慢性乙型肝炎患者树突状细胞功能与单个核细胞乙型肝炎病毒共价闭合环状DNA的关系

目的 探讨慢性乙型肝炎(CHB)患者外周血单个核细胞(PBMC)及树突状细胞(DC)内HBV共价闭合环状DNA(HBV cccDNA)的存在状况,DC成熟度及功能状态与DC或PBMC中HBV cccDNA载量的关系.方法 分离29例CHB患者和10例健康对照者的PBMC,用重组人粒细胞-巨噬细胞集落刺激因子(GM-CS...     

Construction of the HBV S-ecdCD40L fusion gene and effects of HBV S-ecdCD40L modification on function of dendritic cells

We examined the effect of dendritic cells engineered to express an HBV S antigen CD40L fusion gene (HBV S-ecdCD40L). The DNA of HBV S gene and the cDNA of the extracellular domain of human CD40 ligand were linked by cloning. Peripheral blood mononuclear cells (PBMC) from healthy adults were incubated and induced into dendritic cells (DC) in presence of granulocyte/macrophage colony-stimulating factor (GM-CSF) and interleukin-4(IL-4). The DCs were transfected the novel construct, and the impact of the expressed clone assessed. We find that, compared with control groups, modification of DCs with HBV S-ecdCD40L fusion gene resulted in the activation of DCs with upregulated expression of immunologically important cell surface molecules (CD80, CD86 and HLA-DR) and proinflammatory cytokines (IL-12). The DCs modified with HBV S-ecdCD40L are able to stimulate enhanced allogeneic T-cell proliferation in vitro. Thus, the fusion gene HBV S-ecdCD40L can promote DC's activation and enhance its function and may prove to be the foundation for a new type of hepatitis B vaccine.     

乙型肝炎相关肝癌外周血树突状细胞负载肿瘤抗原前后免疫功能的变化

目的探讨肝癌患者外周血单个核细胞(PBMC)来源树突状细胞(DC)表面分子表达及负载肿瘤抗原前后免疫功能变化与免疫逃逸的关系。方法分离18例乙型肝炎相关原发性肝癌、11例乙型肝炎肝硬化患者和10名健康献血者PBMC,体外培养,并加入重组人粒细胞巨噬细胞集落刺激因子(GM-CSF)和白细胞介素-4(IL-4)诱导DC。以共聚焦显微镜和扫描电镜观察形态,以流式细胞仪检测DC表面人类白细胞抗原(HLA)-DR、CD1a、CD80、CD83、CD86等分子表达水平。以HCCLM6肝癌细胞株制备肿瘤抗原,分别负载3种DC,最后以混合淋巴细胞反应(MLR)测定DC负载前后刺激同种异型T淋巴细胞增殖能力,并测定MLR上清液中IL-12的含量。结果肝硬化和肝癌组PBMC、DC得率低于正常组(P<0.05);HLA- DR、CD1a、CD80和CD86等分子表达水平也低于正常组(P<0.05);负载肿瘤抗原前肝硬化和肝癌组刺激同种异型T淋巴细胞增殖能力和MLR上清液中IL-12含量明显低于正常组,负载肿瘤抗原后3组均提高, 并以肝硬化组提高最为明显,但IL-12含量仍低于正常组。结论DC表型和功能缺陷可能是乙型肝炎病毒产生免疫耐受和肝癌细胞免疫逃逸的重要机制。肝硬化患者DC仍有一定功能。     

Effects of lamivudine on the function of dendritic cells derived from patients with chronic hepatitis B virus infection

