自身免疫性肝炎CD4+CD25+high调节性T细胞的研究

目的探讨CD4^＋CD25^＋high调节性T细胞（Tr）在自身免疫性肝炎（AIH）发病中的作用。方法用流式细胞仪技术比较分析AIH患者16例、慢性乙型肝炎（CHB）22例及键康正常人20例外周血中的CD4^＋CD25^＋high细胞，同时用免疫组织化学法检测AIH和CHB患者肝组织Foxp3的表达情况。结果AIH组外周血中CD4^＋CD25^＋high／CD4^＋百分比显著低于正常组（P〈0、05）和CHB组（P〈O．01），并且CHB组显著高于正常组（P〈0．05）；同时AIH组外周血中CD4^＋ T细胞也显著高于CHB组（P〈0．01））；肝组织Foxp3^＋细胞主要分布于肝小叶内窦周隙、汇管区，AIH组肝组织Foxp3^＋表达显著低于CHB组（P〈0．01）。结论CD4^＋CD25^＋high Tr细胞下降可能是自身免疫性肝炎发病的原因之一。     

CD4+CD25+T细胞在CD8+T细胞抗肿瘤免疫中的调节作用

实验旨在研究CD4^＋CD25^＋T细胞在CD8^＋T细胞抗肿瘤免疫中的调节作用。将小鼠脾脏中分离的单个核细胞分为两组．即去除CD4^＋CD25^＋T细胞组和未去除CD4^＋CD25^＋T细胞组,测定树突状细胞提呈的肿瘤抗原多肽刺激不同T细胞增殖活性、细胞因子IFN一1分泌,以及多肽特异性CD8^＋T细胞对同源性胃癌细胞株MFC的杀伤活性。结果显示预先去除未致敏T细胞中的CD4^＋CD25^＋T细胞,所诱导的特异性CD8^＋CTL对肿瘤细胞免疫应答增强,表现为反应性T细胞对树突状细胞提呈的肿瘤抗原多肽增殖反应增强,IFN-γ分泌量提高及CD8＋T细胞对MFC杀伤活性增强。这些结果表明。预先去除未致敏T细胞中的CD4^＋CD25^＋T细胞,肿瘤抗原多肽修饰的树突状细胞肿瘤疫苗效能可明显增加。CD4^＋CD25^＋T细胞在CD8^＋T细胞抗肿瘤免疫中起下调作用。     

Human CD4+CD25+ regulatory T cells

In this report, we review studies of human CD4+CD25+ regulatory T cells (T-reg). Although lagging a few years behind the discovery of these cells in the mouse, the equivalent population of CD4+CD25+ regulatory T cells has also been isolated from human peripheral blood, thymus, lymph nodes and cord blood. In general, the characteristics of this T cell subset are strikingly similar between mouse and man. In the recent explosion of research reports on human CD4+CD25+ cells, although the majority of the characteristics ascribed to these cells appear to be consistent, contrasting results have been found primarily in regards to potential involvement of TGFbeta and production of IL-10. One explanation for this variability may reside in the fact that markedly different techniques are used to isolate human CD4+CD25+ T-reg cells and thus may result in the comparison of T-reg populations that differ in cellular composition and/or activation state. Another potential explanation for differences in human T-reg function may rest on the extreme variability of the culture conditions and TCR stimuli that have been used to test the functional properties of these cells in vitro. The strength of the TCR signal provided to the culture greatly affects the functional outcome of the co-culture and can result in the difference between suppression and full activation. Surprisingly, it appears that stronger stimulation has a greater and more rapid effect on the T-resp cell than on the T-reg cell as it causes T-resp cells to quickly become resistant to suppression. Thus, the details of in vitro culture conditions may at least partially account for disparate findings in regard to the functional characterization of human CD4+CD25+ cells. Here we review the evidence regarding the identification of human CD4+CD25+ regulatory T cells and their possible mechanism(s) of function.     

