慢性乙型肝炎患者病程中CD5^＋B细胞及CD4／CD8的变化研究

目的研究CD5^＋B细胞和CIM／CD8在慢性乙型肝炎发病中的作用，以及他们之间的相关性。方法采用免疫荧光双标记技术和流式细胞仪对48例慢性乙型肝炎患者发病前后周围血中CIM／CD8比例和CD5^＋B细胞的百分率和37例健康对照者进行比较。结果在慢性乙型肝炎患者发病高峰期周围血CIM／CD8比例显著低于病情恢复期，且和健康对照组比较差异有显著性；而CD5^＋B细胞在慢性乙型肝炎患者发病高峰期，显著高于健康对照组和慢性乙型肝炎患者恢复期，差异有显著性。结论慢性乙型肝炎的发病和T细胞免疫功能的紊乱相关，而CD5^＋B可能在乙型肝炎的慢性化机制中发挥作用。     

The Peripheral Deletion of Autoreactive CD8+ T Cells Induced by Cross-presentation of Self-antigens Involves Signaling through CD95 (Fas,Apo-1)

Recently, we demonstrated that major histocompatibility complex class I–restricted cross-presentation of exogenous self-antigens can induce peripheral T cell tolerance by deletion of autoreactive CD8⁺ T cells. In these studies, naive ovalbumin (OVA)-specific CD8⁺ T cells from the transgenic line OT-I were injected into transgenic mice expressing membrane-bound OVA (mOVA) under the control of the rat insulin promoter (RIP) in pancreatic islets, kidney proximal tubules, and the thymus. Cross-presentation of tissue-derived OVA in the renal and pancreatic lymph nodes resulted in activation, proliferation, and then the deletion of OT-I cells. In this report, we investigated the molecular mechanisms underlying this form of T cell deletion. OT-I mice were crossed to tumor necrosis factor receptor 2 (TNFR2) knockout mice and to CD95 (Fas, Apo-1) deficient mutant lpr mice. Wild-type and TNFR2-deficient OT-I cells were activated and then deleted when transferred into RIP-mOVA mice, whereas CD95-deficient OT-I cells were not susceptible to deletion by cross-presentation. Furthermore, cross-presentation led to upregulation of the CD95 molecule on the surface of wild-type OT-I cells in vivo, consistent with the idea that this is linked to rendering autoreactive T cells susceptible to CD95-mediated signaling. This study represents the first evidence that CD95 is involved in the deletion of autoreactive CD8⁺ T cells in the whole animal.     

小鼠CD62L^-／CD62L^＋T细胞体外对抗原刺激的增殖反应

本研究旨在观察CD62L^-／CD62L^＋T细胞应答抗原的能力,了解CD62L分子在移植物抗宿主病（GVHD）中的作用。用DC细胞呈递特异性抗原hCD4刺激T细胞,流式细胞术检测其表面CD62L分子表达;对分选获得的CD62L^-／CD62L^＋两群T细胞再次给予新的抗原（EIA细胞冻融抗原）刺激,用流式细胞术检测CD62L^-及CD62L^＋T细胞在前后两次受到不同抗原刺激后的活化增殖能力。结果显示：T细胞表面CD62L^＋分子在受到抗原刺激后表达下调,CD62L^＋细胞由69．34％降至36．75％,相应的CD62L^-T细胞由30．04％升至63．15％。比较第1天及第7天在高CFSE荧光值区（M1）的细胞数表明,在特异性抗原（hCD4）的刺激下,CD62L^＋T细胞平均百分比值分别为（87．88±1．08）％,（86.88±1．46）％（P〉0．05）;CD62L^-T的测得值分别为（84．52±2．73）％（84．71±2．33）％（P〉0．05）。两群细胞数在第7天与第1天相比均未出现明显增殖;在非特异性抗原刺激下．CD62L^＋T细胞在第1天和第6天于M1区的细胞数平均百分比值分别为（76．494-2．41）％,（22．25±3．29）（P〈0．001）;CD62L^-T测得值分别为（77．35±3．82）％,（74．76±3．90）％（P〉0,05）。此结果说明CD62L^＋T细胞发生了分裂增殖,而CD62L^-T细胞群则没有出现类似的情况。结论：通过体外方法获得了CD62L^-CD62L^＋T细胞,这两类细胞在特异性抗原刺激下朱发生增殖反应,但在非特异性抗原刺激下CD62L^＋T细胞发生了分裂增殖．而CD62L^-T细胞无此反应。此结果表明CD62L^＋T细胞在GVHD发生中有着重要作用,同时也为临床上通过体外方法获得CD62L^-T细胞而选择性地去除移植物中CD62L＋T细胞以减少GVHD的发生提供了思路。     

