伊马替尼对慢性粒细胞白血病患者T细胞免疫功能的影响

目的:探讨伊马替尼(STI571)对慢性粒细胞白血病(CML)患者T细胞免疫功能的影响。方法:以30例CML患者为观察组,32例缺铁性贫血患者为对照组,用流式细胞术(FCM)检测患者骨髓体外加用STI571后CD3+、CD3+CD8-、CD3+CD8+内T淋巴细胞内INF-γ表达水平。结果:STI571干预后,观察组CD3+、CD3+CD8-、CD3+CD8+T淋巴细胞内IFN-γ水平明显降低,与干预前和对照组比较有统计学差异(P0.05),而对照组干预前后CD3+、CD3+CD8-、CD3+CD8+T淋巴细胞内IFN-γ水平变化无统计学意义。结论:STI571能够降低初发CML患者T淋巴细胞内IFN-γ的表达,影响初发CML患者的细胞免疫功能,使免疫功能受到抑制。     

超抗原葡萄球菌肠毒素A拮抗伊马替尼抑制T细胞活化作用的研究

 目的：探讨葡萄球菌肠毒素A(staphylococcal enterotoxin A, SEA)对甲磺酸伊马替尼（imatinib mesylate,IM）抑制T淋巴细胞活化的影响。方法：2 mg／L SEA 和50 nmol/L IM联合作用于Jurkat细胞24 h后,用实时荧光定量PCR技术检测CD3ε和ζ链mRNA表达水平变化;Western blotting技术检测CD3ε和ζ链蛋白水平变化。结果：单纯IM组CD3ε和ζ链mRNA及蛋白表达均表现下调;SEA与IM联合用药组可以逆转IM下调CD3ε和ζ链mRNA及蛋白表达水平作用。SEA拮抗IM抑制作用中,对CD3ε链mRNA表达上调的作用明显大于CD3ζ链。结论:SEA能拮抗IM对T细胞CD3ε和ζ链表达的抑制作用。     

CD4^＋CD25^＋调节性T细胞在α-GalCer预防T1D中的作用机制探讨

目的：研究CD4^＋CD25^＋调节性T细胞在α-GalCer预防NOD小鼠T1D中的作用机制。方法：流式细胞仪分析反复注射α-GalCer的NOD小鼠胰腺引流淋巴结（PLN）CD4^＋CD25^＋T细胞频率,CD4＋CD25＋T细胞中FoxP3＋细胞的比例,CD4＋CD25＋FoxP3^＋T细胞的FoxP3平均荧光强度（MFI）;检测CD4^＋CD25^＋调节性T细胞的抑制功能。用Anti-CD25阻断CD4^＋CD25^＋调节性T细胞的功能。结果：α-GalCer处理过的小鼠的CD4^＋CD25^＋T细胞中FoxP3^＋细胞的比例增加,CD4^＋CD25^＋FoxP3^＋T细胞的FoxP3平均荧光强度（MFI）增强,CD4^＋CD25^＋Treg细胞的抑制功能增强。采用CD4^＋CD25^＋调节性T细胞功能阻断剂后,α-GalCer不能预防T1D的发生。结论：CD4^＋CD25^＋调节性T细胞在α-GalCer预防NOD小鼠T1D中数量增加、功能增强,且是必需的。     

CD4+CD25+Foxp3+T细胞在子痫前期中作用机制的研究

目的 探讨子痫前期(PE)患者外周血中CD4+CD25+Foxp3+T细胞及胎盘组织Foxp3的表达水平.方法 73例PE患者分为MPE组(轻度PE,38例)和SPE组(重度PE,35例),以正常的孕妇作为对照组;采用流式细胞术(FCM)检测外周血中CD4+CD25+Foxp3+T细胞的表达水平,采用免疫组化法(IHC)检测胎盘组织Foxp3的表达水平;将Foxp3与CD4+CD25+Foxp3+T、胎盘重量和阿氏(Apgar)评分进行Spearman相关性分析.结果 SPE组、MPE组外周血中CD4+CD25+Foxp3+T细胞表达水平分别为4.23±0.74％、6.58±0.8％,均低于对照组的7.01±0.95 ％(P＜0.05),SPE组外周血中CD4+CD25+Foxp3+T细胞表达水平低于MPE组(P ＜0.05);SPE组、MPE组胎盘组织中Foxp3的阳性表达率分别为28.57％、47.37％,均低于对照组的82.76％(P ＜0.05),SPE组胎盘组织中Foxp3的阳性表达率显著低于MPE组(P＜0.05);胎盘组织中Foxp3的阳性表达率与CD4+CD25+Foxp3+T细胞表达水平、胎盘重量及Apgar评分均呈正相关(P＜0.01).结论 PE与外周血中CD4+CD25+Foxp3+T细胞表达水平下降密切相关.     