AIM: To investigate if the nucleoside analogue lamivudine (LAM), a potent inhibitor of HBV replication, could restore the function of dendritic cells derived from patients with chronic hepatitis B (CHB) in an Asian population. METHODS: Dendritic cells (DCs) derived from mononuclearcytes of patients with chronic HBV infection were cultured in the presence of IL-4, granulocyte-macrophage colony-stimulating factors (GM-CSF) and gradient concentrations of LAM (0-2 mmol/L). Cell morphology was observed under light microscopy. Cell surface molecules, including HLA-DR, CD80, CD83, and CD1α, were analyzed with flow cytometry. The concentrations of IL-6 and IL-12 in the supernatant were assayed by ELISA. T cell proliferation was assayed by methyl thiazolyl tetrazolium (MTT). RESULTS: The expression of CD1α on DC treated with 0.5 mmol/L LAM (LAM-DC 0.5 mmol/L) was significantly higher than that of DC untreated with LAM (54.1 ± 4.21 vs 33.57 ± 3.14, P < 0.05), and so was the expression of CD83 (20.24 ± 2.51 vs 12.83 ± 2.12, P < 0.05) as well as the expression of HLA-DR (74.5 ± 5.16 vs 52.8 ± 2.51, P < 0.05). Compared with control group, LAM-DC group (0.5 mmol/L) secreted significantly more IL-12 (910 ± 91.5 vs 268 ± 34.3 pg/mL, P < 0.05), had lower levels of IL-6 in the culture supernatant (28 ± 2.6 vs 55 ± 7.36 pg/mL, P < 0.05), markedly enhanced the stimulatory capacity in the allogeneic mixed leukocyte reaction (MLR) (1.87 ± 0.6 vs 1.24 ± 0.51, P < 0.05).CONCLUSION: The lower expression of phenotypic molecules and impaired allogeneic mixed lymphocyte reaction function of dendritic cells derived from patients with HBV infection could be restored in vitro by incubation with LAM.     

慢性乙型肝炎患者外周血树突状细胞表型及抗原提呈能力与HBV载量的关系

目的探讨慢性乙型肝炎(CHB)患者外周血树突状细胞(DCs)表型及抗原提呈能力与HBV载量的关系.方法采集23例CHB患者和8例健康人的抗凝外周静脉血,分离外周血单个核细胞(PBMCs),在重组人白细胞介素4和重组人粒细胞-巨噬细胞集落刺激因子的作用下培养使DCs增殖、成熟,以间接免疫荧光流式细胞技术分别检测DCs表面CD80、CD86、HLA-DR及ICAM-1的表达;将培养成熟的DCs与HBsAg共同孵育,用丝裂霉素C处理后再与自体PBMCs共同培养,在培养结束前12 h加入^3H-TDR,收集细胞,以β液闪计数仪测定cpm值;同期用定量聚合酶链反应技术测定CHB患者外周血HBV载量.结果患者DCs表面CD86、HLA-DR和ICAM-1的表达水平及DCs的抗原提呈能力均显著低于健康对照组;CD80、CD86、HLA-DR及ICAM-1的表达与HBV载量呈显著负相关(分别为P＜0.01,P＜0.01,P＜0.001和P＜0.001);DCs的抗原提呈能力也与HBV载量呈显著负相关(为P＜0.001).结论CHB患者外周血DCs的成熟和功能存在障碍,DCs的抗原提呈能力与血液中HBV的载量密切相关,并可能对HBV的清除产生重要的影响.     

过敏性哮喘患者树突细胞表型及分泌细胞因子的研究

目的观察过敏性哮喘患者树突细胞(DC)表达表面分子(CD1a、CD83、CD40、CD86)和分泌细胞因子(IL12和IL10)的情况,及对原始T细胞分化的影响。方法分别取过敏性哮喘患者(9例)和健康对照者(14例)外周血培养成熟DC。另取无哮喘家族史的新生儿脐血分离得到原始T细胞。将2组DC和原始T细胞共同培养。流式细胞仪测DC表面协同刺激分子CD1a、CD83、CD40、CD86的表达。ELISA测DC分泌的IL12、IL10及T细胞分泌的IFNγ、IL4的含量。结果哮喘组DC表达CD86分子比对照组显著升高(P<001)。哮喘组DC分泌IL12、IL12p40和IL10较对照组显著减少(P<001,P<005)。哮喘组T细胞释放IFNγ较对照组减少(P<005),释放IL4较对照组显著增多(P<001)。哮喘组IL12与IFNγ呈正相关(r=0758,P<005),与IL4呈负相关(r=-0756,P<005);IL10与IL4呈负相关(r=-0685,P<005);IL12与IL10呈正相关(r=0926,P<001)。结论过敏性哮喘患者DC存在缺陷,使原始T细胞向Th2优势分化,IL4等的释放增加,且不能有效地形成T细胞耐受,共同导致过敏性哮喘的发生。     

