受体相互作用蛋白激酶-3参与甲型H1N1流感病毒感染小鼠记忆性CD8＋ T细胞的应答

受体相互作用蛋白激酶-3(receptor-interacting protein kinase 3, RIPK3)是坏死复合体的关键成分之一,介导细胞程序性死亡(programmed cell death,PCD)的发生。前期研究发现流感抗原特异性CD8^＋T细胞的初次应答部分依赖于RIPK3分子,为探讨其在记忆性CD8^＋T细胞应答中的作用,对初次感染后的C57BL/6小鼠在免疫记忆阶段进行了再次感染,并用流式细胞仪检测了流感病毒特异性的记忆性CD8^＋T细胞的表型和功能。结果发现小鼠初次感染甲型 H1N1流感病毒株A/Puerto Rico/8/34后37 d, RIPK3敲除小鼠的CD8^＋T细胞比例及分泌细胞因子γ-干扰素(IFN-γ)和肿瘤坏死因子-α(TNF-α)的能力均显著低于野生型小鼠;在再次感染相同病毒时,RIPK3敲除小鼠流感病毒特异性CD8^＋T细胞比例及分泌细胞因子IFN-γ的能力依旧显著低于野生型小鼠;而CD8^＋中枢型记忆性T细胞(TCM)比例显著高于野生型小鼠,效应型记忆性T细胞(TEM)或效应性T细胞(TEff)比例却显著低于野生型小鼠。提示RIPK3分子参与调节流感病毒特异的记忆性CD8^＋T细胞诱生数量和分泌细胞因子功能,并影响其TCM与TEM/TEff的比例,为深入探索病毒特异的记忆性CD8^＋T细胞应答的分子机制提供了新线索。     

广叶绣球菌多糖对小鼠CD8+T细胞介导的免疫应答调控机制

研究广叶绣球菌多糖(polysaccharides,SLPs)对小鼠CD8⁺T细胞活化、增殖分化以及效应阶段的影响,探索广叶绣球菌多糖对CD8⁺T细胞的免疫应答调控机制。通过腹腔注射环磷酰胺溶液(80mg/kg)构建免疫低下小鼠模型,灌胃广叶绣球菌多糖(低、中和高剂量分别为100、200和400 mg/kg),连续饲养20 d后处死,取脾脏和胸腺。血细胞分析仪测定血常规;MTT检测脾T淋巴细胞的扩增能力;流式细胞术分析脾脏CD8⁺T细胞表面CD28、CTLA-4和PD1以及树突状细胞表面MHCⅠ、CD80和PD-L1的表达量;ELISA测定外周血中TNF-α、IFN-γ、IL-2、IL-10、穿孔素及颗粒酶B的含量;RT-PCR测定脾脏Psmb9、Psmd9、TAP1、TAP2、IFN-γ、IL-2、JAK1、JAK2、STAT1、STAT3、SOCS-3和Blimp-1的mRNA表达量;Westernblot测定pJAK2/JAK2、pSTAT3/STAT3和Blimp-1的蛋白表达量。试验表明广叶绣球菌多糖高剂量组脾...     