CD4+ CD25+ [corrected] regulatory T cells render naive CD4+ CD25- T cells anergic and suppressive

CD4(+) CD25(+) Foxp3(+) naturally occurring regulatory T cells (nTreg) are potent inhibitors of almost all immune responses. However, it is unclear how this minor population of cells is capable of exerting its powerful suppressor effects. To determine whether nTreg mediate part of their suppressor function by rendering naive T cells anergic or by converting them to the suppressor phenotype, we cocultured mouse nTreg with naive CD4(+) CD25(-) T cells from T-cell receptor (TCR) transgenic mice on a RAG deficient (RAG(-/-)) background in the presence of anti-CD3 and interleukin-4 (IL-4) to promote cell viability. Two distinct responder cell populations could be recovered from the cocultures. One population remained undivided in the coculture and was non-responsive to restimulation with anti-CD3 or exogenous IL-2, and could not up-regulate IL-2 mRNA or CD25 expression upon TCR restimulation. Those responder cells that had divided in the coculture were anergic to restimulation with anti-CD3 but responded to restimulation with IL-2. The undivided population was capable of suppressing the response of fresh CD4(+) CD25(-) T cells and CD8(+) T cells, while the divided population was only marginally suppressive. Although cell contact between the induced regulatory T cell (iTreg) and the responders was required for suppression to be observed, anti-transforming growth factor-beta partially abrogated their suppressive function. The iTreg did not express Foxp3. Therefore nTreg are not only able to suppress immune responses by inhibiting cytokine production by CD4(+) CD25(-) responder cells, but also appear to modulate the responder cells to render them both anergic and suppressive.     

The role of self-peptides in the development of CD4+ CD25+ regulatory T cells

The thymus produces a unique lineage of cells known as CD4+ CD25+ regulatory T cells, and the exact processes leading to their development continue to be defined. Highly specific interactions between developing thymocytes and cognate self-antigens expressed by radioresistant elements in the thymus have been shown to drive CD4+ CD25+ regulatory-T-cell development. The self-peptide(s) that mediate thymic selection of CD4+ CD25+ regulatory T cells can also promote their expansion in the periphery, and self-peptides might also play a role in the conversion of CD4+ CD25- T cells into CD25+ regulatory T cells.     

CD4+CD25+调节性T细胞在川崎病免疫发病机制中的作用

目的探讨CD4 CD25 调节性T细胞在川崎病(KD)免疫发病机制中的作用。方法急性期KD患儿25例,正常同年龄对照组25例,KD患儿分别于静脉丙种球蛋白(IVIG)治疗前后直接取血备检,未加任何体外丝裂原刺激培养。采用流式细胞术分别检测外周血CD4 CD25 调节性T细胞比例及CD14 细胞表面共刺激分子的表达;逆转录-聚合酶链反应(RT-PCR)及荧光定量PCR检测外周血CD4 T细胞中Foxp3、CTLA-4和GITR基因mRNA的表达。结果急性期KD患儿外周血CD4 CD25 调节性T细胞比例明显低于同年龄对照组(P<0.01),IVIG治疗后显著上升(P<0.01);急性期KD患儿外周血CD4 T细胞中Foxp3、CTLA-4和GITR基因mRNA表达水平均明显低于正常对照组(P<0.01),IVIG治疗后均有不同程度的恢复(P<0.01);急性期KD患儿CD14 细胞明显过度表达CD80及CD86等共刺激分子(P<0.01),IVIG治疗后CD80及CD86表达均显著下降。结论急性期KD患儿CD4 CD25 调节性T细胞数量减少可能与KD免疫调节功能紊乱有关。     

CD4+CD25+T调节细胞的研究进展

CD4 CD25 TH细胞通过抗原特异性方式或细胞接触的方式抑制自身反应性T细胞的活化,能有效地维持自身免疫耐受,是调节自身反应性T细胞和防止自身免疫病发生的重要调节细胞。     

天然CD4+CD25+Treg细胞的研究进展

天然CD4+ CD25+ Treg细胞在针对自身抗原和外来抗原的免疫应答中起关键控制作用,其缺乏或功能性的缺陷将导致多重病理性的失调.本文就近年在其产生、作用机制以及与免疫耐受的诱导关系等方面的研究进展进行了综述.     

