained its highly significant coefficients for T-cell subpopulations, and was the strongest predictors for variations in CD3^＋, CD4^＋ and CD8^＋ cells and CD4^＋/CD8^＋ ratio after adjustment for age at HBV-infection, maternal HBV-infection status, presence of hepatitis B e antigen and HBV mutation.CONCLUSION： Differences in peripheral T-cell subpopulation profiles can be found in different clinical stages of chronic HBV infection. T-cell impairment is significantly associated with HBV load.

Depletion of CD25^+CD4^+T cells (Tregs) enhances the HBV-specific CD8^+ T cell response primed by DNA immunization

AIM: Persistent hepatitis B virus (HBV) infection is characterized by a weak CD8+ T cell response to HBV. Immunotherapeutic strategies that overcome tolerance and boost these suboptimal responses may facilitate viral clearance in chronically infected individuals. Therefore, we examined whether CD25+CD4+ regulatory T (Treg) cells might be involved in a inhibition of CD8+T cell priming or in the modulation of the magnitude of the 'peak' antiviral CD8+ T cell response primed by DNA immunization. METHODS: B10.D2 mice were immunized once with plasmid pCMV-S. Mice received 500 μg of anti-CD25 mAb injected intraperitoneally 3 d before DNA immunization to deplete CD25+ cells. Induction of HBV-specific CD8+ T cells in peripheral blood mononuclear cells (PBMCs) was measured by S28-39 peptide loaded DimerX staining and their function was analyzed by intracellular IFN-γ staining. RESULTS: DNA immunization induced HBV-specific CD8+ T cells. At the peak T cell response (d 10), 7.1±2.0% of CD8+ T cells were HBV-specific after DNA immunization, whereas 12.7±3.2% of CD8+ T cells were HBV-specific in Treg-depleted mice, suggesting that DNA immunization induced more antigen-specific CD8+ T cells in the absence of CD25+ Treg cells (n = 6, P<0.05). Similarly, fewer HBV specific memory T cells were detected in the presence of these cells (1.3±0.4%) in comparison to Treg-depleted mice (2.6±0.9%) on d 30 after DNA immunization (n - 6, P<0.01). Both IFN-γ production and the avidity of the HBV-specific CD8+ T cell response to antigen were higher in HBV-specific CD8+ T cells induced in the absence of Treg cells. CONCLUSION: CD25+ Treg cells suppress priming and/or expansion of antigen-specific CD8+ T cells during DNA immunization and the peak CD8+ T cell response is enhanced by depleting this cell population. Furthermore, Treg cells appear to be involved in the contraction phase of the CD8+ T cell response and may affect the quality of memory T cell pools. The elimination of Treg cells or their inhibition may be important in immunotherapeutic strategies to control HBV infection by inducing virus-specific cytotoxic T lymphocyte responses in chronically infected subjects.

Uric acid enhances T cell immune responses to hepatitis B surface antigen-pulsed-dendritic cells in mice

AIM： To study the induction of T cellular immune responses in BALB/c mice immunized with uric acid and dendritic cells （DCs） pulsed with hepatitis B virus surface antigen （HBsAg）. METHODS： DCs were generated from bone-marrow cells of BABL/c mice, and then pulsed or unpulsed with HBsAg protein （HBsAg-pulsed-DCs or unpulsed-DCs） in vitro. BABL/c mice were immunized with HBsAg-pulsed- DCs （1 × 10^6） and uric acid, injected through the tail vein of each mouse. The mice in control groups were immunized with HBsAg-pulsed-DCs alone, unpulsed- DCs alone or 200 μg uric acid alone or PBS alone. The immunization was repeated 7 d later. Cytotoxic T lymphocytes （CTLs） in vivo were determined by the CFSE labeled spleen lysis assay. Spleen cells or spleen T cells were isolated, and re-stimulated in vitro with HBsAg for 120 h or 72 h. Production of IFN-γ, and IL-4 secreted by spleen cells were determined by ELISA method; proliferation of spleen T cells were detected by flow cytometry. RESULTS： The cytotoxicities of HBsAg-specific-CTLs, generated after immunization of HBsAg-pulsed-DCs and uric acid, were 68.63% ±11.32% and significantly stronger than that in the control groups （P 〈 0.01）. Compared with control groups, in mice treated with uric acid and HBsAg-pulsed-DCs, the spleen T cell proliferation to HBsAg re-stimulation was stronger （1.34 ± 0.093 vs 1.081±0.028, P 〈 0.01）, the level of IFN-t, secreted by splenocytes was higher （266.575 ± 51.323 vs 135.223 ±32.563, P 〈 0.01） , and IL-4 level wasower （22.385 ± 2.252 vs 40.598 ± 4.218, P 〈 0.01）. CONCLUSION： Uric acid can strongly enhance T cell immune responses induced by HBsAg-pulsed-DCs vaccine. Uric acid may serve as an effective adjuvant of DC vaccine against HBV infection.