α1-肾上腺素受体对胶原诱导性关节炎小鼠Treg细胞功能的影响*

目的: 利用胶原诱导性关节炎 (CIA) 模型小鼠,探讨去甲肾上腺素 (NE) 及其α1-肾上腺素受体 (AR ) 对CIA小鼠Treg细胞的作用。方法: 雄性DBA/1小鼠 32 只,随机分为对照组 (n=8) 和CIA模型组 (n=24)。II型胶原 (CII) 乳剂100 μl 尾根部注射DBA/1小鼠制备CIA小鼠模型,在初次免疫后第 41 日,用免疫荧光法检测小鼠脾脏中CD4⁺T与α1-AR的共定位情况;用Western blot法检测小鼠踝关节和脾脏中α1-AR的蛋白表达。分离纯化CIA小鼠脾脏中CD4⁺ T细胞,用抗CD3和抗CD28的单克隆抗体刺激CD4⁺T细胞,进行细胞培养,分为未加药组和加药组,加药组用NE或α1-AR激动剂苯肾上腺素 (phenylephrine) 处理细胞,用流式细胞术检测CIA小鼠CD4⁺T细胞中Treg的细胞数;用Western blot法检测CIA小鼠CD4⁺T中转化生长因子-β (TGF-β) 和IL-10的蛋白表达。结果: CD4⁺ T细胞能够表达α1-AR;与对照组相比,CIA小鼠踝关节和脾脏中α1-AR的蛋白表达显著降低(P＜0.01);与未加药的CIA小鼠的CD4⁺ T细胞相比,NE加入后的CIA小鼠CD4⁺ T细胞中Treg细胞的功能显著增强(P＜0.01);α1-AR激动剂phenylephrine加入后的CIA小鼠CD4⁺ T细胞中Treg细胞的功能显著增强(P＜ 0.01)。结论: 激活CIA小鼠CD4⁺ T细胞上的α1-AR可增强Treg细胞的功能,促进CD4⁺ T细胞向Treg细胞方向分化,发挥抗炎作用。     

CD8~+CD122~+T细胞在脑缺血过程中作用的研究

目的:探讨CD8+CD122+T细胞在脑缺血过程中的作用及其机制。方法:线栓法建立小鼠大脑中动脉栓塞模型(MCAO);激光共聚焦显微镜检测小鼠脑缺血组织中CD8+CD122+T细胞浸润情况;流式细胞仪检测脑缺血组织中CD8+CD122+T细胞/CD3+T细胞的比例及脾和胸腺中CD8+CD122+T细胞数量变化;RT-PCR方法检测CD8+CD122+T细胞对氧糖剥夺(Oxygen-glucose deprivation,OGD)条件下星形胶质细胞表达TNF-α,IL-1β,IFN-γ的影响。结果:各时间点脑缺血组织中均有CD8+CD122+T细胞浸润,且随脑缺血时间延长,缺血侧脑组织中CD8+CD122+T细胞/CD3+T细胞比例逐渐增加,5 d和7 d组差异显著,与非缺血侧相比,P5d0.05,P7d0.05;MCAO小鼠脾及胸腺中CD8+CD122+T细胞呈现先增高后降低的趋势。星形胶质细胞经OGD处理后,与对照组相比,IFN-γ、TNF-α、IL-1β表达显著增高,PIFN-γ0.01、PTNF-α0.001、PIL-1β0.01;CD122-blocked组与CD8+组相比,IFN-γ、TNF-α、IL-1β表达明显增高,PIFN-γ0.05、PTNF-α0.05、PIL-1β0.01;CD8+组与HBSS组相比,IFN-γ表达降低,P0.05;IL-1β表达有降低的趋势。结论:CD8+CD122+T细胞在脑缺血过程中发挥保护性作用,其保护作用通过CD122抑制星形胶质细胞TNF-α,IL-1β,IFN-γ炎症因子表达实现的。     

N-糖基化在肿瘤细胞逃逸CD8+T细胞中的意义和机制

肿瘤在发生发展过程中会产生异常糖基化结构,改变细胞功能,使其能逃逸机体细胞的免疫识别和免疫攻击,实现免疫逃逸。细胞膜表面蛋白的N-糖基化参与调控肿瘤细胞的增殖、迁移、侵袭、干细胞特性等。近年来,一系列研究进一步证实,肿瘤细胞免疫检查点分子的N-糖基化,以及识别N-糖基化的动物凝集素在肿瘤免疫逃逸CD8⁺T细胞中发挥了重要作用,如PD-L1的N-糖基化能增强其自身蛋白质的稳定性,促进与其受体PD-1的相互作用,并且靶向PD-1、PD-L1蛋白N-糖基化的抗体,能够有效抑制肿瘤免疫逃逸和肿瘤发展。     