清热解毒法与疏肝健脾法对慢性乙型肝炎患者外周血树突状细胞功能的影响

目的:比较清热解毒法与疏肝健脾法对慢性乙型肝炎(CHB)患者外周血树突状细胞(DCs)成熟与功能的影响。方法:采集20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(PBMCs),体外培养使DCs增殖、成熟,大鼠清热解毒和疏肝健脾药物血浆干预;检测DCs表面HLA-DR、CD-1α、CD80及CD86的表达,DCs培养上清液IL-12的水平及DCs刺激同种异体T细胞增殖能力;比较干预前后DCs功能的变化。结果:清热解毒药物血浆、疏肝健脾药物血浆干预后CD80表达率升高,且疏肝健脾组大鼠CD80表达率的提高要超过清热解毒组,而HLA-DR、CD-1α、CD86的表达水平在干预前后差异无显著性意义。两组含药血浆干预后DCs刺激同种异体淋巴细胞增殖的能力提高,但两组药物血浆之间差异无显著性意义。两组含药血浆干预前后DCs分泌IL-12水平无明显变化。结论:清热解毒法和疏肝健脾法都能促进CHB患者DCs功能的恢复,疏肝健脾法对CHB患者DCs功能的影响更为显著。     

慢性HBV感染者、健康人树突状细胞经HBsAg活化后的免疫效应差异

目的:研究慢性HBV感染者、健康人外周血树突状细胞(dendriticcells,DC)经HBsAg活化后的免疫功能的差异.方法:从慢性HBV感染者、健康人外周血中培养扩增DC和CIK,在DC成熟前加入纯的HBsAg刺激,并再与同一来源的CIK共同培养.用流式细胞仪检测DC、CIK表型,用ELISA法检测DC、CIK共培养上清液中的IL-12浓度,用CCK-8比色法测定DC诱导CIK对HepG2.2.15细胞的杀伤活性.结果:未经HBsAg致敏的健康人DC表面标志CDla、CD80及CD83明显高于慢性HBV感染者(P<0.05);经HBsAg致敏的健康人DC表面标志均高于慢性HBV感染者,差异具有统计学意义(P<0.01);慢性HBV感染者经HBsAg致敏的DC表面标志与未经HBsAg致敏无显著性差异.CIK细胞CD3、CD8、CD3、CD56的双阳性表达率,健康人HBsAg致敏者明显高于慢性HBV感染者及未经HBsAg致敏的健康人(P<0.01,P<0.05);慢性HBV感染组HBsAg致敏与未经HBsAg致敏者比较无显著性差异(P>0.05).HBsAg致敏DC诱导CIK对HepG2.2.15细胞的杀伤率,健康人显著高于慢性HBV感染者(P<0.01).健康人HBsAg致敏DC、CIK共培养上清液中的IL-12浓度显著高于慢性HBV感染者(P<0.001);慢性HBV感染者HBsAg致敏与未经HBsAg致敏IL-12含量差异不显著(P>0.05).结论:慢性HBV感染者、健康人DC经HBsAg活化后对HepG2.2.15细胞的免疫效应存在显著差异:健康人高于慢性HBV感染者.     