CTLA-4 x Ig converts naive CD4+CD25- T cells into CD4+CD25+ regulatory T cells

CTLA-4 x Ig was originally designed as an immunosuppressive agent capable of interfering with the co-stimulation of T cells. In the present study, we demonstrate that CTLA-4 x Ig, in combination with TCR ligation, has the additional capacity to convert naive CD4+CD25- T cells into Foxp3+ regulatory T (T(reg)) cells, as well as to expand their numbers. The CD4+CD25+Foxp3+ T(reg) generated by CTLA-4 x Ig treatment in vitro potently suppress effector T cells. Extending this in vivo, we show that systemic administration of CTLA-4 x Ig increases the percentage of CD4+CD25(hi)Foxp3+ cells within mixed lymphocyte reaction-induced murine lymph nodes. Significantly, the in vitro conversion of naive CD4+CD25- T cells into T(reg) cells is antigen-presenting cell (APC) dependent. This finding, together with the further observation that this conversion can also be driven in vitro by an antibody that engages B7-2 ligand, suggests that CTLA-4 x Ig-driven T(reg) induction may be predicated upon active CTLA-4 x Ig to B7-2 signaling within APC, which elicits from them T(reg)-inducing potential. These findings extend CTLA-4 x Ig's functional repertoire, and at the same time, reinforce the concept that T cell anergy and active suppression are not entirely distinct processes and may be linked by some common molecular triggers.     

Complementary role of CD4+CD25+ regulatory T cells and TGF-beta in oral tolerance

CD4(+)CD25(+) regulatory T cells are thought to be generated in the periphery as well as in the thymus. We sought to determine the roles played by CD4(+)CD25(+) T cells and transforming growth factor-beta (TGF-beta) in the induction and maintenance of tolerance generated by oral antigens in BALB/c mice. We found that oral administration of a high dose of ovalbumin (OVA) suppressed OVA-specific proliferation and antibody production in BALB/c mice depleted of CD25(+) cells. In contrast, the unresponsiveness induced by lower doses of OVA was only partially blocked by CD25 depletion prior to feeding. Depletion of CD4(+)CD25(+) cells after mice were orally tolerized did not reverse the tolerant status, indicating that these cells were not required to maintain the established tolerance. Furthermore, the induction of oral tolerance was not hampered by the administration of TGF-beta-neutralizing antibodies. However, in mice depleted of CD25(+) cells, anti-TGF-beta-neutralizing antibodies blocked the induction of tolerance, regardless of whether the mice followed the high- or low-dose regimens of oral OVA. CD25 depletion together with TGF-beta neutralization led the expansion of OVA-specific CD4 T cells against the subsequent antigen challenge, and each treatment alone did not. Our findings indicate that CD4(+)CD25(+) T cells and TGF-beta play a complementary role in the induction of oral tolerance, at least in part, by regulating the expansion of antigen-specific CD4 T cells.     

CD4~+CD25~+T细胞在CD8~+T细胞抗肿瘤免疫中的调节作用

实验旨在研究CD4+CD25+T细胞在CD8+T细胞抗肿瘤免疫中的调节作用。将小鼠脾脏中分离的单个核细胞分为两组,即去除CD4+CD25+T细胞组和未去除CD4+CD25+T细胞组,测定树突状细胞提呈的肿瘤抗原多肽刺激不同T细胞增殖活性、细胞因子IFN-γ分泌,以及多肽特异性CD8+T细胞对同源性胃癌细胞株MFC的杀伤活性。结果显示预先去除未致敏T细胞中的CD4+CD25+T细胞,所诱导的特异性CD8+CTL对肿瘤细胞免疫应答增强,表现为反应性T细胞对树突状细胞提呈的肿瘤抗原多肽增殖反应增强,IFN-γ分泌量提高及CD8+T细胞对MFC杀伤活性增强。这些结果表明,预先去除未致敏T细胞中的CD4+CD25+T细胞,肿瘤抗原多肽修饰的树突状细胞肿瘤疫苗效能可明显增加。CD4+CD25+T细胞在CD8+T细胞抗肿瘤免疫中起下调作用。     