CD4^＋、CD25^＋调节性T细胞在重型乙型肝炎发病中的作用

目的探讨CD4＋、CD25＋调节性T细胞（CD4＋、CD25＋ Tr）在重型乙型肝炎病人发病机制中的作用。方法采用流式细胞术检测重型乙型肝炎病人及对照组外周血CD4＋、CD25＋ Tr的水平及应用PCR测定重型乙型肝炎病人及对照组外周血中HBVDNA滴度。结果重型乙型肝炎组外周血CD4＋、CD25＋ Tr的百分率为（2.63±0.83）%,较慢性乙型肝炎组的（4.15±1.17）%差异有显著性（P〈0.05）,较无症状HBV携带者组及健康对照组差异有非常显著性（P均〈0.01）;重型乙型肝炎组外周血HBVDNA滴度为1.2×10^4copies/ml,较慢性乙型肝炎组（2.3×10^6copies/ml）和无症状HBV携带者（7.8×105copies/ml）差异有非常显著性（P均〈0.01）;不同乙型肝炎病人外周血CD4^＋、CD25^＋ Tr的百分率与HBVDNA滴度正相关。结论CD4^＋、CD25＋^ Tr能抑制T细胞对HBV的免疫反应;重型乙型肝炎患者发病与CD4^＋、CD25^＋ Tr表达过低有关。     

月经周期雌激素变化对外周血CD4＋CD25＋调节性T细胞水平的影响

目的研究正常育龄妇女月经周期中雌激素变化对CD4＋CD25＋调节性T细胞（Treg细胞）水平的影响。方法采用流式细胞术检测20例正常育龄妇女月经周期中不同时期外周血Treg细胞水平;同时采用放射免疫法（RIA）检测外周血中雌激素水平,并分析两者相关性。结果 Treg细胞水平随雌激素的变化而波动,Treg细胞及雌激素水平在月经周期第13天最高,分别为[（20.72±2.24）%、（204.27±24.01）ng.L-1],在月经周期第3天最低,分别为[（11.27±1.23）%、（37.90±8.94）ng.L-1]（均P〈0.05）;Treg细胞水平与雌激素水平呈正相关（r=0.615,P〈0.005）。结论雌激素对体内Treg细胞的表达有调节作用。     

急性髓细胞性白血病细胞培养上清对CD4+和CD8+T细胞增殖和凋亡的影响

为了研究不同的急性髓细胞性白血病（AML）细胞株培养上清对CD4^＋和CD8^＋T细胞增殖以及凋亡的影响,探讨AML的免疫抑制的形成机制,将3种AML细胞株（HL-60、NB4和U937）培养上清和普通培养液按不同比例混合,用于培养CFSE染色的淋巴细胞.抗CD3抗体和抗CD28抗体刺激3天后,标记7AAD和相应荧光抗体.利用流式细胞术检测不同T细胞亚群CFSE荧光强度和7AAD表达率的变化,分析其增殖和凋亡变化情况.结果表明：3种AML细胞株中有2种（HL-60和NB4）培养上清可显著抑制CD4^＋T细胞和CD8^＋T细胞的增殖,并随浓度增加而增强.同样,HL-60和NB4细胞株培养上清亦可抑制刺激后的CD4^＋T细胞的凋亡,但对刺激后的CD8^＋T细胞的凋亡并无明显影响.相反,HL-60和NB4细胞株培养上清可显著增加增殖的CD8^＋T细胞的凋亡.结论：AML细胞株培养上清液对CD4^＋T细胞和CD8^＋T细胞增殖的抑制以及对增殖的CD8^＋T细胞凋亡的诱导作用,可能是AML患者免疫功能缺陷的机制之一.     