γδ+T细胞与真菌感染

近年来,随着免疫功能低下宿主数量的增加、耐药菌的多发以及新型抗真菌药物的研发进展缓慢等原因,全球真菌感染的发病率呈现逐年上升趋势,感染菌株也发生了变迁,白念珠菌的比例在逐渐减少而非白念珠菌呈上升趋势,同时耐唑类烟曲霉感染以及隐球菌病也均呈上升趋势。T细胞介导的免疫应答在抗真菌感染中占据重要地位,T细胞受体(T cell receptor, TCR)是T细胞上识别和结合抗原并介导机体免疫应答的关键分子。根据T细胞表面TCR的类型,可将T细胞分为αβ⁺T细胞和γδ⁺Τ细胞两类。随着研究的深入,γδ⁺T细胞在真菌感染中的免疫应答也逐渐被揭示,其参与过继免疫以及辅助疫苗接种的潜能逐步被挖掘。该文就γδ⁺T细胞在常见真菌感染性疾病中的作用以及其未来展望作一综述。     

HIV/HCV共感染者抗逆转录病毒治疗后免疫恢复情况

由于具有相同的传播途径,人类免疫缺陷病毒(Human immunodeficiency virus,HIV)和丙型肝炎病毒(Hepatitis C virus,HCV)共感染非常普遍,但是关于合并感染的程度,两种病毒之间的相互关系,在艾滋病抗逆转录病毒治疗(Antiretroviral therapy,ART)前后,HCV合并感染对HIV患者免疫细胞恢复的影响仍不明确。为了通过分析CD4⁺和CD8⁺T淋巴细胞数的变化,以了解辽宁省HIV/HCV共感染者ART后免疫恢复的情况,本研究从辽宁省艾滋病抗病毒治疗数据库中筛选符合要求的HIV感染者和HIV/HCV共感染者,收集感染者基本人口学资料及HCV抗体检测结果、HIV/HCV共感染途径等资料。采用t检验或卡方检验进行组间比较,采用Kaplan-Meier乘积极限法绘制生存分析函数图。结果显示,本研究共纳入HIV感染者12742人,HIV/HCV共感染者340人。HIV感染者和HIV/HCV共感染者的不同人口学特征均差异显著(P<0.001)。HIV感染和HIV/HCV共感染者ART治疗后CD4⁺细胞数和CD4⁺/CD8⁺比值显著升高(P<0.05),CD8⁺细胞数比ART前显著下降(P<0.05)。HIV/HCV共感染者随着ART时长,CD4⁺T淋巴细胞数恢复情况始终显著低于HIV感染者(P<0.05)。生存分析曲线表明,HCV/HIV共感染者从艾滋病诊断开始随着ART的治疗CD4⁺细胞恢复情况显著低于HIV感染者,Log-Rank检验统计量为4.483(P=0.034)。本研究揭示,HCV感染对ART患者CD4⁺和CD8⁺T淋巴细胞的恢复有影响。ART后HIV/HCV共感染者中CD4⁺T淋巴细胞计数的改善低于HIV单一感染者,并且单一感染患者对ART的反应比合并感染患者更好。因此,建议在启动ART之前,对每个感染HIV的患者进行HCV抗体筛查。     

CD4+CD25+FoxP3+ 调节性T 细胞与黑龙江省HIV/AIDS 患者病情 相关性的研究

目的:比较黑龙江省HIV/AIDS患者与健康对照者(healthy controls,HCs)外周血CD4+CD25+FoxP3+调节性T细胞数量、免疫抑制功能的变化,探讨CD4+CD25+FoxP3+调节性T细胞在HIV/AIDS感染过程中的作用。方法:采用流式细胞仪检测21例HIV/AIDS患者及20例健康对照组的外周血CD4+CD25+FoxP3+调节性T细胞数量的百分比及绝对数量;采用共同培养方法检测HIV/AIDS患者外周血CD4+CD25+FoxP3+调节性T细胞免疫抑制功能的变化;实时荧光定量聚合酶链反应(RT-FQ-PCR)检测HIV/AIDS患者外周血CD4+CD25+FoxP3+调节性T细胞中FoxP3mRNA的表达。结果:黑龙江省HIV/AIDS患者外周血CD4+CD25+FoxP3+调节性T细胞比率明显高于HCs(P<0.01),而CD4+CD25+FoxP3+调节性T细胞的绝对计数显著下降,且与CD4+T细胞绝对计数成反比;混合淋巴细胞共同培养结果显示,HIV/AIDS患者外周血CD4+CD25+FoxP3+调节性T细胞的抑制功能无明显变化;HIV/AIDS患者外周血CD4+CD25+FoxP3+调节性T细胞的FoxP3 mRNA相对表达量无显著变化。结论:黑龙江省HIV/AIDS患者CD4+CD25+FoxP3+调节性T细胞的数量变化与病情相关。     