DC-SIGN在慢性乙型肝炎病毒感染时树突状细胞成熟活化中的作用

目的研究慢性HBV感染时,DC-SIGN在树突状细胞（DC）成熟和活化中介导的作用。方法将α-甘露糖苷酶抑制剂-基夫碱作用于HepG2.2.15细胞,收获上清中的高甘露糖型HBV颗粒,并于第5 d加入到外周血单核细胞衍生的DC培养基中,培养至第7 d,采用流式细胞仪检测DC表面CDla、CD83、CD80、CD86、HLA-DR分子的表达,MTT法检测DC刺激淋巴细胞增殖的能力,ELISA法检测DC分泌IL-12的水平。结果高甘露糖型HBV组,与天然的HBV组相比,DC表面CDla、CD83、CD80、CD86、HLA-DR分子的表达增加,分泌IL-12的水平升高,刺激同种异体淋巴细胞增殖的能力亦明显增强,且上述效应均可被DC-SIGN特异性抗体所阻断。结论 DC-SIGN识别高甘露糖型HBV后可以促进DC的成熟和活化,天然的HBV可能利用α-甘露糖苷酶参与的去甘露聚糖修饰来逃避DC-SIGN的识别,从而诱导DC功能的缺陷。     

Direct ex vivo analysis of dendritic cells in patients with hepatocellular carcinoma

AIM: To analyze the phenotype and function of dendritic cells (DC) from patients with hepatocellular carcinoma (HCC) in order to understand their role in this disease. METHODS: Myeloid dendritic cells were enumerated in peripheral blood of HCC patients. CD80, CD83, CD86 and HLA-DR expression on naive and stimulated myeloid dendritic cells from peripheral blood were analyzed. Myeloid dendritic cells were isolated from peripheral blood and their function was tested. Phagocytosis was analyzed using FITC-dextran beads, peptide specific stimulation, the capacity to stimulate allogeneic T cells and secretion of cytokines upon poly dI:dC was tested. RESULTS: Myeloid dendritic cells were reduced in patients with HCC. No differences in CD80, CD83, CD86 and HLA-DR expression were found on naive and stimulated myeloid dendritic cells from HCC patients and healthy controls. Normal phagocytosis or stimulation of peptide specific T cells was observed in contrast to an impaired allo-stimulatory capacity and a reduced IL-12 secretion. CONCLUSION: Impaired IL-12 production of mDCs in patients could lead to an impaired stimulatory capacity of naive T cells suggesting that IL-12 directed therapies may enhance tumor specific immune responses in HCC patients.     

e抗原阳性慢性乙型肝炎患者外周血树突状细胞Toll样受体3的表达及意义

目的探讨Toll样受体3（TLR3）的表达与HBV感染后宿主免疫清除障碍的关系。方法选取轻度CHB患者50例,健康对照者48名,其外周血用免疫磁珠细胞分选法获得纯化的CD14^＋单核细胞,用RPMI 1640培养基培养,并且用人粒细胞-巨噬细胞集落刺激因子和hIL-4诱导单核细胞成为未成熟的髓样树突状细胞（mDC）,加入聚肌胞刺激后获得成熟的mDC。分别在剌激后0、12、24、48h用流式细胞仪检测TLR3、CD86、HLA-DR和CD1a的表达,实时PCR检测TLR3的表达变化。结果健康对照组中mDC在刺激后24h,TLR3表达较0 h时上调显著（P〈0.05）,48h时TLR3的表达与0h相比差异无统计学意义（P〉0.05）;患者组在刺激后12、24h TLR3的表达与0h时相比,上调不明显,48h时TLR3的表达显著上调（P〈0.05）。实时PCR检测mDC上TLR3 mRNA结果发现,对照组TLR3 mRNA在刺激后12h的表达水平较0h显著上升（P〈0.05）,也显著高于患者组刺激后0、12、24h的表达水平;患者组刺激后48h的TLR3 mRNA表达水平较0h显著上升（P〈0.05）。与0h比较,健康对照组在刺激后12、24h和48h,CD86的表达水平显著高于患者组（P〈0.05）。患者组与对照组间CD1a和HLA-DR的表达差异无统计学意义。结论慢性HBV感染者mDC受聚肌胞刺激后TLR3表达异常,协同刺激因子CD86表达低下,可能造成宿主对HBV感染的免疫清除障碍,导致疾病慢性化。     