慢性乙型肝炎患者外周血CD4^＋CD25^＋调节性T细胞的检测与意义

目的：探讨慢性乙型肝炎患者外周血CD4^＋CD25＋调节性T细胞（Treg）频率的变化及其意义。方法：分离20例慢性乙型肝炎（CHB）患者和10例健康者的外周血单个核细胞,以CD4、CD25、CD127单克隆抗体标记细胞后以流式细胞仪检测并分析Treg频率。采用实时荧光定量RT—PCR检测血清HBVDNA载量。结果：CHB组的Treg频率高于健康对照组（P〈0．05）,HBeAg阳性CHB组Treg频率高于HBeAg阴性CHB组（P〈0．01）,乙型肝炎肝硬化组Treg频率高于无肝硬化CHB组（P＜0．01）;CHB患者的Treg频率与HBVDNA载量成直线正相关（r=0．87,P＜0．01）。结论：慢性乙型肝炎患者外周血Treg频率明显升高,且与病毒复制和肝脏慢性病变程度有关。     

单倍体相合骨髓移植后CD4~+CD25~+ T细胞免疫恢复的临床研究

本研究探讨单倍体相合骨髓移植后CD4+CD25+T细胞免疫恢复及其与移植物抗宿主病(GVHD)和复发的关系。采集27例单倍体相合骨髓移植患者在移植后不同时间内的外周血标本,用流式细胞仪检测分析CD4+CD25+T细胞百分比和绝对数,同时比较该细胞亚群恢复与GVHD和白血病复发的关系。结果表明:经过G-CSF动员后供者外周血中CD4+CD25+细胞百分比明显增高(p0.05)。移植后30天CD4+CD25+细胞恢复到正常水平的20%,但在移植后3个月内恢复颇为缓慢,直到180天才恢复到正常水平的50%。CD4+CD25+细胞恢复与急性GVHD的发生无关,但是在慢性GVHD组CD4+CD25+显著增高。移植后1年内未发现复发与CD4+CD25+细胞绝对计数有关。结论:在骨髓移植后给予抗CD25抗体预防GVHD的治疗模式下,CD4+CD25+细胞恢复与急性GVHD的发生无关,但与慢性GVHD的发生似乎有关,而与白血病的复发的关系不明确。     

白三烯受体拮抗剂对毛细支气管炎外周血CD_4~+CD_(25)~+Treg的影响及疗效观察

目的探讨白三烯受体拮抗剂(孟鲁司特)对毛细支气管炎患儿外周血CD4+CD25+调节性T细胞(Treg)的影响并观察其疗效。方法将48例毛细支气管炎患儿按入院顺序分成孟鲁司特干预组和常规治疗组,常规治疗组采取综合治疗,孟鲁司特干预组在综合治疗的基础上加用孟鲁司特4 mg,每晚1次口服。检测2组患者治疗前后外周血中CD4+CD25+Treg的水平,并观察2组患者咳嗽、喘憋、肺部体征的持续时间。结果治疗前2组患儿外周血CD4+CD25+Treg占CD4+T细胞的百分比均明显低于健康对照组,差异有统计学意义(P0.01);治疗后孟鲁司特干预组外周血中CD4+CD25+Treg水平较常规治疗组显著上升(P0.05),同时咳嗽、喘憋、肺部体征持续时间与常规治疗组比较有统计学意义(P0.01)。结论孟鲁斯特纳可缩短病程,提高毛细支气管炎患儿外周血CD4+CD25+Treg的水平,在毛细支气管炎的治疗中起重要作用。     

Somatic mutation of the CD95 gene in human B cells as a side-effect of the germinal center reaction