类风湿性关节炎患者CD4+CD25+Foxp3+调节性T细胞检测及意义

目的:研究CD4 CD25 FoxP3 调节性T细胞在类风湿关节炎患者(RA)外周血中的比例改变,并探讨其在疾病进程中的意义.方法:选取活动期及稳定期RA患者,采用细胞内染色的流式细胞术及定量PCR的方法,分别在蛋白质和mRNA水平检测FoxP3表达,并与正常人进行比较.结果:RA患者CD4和CD25双阳性细胞所占比例与对照组没有明显差异,而活动期患者外周血CD4 CD25high和CD4 CD25 FoxP3 细胞明显低于稳定期和对照组(P＜0.05).FoxP3 mRNA表达水平与蛋白质表达水平变化相一致.结论:类风湿性关节炎活动期时CD4 CD25 FoxP3 调节性T细胞明显减少,这群调节性T细胞可能参与了类风湿性关节炎的病理进程.     

慢性HBV感染患者肝组织内CD4+CD25+调节性T淋巴细胞的表达

目的 观察慢性HBV感染患者免疫耐受期与免疫清除期肝组织中CD4+ CD25+调节性T细胞的表达及分布情况.方法 应用免疫组织化学法检测19例免疫耐受期及12例免疫清除期慢性乙型肝炎患者肝组织中FoxP3的表达,6例正常肝组织为对照.结果 FoxP3阳性信号位于淋巴细胞胞核内,阳性细胞主要聚集在汇管区,肝窦内亦可见散在单个淋巴细胞呈阳性.在免疫耐受期及免疫清除期患者肝组织中FoxP3较正常肝组织明显增加(P<0.01),免疫清除期患者肝组织内Fox P3明显高于免疫耐受期患者(P<0.01).免疫清除期患者肝组织中FoxP3阳性标记指数与ALT、HBeAg及HBV-DNA水平无明显相关性.免疫耐受期与免疫清除期两组相比,在年龄、ALT、TBIL、PTA、HBeAg及HBV-DNA水平方面差异均有统计学意义.结论 肝组织中CD4+ CD25+调节性T细胞在慢性HBV感染慢性化和抑制免疫,控制肝脏炎症反应方面可能起了重要作用.     

CD4+CD25+Treg在急性淋巴细胞白血病患者外周血中的表达及其体外实验研究

目的初步探讨CD4 CD25 调节性T细胞(CD4 CD25 regulatory T cells,CD4 CD25 Treg)在急性淋巴细胞白血病(acute lymphocytic leukemia,ALL)患者化疗前及化疗缓解后外周血中的表达水平,并研究患者血清能否诱导外周血CD4 CD25-T细胞转化为CD4 CD25 Treg。方法①采用流式细胞术分别检测ALL初诊组、化疗完全缓解或部分缓解组及正常对照组外周血中CD4 CD25 T细胞所占比例,然后通过荧光定量RT-PCR检测各组外周血中转录因子Foxp3mRNA的表达水平,并逐层分析比较。②采集正常人外周血单个核细胞后,对照组用正常人血清,实验组用患者血清并分别设浓度梯度进行培养,72h后采用流式细胞术、荧光定量RT-PCR分别检测CD4 CD25 T细胞和Foxp3mRNA表达。结果ALL化疗缓解组CD4 CD25 T细胞及Foxp3mRNA表达水平均明显高于ALL初诊组和正常对照组(P<0.05),后两者之间CD4 CD25 T细胞水平无统计学差异(P>0.05),但ALL初诊组Foxp3mRNA含量较正常对照组明显升高(P<0.01),差异具有统计学意义;并且血清培养对照组CD4 CD25 T细胞水平及Foxp3mRNA含量均明显低于实验组(P<0.05),且其表达并不随血清浓度的增加而升高。结论CD4 CD25 Foxp3 Treg在ALL初诊组及化疗缓解组患者外周血中比例明显升高,且初步表明患者血清中的可溶性物质可诱导外周血CD4 CD25 T细胞转化为CD4 CD25 Treg,提示CD4 CD25 Treg可能是ALL免疫抑制的一个重要原因。     

CD4+CD25+调节性T细胞在肿瘤免疫中的作用

CD4+CD25+调节性T细胞(Tr)是体内自然发生的调节性T细胞的重要亚群,具有无反应性和免疫抑制两大特性,主要通过与靶细胞的直接接触而起作用,其在体内不仅参与自身免疫性疾病、移植排斥反应等,还在肿瘤的发生、发展及免疫治疗中发挥重要作用.近几年来,Tr在肿瘤免疫中的作用倍受关注.     