Immune response pattern varies with the natural history of chronic hepatitis B

BACKGROUND Chronic hepatitis B is a highly heterogeneous disease that can be divided into four phases: Immune tolerant(IT), immune active(IA), inactive carrier(IC) and hepatitis B envelope antigen(HBeAg)-negative hepatitis(ENEG).AIM To investigate the immune status of natural killer(NK) and T cells in different phases of chronic hepatitis B.METHODS The frequency, phenotype and function of circulating NK cells, as well as nonantigen-specific and hepatitis B virus(HBV)-specific T cell responses were detected by flow cytometry in healthy and HBV-infected subjects.RESULTS The ability of NK cells to produce IFN-γ was markedly attenuated in HBVinfected patients overall but was less compromised in IC patients. Patients in the IT and IA phases also displayed significantly lower TNF-α production compared to healthy subjects. NK cells were phenotypically activated in the IA and ENEGphases, as evidenced by the upregulation of NKp44 in CD56^(bright) NK cells and CD69 in CD56^(dim) NK cells. Furthermore, global T-cells from the ENEG phase displayed a proinflammatory cytokine profile with upregulated IFN-γ and TNF-αexpression, while this profile was suppressed in IT and IA patients. Finally, core and S antigen-specific T cell responses were significantly stronger after in vitro expansion in the IC phase compared to other phases.CONCLUSION Our findings demonstrate the changes in immune response pattern during the natural history of HBV infection. Both NK and T cells are functionally impaired in the IT and IA phases. With the spontaneous clearance of HBeAg and hepatitis B surface antigen decline, NK cell cytokine production and HBV-specific T responses are partially restored in IC phase, and the ENEG phase is dominated by nonantigen-specific T cell responses.

HBV相关原发肝细胞癌患者T淋巴细胞、壳酶蛋白和DR-70表达水平差异

目的探讨不同临床分型乙型肝炎病毒(HBV)感染患者外周血T淋巴细胞、壳酶蛋白、纤维蛋白降解复合物(DR-70)表达水平的变化及临床意义,分析肝细胞癌患者T淋巴细胞、壳酶蛋白和DR-70的相关性。方法回顾性选取2017年9月至2022年9月烟台市奇山医院收治的慢性HBV感染患者173例作为试验组[男114例,女59例,年龄(45.38±12.72)岁],再根据病情分为乙型肝炎病毒携带者59例、慢性乙型肝炎患者51例、肝硬化患者31例和肝细胞癌患者32例,以同期健康体检者40例作为对照组[男22例,女18例,年龄(39.15±14.95)岁]。运用流式细胞术检测各研究对象外周血T淋巴细胞亚群表达水平,采用酶联免疫吸附试验双抗体夹心法定量检测外周血DR-70水平,应用磁微粒化学发光法检测外周血壳酶蛋白水平。两两比较采用Games-Howell检验,Welch方差用于分析组间方差不齐。Kruskal-Wallis H检验用于非正态分布的计量资料比较,采用χ^(2)检验和Pearson相关分析法进行计数资料组间比较和相关性分析。结果肝细胞癌组CD3^(+)表达水平[(61.43±19.26)%]最低,肝硬化组CD3^(+)CD8^(+)表达水平[(17.89±9.15)%]最低,与对照组比较,差异均有统计学意义(均P<0.05);CD3^(+)CD4^(+)水平在试验组各小组中升高程度不同,肝硬化组最高[(37.16±13.84)%],与对照组比较,差异均有统计学意义(均P<0.05)。慢性乙型肝炎组、肝硬化组和肝细胞癌组外周血DR-70和壳酶蛋白水平均不同程度升高(均P<0.01),且均在肝细胞癌组中表达水平[(30.11±9.96)mg/L、(213.11±39.76)μg/L]最高(均P<0.01)。肝细胞癌组患者外周血CD3^(+)T淋巴细胞表达占比与DR-70水平呈负相关(r=-0.291,P=0.037)。结论血清DR-70和壳酶蛋白在细胞肝癌中高表达,与T淋巴细胞亚群联合检测可用于评估慢性肝病患者疾病进展程度,有助于慢性乙型肝炎的临床诊疗,特别是对肝脏肿瘤的早期诊断具有较大的应用价值。