Somatic hypermutation specifically modifies rearranged immunoglobulin (Ig) genes in germinal center (GC) B cells. However, the bcl-6 gene can also acquire somatic mutations during the GC reaction, indicating that certain non-Ig genes can be targeted by the somatic hypermutation machinery. The CD95 gene, implicated in negative selection of B lymphocytes in GCs, is specifically expressed by GC B cells and was recently identified as a tumor suppressor gene being frequently mutated in (post) GC B cell lymphomas. In this study, the 5' region (5'R) and/or the last exon coding for the death domain (DD) of the CD95 gene were investigated in naive, GC, and memory B cells from seven healthy donors. About 15% of GC and memory, but not naive, B cells carried mutations within the 5'R (mutation frequency 2.5 x 10(-4) per basepair). Mutations within the DD were very rare but could be efficiently selected by inducing CD95-mediated apoptosis: in 22 apoptosis-resistant cells, 12 DD mutations were found. These results indicate that human B cells can acquire somatic mutations of the CD95 gene during the GC reaction, which potentially confers apoptosis resistance and may counteract negative selection through the CD95 pathway.     

沙利度胺对多发性骨髓瘤患者CD4^＋CD25^＋调节性T细胞作用的临床研究

本研究探讨沙利度胺治疗前后多发性骨髓瘤（MM）患者CD4^＋CD25^＋调节性T细胞的比例及变化规律，为有效的免疫治疗提供理论依据。采用流式细胞术检测MM患者外周血CD3、CD4、CD8、NK及CD4^＋CD25^＋Treg细胞的比例；采用成组设计的两样本均数比较的t检验进行统计学分析，以P〈0．05为检验水准。结果表明：MM患者治疗前CD4^＋CD25^＋highT比例较正常人明显升高（P〉0．01），沙利度胺治疗有效患者的CD4^＋CD25^＋highT比例较治疗前明显降低（P〈0．01），治疗无效者Treg比例无显著变化（P〉0．05）。16例经化疗完全缓解，CD4^＋CD25^＋highT比例为6．91±1．12％，较治疗前升高，但无显著性差异（P〉0．05）。沙利度胺治疗有效者CD3^＋T、CD4^＋T、NK细胞比例及CD4／CD8比值较治疗前明显升高（P〉0．05或0．01），CD8^＋T治疗前后无显著变化（P〉0．05）。结论：CD4^＋CD25^＋Treg细胞的免疫抑制作用可能是MM免疫逃逸的重要机制，下调MM患者CD4^＋CD25^＋Treg可能是沙利度胺治疗MM有效的机制之一。     

骨髓间充质干细胞在CD4+CD25+调节性T细胞减轻大鼠移植物抗宿主反应中的作用

本研究探讨间充质干细胞(MSC)对GVHD的作用及其机制.建立大鼠同种异体骨髓移植模型,同时输入供者的T淋巴细胞诱导出移植物抗宿主反应,联合或不联合移植供体来源的MSC,观察受鼠的GVHD的发生情况;利用双荧光标记抗体标记受鼠脾脏和胸腺单个淋巴细胞,通过流式细胞术分析CD4+CD25+调节性T细胞亚群比例的变化,分析MSC的作用机制.结果显示实验组的GVHD的发生程度减轻,存活率提高,而CD4/CD8比值在GVHD组出现不同程度的减少,CD4+CD25+调节性T细胞在实验组中的脾淋巴细胞和胸腺淋巴细胞的比例分别为31.55±7.58%、93.20±2.69%,在GVHD组中的比例分别为20.90±1.90%、57.17±6.79%,实验组中CD4+CD25+调节性T细胞比例比GVHD组中增多,具有显著性差异.结论MSC能有效抑制HSC移植后致死性GVHD的发生,提高生存率,同时MSC可能通过作用于体内调节性T淋巴细胞而间接发挥了抑制GVHD的作用.     