CD4+CD25+调节性T细胞在自身免疫性肝炎发病中的作用

目的:比较自身免疫性肝炎(autoimmune hepatitis,AIH)患者与健康对照者(healthy controls,HCs)外周血CD4+CD25+调节性T细胞(CD4+CD25+Tregs)数量、免疫抑制功能的变化,探讨CD4+CD25+Tregs参与AIH发病的可能机制.方法:采用流式细胞仪检测8例AIH患者及15例健康对照组的外周血CD4+CD25+Tregs数量的百分比及绝时数量;采用共同培养方法检测AIH患者外周血CD4+CD25+Tregs的免疫抑制功能的变化;实时荧光定量聚合酶链反应(RT-FQ-PCR)检删AIH患者外周血CD4+CD25+Tregs中FoxP3mRNA的表达.结果:AIH患者外周血CD4+CD25+Tregs数量明显低于HCs(p<0.01);混合淋巴细胞共同培养结果显示,AIH患者外周血CD4+CD25+Tregs抑制功能明显低于HCs组(p<0.01);AIH患者外周血CD4+CD25+Tregs的FoxP3 mRNA相对表达量显著降低,与HCs组比较有显著性差异(p<0.01).结论:CD4+CD25+Tregs细胞的数量的减少和Foxp3表达的降低所造成的CD4+CD25+Tregs细胞免疫抑制功能受损可能是AIH发病的一个因素.     

不同基因型幽门螺杆菌感染与消化性溃疡患者血清炎症因子及CD4+T细胞、PINP水平的关系

目的探讨不同基因型H.pylori感染与消化性溃疡(PU)患者血清炎症因子及CD4⁺T细胞、Ⅰ型原胶原N端前肽(PINP)水平的关系,为后续研究提供参考。方法选择2017年8月至2019年3月于我院消化科就诊的122例PU患者为研究对象,其中H.pylori阴性患者50例[HP(-)组],H.pyloriⅠ型感染患者38例[HP(Ⅰ)组],H.pyloriⅡ型感染患者34例[HP(Ⅱ)组],对比各组患者血清炎症因子IL-17、IL-10、TNF-α和PINP及CD4⁺T淋巴细胞水平。采用Logistic回归对不同菌型H.pylori感染患者血清炎症因子及CD4⁺T细胞、PINP水平的相关性进行评估,并结合ROC曲线对其相应诊断价值进行评估。结果HP(-)组患者IL-17、IL-10、TNF-α水平最低,HP(Ⅰ)组患者IL-17、IL-10、TNF-α水平最高,组间差异有统计学意义(均P<0.001)。HP(-)组患者CD4⁺T细胞及PINP水平最低,HP(Ⅰ)组CD4⁺T细胞及PINP水平最高,组间差异有统计学意义(均P<0.001)。多因素Logistic回归显示,血清炎症因子及CD4⁺T细胞、PINP水平与H.pyloriⅠ型、H.pyloriⅡ型感染均有显著正相关性(均P<0.05)。ROC曲线分析显示,IL-17、IL-10、TNF-α、CD4⁺T细胞和PINP诊断H.pyloriⅠ型感染的AUC分别为0.863(95%CI:0.786~0.941)、0.844(95%CI:0.754~0.935)、0.907(95%CI:0.847~0.967)、0.921(95%CI:0.864~0.977)、0.742(95%CI:0.639~0.845),而诊断H.pyloriⅡ型感染的AUC分别为0.711(95%CI:0.599~0.823)、0.747(95%CI:0.641~0.854)、0.930(95%CI:0.874~0.986)、0.918(95%CI:0.861~0.974)、0.736(95%CI:0.631~0.840)。H.pylori阴性与CD4⁺T细胞和PINP水平无明显相关性(r=0.226,P=0.225),H.pyloriⅠ型、H.pyloriⅡ型感染与CD4⁺T细胞和PINP水平具有显著正相关性(r=0.428、0.367,P=0.007、0.033)。结论血清炎症因子及CD4⁺T细胞和PINP水平与PU患者H.pylori感染具有相关性,可作为临床辅助监测指标。     