乙型肝炎患者HBcAg18-27表位特异性细胞毒性T细胞的研究

目的对乙肝患者尤其是慢性乙肝患者外周血HBcAg18-27表位特异性细胞毒性T细胞(CTL)的分布频率及功能状态进行研究。方法应用多色流式分析结合HLA-A*0201限制性表位肽/五聚体复合物技术对乙肝患者外周血HBcAg18-27表位特异性CTL进行精确定量,应用胞内细胞因子染色技术结合流式细胞分析技术研究HBcAg18-27表位特异性CTL穿孔素,颗粒酶B,干扰素-γ的分泌水平。结果在急性与慢性乙型肝炎患者外周血中均可测到HBcAg18-27表位特异性CTL,两者的分布频率存在显著性差异。慢性乙肝患者外周血中HBcAg18-27表位特异性CTL分泌穿孔素,颗粒酶B,干扰素的水平明显降低。结论HBcAg18-27表位特异性CTL在乙型肝炎病毒清除中起到重要作用,慢性乙肝患者外周血HBcAg18-27表位特异性CTL存在功能缺陷。

HBsAg体外冲击的慢性乙肝患者树突状细胞的生物学特性及其对HBV特异性CTL的诱导作用

目的 :研究HBsAg冲击的慢性乙肝患者单核细胞来源的树突状细胞 (DCs)的功能状况及体外对HBV特异性CTL的诱导作用 ,初步探讨诱导特异性抗HBV细胞免疫的途径。方法 :分离慢性乙肝患者外周血单核细胞 ,以GM CSF +IL 4 +TNF α培养诱导DCs,加入HBsAg冲击以诱导HBV特异性DCs。采用FCM测定细胞表面免疫分子CD1a、CD83、CD86、CD80、CD4 0以及HLA DR的表达水平 ,ELISA法检测培养上清中细胞因子IL 6、IL 12的分泌含量 ,MTT法测定DC刺激同种异体淋巴细胞增殖的能力 ,LDH法检测DC诱导的患者外周血T细胞对HepG2 2 2 15 (转染HBVDNA)、HepG2肝癌细胞株及K5 6 2白血病细胞株的细胞毒作用。结果 :HBsAg冲击的DC其表达CD1a、CD83、CD86、CD80、CD4 0、HLA DR表面分子明显高于对照组 (P <0 0 1,P <0 0 5 ) ,分泌IL 12的水平也高于对照组 (P <0 0 1) ,而分泌IL 6的水平则较对照组显著降低(P <0 0 1) ;HBsAg冲击的DC刺激同种异体淋巴细胞增殖的能力明显增强 (P <0 0 5 ) ,并可有效地诱导自体CTL对转HBV基因的HepG2 2 2 15细胞高效特异性杀伤作用 (P <0 0 1)。结论 :慢性乙型肝炎患者单核细胞来源的DCs经HBsAg抗原冲击后 ,生物学活性增强 ,并且能有效地诱导对HBV特异性反应的CTL。

慢性乙型肝炎患者树突状细胞诱导的HBV特异性细胞毒性T淋巴细胞PD-1的表达

目的探讨慢性乙型肝炎(CHB)患者树突状细胞(DC)诱导的HBV特异性细胞毒性T细胞(CTL)表面程序性死亡受体1(PD-1)的表达情况及其与HBV DNA的关系。方法采集30例CHB患者和10例健康人的抗凝外周静脉血,分离外周血单个核细胞(PBMC),在白细胞介素(IL)-4和粒-巨噬细胞集落刺激因子(GM-CSF)的作用下培养使DC增殖、成熟,培养第4 d加入纯化的HBsAg进行冲击。采同一患者外周血,分离出自体T淋巴细胞,用含重组人白细胞介素(rhIL)-2的培养基维持T细胞的生长,培养第5 d与HBsAg冲击的DC共培养。以流式细胞技术检测CTL的PD-1表达,并分析PD-1表达水平与HBV DNA的关系。结果与健康对照组比较,CHB组DC诱导的HBV特异CTL的PD-1的表达明显升高(P=0.000)。且HBeAg阳性组PD-1的表达率较HBeAg阴性组明显升高(P=0.000)。CHB患者DC诱导的HBV特异性CTL的PD-1表达率与血清HBV DNA拷贝数的对数值呈正相关(r=0.53,P=0.008)。结论 CHB患者DC诱导的HBV特异性CTL高表达PD-1分子,为HBV慢性感染过程中CTL功能低下,病毒难以清除提供了另一条重要线索。

