Characterization of a murine thymic CD4~ T cell subset-TCRαβ~ 3G11~- 6C10~- CD4~ CD8~- thymocytes

The presence of a relatively mature CD4 ~ CD8~- (SP) T cell subset in mouse thymus has been demonstrated. Composing of 10% of total CD4SP thymocytes, this subset is defined by the absence of 3G11 and 6C10 expression with a phenotype of CD69~( /-), HSA~(med/lo) and heterogeneous for Qa-2 expression. The proliferation capability of TCRαβ~ 3G11~- 6C10~- CD4~ CD8~- thymocytes was high while using Con A stimulus. And Con A stimulation could result in secretion of IL-4, IL-10, IL-6 and a little amount of IFNγ. IL-2 was barely detectable. This is distinct from typical Th0 type cytokines. The cells of this subset were NK1.1 negative, but strongly expressed GATA-3 mRNA. The results suggest that the CD4~ subset of 3G11~- 6C10~- NK1.1~- phenotype possesses immunocompetent cells with functions characteristic of Th2-like cytokines, which may indicate the cells at transitional status from Th0 to Th2, with a propensity to Th2.     

TCRαβ+3G11-6C10-CD4+CD8-胸腺髓质细胞亚群的特性分析

CD4+CD8-及CD4-CD8+单阳性(SP)胸腺细胞是不均一的细胞群体,存在功能成熟的分化过程并同时伴随有表型的变化.为深入研究CD4+SP中的不同表型和不同功能状态的细胞群体,利用多种抗体加补体杀伤和细胞panning方法,分离得到小鼠3G11-6C10-CD4+CD8-胸腺髓质细胞亚群.该群细胞为TCRαβ+CD69loHSAmed/lo,有15%的Qa-2分子表达.可接受Con A的刺激进行增殖应答并分泌IL-6,IL-4和IL-10等Th2型细胞因子及低水平的IFNγ,但不分泌IL-2.根据3G11-6C10-CD4+CD8-胸腺细胞的表型和功能特点,推测该群细胞是正常的胸腺细胞亚群之一,处于CD4+SP成熟过程的中后期,是Th0向Th2转化的过渡型细胞.     

抗CD3mAb诱导TN细胞向过渡型CD8单阳性细胞分化

本实验观察了在IL-7维持TN细胞生长的体外细胞培养系统中,抗CD 3 mAb对TN细胞分化的作用。发现抗CD 3 mAb在体外能诱导TN细胞分化产生CD 4~-CD 8~ 及部分CD 4~(lo)CD 8~ 细胞。由于多数CD 8~ 细胞为TCRβ~-,故抗CD 3 mAb诱导产生的CD 4~-CD 8~ 细胞是DN向DP分化的不成熟过渡状态细胞。抗TCR βmAb也能诱导CD 4~-CD 8~ 细胞产生,但其诱导分化能力弱于抗CD3 mAb。在体外细胞培养条件下,抗CD 3mAb诱导的DN→DP转化伴有IL-2 Rα表达下调,并且IL-7诱导的TCRβ分子表达也受到抑制。当TN细胞在IL-7条件下培养3天后,抗CD 3 mAb便失去诱导TN细胞分化的能力,表明抗CD 3 mAb诱导的TN细胞分化可能是通过细胞表面pre-TCR复合体进行的。     

乳腺癌中CD55高表达细胞的生物学特性

目的探讨乳腺癌细胞株MCF7中CD55高表达细胞的生物学特性。方法应用抗CD55抗体及Hoechst33342染料对乳腺癌细胞株MCF7细胞进行荧光染色,应用FACS-Vantage和FACS Vantage SE分选CD55hi和CD55lo细胞、SP和MP细胞,对比两组细胞在两种染色中的分群所在、对C2-ceramide诱导凋亡的耐受能力、及应用RT-PCR和免疫组化来检测Bcl-2、TMEM23在两组细胞中的表达。结果分选的CD55hi和CD55lo细胞再用Hoechst 33342染色时,分别位于SP和MP区域中。在C2-ceramide存在的情况下,CD55hi细胞比CD55lo细胞对凋亡刺激具有更高的耐受性。在CD55hi和SP细胞中Bcl-2及TMEM23的表达水平分别比在CD55lo和MP细胞中高。结论 CD55高表达细胞具有与癌干细胞相似的生物学特性,CD55可以推测为乳腺癌干细胞的一个表面标记。     