老年初诊急性髓细胞白血病患者CD4+CD25+调节性T细胞的表达

背景：研究证实,很多恶性肿瘤患者体内CD4⁺CD25⁺调节性T细胞存在高表达,近期也有研究发现,急性髓细胞白血病患者外周血CD4⁺CD25⁺调节性T细胞同样表现出高比例表达。 目的：分析老年初诊急性髓细胞白血病患者CD4⁺CD25⁺调节性T细胞的表达特点。 方法：纳入初诊急性髓细胞白血病患者92例,将年龄在60岁以下者设为中青年组(n=22),年龄在60岁以上者设为老年观察组(n=70)。在老年观察组中,32例经规范化疗后完全缓解,设为完全缓解组;将余下38例设为老年组,依据FAB分型标准,分为M2 6例、M3 19例、M4 7例、M5 6例。另选择同期体检健康人群42名作为正常对照组。抽取受试者外周静脉血,检测CD4⁺CD25⁺调节性T细胞表达情况。 结果与结论：老年组、完全缓解组CD4⁺CD25^highFOXP3⁺调节性T细胞比例高于正常对照组(P < 0.01),并且老年组CD4⁺CD25^high FOXP3⁺调节性T细胞比例高于完全缓解组(P < 0.01)。老年组、完全缓解组CD4⁺FOXP3⁺T细胞比例高于正常对照组(P < 0.01),并且老年组CD4⁺ FOXP3⁺T细胞比例高于完全缓解组(P < 0.01)。老年组CD4⁺CD25^high FOXP3⁺调节性T细胞与CD4⁺ FOXP3⁺T细胞比例高于中青年组(P < 0.01)。老年组不同分型间CD4⁺CD25^high FOXP3⁺调节性T细胞和CD4⁺ FOXP3⁺T细胞比例比较差异均无显著性意义(P > 0.05)。Pearson相关性检验结果显示,老年初诊急性髓细胞白血病患者外周血CD4⁺CD25^high FOXP3⁺调节性T细胞比例和CD4⁺ FOXP3⁺T细胞比例呈正相关(r=0.87,P=0.019)。表明老年初诊急性髓细胞白血病患者CD4⁺CD25⁺调节性T细胞比例高于健康人群和中青年急性髓细胞白血病患者。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接：     

CD4+CD25+调节性T细胞的发育与胸腺CD4-CD25+细胞关联性的探讨

目的:探讨CD4 CD25 调节性T细胞(CD4 CD25 regulatoryTcells,CD4 CD25 Tr)的发育及其与胸腺CD4-CD25 细胞的关系。方法:以流式细胞术检测小鼠从出生至发育成熟过程中,胸腺、脾脏、淋巴结和外周血中CD4 CD25 Tr比例变化,以及胸腺CD4-CD25 细胞比例变化;通过磁激活细胞分选(MACS)从小鼠淋巴结纯化CD4 CD25 T和CD4 CD25-T细胞,经CFDA-SE标记,以多种刺激形式诱导增殖。结果:小鼠出生1d到10周的发育过程中,胸腺CD4 CD25 Tr比例一直比较恒定,但在脾脏、淋巴结和外周血,随鼠龄增加而不断升高,从1d龄到1周时升高最迅速,其后的升高速度逐渐减慢,10周龄时达平台期。胸腺中CD4-CD25 细胞在出生1d的小鼠比例非常高,1d龄到1周龄期间迅速下降,10周龄时达平台期。ConA不能诱导CD4 CD25 Tr和CD4 CD25-T细胞增殖,但CD4 CD25 Tr出现一过性细胞增大;佛波醇酯加离子霉素能诱导CD4 CD25 Tr和CD4 CD25-T细胞增殖;包被的抗CD3抗体加可溶性抗CD28抗体能刺激CD4 CD25-T细胞增殖,但CD4 CD25 Tr不增殖,加入高浓度IL-2,CD4 CD25-T细胞增殖更强,CD4 CD25 Tr出现增殖。结论:胸腺CD4-CD25 细胞很有可能是CD4 CD25 Tr的前体。