急性冠状动脉综合征患者外周血CD4~+及CD4~+ CD28~(null) T细胞活化后IKCa1通道的表达及意义

目的:研究急性冠状动脉综合征(ACS)患者外周血中CD4+T细胞及CD4+CD28null亚型活化前后IKCa1钾通道数目的变化以及IKCa1钾通道阻滞剂对活化CD4+T细胞效应分子表达的影响,探讨IKCa1钾通道对不稳定斑块的意义.方法:用免疫磁珠法分离出24例ACS患者外周血中的CD4+T细胞,其中12例进一步分出亚型CD4+CD28nullT细胞,采用全细胞膜片钳技术记录细胞活化前及活化3 d后的IKCa1钾电流.CD4+T细胞活化3 d后分别加入终浓度为0 2、1、5 μmol/L特异性IKCa1钾通道阻滞剂TRAM-34,再继续活化3 d,用反转录-PCR法检测干扰素-γ及颗粒酶B mRNA的表达.结果:活化后CD4+、CD4+CD28nullT细胞的IKCa1通道数目分别增加了9倍和8倍[活化前后2种细胞的通道数分别为(45±3)∶(439±33), (56±4)∶(497±45),均P<0 01].2种细胞的通道密度也分别增加了约3倍(P<0 01).活化前及活化后2种细胞的通道数目及通道密度均无差别.不同浓度的TRAM-34均下调CD4+T细胞活化后干扰素-γ、颗粒酶B mRNA的表达,各浓度组间干扰素-γ、颗粒酶B mRNA的表达差异均有统计学意义(P<0 01),浓度越高,各mRNA表达越低.结论:ACS患者外周血CD4+及CD4+CD28nullT细胞活化后IKCa1的通道数目及通道密度均明显增加,特异性IKCa1通道阻滞剂TRAM-34呈浓度依赖性地抑制CD4+T细胞活化时干扰素-γ及颗粒酶B mRNA的表达,提示CD4+T细胞的IKCa1钾通道可作为预防动脉粥样斑块不稳定的潜在治疗靶点.     

Inhibitory effects of candesartan on KCa3.1 potassium channel expression and cell culture and proliferation in peripheral blood CD4+T lymphocytes in Kazakh patients with hypertension from the Xinjiang region

Background and aim: Increasing evidence confirms that potassium channels are essential for lymphocyte activation, suggesting an involvement in the development of hypertension. Moreover, chronic inflammation is regarded as a direct or indirect manifestation of hypertension, highlighting the theoretical mechanisms. In this study, we investigated changes in KCa3.1 potassium channel expression in the blood of hypertensive and healthy Kazakh people in north-west China.

Methods: Flow cytometry technology was used for T-lymphocyte subtype analysis. Changes in the messenger RNA and protein expression of the KCa3.1 potassium channel in CD4⁺ T lymphocytes were detected using real-time quantitative polymerase chain reaction and western blots, using CD4⁺ T-cell samples from hypertensive Kazakh patients divided into candesartan and TRAM-34 treatment groups, and healthy case controls. Peripheral blood CD4⁺ T lymphocytes were activated and proliferated in vitro and then incubated for 0, 24, and 48 h under various treatment conditions. Changes in CD4⁺ T-lymphocytic proliferation were determined using Cell Counting Kit-8 and electron microscope photography.

Results: Expression of KCa3.1 was significantly higher in the hypertensive patients than in the controls (p < 0.05). Compared with the healthy group, Kazakh hypertensive patients had a reduced proportion of CD4⁺ T lymphocytes (p < 0.05).Candesartan and TRAM-34 intervention for 24 h and 48 h inhibited the expression of Kv1.3 and KCa3.1 at mRNA and protein level (p < 0.05).

Conclusions: Increase in functional KCa3.1 channels expressed in CD4⁺ T lymphocytes of Kazakh patients with hypertension was blocked by candesartan, providing theoretical support for hypertension treatment at the cellular ion channel level. Candesartan may potentially regulate hypertensive inflammatory responses by inhibiting T-lymphocytic proliferation and KCa3.1 potassium channel expression in CD4 ⁺ T lymphocytes.     