香菇多糖注射液对直肠癌根治术后患者纤维蛋白水平及免疫功能的影响

目的:研究香菇多糖注射液对直肠癌根治术后患者纤维蛋白水平及免疫功能的影响。方法:将2010年5月-2014年10月期间在我院接受直肠癌根治术的患者随机分为两组,观察组术后接受香菇多糖联合FOLFOX-4化疗,对照组术后接受FOLFOX-4化疗,观察两组患者化疗过程中的不良反应,测定化疗前后纤维蛋白水平及免疫功能指标。结果:观察组患者在化疗过程中消化道反应、肝功能损伤、骨髓抑制、周围神经毒性、口腔黏膜损伤、脱发的发生率均显著低于对照组(P0.05);化疗后,对照组患者外周血中CD3~+CD4~+CD8~-细胞、CD3~+CD4~-CD8~+细胞、CD19~+细胞、CD3~-CD56~+细胞的含量以及血清Ig M、Ig A、Ig G、FIB的含量显著低于化疗前(P0.05),观察组患者外周血中CD3~+CD4~+CD8~-细胞、CD3~+CD4~-CD8~+细胞、CD19~+细胞、CD3~-CD56~+细胞的含量以及血清Ig M、Ig A、Ig G的含量与化疗前无显著性差异(P0.05),血清FIB含量显著低于化疗前(P0.05);观察组患者化疗后外周血中CD3~+CD4~+CD8~-细胞、CD3~+CD4~-CD8~+细胞、CD19~+细胞、CD3~-CD56~+细胞的含量以及血清Ig M、Ig A、Ig G、FIB的含量显著高于对照组(P0.05),血清FIB含量显著低于对照组(P0.05)。结论:香菇多糖注射液辅助治疗能够减轻直肠癌根治术后FOLFOX-4化疗的毒副作用、改善免疫功能。     

宫颈癌患者外周血CD4+CD25+high调节性T细胞的表达及意义

目的:探讨宫颈癌患者外周血中CD4~ CD25~( high)调节性T(regulator T cells,Tr)的表达及意义。方法:采用流式细胞术检测52例宫颈癌患者,35例健康女性外周血中CD4~ CD25~( high)Tr、细胞毒性T细胞(cytotoxic T lymphocytes,CTL)和NK细胞,采用ELISA检测血清中-干扰素(interferon,IFN-)的表达水平。结果:宫颈癌患者外周血CD4~ CD25~( high)Tr占CD4~ T淋巴细胞的百分比为(7.18±2.32)%,高于健康女性组(P<0.05);宫颈癌患者外周血CD4~ CD25~( high)Tr水平与CTL、NK细胞及IFN-水平呈负相关。结论:宫颈癌患者外周血中具免疫抑制活性的CD4~ CD25~( high)Tr水平较高,参与宫颈癌患者的肿瘤免疫抑制。     

CD4+CD25+调节性T细胞发挥效应的分子机制

调节性T细胞是一群具有免疫调节(或免疫抑制)作用的细胞,Foxp3 CD4 CD25 调节性T细胞约占CD4 T细胞的5%￣15%,主要是CD4 CD8-CD25-单阳性胸腺细胞在胸腺的自然选择过程中产生的,也可以通过外周诱导而产生。它通过细胞接触依赖机制和抑制性细胞因子依赖机制主动抑制自身免疫T细胞的活化,维持自稳状态。现对Foxp3 CD4 CD25 T细胞群的一些特征性分子在其效应机制中的作用进行综述。     