三氧化二砷对伊马替尼耐药细胞株32Dp210T315I的体外抑制作用研究

目的 探讨三氧化二砷( ATO)对伊马替尼(IM)产生耐药性的慢性粒细胞性白血病(CML)细胞是否具有抑制细胞生长的作用.方法 小鼠髓系造血细胞株32D细胞经处理使其变为表达p210Bcr-Abl的32Dp210细胞,以此作为野生型细胞.32Dp210和伊马替尼耐药细胞株32Dp210T315I分别在含有10％ FBS,2％ L-glutamine和1％ Penicillin-Streptomycin的RPMI1640和IMDM培养体系中培养.细胞株分别在不同浓度的三氧化二砷、伊马替尼作为对照的没有药物作用的培养体系中培养.在24h和48 h后,MTT实验检测细胞增殖,Annexin-V staining实验检测细胞凋亡.结果 在体外试验中,我们发现三氧化二砷对32Dp210和32Dp210T315I具有剂量依赖的抑制作用,对32Dp210T315I细胞的抑制比对32Dp210细胞更为有效.三氧化二砷对32Dp210T315I细胞的50％抑制浓度(IC50)是1μmol/L,远低于32Dp210的IC50值(4μmol/L).2μmol/L三氧化二砷可以明显诱导约90％的32Dp210T315I细胞凋亡,比32Dp210的凋亡率(30％)高很多.结论 ATO具有作为一种生长抑制剂和诱导伊马替尼耐药细胞凋亡的特性,也使其成为一种新的治疗伊马替尼耐药CML患者的治疗途径.     

慢性髓细胞白血病患者骨髓基质细胞与K562细胞共培养对伊马替尼耐药的影响

背景：伊马替尼耐药是慢性髓细胞白血病治疗的一个主要问题,研究证实白血病细胞可通过与骨髓基质细胞黏附而获得耐药表型,但对于黏附功能缺陷的慢性髓细胞白血病而言,骨髓基质细胞在伊马替尼耐药形成中的作用及其机制尚不清楚。 目的：体外模拟慢性髓细胞白血病患者骨髓微环境,探讨其对伊马替尼敏感性的影响及可能机制。 方法：分离、培养确诊但未经治疗的慢性髓细胞白血病患者骨髓基质细胞,与白血病细胞株K562细胞共培养构建慢性髓细胞白血病骨髓基质细胞-K562细胞共培养模型。MTT法检测0.2-3.2 μmol/L伊马替尼作用  48 h对K562细胞的增殖抑制率;将K562细胞暴露于0.5 μmol/L伊马替尼72 h,流式细胞术检测K562细胞凋亡率及CXCR4表达。将0.5 μmol/L伊马替尼作用4 h并以Calcein-AM荧光标记的K562细胞接种于基质细胞层培养24 h,去除悬浮细胞,收集黏附的K452细胞通过检测荧光强度计算细胞黏附率。 结果与结论：慢性髓细胞白血病骨髓基质细胞与K562细胞共培养减弱了0.2-3.2 μmol/L伊马替尼对K562细胞的增殖抑制作用;0.5 μmol/L伊马替尼处理72 h,共培养组K562细胞凋亡率显著低于悬浮组(P=0.020)。悬浮组和共培养组伊马替尼作用后K562细胞CXCR4表达阳性率均显著高于作用前(P=0.001)。0.5 μmol/L伊马替尼作用4 h使K562细胞与骨髓基质细胞的黏附率由(32.18±6.17)%提升至(68.97±11.08)%,差异有显著性意义(P=0.022)。结果表明慢性髓细胞白血病患者骨髓基质细胞与K562细胞共培养,能介导对伊马替尼耐药,可能与共培养及伊马替尼诱导K562细胞CXCR4的表达有关,但更多的机制还需深入研究。     