Type 1 and type 2 cytokine-producing CD4+ and CD8+ T cells in primary antiphospholipid syndrome

Antiphospholipid syndrome (APS) is an autoimmune condition characterized by thrombosis and/or recurrent fetal loss as well as the presence of autoantibodies against epitopes present on phospholipid-binding proteins. The role of cellular immunity in the pathogenesis of the syndrome remains unclear. We studied the cellular phenotype and the production of type 1 [interferon (IFN)-, interleukin (IL)-2] and type 2 (IL-4, IL-10) cytokines by CD4+ and CD8+ T-lymphocyte subsets in 13 patients with untreated primary APS (PAPS) and in 32 healthy controls. The production of cytokines was determined in T cells after a 5-h culture with or without mitogenic stimulation using a flow cytometric method of intracellular cytokine staining. In six of the patients these studies were repeated 6 months later. In PAPS patients we found a reduced percentage of circulating CD4+CD45RA+ and an increased percentage and absolute number of CD8+HLA-DR+ cells. A type 1 response was observed in the patients unstimulated cells, indicated by an increase in IFN--producing CD8+, IL-2-producing CD4+ T cells, and a decrease in IL-4-producing CD4+ and CD8+ T cells. Similar results were obtained in the patients at follow-up. Taken together, these results suggest a chronic in vivo stimulation of CD4+ and CD8+ T cells in PAPS patients exhibiting a type 1 polarization. Changes of cellular immunity may contribute to the pathogenesis of the clinical manifestations of the syndrome and might be proven to be useful targets for therapeutic interventions in the future.     

Prevention of spontaneous arthritis by inhibiting homeostatic expansion of autoreactive CD4+ T cells in the K/BxN mouse model

OBJECTIVE: K/BxN-transgenic mice are a model of autoimmune arthritis, similar to rheumatoid arthritis. This study was undertaken to determine whether inhibition of lymphopenia-provoked homeostatic expansion can prevent spontaneous development of disease in the K/BxN model. METHODS: To inhibit homeostatic expansion of autoreactive T cells, K/BxN mice with disease in the preclinical stage were adoptively transferred with CD4+ T cells purified from nontransgenic BxN or Thy1.1+ BxN mice. To observe the profile of proliferation of CD4+ T cells derived from the hosts, carboxyfluorescein diacetate succinimidyl ester-labeled autologous CD4+ T cells were cotransferred to K/BxN mice together with BxN CD4+ T cells. Disease onset and progression were scored, and the dynamics and phenotypes of recipient CD4+ T cells were determined by flow cytometry, before and after cell infusion. RESULTS: During the preclinical phase of disease, K/BxN mice exhibited CD4+ T lymphopenia, which was followed by a compensatory expansion of these cells during the early clinical phase. The majority of CD4+ T cells acquired a memory phenotype (CD44(high),CD62L(low),CD25-), which is a hallmark of homeostatically expanding cells. Importantly, K/BxN mice subjected to syngeneic T cell transfer did not develop symptoms of arthritis and also possessed fewer transgenic T cell receptor-encoded Vbeta6+,CD4+ T cells. This effect was associated with decreased proliferation of recipient-derived CD4+ T cells but not with the function of CD25+ T regulatory cells present in donor cells. CONCLUSION: These results provide the first evidence that lymphopenia-associated homeostatic proliferation of autoreactive CD4+ T cells potentiates autoimmune arthritis, and that inhibition of this process protects mice from the development of this pathologic condition.     

Programmed death 1 ligand signaling regulates the generation of adaptive Foxp3+CD4+ regulatory T cells

Although mature dendritic cells (DCs) are potent initiators of adaptive immune response, immature steady-state DCs contribute to immune tolerance. In this study, we show that ex vivo splenic DCs are capable of inducing conversion of naïve CD4⁺ T cells to adaptive Foxp3⁺CD4⁺ regulatory T cells (aTreg) in the presence of TGF-β. In particular, when compared with splenic CD8α⁻ DCs, the CD8α⁺ DC subset were superior in inducing higher frequencies of conversion. This was not attributable to the difference in basal level of costimulation, because deficiency of CD40 or CD80/86 signaling did not diminish the differential induction of Foxp3. Conversion was regulated by DC maturation status. Further insights into the molecular mechanisms of conversion were gained by analyzing the contribution of several costimulatory and coinhibitory receptors. Costimulatory signals through GITR suppressed conversion, whereas coinhibitory signaling via programmed death 1 ligand (PD-L1) but not PD-L2 was required for conversion. Ex vivo PD-L1^−/− DCs failed to support Foxp3 induction in the presence of TGF-β. In vivo blocking PD-L1 signaling abolished conversion in a tumor-induced aTreg conversion model. Collectively, this study highlights the cellular and molecular parameters that might be exploited to control the de novo generation of aTregs and peripheral tolerance.     