e抗原阳性慢性乙型肝炎患者外周血树突状细胞干扰素β的表达

目的探讨慢性乙型肝炎患者树突状细胞干扰素β（IFN—β）表达与乙型肝炎病毒（HBV）感染后宿主免疫清除障碍的关系。方法选择e抗原阳性慢性乙型肝炎患者52例，健康对照48例，用免疫磁珠细胞分选乙型肝炎e抗原（HBeAg）法从外周血获得纯化的CD14^＋单核细胞，并用hOMCSF、hIL-4诱导单核细胞成为未成熟的髓样树突状细胞（mDC），加入polyI：C（25ug／ml）刺激后获得成熟的mDC，在刺激后0h、12h、24h、48h用流式细胞仪检测细胞表面分化抗原CD86、HLA-DR、CD1a，real—time PCR检测IFN8的表达变化。用ELISA方法检测mDC细胞上清液中IFN-β、IL-12、IL-10的浓度变化。结果两组mDC上0h IFN-β mRNA表达水平及细胞上清液中IFN—β浓度差异无统计学意义（P〉0．05）。健康对照组mDC在12hIFN—β mRNA表达水平及IFN-β浓度与0h相比显著升高（P〈0．05），较患者组0h、12h、24h、48h IFN—β表达显著升高（P〈0．05）。而患者组mDC刺激后12h、24h和48hIFN—β mRNA及IFN-β表达水平与0h相比无显著变化。与0h比较，健康对照组12h、24h、48hCD86表达水平较患者组显著上升（P〈0．05）。两组之间CD1a、HLA—DR表达差异无统计学意义。二组IL-10及IL-120h表达水平差异无统计学意义（P〉0．（15），患者组IL-10表达24h及48h与0h相比明显上升（P〈0．05）。而对照组12h、24h、48hIL-10表达水平没有明显上升。与之相反，患者组12h、24h、48hIL-12表达与0h相比表达水平没有明显上升，对照组在12hIL-12表达水平与0h相比差异有统计学意义（P〈0．05），24h、48hIL-12表达水平继续升高（P〈0．05）。结论慢性HBV感染者mDC受polyI：C刺激后IFN-β表达异常，协同刺激因子CD86表达低下，可能造成宿主对HBV感染的免疫清除障碍，导致疾病慢性化。     

来氟米特对狼疮患者树突状细胞作用机制的初探

目的　探讨来氟米特(LEF)处理前后系统性红斑狼疮(SLE)患者树突状细胞(DC)表面标志及功能的改变,揭示LEF治疗SLE的作用机制,为开展“抑制性DCs”治疗SLE奠定实验基础。方法　(1)分离SLE患者外周血单核细胞,用细胞因子诱导DC成熟, LEF组再加入A7717262(来氟米特的活性代谢产物)培养。第9天收集DC细胞,流式细胞仪检测CD80、CD83、CD86和HLA DR的表达。(2)分别将A771726处理或不处理的第9天DC和T细胞进行培养, 72h后用MTT法检测DC刺激淋巴细胞增殖的能力,FACS检测T细胞亚群和ELISA检测培养上清中IL 10和IFNγ水平。结果A771726处理后虽DC形态无改变,但DC表达CD83、CD86和HLA DR百分数较对照组均明显降低(72 70±1 77vs 79 36±4 80, 63 50±14 06vs. 83 91±9 81, 80 44±12 56vs. 90 51±8 63,P值均<0 01)。A771726处理后的DC,其刺激T细胞增殖相应的吸光度值明显降低,混合培养的上清液中IL 10水平较无A771726处理的DC与T细胞的混合培养上清液明显降低,而IFNγ两者间无显著差异;但见CD 4 CD 25CTLA 4 T细胞百分比增高。结论　LEF在体外可抑制SLE患者外周血DC的成熟;未成熟DC能抑制T细胞增殖及T细胞向Th2 细胞转化,诱导CD 4 CD 25CTLA 4 T细胞产生,从而纠正SLE患者的部分免疫紊乱。     