伊马替尼对醋酸去氧皮质酮诱导的盐敏感性高血压大鼠心肌纤维化的干预作用

目的: 研究血小板源性生长因子受体拮抗剂伊马替尼(IMA)对醋酸去氧皮质酮(DOCA)诱导的盐敏感性高血压大鼠心肌纤维化的干预作用及相关机制。方法: 60只雄性SD大鼠行右肾切除术,术后给予1%NaCl和0.2%KCl饮水4周并随机分为3组:对照组(control组);DOCA组;DOCA+IMA组。尾套法测定大鼠动脉收缩压(SBP),HE染色观察心肌组织炎症反应情况,苦味酸-天狼星红染色观察大鼠心肌间质胶原容积分数(CVF)和血管周围胶原面积比(PVCA),免疫组化法观察心肌组织单核巨噬细胞抗原(ED-1)表达,免疫印迹法检测血小板源性生长因子(PDGF-A和PDGF-C)、血小板源性生长因子受体α(PDGFRα)和磷酸化血小板源性生长因子受体α(p-PDGFRα)表达。结果: (1)DOCA组和DOCA+IMA组大鼠SBP显著升高,两组相比无显著差异(P>0.05),但均显著高于对照组(P<0.01);(2)DOCA组出现严重心肌纤维化,其CVF和PVCA值明显高于对照组(P<0.01),DOCA+IMA组CVF和PVCA值虽高于对照组(P<0.05),但较DOCA组显著减小(P<0.05);(3)与对照组相比,DOCA组及DOCA+IMA组心肌间质可见明显炎症渗出及单核巨噬细胞浸润;(4)DOCA组及DOCA+IMA组PDGF-A、PDGF-C和PDGFRα表达均明显高于对照组(P<0.01),但DOCA+IMA组p-PDGFRα表达较DOCA组明显减少(P<0.05)。结论: 盐皮质激素致心肌纤维化与心肌组织炎症反应、单核巨噬细胞浸润增加及PDGF-A、PDGF-C、PDGFRα表达增多有关,应用伊马替尼可以抑制这一纤维化过程,其机制可能与其抑制成纤维细胞表面PDGFRα活性、中断PDGFs信号途径介导的成纤维细胞分裂增殖相关。     

卡博替尼、克唑替尼和奥西替尼 对小鼠髓源抑制性细胞亚型和凋亡的影响

目的探讨卡博替尼、克唑替尼和奥斯替尼(AZD9291)对小鼠骨髓或脾脏源性抑制细胞(MDSCs)亚群比例、凋亡及增殖的影响。方法免疫磁珠法分离BALB/c小鼠(雄性)骨髓G-MDSCs和M-MDSCs,分别加入卡博替尼(0.01、0.1、0.3和0.9μmol/L)、克唑替尼(0.2、2、20和200μg/mL)或AZD9291(0.01、0.1、1和10μmol/L)培养24 h,采用流式细胞术(FCM)检测3种靶向药物对MDSCs亚型的影响,CCK-8法检测MDSCs增殖;流式细胞分选仪分选小鼠骨髓Gr-1~+CD11b~+细胞,检测Gr-1~+CD11b~+细胞凋亡。结果克唑替尼处理组骨髓粒细胞型MDSCs(G-MDSCs)、单核细胞型MDSCs(M-MDSCs)比例均下降(P0.05);卡博替尼处理组脾脏G-MDSCs比例下降(P0.05);卡博替尼、克唑替尼处理骨髓MDSCs后早期凋亡比例增加(P0.05),AZD9291处理的MDSCs凋亡比例无明显变化。结论卡博替尼和克唑替尼可能通过诱导MDSCs凋亡降低MDSCs比例。     

苹果酸舒尼替尼抑制膀胱癌T24细胞系的体外增殖

 摘要：目的：探讨苹果酸舒尼替尼对人膀胱癌T24细胞系体外增殖的影响。方法：取人膀胱癌T24细胞系悬液, 分别加入浓度为0.625、1.25、2.5、5、10 和 20μmol/L的苹果酸舒尼替尼,分别于24、48、72 h进行处理,用细胞毒抑制实验（MTT法）检测药物对其生长的影响。结果：苹果酸舒尼替尼可浓度依赖性抑制人膀胱癌细胞系T24细胞增殖,当药物浓度>5μmol/L时,苹果酸舒尼替尼与顺铂比较,对T24细胞系具有更强的抑制作用（P<0.05）。这种抑制作用随着药物培育时间延长（24、48、72ｈ）而增强,表现为IC50值显著降低, 但其抑制能力与顺铂比较无显著差别（P>0.05）。结论：苹果酸舒尼替尼可呈浓度和时间依赖地抑制膀胱癌T24细胞系增殖。     

肝癌细胞来源LC3B阳性的细胞外囊泡诱导CD8 +T细胞耗竭的作用机制研究

目的:探讨肝癌细胞来源分泌型自噬体,即一群表达自噬标志LC3B的细胞外囊泡(LC3B + extracellular vesicles, LC3B +EVs)对CD8 +T细胞功能耗竭的影响及其作用机制。 方法:流式细胞术检测肝癌患者外周血和腹水中LC3B +E...     