Methyl-cpg-binding Domain Protein 2 Silencing Inhibits Th17 Differentiation of CD4+T cells Induced by Ovalbumin

Background: Little is known about MBD2’s epigenetic regulation in the immune pathogenesis of CD4+T cell differentiation.Objective: This study attempted to explore the mechanism of methyl-cpg-binding domain protein 2 (MBD2) in CD4+T cell differentiation stimulated by environmental allergen ovalbumin (OVA).Methods: Mononuclear cells were separated from the spleen tissues of male C57BL/6 mice. The OVA interfered with the differentiation of splenic mononuclear cells and CD4+T cells. The CD4+T cells were obtained by magnetic beads and identified by CD4 labeled antibody. CD4+T cells were transfected with lentivirus to silence MBD2 gene. A methylation quantification kit was used to detect 5-mC levels.Results: The purity of CD4+T cells reached 95.99% after magnetic beads sorting. Treatment with 200 μg/mL OVA stimulated the CD4+T cells differentiation to Th17 cells and promoted the secretion of IL-17. After being induced, the Th17 cell ratio increased. 5-Aza inhibited the Th17 cell differentiation and the IL-17 level in a dose-dependent manner. Under the intervention of the Th17 induction and 5-Aza, MBD2 silencing inhibited the differentiation of Th17 cell, and decreased the IL-17 and 5-mC levels in the cell supernatants. MBD2 silencing reduced the scale of the Th17 cell and IL-17 levels in the OVA-treated CD4+T cells.Conclusion: MBD2 affected IL-17 and 5-mC levels by mediating the Th17 cell differentiation in splenic CD4+T cells that were interfered with 5-Aza. OVA induced Th17 differentiation and increased IL-17 levels, inhibited by MBD2 silencing.     

Type 1 Diabetes Development Requires Both CD4+ and CD8+ T cells and Can Be Reversed by Non-Depleting Antibodies Targeting Both T Cell Populations

Type 1 diabetes development in NOD mice appears to require both CD4⁺ and CD8⁺ T cells. However, there are some situations where it has been suggested that either CD4⁺ or CD8⁺ T cells are able to mediate diabetes in the absence of the other population. In the case of transgenic mice, this may reflect the numbers of antigen-specific T cells able to access the pancreas and recruit other cell types such as macrophages leading to a release of high concentrations of damaging cytokines. Previous studies examining the requirement for CD8⁺ T cells have used antibodies specific for CD8α. It is known that CD8α is expressed not only on αβ T cells, but also on other cell types, including a DC population that may be critical for presenting islet antigen in the pancreatic draining lymph nodes. Therefore, we have re-examined the need for both CD4⁺ and CD8⁺ T cell populations in diabetes development in NOD mice using an antibody to CD8β. Our studies indicate that by using highly purified populations of T cells and antibodies specific for CD8⁺ T cells, there is indeed a need for both cell types. In accordance with some other reports, we found that CD4⁺ T cells appeared to be able to access the pancreas more readily than CD8⁺ T cells. Despite the ability of CD4⁺ T cells to recruit CD11b class II positive cells, diabetes did not develop in the absence of CD8⁺ T cells. These studies support the observation that CD8⁺ T cells may be final effector cells. As both T cell populations are clearly implicated in diabetes development, we have used a combination of non-depleting antibodies to target both CD4-positive and CD8-positive cells and found that this antibody combination was able to reverse diabetes onset in NOD mice as effectively as anti-CD3 antibodies.     