Selective expansion and enhanced anti-tumor effect of antigen-specific CD4+ T cells by retrovirus-mediated IL-15 expression

Mounting evidence has demonstrated that CD4⁺ T cells play an important role in anti-tumor immune responses. Thus, adoptive transfer of these cells may have great potential for anti-cancer therapy. However, due to the difficulty to generate sufficient tumor-specific CD4⁺ T cells, the use of CD4⁺ T cells in tumor therapy is limited. It has been found that IL-15 transfection enhances the proliferation and anti-tumor activity of tumor-specific CD8⁺ T cells, but the effect of IL-15 transfection on CD4⁺ T cells remains unknown. Here, the effects of retrovirus-mediated IL-15 expression in Ova-specific CD4⁺ T cells from Do11.10 mice were evaluated and it was discovered that IL-15 transfected CD4⁺ T cells expressed both soluble and membrane-bound IL-15. Retrovirus-mediated IL-15 expression led to a selective expansion of antigen-specific CD4⁺ T cells by inhibiting their apoptosis. Invivo IL-15 transfected CD4⁺ T cells were more effective in suppressing tumor growth than control retroviral vector transfected ones. To ensure the safety of the method, the employment of thymidine kinase gene made it possible to eliminate these transgenic CD4⁺ T cells following ganciclovir treatment. Together, we show that IL-15 transfection induced a selective expansion of antigen-specific CD4⁺ T cells ex vivo and enhanced their tumor-suppression effects in vivo. This has an important significance for improving the efficacy of adoptive T cell therapy.     

CD177~+中性粒细胞在溃疡性结肠炎患者外周血中的表达及临床意义

目的:通过对比CD177~+中性粒细胞在溃疡性结肠炎(UC)患者与正常对照者外周血中的表达差异,分析CD177~+中性粒细胞在溃疡性结肠炎发生发展中的临床意义。方法:收集30例UC患者及20例正常对照者外周血,采用流式细胞术检测中性粒细胞CD177~+中性粒细胞表达情况,对比两组CD177表达差异。结果:UC患者外周血中CD177~+中性粒细胞表达明显高于正常对照组(P 0. 01),中度活动UC外周血CD177~+中性粒细胞表达较轻度者明显增高(P 0. 05),UC患者外周血CD177~+中性粒细胞%与Mayo评分呈显著正相关(r=0. 384,P=0. 036)。结论:CD177~+中性粒细胞在UC患者外周血表达明显增高,且与疾病活动程度密切相关,能够反映UC患者临床疾病活动程度。     

The tumor immunosuppressive microenvironment impairs the therapy of anti-HER2/neu antibody

It has been well established that immune surveillance plays critical roles in preventing the occurrence and progression of tumor. More and more evidence in recent years showed the host anti-tumor immune responses also play important roles in the chemotherapy and radiotherapy of cancers. Our previous study found that tumor- targeting therapy of anti-HER2/neu mAb is mediated by CD8⁺ T cell responses. However, we found here that enhancement of CD8⁺ T cell responses by combination therapy with IL-15R/IL-15 fusion protein or anti-CD40, which are strong stimultors for T cell responses, failed to promote the tumor therapeutic effects of anti-HER2/neu mAb. Analysis of tumor microenviornment showed that tumor tissues were heavily infiltrated with the immunosuppressive macrophages and most tumor infiltrating T cells, especially CD8⁺ T cells, expressed high level of inhibitory co-signaling receptor PD-1. These data suggest that tumor microenvironment is dominated by the immunosuppressive strategies, which thwart anti-tumor immune responses. Therefore, the successful tumor therapy should be the removal of inhibitory signals in the tumor microenvironment in combination with other therapeutic strategies.     