Mechanisms of resistance to imatinib mesylate in KIT-positive metastatic uveal melanoma

Imatinib mesylate is used in targeted therapy of cancer to inhibit type III tyrosine kinase receptors, such as KIT and platelet-derived growth factor receptors (PDGFRs). Expression of KIT in uveal melanoma (UM) suggests that this receptor may be the target of imatinib mesylate therapy. However, phase II multicenter clinical studies have shown no effect of imatinib mesylate in patients with unresectable liver metastases of UM. We therefore investigated which molecular mechanisms promote imatinib mesylate-resistance in metastatic UM. Expression of KIT, stem cell factor (SCF), PDGFRα and PDGFRβ, was analyzed by RT-PCR, immunostaining, and Western blot in twenty-four samples of UM liver metastases, as well as UM primary tumor and metastatic cell lines. Soluble SCF was quantified in UM cell lines using enzyme-linked immunosorbent assay. Cell viability of UM cell lines treated with imatinib mesylate and grown in SCF-supplemented medium or in microvascular endothelial cells-conditioned medium was studied by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assays. UM liver metastases and cell lines expressed KIT and SCF, but not the PDGFRs. Ninety-five percent of liver metastases expressed KIT at the protein level, but PDGFRs were not detected in these samples. Imatinib mesylate reduced the viability of UM metastatic cell lines in a concentration-dependent manner, but an increased resistance to this drug was observed when cells were incubated in SCF-supplemented or microvascular endothelial cells-conditioned medium. This study provides evidence that tumor microenvironment cytokines such as SCF may promote resistance to imatinib mesylate in metastatic UM.     

Mechanisms of peripheral T cell deletion: anergized T cells are Fas resistant but undergo proliferation-associated apoptosis

The complementary receptor pair Fas ligand: Fas controls apoptosis during activation-induced cell death (AICD) of peripheral T cells sensitized for the Fas signal pathway by interleukin-2 (IL-2). In the present study, we used the bacterial superantigen staphylococcal enterotoxin B (SEB) to anergize ligand-reactive peripheral T cells in wild-type and Fas-defective lpr mice. In a second step, we investigated whether apoptosis in anergized and thus operationally IL-2-defective peripheral T cells is triggered via the Fas signal pathway. We report here that SEB-driven anergy induction and deletion of anergized peripheral Vβ8⁺ T cells is similar in wild-type and healthy C3H/lpr mice. In monitoring SEB-driven Vβ8⁺ T cell apoptosis in situ, we observe in both wild-type and lpr mice an intimate association between proliferation and apoptosis of anergized Vβ8⁺ T cells. We further show that Vβ8⁺ T cells activated in vitro from wild-type mice express a Fas-sensitive phenotype determined by Fas cross-linking which causes apoptosis. In contrast, Vβ8⁺ T cells anergized in vivo from wild-type mice are Fas resistant. As expected, T cells from lpr mice activated in vitro or anergized in vivo are Fas resistant. Taken together, these data indicate that both in wild-type and Fas-defective C3H/lpr mice, anergized T cells become deleted via a Fas-independent, proliferation-associated apoptosis signal pathway.     

Human T cells with a type-2 cytokine profile are resistant to apoptosis induced by primary activation: consequences for immunopathogenesis

The mechanisms leading to a relative dominance of T cells producing type 2 cytokines in certain human immune disorders are still unclear. We investigated the relative susceptibility to apoptosis induced by primary in vitro activation of human type 1 (producing interferon-gamma (IFN-gamma)) or type 2 (producing IL-4) T cells. Peripheral blood lymphocytes were isolated from patients with immune disorders characterized by expansion of type 2 cells (four with AIDS and hyper-IgE/hypereosinophilia, one with Churg-Strauss syndrome, and one with idiopathic hypereosinophilic syndrome) or from individuals with normal cytokine balances. Cells were stimulated for 16 h with ionomycin and phorbol ester, and apoptosis of cytokine-producing cells was assessed by flow cytometry. T cells with a type-2 cytokine profile, i.e. producing IL-4 alone, were significantly more resistant to activation-induced apoptosis than those producing IFN-gamma alone. This was observed in AIDS patients, whose type 2 cells were mostly CD8+, as well as in the patients with Churg-Strauss and with hypereosinophilic syndrome. CD4+ and CD8+ IL-4-producing cells were equally resistant to apoptosis. Lower susceptibility to apoptosis of type-2 T cells was also observed in subjects with normal cytokine balances. Bcl-2 expression was high in type-2 cells and in viable type-1 cells, whereas it was low in apoptotic type-1 cells. Resistance to activation-induced apoptosis may explain the expansion of cells producing type-2 cytokines in certain immune disorders.     

树突状细胞的凋亡与调控

树突状细胞(DC)是已发现的功能最强的抗原提呈细胞,它是启动、调控及维持免疫应答的中心环节。近年来,研究者致力于阐明DC的生物学特性及功能,期望有效地将DC引入重大疾病的临床研究与应用,为现代医学揭开新的一页。