CD4+ CD25+ CD127dim/-调节性T淋巴细胞对肝星状细胞增殖及功能的影响

目的 了解CD4+ CD25+ CD127dim/-调节性T淋巴细胞在体外对肝星状细胞(HSC)增殖以及功能的影响,初步探讨调节性T淋巴细胞促肝纤维化的机制。方法传代培养HSC LX-2,将免疫磁珠细胞分选(MASC)法分离所得慢性乙型肝炎患者调节性T淋巴细胞与HSC LX-2按不同方式共培养5d,以单独培养的HSC作为对照,细胞计数试剂盒-8（CCK-8）法检测共培养HSC增殖情况,ELISA法检测上清液中转化生长因子(TGF)β1含量,放射免疫法检测HSC分泌HA、PCⅢ水平。统计学处理采用LSD-t检验。结果 5例调节性T淋巴细胞与HSC比例为1.5∶1时HSC增殖最为明显,10例直接接触共培养与使用Transwell系统共培养调节性T淋巴细胞与HSC吸光度值分别为(0.713±0.032)、(0.735±0.028) cpm,均较对照组的（0.677±0.029）cpm增殖明显(t=5.4003,8.7878;均P＜0.01)。10例直接接触共培养与Transwell组细胞上清液中TGFβ1浓度分别为(781.59±76.45)、（813.53±60.62）pg/mL,显著高于对照组的(722.51±59.66) pg/mL（t=4.0014,6.1653;均P＜0.01）;HA浓度分别为（433.57±27.90）、（445.40±23.73）ng/mL,显著高于对照组的（415.83±19.44）ng/mL（t=3.3124,5.5231;均P＜0.01）;PCⅢ浓度分别为(21.93±1.71)、(23.12±1.87) ng/mL,显著高于对照组的（20.10±1.49）ng/mL(f=4.8082,7.9436;均P＜0.01)。且Transwell组各项结果均显著高于直接接触组(t=3.3875,2.1639,2.2107,3.1354;均P＜0.05)。结论CD4+ CD25+ CD127dim调节性T淋巴细胞可促进共培养的HSC增殖及其HA、PCⅢ的分泌。体外实验证明,CD4+ CD25+ CD127dim/-调节性T淋巴细胞具有促进肝纤维化的重要作用。     

高龄肝癌患者CD4+CD25+调节性T细胞及转化生长因子-β1检测的临床意义

目的 探讨检测老年原发性肝癌患者外周血CD4+ CD25+调节性T细胞(Treg)及血清转化生长因子(TGF)-β1的临床意义. 方法 应用流式细胞学方法和酶联免疫吸附测定方法分别检测80岁以上老年健康者20例、原发性肝癌患者22例、转移性肝癌患者25例外周血Treg占总CD4+T细胞的比例和血清TGF-β1浓度. 结果 老年原发性肝癌、转移性肝癌患者外周血Treg占总CD4+T细胞的比例与老年健康对照组比较均明显升高,差异有统计学意义(P＜0.01).老年原发性肝癌患者外周血T reg总CD4+T细胞比例较老年转移性肝癌患者亦明显升高,差异有统计学意义(P＜0.05).老年原发性肝癌、转移性肝癌患者血清TGF-β1浓度与老年健康对照组比较均明显升高,差异有统计学意义(P＜0.01).老年原发性肝癌患者血清TGF-31浓度较老年转移性肝癌患者亦明显升高,差异有统计学意义(P＜0.01).相关分析显示,原发性肝癌患者外周血Treg占总CD4+T细胞的比例与病理分期、血清TGF-β1浓度呈正相关(r=0.782、r=0.698,P＜0.01),与Karnofsky功能状态(KPS)评分负相关(r=-0.643,P＜0.01). 结论 高龄原发性肝癌患者外周血Treg比例明显升高,且与血清TGF-β1浓度、病理分期及KPS评分具有一定的相关性.检测老年原发性肝癌患者外周血Treg占总CD4+T细胞的比例,可能有助于评估老年原发性肝癌患者病情进展情况及判断其预后.     