低氧对CD34~ 造血干/祖细胞增殖分化及其对细胞因子依赖性的影响

采用免疫磁珠法分离脐血CD34 造血干 /祖细胞 ,进行低氧和常氧条件下单个核细胞 (MNC)及CD34 细胞的半固体及液体培养 ,计细胞总数和集落产率 ,并通过流式细胞仪检测细胞表型和细胞周期 ,以探讨造血干/祖细胞在低氧环境下增殖分化性能的改变及其对细胞因子反应性的变化。结果显示 :CD34 细胞在低氧条件下生成的BFU E集落数 ( 32 4 8± 41 4/10 4 细胞 )明显增多 (对照为 191 2± 34 5 /10 4 细胞 ,P <0 0 1) ;在无细胞因子存在的液体培养体系中 ,低氧组的BFU E产率 ( 15 2 4± 2 2 6 /10 4 细胞 )明显高于常氧组 ( 74 2± 9 3/10 4 细胞 ,P <0 0 1) ;低氧培养细胞中CD34 细胞的比例高于对照 2 5± 1 2倍 (P <0 0 5 )。但MNC生成的BFU E在常氧和低氧条件下无显著差异。这些结果表明 :体外低氧环境能显著增加CD34 造血干 /祖细胞形成红系祖细胞的产率 ,且使其对细胞因子的依赖性降低 ,并对早期红系祖细胞的维持有增强作用 ,但对粒系祖细胞的增殖则有抑制作用     

SLE带状疱疹患者外周血CD4~+CD28~+和CD4~+CD25~+FoxP3~+调节性T细胞的表达及相关性研究

目的:检测系统性红斑狼疮(systemic lupus erythematosus,SLE)合并带状疱疹患者外周血CD4~+CD28~+和CD4~+CD25~+Fox P3~+调节性T细胞的表达及相关性,探讨其在SLE合并带状疱疹发病中的临床意义。方法:采用流式细胞术检测30例SLE患者、30例SLE合并带状疱疹患者及30例健康对照者外周血中CD4~+/CD8~+T淋巴细胞亚群表面CD28的表达及CD4~+CD25~+Fox P3~+Treg细胞的表达水平,并分析SLE合并带状疱疹患者外周血CD4~+CD28~+和CD4~+CD25~+Fox P3~+调节性T细胞表达的相关性。结果:SLE合并带状疱疹组患者急性期外周血CD4~+T淋巴细胞比率、绝对计数显著降低,CD4~+、CD8~+T淋巴细胞表面的CD28表达下调,CD4~+CD25~+Fox P3~+Treg细胞水平显著高于SLE组及健康对照组,SLE合并带状疱疹组患者外周血CD4~+CD25~+Fox P3~+Treg水平与CD4~+CD28~+水平成负相关(P均0.05)。结论:SLE合并带状疱疹患者CD4~+、CD8~+T细胞活化异常,CD4~+CD25~+Fox P3~+Treg细胞可能参与抑制了T细胞的活化。     

人造血干/祖细胞多态性的研究:Ⅲ.骨髓CD34~ 造血干/祖细胞功能亚群的分析

CD 34~ 造血干/祖细胞(HSC/HPC)是十分异质性的,由多个不同功能亚群所构成,在分化方向与重建造血等方面差异显著。本文对正常人骨髓CD 34~ HSC/HPC各亚群进行了较全面的分析。首先以阳性选择策略,采用Isolex~(TM) 50免疫磁球分选术富集骨髓CD 34~ HSC/HPC,其纯度>90%,随之采用免疫荧光抗体双标记二维流式细胞仪对其测定,发现高纯度的CD 34~ HSC/HPC可分为八个不同亚群:1.CD 34~ /CD 71~-(23.4%—56.6%)与CD 34~ /CD 71~ (33.4%—66.6%);2.CD34~ /CD 45~-(80.8%—82.5%)与CD34~ /CD 45~ (8.1%—11.2%);3.CD 34~ /CD 33~-(20.4%—80.6%)与CD 34~ /CD 33~ (14.6%—64.8%);4.CD 34~ /DR~-(6.3%—11.0%)与CD 34~ /DR~ (82.8%—85.5%)。用免疫胶体金——免疫桥酶联组化双染色对上述亚群进一步分析的结果与流式细胞仪的高度一致,为研究各亚群的功能与生物学特性提供了坚实基础     

CD30/CD30 ligand and CD40/CD40 ligand in malignant lymphoid disorders

CD30 and CD40 are members of the tumor necrosis factor (TNF) receptor family. These two receptors have pleiotropic biologic functions including induction of apoptosis and enhancing cell survival. This review will discuss the pattern of expression of these receptors in malignant lymphoid disorders and their prospective ligands. Understanding issues related to these two ligands and their receptors in lymphoid malignancies may help to improve the classification of these diseases and could open the doors for new treatment strategies.     