High affinity soluble ILT2 receptor: a potent inhibitor of CD8+ T cell activation

Using directed mutagenesis and phage display on a soluble fragment of the human immunoglobulin superfamily receptor ILT2 (synonyms: LIR1, MIR7, CD85j), we have selected a range of mutants with binding affinities enhanced by up to 168,000-fold towards the conserved region of major histocompatibility complex (MHC) class I molecules. Produced in a dimeric form, either by chemical cross-linking with bivalent polyethylene glycol (PEG) derivatives or as a genetic fusion with human IgG Fc-fragment, the mutants exhibited a further increase in ligand-binding strength due to the avidity effect, with resident half-times (t_1/2) on the surface of MHC I-positive cells of many hours. The novel compounds antagonized the interaction of CD8 co-receptor with MHC I in vitro without affecting the peptide-specific binding of T-cell receptors (TCRs). In both cytokine-release assays and cell-killing experiments the engineered receptors inhibited the activation of CD8⁺ cytotoxic T lymphocytes (CTLs) in the presence of their target cells, with sub-nanomolar potency and in a dose-dependent manner. As a selective inhibitor of CD8⁺ CTL responses, the engineered high affinity ILT2 receptor presents a new tool for studying the activation mechanism of different subsets of CTLs and could have potential for the development of novel autoimmunity therapies.     

Interaction between superantigen and T-cell receptor Vβ element determines levels of superantigen-dependent cell-mediated cytotoxicity of CD8+ T cells in induction and effector phases

Specific superantigens activate different T-cell fractions with distinct TCR Vβ elements in association with MHC class II molecules and also induce SDCC against MHC class II⁺ target cells. In the present study, to determine whether the responsiveness of each CD8⁺ T-cell fraction expressing a different TCR Vβ element is primarily determined by the TCR Vβ, we compared the levels of proliferation and SDCC in Vβ3⁺ and Vβ11⁺ T cells upon stimulation with SEA. Upon stimulation with SEA_wt, the levels of proliferation were higher in Vβ3⁺ T cells than in Vβ11⁺ T cells. The levels of SDCC were also higher for the combination of Vβ3⁺ T cells and SEA_wt than for the combination of Vβ11⁺ T cells and SEA_wt during both the induction phase and the effector phase. In addition, upon stimulation with SEA_m, the levels of proliferation were higher in Vβ11⁺ T cells than in Vβ3⁺ T cells. And then, the levels of SDCC were also higher for the combination of Vβ11⁺ T cells and SEA_m than for the combination of Vβ3⁺ T cells and SEA_m during both the induction phase and the effector phase. These results suggest that the SAG-responsiveness of each CD8⁺ T-cell fraction expressing a different TCR Vβ element is primarily determined by the interaction between the TCR Vβ element and the SAG.     