CD4+CD25+ Immunoregulatory T Cells Suppress Polyclonal T Cell Activation In Vitro by Inhibiting Interleukin 2 Production

Peripheral tolerance may be maintained by a population of regulatory/suppressor T cells that prevent the activation of autoreactive T cells recognizing tissue-specific antigens. We have previously shown that CD4⁺CD25⁺ T cells represent a unique population of suppressor T cells that can prevent both the initiation of organ-specific autoimmune disease after day 3 thymectomy and the effector function of cloned autoantigen-specific CD4⁺ T cells. To analyze the mechanism of action of these cells, we established an in vitro model system that mimics the function of these cells in vivo. Purified CD4⁺CD25⁺ cells failed to proliferate after stimulation with interleukin (IL)-2 alone or stimulation through the T cell receptor (TCR). When cocultured with CD4⁺CD25⁻ cells, the CD4⁺CD25⁺ cells markedly suppressed proliferation by specifically inhibiting the production of IL-2. The inhibition was not cytokine mediated, was dependent on cell contact between the regulatory cells and the responders, and required activation of the suppressors via the TCR. Inhibition could be overcome by the addition to the cultures of IL-2 or anti-CD28, suggesting that the CD4⁺CD25⁺ cells may function by blocking the delivery of a costimulatory signal. Induction of CD25 expression on CD25⁻ T cells in vitro or in vivo did not result in the generation of suppressor activity. Collectively, these data support the concept that the CD4⁺CD25⁺ T cells in normal mice may represent a distinct lineage of “professional” suppressor cells.     

HIV-Resistant and HIV-Specific CAR-Modified CD4+ T Cells Mitigate HIV Disease Progression and Confer CD4+ T Cell Help In Vivo

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2B4, the Natural Killer and T Cell Immunoglobulin Superfamily Surface Protein,Is a Ligand for CD48

2B4 is a cell surface glycoprotein related to CD2 and implicated in the regulation of natural killer and T lymphocyte function. A recombinant protein containing the extracellular region of mouse (m)2B4 attached to avidin-coated fluorescent beads bound to rodent cells, and binding was completely blocked by CD48 monoclonal antibodies (mAbs). Using surface plasmon resonance, we showed that purified soluble mCD48 bound m2B4 with a six- to ninefold higher affinity (K _d ≈ 16 μM at 37°C) than its other ligand, CD2. Human CD48 bound human 2B4 with a similar affinity (K _d ≈ 8 μM). The finding of an additional ligand for CD48 provides an explanation for distinct functional effects observed on perturbing CD2 and CD48 with mAbs or by genetic manipulation.     

阿德福韦酯对慢性乙型肝炎患者CD4~+ CD25~+调节性T细胞表达水平的影响

目的:观察阿德福韦酯对慢性乙型肝炎(慢乙肝)患者血清CD4+CD25+调节性T细胞(CD4+CD25+regulatory T cells,CD4+CD25+Treg)表达水平的影响,揭示CD4+CD25+Treg在慢乙肝患者免疫发病机制中的作用,及阿德福韦酯治疗对机体的免疫调节机制的临床价值。方法:采用流式细胞术对66例慢乙肝患者(HBeAg阳性慢乙肝患者36例,HBeAg阴性慢乙肝患者30例)阿德福韦酯治疗前和治疗12、24、36及48周外周血CD4+CD25+Treg进行检测。同时采用实时荧光聚合酶链反应(PCR)检测相应时间点的血清HBVDNA。结果:外周血清CD4+CD25+Treg治疗前为(4.05±2.39)%,明显高于正常对照组的(2.26±1.42)%(P<0.01);治疗后CD4+CD25+Treg为(2.38±1.75)%,明显低于治疗前(P<0.01),与正常对照组相当(P>0.05)。CD4+CD25+Treg水平与病毒定量呈正相关。结论:阿德福韦酯抗病毒治疗后能使病毒载量下降,导致CD4+CD25+Treg下降,使免疫功能恢复。     