钙通道和Na+/H+交换在表皮生长因子促肝癌细胞生长中的作用

目的许多生长因子如表皮生长因子(EGF),与肿瘤的发生密切相关.EGF与表皮生长因子受体(EGFR)结合,通过一系列的信息传导,导致肝癌细胞的增生.但受体后的信息传导机制尚不清楚.本实验探讨酪氨酸激酶、蛋白激酶C、Na+/H+交换、钙调蛋白和电压依赖性钙通道在EGF促肝癌细胞生长中的作用.方法本研究于无血清RPMI1640中培养肝癌细胞SMMC7721,采用3H-Thymidine(3H-TdR)掺入的方法,检测肝癌细胞DNA合成速率,研究酪氨酸激酶、蛋白激酶C、Na+/H+交换、钙调蛋白和电压依赖性钙通道在EGF促肝癌细脆生长中的作用.结果EGF 10-9M对肝癌细脆的生长有极显著促进作用,与对照组比较差异有显著意义(P＜0.05),酪氮酸激酶阻滞剂Genistein对EGF的促肝癌细胞生长作用具有极显著抑制作用(P＜0.001).钙调蛋白阻滞剂W-7、蛋白激酶C阻滞剂H-7和Na+/H+交换阻滞剂amiloride对EGF的促肝癌细胞生长作用具有显著抑制作用(P＜0.001,P＜0.01,P＜0.05),而对基础状态细胞的3H-TdR掺入值无显著影响(P＞0.05).电压依赖性钙通道阻滞剂Varapamil对BGF的促肝癌细胞生长作用无显著抑制作用(P＞0.05),对基础状态细胞的3H-TdR掺入值亦无显著影响(P＞0.05).结论结果显示,酪氨酸激酶、蛋白激酶C、Na+/H+交换及依赖钙-钙调蛋白途径在BGF的作用中起关键作用.电压依赖性钙通道与EGF的作用无关.     

Control of type 1 diabetes by CD4+Foxp3+ regulatory T cells: lessons from mouse models and implications for human disease

In recent years, there has been a revival of the concept of CD4⁺ regulatory T (T_reg) cells as being a central control point in various immune responses, including autoimmune responses and immunity to transplants, allergens, tumours and infectious microbes. The current literature suggests that T_reg cells are diverse in their phenotype and mechanism(s) of action, and as such, may constitute a myriad of naturally occurring and induced T cell precursors with variable degrees of regulatory potential. In this review, we summarize research from various laboratories, including our own, showing that CD4⁺Foxp3⁺ T_reg cells are critical in the control of type 1 diabetes (T1D) in mouse models and humans. In this review, we also discuss cellular and molecular determinants that impact CD4⁺Foxp3⁺ T_reg cell development and function and consequential resistance to organ‐specific autoimmune disease. Recent advances in the use of CD4⁺Foxp3⁺ T_reg cellular therapy to promote immunological tolerance in the absence of long‐term generalized immunosuppression are also presented. Copyright © 2009 John Wiley & Sons, Ltd.     

Co-expression of CD30 ligand and interleukin 4 (IL-4) receptors by acute myeloid leukaemia blasts is associated with the expansion of IL-4-producing CD30+ normal T cells

CD30 ligand (CD30L), but not its cognate receptor CD30, is frequently expressed on acute myeloid leukaemia (AML) blasts. In the present study, we found that leukaemic blasts presenting surface CD30L displayed a characteristic cytokine-receptor pattern that makes them ideal targets for those cytokines usually produced by Th2-type cell subsets. In particular, even though a broad distribution of Th2 cytokine receptors by AML blasts was shown, we demonstrated the almost exclusive expression of interleukin 4 (IL-4) receptor (R), in the absence of its cognate cytokine, by CD30L+ AML. Furthermore, a number of Th2-associated markers, including CD30, IL-4 and GATA-3, were expressed by residual T cells derived from CD30L+ AML but not from CD30L- AML, in which the presence of the Th1-associated marker LAG-3 was documented in some cases. The production of IL-4 in the absence of interferon gamma (IFN-gamma) was also detected in CD3+/CD30+ T cells from CD30L+ AML. These results, along with the shift toward IL-4-producing specific T-cell clones observed in CD30L+ AML samples by enzyme-linked Immunospot (ELISpot) assay, were consistent with the hypothesis of a Th2 polarization taking place in T cells from CD30L+ AML. The notion that IL-4 was able to enhance in vitro proliferation of CD30L+/IL-4R+ purified leukaemic blasts suggests that the selective interaction of IL-4-producing CD30+ T cells with CD30L+ leukaemic progenitors may have a role in the progression of this particular AML subset.     

