高场强电磁脉冲对Jurkat细胞IFN-γ和IL-4蛋白表达的定量分析

目的 :研究电磁脉冲 (EMP)辐照对白血病肿瘤细胞株Jurkat细胞分泌细胞因子IFN -γ和IL - 4的影响 ,探讨EMP对Jurkat细胞损伤机制。方法 :Jurkat细胞经EMP照射后即刻、1h、 6h、 12h、 2 4h、 4 8h、 72h共 7个时相点 ,细胞悬液甩片 ,4 %多聚甲醛 4℃固定 ,自然晾干 ,进行SP法的IFN -γ和IL - 4蛋白免疫组化染色。在光镜 10× 4 0倍视野下 ,应用CMIAS-H图像分析仪对阳性细胞的图像分析参数积分光密度值 (IOD)进行统计分析。结果 :免疫组化结果表明 ,场强 6× 10 4 V/m的电磁脉冲能使Jurkat细胞IFN -r表达持续性减少 ,差异非常显著 (P <0 0 1) ,而IL - 4变化不明显 (P >0 0 5 )。结论 :EMP辐照后Th1型的细胞因子IFN-γ明显减少 ,而Th2型的细胞因子IL - 4未见显著变化 ,提示 :EMP辐照后机体中受到影响的主要是细胞免疫 ,而体液免疫功能未受到明显影响     

氢化可的松抑制Jurkat细胞的调节性体积减小

目的 :研究氢化可的松对Jurkat细胞调节性体积减小 (regulatoryvolumedecrease ,RVD)的影响及可能的机制。方法 :通过MoticImagesAdvanced 3.1软件系统实时监测细胞体积的变化 ,并通过3 H掺入实验观察Jurkat细胞增殖。结果 :氢化可的松对Jur kat细胞RVD具有剂量依赖性的抑制作用 ,在 10 -4和 10 -3 mol·L-1时可以明显抑制Jurkat细胞的RVD ,而在 10 -9、10 -7和 10 -5mol·L-1时对Jurkat细胞的RVD没有明显影响。钾通道阻断剂奎宁 (quinine)亦可以抑制Jurkat细胞的RVD。氢化可的松和奎宁在10 -3 mol·L-1均可明显抑制Jurkat的增殖 (包括自然增殖和ConA诱导增殖 )。结论 :氢化可的松对Jur kat细胞RVD的抑制可能是通过钾通道起作用     

Characterization of the modes of action of deoxynivalenol (DON) in the human Jurkat T-cell line

Abstract

Deoxynivalenol (DON) is one of the most abundant mycotoxins worldwide and mostly detected in cereals and grains. As such, DON poses a risk for many adverse health effects to human and animals. In particular, immune cells are very sensitive to DON, with the initiating step leading to toxicity being a binding to the eukaryotic 60S ribosomal subunit and induction of ribotoxic stress. The present study aimed to: (1) extend insight into the mechanism of action (MOA) of DON in immune cells; and (2) understand why immune cells are more sensitive to DON than most other cell types. Previously published microarray studies have described the effects of DON on immune cells. To build upon these findings, here, immunocytological and biochemical studies were performed using human T-lymphocyte Jurkat cells that were exposed for 3?h to 0.5?µM DON. Induction of ER stress by DON was confirmed by immunocytology demonstrating increased protein expression of two major ER stress markers ATF3 and DDIT3. T-cell activation was confirmed by induction of phosphorylation of protein kinases JNK and AKT, activation of NF-κB (p65), and increased expression of NFAT target gene NUR77; each of these are known inducers of the T-cell activation response. Induction of an oxidative stress response was also confirmed by monitoring the nuclear translocation of major oxidative stress markers NRF2 and KEAP1, as well as by changes (i.e. decreases) in cell levels of reduced glutathione. Lastly, this study showed that DON induced cleavage of caspase-3, an event known to mediate apoptosis. Taken together, these results allowed us to formulate a potential mechanism of action of DON in immune cells, i.e. binding to eukaryotic 60S ribosomal subunit?→?ribotoxic stress?→?ER stress?→?calcium release from the ER into cytoplasm?→?T-cell activation and oxidative stress?→?apoptosis. It is proposed that immune cells are more sensitive to DON than other cell types due to the induction of a T-cell activation response by increased intracellular calcium levels.     

螺内酯诱导人急性白血病细胞Jurkat凋亡的作用研究

目的研究螺内酯对人急性白血病细胞Jurkat体外增殖的抑制及诱导凋亡的作用。方法将终浓度分别是10、50及100μmol/L的螺内酯加入Jurkat细胞的培养体系中,24 h内每隔4 h通过MTT法分析Jurkat细胞的增殖抑制率,Annexin V/PI流式细胞术法分析Jurkat细胞的早期凋亡率。结果螺内酯与Jurkat细胞共同培养12 h后,螺内酯能显著增加对细胞的增殖抑制作用,并且与药物浓度成正相关,各浓度组的抑制率随着培养时间的延长而升高,与药物干预时间成正相关;螺内酯处理Jurkat细胞24 h,各浓度组诱导细胞凋亡率分别为:10μmol/L组(11.2±0.35)%、50μmol/L组(29.8±1.27)%及100μmol/L(56.5±1.41)%,各个浓度组诱导细胞凋亡率与药物浓度成正相关。结论螺内酯对人T淋巴细胞白血病Jurkat细胞具有抑制增殖和诱导凋亡的作用,提示该药可能具有潜在抑瘤作用。     

催乳素及其受体与Jurkat细胞CD154表达之间的关联

目的探讨催乳素(PRL)/催乳素受体(PRLr)与免疫细胞活化有关的协同刺激信号间的关系,以期发现PRL/PRLr在免疫调节方面的作用机制。方法①将JurkatD1．1细胞随机分为4组,用重组人催乳素(rhPRL)及植物血凝素(PHA)共同刺激JurkatD1．1细胞,预先加或不加鼠抗人催乳素受体抗体,流式细胞仪检测JurkatD1．1细胞表面抗原CD154的表达。②免疫组织化学法再次证实以上结果。结果在rhPRL和PHA共同作用下,Jurkat细胞CD154表达量[(20．8±7．0)％]较空白对照组[(2．6±0．5)％]明显增加(t=8．84,P＜0．01)。预先加入鼠抗人催乳素受体抗体后再加入rhPRL和PHA,CD154的表达量[(2．6±0．6)％]无明显升高(t=0．04,P＞0．05)。结论PRL可通过PRL/PRLr介导的途径促进T细胞CD154的表达,参与免疫反应。