三七皂苷对人骨髓CD34+造血干/祖细胞的增殖分化作用

为了探讨三七皂苷 (PNS)对人骨髓CD34+ 造血干 /祖细胞的刺激增殖和诱导分化的作用 ,用DynalM 4 5 0CD34+ 免疫磁珠阳性选择法获取高纯度的人骨髓CD34+ 细胞 ,采用多向祖细胞 (CFU Mix)体外集落培养和流式细胞术检测细胞增殖与分化。结果显示 :经免疫磁珠阳性选择 ,从骨髓细胞收获的CD34+ 细胞获得率为 (1.0 3±0 .74 ) % ,流式细胞术分析纯度达到 86 % - 93%。PNS 10mg/L和 2 5mg/L能刺激CD34+ 细胞增殖 ,使CFU Mix集落生成增加 ,2 5mg/L的PNS对CFU Mix产率提高 (34.7± 16 .0 ) % (P <0 .0 1) ,是促进造血的最适浓度 ;PNS2 5 ,5 0和 10 0mg/L时 ,能诱导CD34+ 细胞向粒系细胞分化 ,粒系表面标记CD33+ 和CD15 + 的细胞百分比均明显高于无PNS的对照组 ,而红系细胞表面标记CD71+ 和G A+ 细胞百分比则无明显变化。结论 :PNS对CD34+ 造血干 /祖细胞不但具有显著的刺激增殖作用 ,而且能够诱导其向粒系细胞定向分化的效应     

Dual Targeting of Mesothelin and CD19 with Chimeric Antigen Receptor-Modified T Cells in Patients with Metastatic Pancreatic Cancer

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人参二醇促骨髓CD34+细胞增殖和分化的研究

本研究探讨人参二醇（PDS）对正常人骨髓CD34^＋细胞的促进增殖和诱导分化作用。用吸附单克隆抗体的免疫磁珠技术从正常人骨髓分离出CD34^＋细胞,采用琼脂半固体多向祖细胞集落（CFU-Mix）培养方法观察PDS对CD34^＋细胞的增殖作用;用液体培养使CD34^＋细胞增殖,并向红系、粒系定向生长,用流式细胞仪分析PDS诱导后细胞表面标记变化。结果显示：免疫磁珠分离CD34^＋细胞的获得率占骨髓有核细胞（MNC）的（1.0±0.15）%;活细胞比例占（95.6±1.2）%,CD34^＋细胞富集度达（86.8±2.8）%。中浓度PDS（25mg/L）能够有效地促进CD34^＋细胞增殖,生成CFU-Mix集落,提高率为（56.3±3.5）%,与对照相比较有显著差异（p〈0.01）。液体培养生成粒系、红系细胞的数量明显增高,与对照相比差异有显著性,提高率分别为（35.6±3.2）%和（22.3±2.1）%,与对照相比差异有显著性（p〈0.01）,且呈剂量依赖性。经PDS诱导14天后,细胞表面分化标记明显增高,CD33^＋细胞在PDS50mg/L时最高,CD71^＋细胞在25mg/L时最高,G-A^＋细胞在10mg/L时最高,而CD15^＋细胞数量无明显变化。结论：PDS不但促进CD34^＋细胞增殖,且能诱导其定向分化,提示PDS具有类似造血生长因子和协同生长因子的效应。     

慢性乙肝患者外周血CD4+细胞HLA-DR、CD8+细胞CD28表达的检测及其意义

目的 检测乙肝患者外周血CD4^＋淋巴细胞表面HLA-DR和CD8^＋淋巴细胞表面CD28的表达情况,评价乙肝患者的细胞免疫状态。方法 荧光抗体CD4-PECY5、HLA-DR-FITC和CD8-PE、CD28-FITC标记淋巴细胞,流式细胞仪分别测定患者CD4^＋淋巴细胞表面HLA-DR和CD8^＋淋巴细胞表面CD28表达的百分率,并与HBV-DNA结果比较。结果 ①与正常对照组比较,乙肝患者组外周血CD4^＋淋巴细胞表面HLA-DR的表达显著升高（P〈0.001）,CD8^＋淋巴细胞表面CD28的表达显著降低（P〈0.01）;②乙肝患者DNA阳性（〉4000拷贝/ml）与阴性（〈4000拷贝/ml）组CD4^＋淋巴细胞表面HLA-DR和CD8^＋淋巴细胞表面CD28的表达比较均无显著性差异（P〉0.1）。结论 乙肝患者外周血CD4^＋细胞的免疫活化增强,CD8^＋细胞与抗原递呈细胞结合的作用减弱;淋巴细胞的活化情况与病毒复制情况及含量多少无关。