乙型肝炎病毒感染对造血干细胞活性的影响

目的 了解HBV感染对脐血来源的造血干细胞活性的影响.方法 将分离纯化的健康脐血CD34+细胞,在含有干细胞生长因子(SCF)、酪氨酸激酶受体家族Ⅲ配体(FL)、促血小板生成素(TPO)、IL-3和10%FBS的IMDM培养基中扩增,同时加入高拷贝HBV,观察干细胞扩增与病毒复制规律;干细胞扩增后,在巨细胞集落刺激因子(GM-CSF)和IL-4作用下诱生树突状细胞,对干细胞及树突细胞进行形态学观察,并检测其表面分子的表达.两组间比较采用独立t检验,多组间比较采用方差分析.结果 感染HBV的造血干细胞自然增殖能力明显低于正常干细胞(P<0.01);加入细胞因子后细胞增殖增加(P<0.01),细胞内HBV DNA复制也增加(P<0.01),但其干细胞增殖仍低于正常干细胞加细胞因子组(P<0.05).电子显微镜观察发现HBV感染干细胞后胞质内出现Dane颗粒;HBV感染的干细胞经诱导为树突状细胞后,其免疫表型CD80、CD86、CD1a、HLA-DR的表达均低于未感染组(P<0.01).结论 HBV可以感染CD34+造血干细胞,并随干细胞增殖而复制增加,HBV不仅抑制造血干细胞增殖,而且下调干细胞分化来源的树突状细胞免疫表型的表达.     

Entecavir up-regulates dendritic cell function in patients with chronic hepatitis B

AIM： To investigate the in vitro effect of entecavir （ETV on the function of dendritic cells （DCs） derived from chronic hepatitis B （CHB） patients. METHODS： Mononuclear cells were isolated from peripheral blood of patients with CHB. DCs wer incubated with RPMI-1640 medium supplemented wit fetal bovine serum, IL-4, granulocyte-macrophag colony-stimulating factor （GM-CSF）. DCs were treate with or without ETV on the fourth day. Cell surfac molecules, including CD1a, CD80, CD83 and HLA-DR were assessed by flow cytometry. Concentrations of IL- and IL-12 in the supernatant were assayed by enzyme linked immunosorbent assay （ELISA）. The ability of th generated DCs to stimulate lymphocyte proliferation wa observed. RESULTS： Compared with CHB control group, th expression levels of CD1a （29.07 ± 3.20 vs 26.85 ± 2.80 CD83 （25.66 ± 3.19 vs 23.21 ± 3.10）, CD80 （28.00 ± 2.7 vs 25.75 ± 2.51） and HLA-DR （41.96 ± 3.81 vs 32.20 ± 3.04） in ETV-treated group were higher （P 〈 0.05）. ETV treated group secreted significantly more IL-12 （157.6 ± 26.85 pg/mL vs 132.60 ± 22.00 pg/mL （P 〈 0.05） an had a lower level of IL-6 in the culture supernatant （83.0 ± 13.88 pg/mL vs 93.60 ± 13.61 pg/mL, P 〈 0.05） tha CHB control group. The ability of DCs to stimulate th proliferation of allogeneic lymphocytes was increase in ETV-treated group compared with CHB control grou （1.53 ± 0.09 vs 1.42 ± 0.08, P 〈 0.05）.CONCLUSION： Entecavir can enhance the biological activity of DCs derived from CHB patients.     