Follicular lymphoma intratumoral CD4+CD25+GITR+ regulatory T cells potently suppress CD3/CD28-costimulated autologous and allogeneic CD8+CD25- and CD4+CD25- T cells

Regulatory T cells (T(R)) play a critical role in the inhibition of self-reactive immune responses and as such have been implicated in the suppression of tumor-reactive effector T cells. In this study, we demonstrate that follicular lymphoma (FL)-infiltrating CD8+ and CD4+ T cells are hyporesponsive to CD3/CD28 costimulation. We further identify a population of FL-infiltrating CD4+CD25+GITR+ T(R) that are significantly overrepresented within FL nodes (FLN) compared with that seen in normal (nonmalignant, nonlymphoid hyperplastic) or reactive (nonmalignant, lymphoid hyperplastic) nodes. These T(R) actively suppress both the proliferation of autologous nodal CD8+CD25- and CD4+CD25- T cells, as well as cytokine production (IFN-gamma, TNF-alpha and IL-2), after CD3/CD28 costimulation. Removal of these cells in vitro by CD25+ magnetic bead depletion restores both the proliferation and cytokine production of the remaining T cells, demonstrating that FLN T cell hyporesponsiveness is reversible. In addition to suppressing autologous nodal T cells, these T(R) are also capable of suppressing the proliferation of allogeneic CD8+CD25- and CD4+CD25- T cells from normal lymph nodes as well as normal donor PBL, regardless of very robust stimulation of the target cells with plate-bound anti-CD3 and anti-CD28 Abs. The allogeneic suppression is not reciprocal, as equivalent numbers of CD25+FOXP3+ cells derived from either normal lymph nodes or PBL are not capable of suppressing allogeneic CD8+CD25- and CD4+CD25- T cells, suggesting that FLN T(R) are more suppressive than those derived from nonmalignant sources. Lastly, we demonstrate that inhibition of TGF-beta signaling partially restores FLN T cell proliferation suggesting a mechanistic role for TGF-beta in FLN T(R)-mediated suppression.     

CD154 (CD40 ligand)

CD40 ligand, a type II transmembrane protein recently renamed CD154, was originally considered restricted to activated T lymphocytes, functioning as a mediator of T cell-dependent B cell activation, proliferation, and differentiation. However, the spectrum of CD154 expression and function has broadened considerably during recent years, establishing new roles as a central mediator of immunity and inflammation for this member of the tumor necrosis factor (TNF) gene superfamily. The emerging picture indicates that ligation of the receptor CD40 via CD154, most potently in its trimeric form, functions in two ways. CD154 modulates physiologic processes, such as T cell-mediated effector functions and general immune responses required for appropriate host defense, but also triggers the expression of pro-inflammatory mediators, such as cytokines, adhesion molecules, and matrix degrading activities, all of which are associated with the pathogenesis of chronic inflammatory diseases, e.g., autoimmune disorders, arthritis, atherosclerosis, and cancer. Accordingly, CD40/CD154 interactions have advanced as a potential therapeutic target for these diseases, whereby two opposing strategies, interruption as well as enhancement of CD40 signaling, are explored for beneficial outcomes.     

CD30/CD30 ligand (CD153) interaction regulates CD4+ T cell-mediated graft-versus-host disease

CD30, a TNFR family member, is expressed on activated CD4(+) and CD8(+) T cells and B cells and is a marker of Hodgkin's lymphoma; its ligand, CD30L (CD153) is expressed by activated CD4(+) and CD8(+) T cells, B cells, and macrophages. Signaling via CD30 can lead to proliferation or cell death. CD30-deficient (-/-) mice have impaired thymic negative selection and increased autoreactivity. Although human alloreactive T cells preferentially reside within the CD30(+) T cell subset, implicating CD30 as a regulator of T cell immune responses, the role of CD30/CD153 in regulating graft-vs-host disease (GVHD) has not been reported. We used a neutralizing anti-CD153 mAb, CD30(-/-) donor mice, and generated CD153(-/-) recipient mice to analyze the effect of CD30/CD153 interaction on GVHD induction. Our data indicate that the CD30/CD153 pathway is a potent regulator of CD4(+), but not CD8(+), T cell-mediated GVHD. Although blocking CD30/CD153 interactions in vivo did not affect alloreactive CD4(+) T cell proliferation or apoptosis, a substantial reduction in donor CD4(+) T cell migration into the gastrointestinal tract was readily observed with lesser effects in other GVHD target organs. Blockade of the CD30/CD153 pathway represents a new approach for preventing CD4(+) T cell-mediated GVHD.     