CD137-CD137L信号通过TRAF6/JNK/AP-1通路调控小鼠血管平滑肌细胞活化T细胞核因子c1表达

目的探讨CD137-CD137L信号是否通过肿瘤坏死因子受体相关因子6/c-Jun氨基末端激酶/活化蛋白1(TRAF6/JNK/AP-1)途径调控小鼠血管平滑肌细胞(VSMC)活化T细胞核因子c1(NFATc1)的表达。方法采用组织块原代培养小鼠VSMC,第3~5代细胞用于实验。VSMC分为6组:对照组、CD137刺激组、CD137抑制组、siTRAF6干预组、siJNK干预组、siAP-1干预组。Western blot检测各组TRAF6、磷酸化JNK(p-JNK)、磷酸化AP-1(p-AP-1)、NFATc1蛋白表达水平。免疫荧光法检测各组TRAF6、p-JNK、p-AP-1、NFATc1荧光表达。结果 (1)与对照组相比,CD137刺激组(CD137-CD137L信号激活)TRAF6、p-JNK、p-AP-1、NFATc1蛋白表达水平明显升高(P0.05);与CD137刺激组相比,CD137抑制组(CD137-CD137L信号抑制)TRAF6、p-JNK、p-AP-1、NFATc1蛋白表达水平明显降低(P0.05)。(2)采用siRNA技术分别沉默TRAF6、JNK、AP-1后,与CD137刺激组相比,siTRAF6干预组TRAF6、p-JNK、p-AP-1、NFATc1表达明显减少(P0.05);siJNK干预组TRAF6表达无改变,而p-JNK、p-AP-1、NFATc1表达明显减少(P0.05);siAP-1干预组TRAF6、p-JNK表达无明显改变,而p-AP-1、NFATc1表达明显减少(P0.05)。(3)免疫荧光检测显示:CD137刺激组TRAF6、p-JNK、p-AP-1、NFATc1荧光表达量升高(P0.05);CD137抑制组TRAF6、p-JNK、p-AP-1、NFATc1荧光表达量明显降低(P0.05);siTRAF6干预组、siJNK干预组、siAP-1干预组TRAF6、p-JNK、p-AP-1、NFATc1荧光表达量与上述蛋白表达结果一致。结论 CD137-CD137L信号可通过TRAF6/JNK/AP-1通路影响NFATc1的表达。     

Expression of programmed cell death protein 1 and T‐cell immunoglobulin‐ and mucin‐domain‐containing molecule‐3 on peripheral blood CD4+CD8+ double positive T cells in patients with chronic hepatitis C virus infection and in subjects who spontaneously cleared the virus

Chronic hepatitis C virus (HCV) infection is characterized by increased proportion of CD4+CD8+ double positive (DP) T cells, but their role in this infection is unclear. In chronic hepatitis C, immune responses to HCV become functionally exhausted, which manifests itself by increased expression of programmed cell death protein 1 (PD‐1) and T‐cell immunoglobulin‐ and mucin‐domain‐containing molecule‐3 (Tim‐3) on T cells. The aim of our study was to determine PD‐1 and Tim‐3 phenotype of DP T cells in subjects with naturally resolved and chronic HCV infection. Peripheral blood mononuclear cells from 16 patients with chronic infection and 14 subjects who cleared HCV in the past were stained with anti‐CD3, anti‐CD4, anti‐CD8, anti‐PD‐1 and anti‐Tim‐3 antibodies and, in 12 HLA‐A*02‐positive subjects, MHC class I pentamer with HCV NS3₁₄₀₆ epitope. In chronic and past HCV infection, proportions of total DP T cells and PD‐1+ DP T cells were similar but significantly higher than in healthy controls. DP T cells were more likely to be PD‐1+ than either CD4+ or CD8+ single positive (SP) T cells. HCV‐specific cells were present in higher proportions among DP T cells than among CD8+ SP T cells in both patient groups. Furthermore, while the majority of HCV‐specific DP T cells were PD‐1+, the proportion of HCV‐specific CD8+ T cells which were PD‐1+ was 4.9 and 1.9 times lower (chronic and past infection, respectively). PD‐1 and Tim‐3 were predominantly expressed on CD4^highCD8^low and CD4^lowCD8^high cells, respectively, and co‐expression of both markers was uncommon.