Dendritic cells are functionally defective in multiple myeloma: the role of interleukin-6

We studied concentration, phenotype, and function of peripheral blood (PB) dendritic cells (DCs) from patients with multiple myeloma (MM). The absolute number of circulating precursors of myeloid and plasmacytoid DCs was significantly lower in MM patients than in healthy subjects. After maturation, PBDCs from MM patients showed significantly lower expression of HLA-DR, CD40, and CD80 antigens and impaired induction of allogeneic T-cell proliferation compared with controls. Remarkably, they were not capable of presenting the patient-specific tumor idiotype to autologous T cells. Conversely, DCs generated in vitro from CD14(+) monocytes from the same patients, and PBDCs freshly isolated from healthy donors efficiently stimulated allogeneic and autologous T cells. To clarify the mechanism of PBDC deficiency in MM, we investigated the effects of the main plasma cell growth factor, interleukin-6 (IL-6), on the development of DCs from CD34(+) cells. IL-6 inhibited the colony growth of CD34(+) DC progenitors and switched the commitment of CD34(+) cells from DCs to CD14(+) CD1a(-) CD86(-)CD80(-) CD40(+/-)HLA-DR +/- monocytic cells exerting potent phagocytic activity but no antigen-presentation capacity. This effect was reversed by anti-IL-6 antibodies. Growing CD34(+) cells in the presence of autologous serum (without IL-6) also suppressed the development of functional DCs. This study demonstrates that PBDCs from MM patients are functionally defective, partially because of IL-6-mediated inhibition of development. This brings into question the advisability of using PBDCs as antigen carriers for immunotherapy trials in MM. The results also suggest a novel mechanism whereby myeloma cells escape immune recognition.     

乙型肝炎病毒在造血干细胞内复制及对其免疫活性的影响

目的 研究不同载量HBV感染脐血来源的CD34~+造血干细胞(HSC)的一般规律,以及探讨HBV感染HSC后诱生的树突状细胞(DC)的功能状态.方法 无菌条件下采集脐血,磁珠分离仪分离纯化CD34~+ HSC.把CD34~+ HSC分为HBV感染组及对照组,用免疫组织化学及原位杂交方法检测HSC内病毒感染情况.分3组将HSC接种于24孔板连续培养12 d,各组分别加入细胞因子组合及不同病毒载量HBV(A组1×10~7拷贝/mL,,B组1×10~5拷贝/mL,C组1×10~3拷贝/mL)的血清,于培养的0、1、6、12 d检测各组细胞数,上清液及细胞中HBV DNA拷贝数.用两步法诱生的DC作为刺激细胞,以异基因健康者外周血T淋巴细胞作为反应细胞,噻唑蓝比色法检测DC对同种异体T淋巴细胞的刺激增殖作用.组间比较采用t检验.结果 免疫组织化学检测结果显示,HBV感染12 d的HSC中可检测到HBsAg的表达,而未感染的HSC中无HBsAg阳性细胞.原位杂交检测结果显示,HBV感染12 d的HSC中可检测到HBV DNA,未感染的HSC中无阳性细胞.C组第1天的细胞增殖与A、B组比较无明显差异,第6、12天细胞增殖高于A、B组,且第6天的细胞计数差异有统计学意义(t=5.125,t=6.327;均P<0.05).在第12天A组细胞内可检出1×10~6拷贝/mL HBV DNA,B组可检出1×10~3拷贝/mL,C组则12 d内均不能检出.上清液检出情况与细胞内相符.混合淋巴细胞反应显示HBV感染组诱生的DC对同种异体T淋巴细胞刺激增殖作用明显低于对照组,且差异有统计学意义(在DC与T淋巴细胞的比例达到0.05时,t=3.156,P<0.05;在比例达到0.1、0.5时,t=4.873,t=5.103,均P<0.01).结论 HBV可以在CD34~+ HSC内复制并随HSC扩增而同步增加.HBV感染的HSC诱生的DC对同种异体T淋巴细胞刺激增殖能力减低,即HBV感染HSC后其分化的免疫细胞的生物活性降低.     