成人t(8;21)急性髓系白血病患者初诊Ki-67的表达特征及预后意义

目的:研究成人t(8; 21)急性髓系白血病(AML)初诊Ki-67抗原的表达特征及预后意义。方法:采集2012年7月至2019年2月本院57例成人初诊t(8; 21) AML患者的新鲜骨髓标本,采用流式细胞术(FCM)检测CD34和Ki-67抗原,分析Ki-67表达与患者初诊生物学特征、疗效及复发的关系。结果:全部患者中,CD34~+Ki-67~+细胞比例的中位值为30. 5%(范围:10. 0%～65. 8%);通过受试者工作特征(ROC)曲线确定CD34~+Ki-67~+细胞比例的最适分界阈值,CD34~+Ki-67~+细胞高比例与初诊c-KIT基因突变阳性及WT1转录本低水平均明显相关(P=0. 001; P=0. 042)。随访的36例患者中,CD34~+Ki-67~+高比例比低比例患者具有明显更高的1年累积复发(CIR)率(P=0. 035);此外,初诊WT1转录本低水平和微小残留病(MRD)高水平(2个疗程巩固治疗后RUNX1-RUNX1T1转录本水平下降3-log)均与更高的1年CIR率明显相关(P 0. 0001;P=0. 041),初诊c-KIT基因突变阳性和白细胞计数 10×109/L的患者分别有较高的1年CIR率趋势(P=0. 091; P=0. 054)。联合分组显示,MRD高水平同时CD34~+Ki-67~+细胞高比例的患者比其他患者具有明显更高的1年CIR率(P 0. 0001)。结论:初诊骨髓高比例的CD34~+Ki-67~+可能是成人t(8; 21) AML患者预后不良因素,MRD联合初诊CD34~+Ki-67~+细胞比例可能比单纯MRD更好地预测复发。     

厚朴酚联合吉非替尼对A549非小细胞肺癌细胞的干预作用*

目的: 探讨厚朴酚与吉非替尼协同影响非小细胞肺癌A549细胞的作用。方法: 以浓度为6.25～500 μmol/L厚朴酚、0.625～100 μmol/L吉非替尼分别处理A549细胞24 h,CCK-8实验检测细胞活力 (n=3),选24 h及100 μmol/L厚朴酚与5 μmol/L吉非替尼作后续处理(n=3);采用对照组、厚朴酚组、吉非替尼组和厚朴酚+吉非替尼组的析因分析设计;克隆形成检测细胞增殖;蛋白印迹测蛋白表达;流式细胞术检测细胞凋亡及分选CD44⁺和CD133⁺细胞。结果: 与对照组比,厚朴酚和吉非替尼组的克隆形成率显著降低(P＜0.05);凋亡率显著升高(P＜ 0.05);CD44⁺和CD133⁺细胞数量显著减少(P＜0.05);Ki67和PCNA及干细胞标记蛋白SOX2和OCT4表达显著下调(P＜0.05);Bax/Bcl-2表达比例显著上调(P＜0.05)。与厚朴酚组或吉非替尼组比较,厚朴酚+吉非替尼组进一步促进了上述改变(P＜0.05),且凋亡率、Bax/Bcl-2、SOX2和OCT4等指标都存在厚朴酚和吉非替尼的交互作用(P＜ 0.05)。结论: 厚朴酚与吉非替尼促进A549细胞凋亡和抑制其干细胞样特性,且联合用药效果优于单一给药。二者对A549细胞的抑癌作用有交互影响。     

Role of the plasma membrane ROS-generating NADPH oxidase in CD34+ progenitor cells preservation by hypoxia

Hypoxia favored the preservation of progenitor characteristics of hematopoietic stem and progenitor cells (HSPCs) in bone marrow. This work aimed at studying the role of reactive oxygen species (ROS)-generating NADPH oxidase system regulated by hypoxia in ex vivo cultures of cord blood CD34⁺ cells. The results showed that NADPH oxidase activity and ROS generation were reduced in hypoxia with respect to normal oxygen tension. Meanwhile the ROS generation was found to be inhibited by diphenyleneiodonium (the NADPH oxidase inhibitor), or N-acetylcysteine (the ROS scavenger). Accordingly NADPH oxidase mRNA and p67 protein levels decreased in hypoxia. The analysis of progenitor characteristics, including the proportion of cultured cells expressing the HSPCs marker CD34⁺CD38⁻, colony production ability of the colony-forming cells (CFCs), and the re-expansion capability of the cultured CD34⁺ cells, showed that either 5% pO₂ or reduced ROS favored preserving the characteristics of CD34⁺ progenitors, and promoted the expansion of CD34⁺CD38⁻ cells as well. The above results demonstrated that hypoxia effectively maintained biological characteristics of CD34⁺ cells through keeping lower intracellular ROS levels by regulating NADPH oxidase.