慢性乙型肝炎患者HBV特异性细胞毒性T细胞PD-1的表达研究

目的检测慢性乙型病毒性肝炎患者外周血中HBV特异性CD8+细胞毒性T淋巴细胞表面细胞程序性死亡受体1(programmed cell death1,PD-1)的表达情况。方法采集慢性乙型肝炎患者外周血,直接离体情况下利用MHC-I-肽-五聚体技术标定HBV表位特异性细胞毒性T淋巴细胞以及荧光抗体标记细胞表面PD-1分子,经流式细胞仪检测分析。结果在慢性乙型肝炎患者,HBV核心抗原18-27特异性CTL表达PD-1上调,达(79.0±12.5)%,显著高于总CD8+T细胞(27.7±14.8)%,以及CMV特异性CTL(20.6±5.9)%。结论慢性乙肝患者HBV特异性CTL高表达PD-1分子,可能与慢性乙肝患者HBV特异性CTL功能低下密切相关。

慢性乙肝患者PBMC中HBV感染及其对T细胞亚群的影响

目的 :探讨乙肝病毒 (HBV)感染外周血单个核细胞 (PBMC)对T细胞亚群的影响。方法 :应用聚合酶链反应 (PCR)检测了 6 0例慢性乙肝患者PBMC中HBVDNA ,同时应用直接致敏红细胞花环法检测患者T细胞亚群。结果 :慢性乙肝患者PBMC中HBVDNA总检出率为 6 8.3% ,与PBMC中HBVDNA阴性组相比 ,HBVDNA阳性组患者CD8细胞增加 ,CD4 /CD8细胞比值显著下降。结论 :慢性乙肝患者T细胞亚群变化与HBV感染PBMC有关 。

慢性乙型肝炎患者HBV特异性CTL、非特异性CTL的变化和意义

目的探讨慢性乙型肝炎(CHB)患者的外周血HBV特异性CTL、非特异性CTL的变化和意义。方法对80例人白细胞抗原(HLA)-A2阳性的CHB患者用流式细胞仪检测外周血HBV特异性CTL、非特异性CTL和T细胞亚群,对20例HLA-A2阳性的急性乙型肝炎(AHB)患者作HBV特异性CTL、非特异性CTL的检测,30例健康献血员作非特异性CTL和T细胞亚群的检测作为对照。结果80例CHB患者的HBV特异性CTL低于急性乙型肝炎患者,分别为(0.32±0.11)%和(1.1±0.31)%,t=7.704,P=0.000,非特异性CTL高于正常对照组,分别为(18.23±5.13)%和(15.83±4.99%),t=2.220,P=0.028。结论CHB患者的HBV特异性CTL较低,一方面是导致HBV慢性持续感染的主要原因,另一方面启动了非特异性CTL引起肝功能损害。

乙肝患者HBV特异性细胞毒T淋巴细胞的分析

目的分析急性乙肝患者外周血中HBV特异性细胞毒T淋巴细胞(CTL)的表达特点及其在免疫应答机制中的作用。方法采集2008年10月-2010年6月于解放军302医院就诊的40例急性乙肝患者血样进行人白细胞抗原-A2(HLA-A2)检测,对其中18例HLA-A2阳性患者取病程极期及恢复期外周血,分离单个核细胞,并以6例HLA-A2阴性急性乙肝患者、18例HLA-A2阳性慢性乙肝患者和6例HLA-A2阳性健康正常人作为对照,经CD3、CD8单克隆抗体和HBV多肽抗原(HBsAg183-191,HB-sAg335-343)特异性五聚体(pentamer)染色后,采用流式细胞仪检测HBV特异性CTL频率,Cell-quest软件分析结果。同时检测患者发病极期丙氨酶转氨酶(ALT)峰值及HBV DNA载量,并进行相关性分析。结果 18例HLA-A2阳性急性乙肝患者急性期HB-sAg183-191的特异性CTL频率为0.23%±0.18%,HBsAg335-343特异性CTL频率为0.49%±0.31%,较HLA-A2阳性慢性乙肝患者发病极期上述抗原的特异性CTL频率(分别为0.07%±0.03%和0.08%±0.04%)明显升高(P<0.01);HBsAg183-191的特异性CTL频率与ALT峰值无显著相关性(r=0.4506,P=0.0528),而HBsAg335-343特异性CTL频率与ALT水平呈正相关(r=0.5642,P=0.0119),但上述CTL频率均与乙肝病毒载量无明显相关。与发病极期相比,患者在恢复期HBsAg335-343特异性CTL频率明显降低(P=0.011)。HLA-A2阴性急性乙肝患者及HLA-A2阳性正常人均未检出上述2种抗原的特异性CTL。结论 HBV特异性CTL在病毒清除和肝损伤中具有重要作用,针对不同HBV抗原表位的CTL,其作用可有一定差别。