Maturation and function of human dendritic cells are regulated by B lymphocytes

Mature dendritic cells (DCs) are stimulators of T-cell immune response, whereas immature DCs support T-cell tolerance. Murine B cells can inhibit the production of IL-12 by DCs and thereby hinder the inflammatory response. Notwithstanding the importance of this modulation, only a few studies are available in humans. Here, we have developed an in vitro model of cocultures to assess its significance. We establish that human activated B cells restrained the development of monocytes into immature DCs and their differentiation into mature DCs. In addition, they decreased the density of HLA-DR from mature DCs, the expression of CD80 and CD86 coactivation molecules, the production of IL-12p70 required for antigen presentation and Th1 differentiation, and inhibited the DC-induced T-cell proliferation. These modulations were mediated by CD19(+)IgD(low)CD38(+)CD24(low)CD27(-) B cells and needed direct cell-to-cell contacts that involved CD62L for the control of CD80 and CD86 expression and a soluble factor for the control of IL-12 production. Moreover, mature DCs from patients with systemic lupus erythematosus displayed insensitivity to the regulation of IL-12. Overall, it appears that human B cells can regulate DC maturation and function and that inefficient B-cell regulation may influence an improper balance between an effector inflammatory response and tolerance induction.     

慢性乙型肝炎患者浆样树突状细胞体外诱导CD4+CD25+调节性T细胞的研究

目的 观察慢性乙型肝炎患者,乙型肝炎恢复者和健康人浆样树突状细胞(pDCs)体外诱导CD4+CD25+调节性T细胞(CD4+CD25+Treg)能力的差异,为阐明HBV感染慢性化的机制奠定基础.方法 采用免疫磁珠分离法体外分离46例慢性乙型肝炎患者,10例乙型肝炎恢复者和25名健康人外周血单个核细胞中pDCs,并将其分别与健康人CD4+CD45RA+初始T细胞共培养.采用HBcAg或破伤风毒素对去除CD25+细胞的外周血单个核细胞进行增殖刺激后,使用流式细胞仪及RT-PCR对pDCs-T共培养细胞中CD4+CD25+Treg的数量、表型及FOXP3基因表达情况进行测定;采用酶联免疫吸附法对共培养细胞上清液中的白细胞介素-10和转化生长因子β1进行了进一步检测.两组数据比较采用Mann Whitney U-test.结果 当细胞增殖刺激物为HBcAg时,细胞增殖幅度慢性乙型肝炎患者组为(7999.36±374.74)cpm,乙型肝炎恢复者组为(11 282.56±1174.46)cpm和健康人组为(12 304.58±1462.81)cpm,慢性乙型肝炎患者组细胞增殖幅度明显小于乙型肝炎恢复者组和健康人组,U=0～22.0,P值均<0.05·乙型肝炎恢复者组和健康人组间增殖幅度差异无统计学意义.当增殖刺激物为破伤风毒素时,细胞增殖幅度与阳性对照组之间,差异无统计学意义.CD4+CD25+Treg比例慢性乙型肝炎患者组为5.99%±1.85%,乙型肝炎恢复者组为3.04%±0.79%,健康人组为3.01%±1.53%,慢性乙型肝炎患者组中韵CD4+CD25+Treg比例明显高于乙型肝炎恢复者组和健康人组,U=6.0～71.5,P值均<0.05.3组人群pDCs-T共培养细胞的CD4+CD25+T细胞均检测到Fox p3 RNA,而在CD4+CD25 T细胞中,均未检测到Fox p3RNA.3组人群pDCs-T共培养细胞实验组上清液的白细胞介素-10和转化生长因子β1含量均明显高于阳性对照组.结论 pDCs以诱导CD4+CD25+Treg形式参与了乙型肝炎的慢性化.