CD134L engagement enhances human B cell Ig production: CD154/CD40, CD70/CD27, and CD134/CD134L interactions coordinately regulate T cell-dependent B cell responses

CD134 is a member of the TNFR family expressed on activated T cells, whose ligand, CD134L, is found preferentially on activated B cells. We have previously reported that the CD70/CD27 interaction may be more important in the induction of plasma cell differentiation after the expansion phase induced by the CD154/CD40 interaction has occurred. When CD134-transfected cells were added to PBMCs stimulated with pokeweed mitogen, IgG production was enhanced in a dose-dependent fashion. Addition of CD134-transfected cells to B cells stimulated with Staphylococcus aureus Cowan I strain/IL-2 resulted in little if any enhancement of B cell IgG production and proliferation. We found that while CD134-transfected cells induced no IgG production by themselves, it greatly enhanced IgG production in the presence of CD40 stimulation or T cell cytokines such as IL-4 and IL-10. The addition of CD134-transfected cells showed only a slight increase in the number of plasma cells compared with that in the culture without them, indicating that an increased Ig production rate per cell is responsible for the observed enhancing effect of CD134L engagement rather than increase in plasma cell generation. These results strongly suggest different and sequential roles of the TNF/TNFR family molecules in human T cell-dependent B cell responses through cell-cell contacts and the cytokine network.     

Mesenchymal stromal cells impair the differentiation of CD14(++) CD16(-) CD64(+) classical monocytes into CD14(++) CD16(+) CD64(++) activate monocytes

Background aimsMesenchymal stromal cells (MSC) possess immunomodulatory activity both in vitro and in vivo. However, little information is available regarding their function during the initiation of immunologic responses through their interactions with monocytes. While many studies have shown that MSC impair the differentiation of monocytes into dendritic cells and macrophages, there are few articles showing the interaction between MSC and monocytes and none of them has addressed the question of monocyte subset modulationMethodsTo understand better the mechanism behind the benefit of MSC infusion for graft-versus-host treatment through monocyte involvement, we performed mixed leucocyte reactions (MLR) in the presence and absence of MSC. After 3 and 7 days, cultures were analyzed by flow cytometry using different approachesResultsMSC induced changes in monocyte phenotype in an MLR. This alteration was accompanied by an increase in monocyte counting and CD14 expression. MSC induced monocyte alterations even without contact, although the parameters above were more pronounced with cell–cell contact. Moreover, the presence of MSC impaired major histocompatibility complex (MHC) I and II, CD11c and CCR5 expression and induced CD14 and CD64 expression on monocytes. These alterations were accompanied by a decrease in interleukin (IL)-1β and IL-6 production by these monocytes, but no change was observed taking into account the phagocytosis capacity of these monocytesConclusionsOur results suggest that MSC impair the differentiation of CD14⁺⁺ CD16^? CD64⁺ classical monocytes into CD14⁺⁺ CD16⁺ CD64⁺⁺ activated monocytes, having an even earlier role than the differentiation of monocytes into dendritic cells and macrophages.     

A ligand for CD5 is CD5

Recognition by scavenger receptor cysteine-rich domains on membrane proteins regulates innate and adaptive immune responses. Two receptors expressed primarily on T cells, CD5 and CD6, are linked genetically and are structurally similar, both containing three scavenger receptor cysteine-rich domains in their extracellular regions. A specific cell surface interaction for CD5 has been difficult to define at the molecular level because of the susceptibility of CD5 protein to denaturation. By using soluble CD5 purified at neutral pH to preserve biological activity, we show that CD5 mediates species-specific homophilic interactions. CD5 domain 1 only is involved in the interaction. CD5 mAbs that have functional effects in humans, rats, and mice block homophilic binding. Ag-specific responses by mouse T cells in vitro were increased when engagement of human CD5 domain 1 was inhibited by mutation or by IgG or Fab fragment from a CD5 mAb. This showed that homophilic binding results in productive engagement. Enhancement of polyclonal immune responses of rat lymph node cells by a Fab fragment from a CD5 mAb shown to block homophilic interactions provided evidence that the extracellular region of CD5 regulates inhibition in normal cells. These biochemical and in vitro functional assays provide evidence that the extracellular region of CD5 regulates immunity through species-specific homophilic interactions.