多表位组合肽诱导HLA-A2^+人PBMC产生抗原特异性CD8^+T细胞应答的研究

目的 探讨基于HBV抗原优势表位的治疗性多肽抗原组分、结构与体外诱导CD8+ T细胞应答之间的关系。方法 用计算机辅助分子设计技术 ,设计基于HBV抗原免疫优势性CTL表位、B细胞表位和破伤风类毒素通用Th细胞表位的 3种治疗性多肽候选疫苗分子 ,经Merrifield固相多肽合成技术合成 ,并经HPLC纯化、鉴定。以HLA A2 + 健康人和慢性乙型肝炎患者的PBMC为实验对象 ,进行体外诱导CD8+ T细胞应答的免疫学功能研究。结果 所设计治疗性多肽分子可在体外诱导较强的抗原特异性CD8+ CTL应答 ;“ AAA ”铰链区设计和“Th +B”细胞表位的引入可增强CTL表位肽的免疫原性。结论 提示在治疗性表位多肽疫苗的分子设计中 ,短而高柔性的“铰链区”设计和“Th +B”

慢性HBV感染者外周血T淋巴细胞亚群和NK细胞活性变化

探讨慢性HBV感染者外周血T淋巴细胞亚群及NK细胞活性变化情况。应用流式细胞法检测所有研T淋巴细胞亚群和NK细胞。慢性乙肝、肝炎肝硬化和慢性重型乙肝组患者CD3+、CD4+百分率及CD4+／CD8+比值与正常组比较均有所下降,且慢性重型乙肝组患者CD4+百分率和CD4+／CD8+比值与正常组比较差异有显著性。各临床类型慢性HBV感染者NK细胞百分率均降低,与正常对照组比较有统计学意义。慢性HBV感染者细胞免疫功能低下。检测T淋巴细胞亚群及NK细胞活性变化对判断病变程度、指导临床治疗具有一定参考价值。

慢性乙型肝炎患者HBV特异性CTLs的KIR表达研究

目的检测慢性乙型肝炎患者外周血中HBV特异性CTL细胞表面杀伤细胞抑制性受体(KIR)的表达情况。方法利用MHC-Ⅰ-肽-五聚体(pentamer)技术结合流式三色分析技术,直接离体情况下检测(directex vivo)慢性乙型肝炎患者不同HBV特异性CTL细胞表面KIR的表达情况。结果在慢性乙型肝炎患者,KIR阳性的CD8+T细胞明显增加;KIR阳性的HBcAg(18-27)特异性CTL、HBeAg(335-343)特异性CTL、HBp(575-583)特异性CTL的百分比分别为12%、20%、35%。结论慢性乙型肝炎患者不同HBV特异性CTL表达KIR,这可能与慢性乙型肝炎患者HBV特异性CTL功能低下密切相关。

慢性乙型肝炎患者HBV特异性CTL的CD28表达研究

目的检测慢性乙型肝炎患者HBV特异性CTL的CD28表达情况。方法利用MHC-Ⅰ-肽五聚体（pentamer）技术结合流式多色分析技术，直接离体情况下（direct ex vivo）检测慢性乙型肝炎患者3个HLA-A2限制性的HBV表位特异性CTL表达CD28的情况。结果在22例HLA-A2^＋患者中，检测出HBcAg（18—27）特异性CTL有13例，频率为0．05％-0．16％；CD28^＋的HBcAg（18—27）特异性CTL的百分比为40％（23％-61％）。检测出HBeAg（335—343）有8例，频率为0.05％-0．24％；CD28%＋的HBeAg（335—343）特异性CTL的百分比为43％（36％-60％）。检测出HBp（575—583）特异性CTL有9例，频率为0．05％-0．19％；CD28^＋的HBpAg（575—583）特异性CTL的百分比为61％（45％-70％）。结论不同HBV抗原表位特异性CTL的CD28表达情况不同。