IFN-γ活化小鼠腹腔巨噬细胞抗弓形虫作用的剂量相关性及其与TNF-α的协同作用

目的：揭示ＩＦＮ－γ抗弓形虫作用的剂量相关性及ＴＮＦ－α对ＩＦＮ－γ是否存在协同作用。方法：本实验体外以不同剂量ＩＦＮ－γ单独或与ＴＮＦ－α联合刺激昆明鼠腹腔巨噬细胞，观察其对入侵的ＲＨ株速殖子的作用及培养上清中ＮＯ的水平。结果：随着ＩＦＮ－γ剂量的增大，巨噬细胞抗虫作用增强，培养上清中ＮＯ水平增高；虫体入侵后２４ｈＮＯ水平与细胞内虫体数呈显著负相关。结论：ＩＦＮ－γ可激活巨噬细胞抑制和杀灭入侵的弓形虫，并与剂量有关，ＴＮＦ－α对此有协同作用，ＮＯ是抗虫作用中重要的效应因子     

IFN-γ联合TNF-α活化小鼠腹腔巨噬细胞抗不同毒力株弓形虫的作用

目的： 比较ＩＦＮ－γ联合ＴＮＦ－α体外活化的小鼠腹腔巨噬细胞（ＭΦ） 对强毒株ＲＨ株及弱毒株Ｆｕｋａｙａ株的抗虫作用。方法： 体外以ＩＦＮ－γ与ＴＮＦ－α联合活化昆明系小鼠腹腔ＭΦ,观察其对入侵的ＲＨ株及Ｆｕｋａｙａ株速殖子的抗虫作用, 测定培养上清中ＮＯ的水平。结果： 在以ＩＦＮ－γ１００Ｕ＋ ＴＮＦ－α１００Ｕ 活化的ＭΦ中, 入侵２４ｈ 后的ＲＨ株弓形虫速殖子被完全杀灭, 而Ｆｕｋａｙａ 株速殖子则缓慢增殖, 且前者培养上清中ＮＯ水平显著高于后者。结论：ＩＦＮ－γ活化的ＭΦ对入侵的ＲＨ 株和Ｆｕｋａｙａ株速殖子的抗虫作用存在差异,这可能与ＮＯ的水平有关。     

IFN-γ联合TNF-α活化小鼠腹腔巨噬细胞抗不同毒力株弓形虫的作用

目的： 比较ＩＦＮ－γ联合ＴＮＦ－α体外活化的小鼠腹腔巨噬细胞（ＭΦ） 对强毒株ＲＨ株及弱毒株Ｆｕｋａｙａ株的抗虫作用。方法： 体外以ＩＦＮ－γ与ＴＮＦ－α联合活化昆明系小鼠腹腔ＭΦ,观察其对入侵的ＲＨ株及Ｆｕｋａｙａ株速殖子的抗虫作用, 测定培养上清中ＮＯ的水平。结果： 在以ＩＦＮ－γ１００Ｕ＋ ＴＮＦ－α１００Ｕ 活化的ＭΦ中, 入侵２４ｈ 后的ＲＨ株弓形虫速殖子被完全杀灭, 而Ｆｕｋａｙａ 株速殖子则缓慢增殖, 且前者培养上清中ＮＯ水平显著高于后者。结论：ＩＦＮ－γ活化的ＭΦ对入侵的ＲＨ 株和Ｆｕｋａｙａ株速殖子的抗虫作用存在差异,这可能与ＮＯ的水平有关。     

TNF-α对IFN-γ抗弓形虫效应中的作用的影响

应用３Ｈ－尿嘧啶（３Ｈ－Ｕ）特异性标记弓形虫在小鼠腹腔巨噬细胞（ＭｏｕｓｅＰｅｒｉｔｏｎｅａｌＭａｃｒｏｐｈａｇｅ，ＭＰＭ）内的增殖实验，观察了ＴＮＦ－α及ＴＮＦ－α在ＩＦＮ－γ诱导的ＭＰＭ抗弓形虫效应中的作用。结果表明：单独用高浓度ＴＮＦ－α只能诱导ＭＰＭ轻微的抗弓形虫效应（１９％左右），而与亚刺激量的ＩＦＮ－γ相结合几乎可以完全抑制弓形虫的增殖；抗ＴＮＦ－α可消除ＩＦＮ－γ诱导的ＭＰＭ的抗弓形虫的效应，其作用只发生在ＩＦＮ－γ诱导ＭＰＭ的最初阶段     

IL-4、IL-6对IFN-γ诱导的小鼠腹腔巨噬细胞抗弓形虫作用的影响

本文以Ｃ５７ＢＬ／６小鼠腹腔巨噬细胞（Ｍｏｕｓｅｐｅｒｉｔｏｎｅａｌｍａｃｒｏｐｈａｇｅ,ＭＰＭ）为靶细胞,通过３Ｈ－尿嘧啶（３Ｈ－Ｕ）特异性标记的弓形虫在ＭＰＭ内的增殖实验,研究了ＩＬ－４、ＩＬ－６对ＩＦＮ－γ诱导的ＭＰＭ抗弓形虫作用的影响。结果表明,ＩＬ－４能够部分抑制弓形虫在ＭＰＭ内的增殖,且与ＩＦＮ－γ具有相加作用;ＩＬ－６促进弓形虫在ＭＰＭ内的增殖,且可部分逆转ＩＦＮ－γ诱导的ＭＰＭ抗弓形虫作用;抗ＴＮＦ－α抗体能够逆转ＩＦＮ－γ的抗弓形虫作用,但对ＩＬ－４及ＩＬ－６则无明显影响     

IL—4,IL—6对IFN—γ诱导的小鼠腹腔巨噬细胞抗弓形虫作用？…

本文以Ｃ５７ＢＬ／６小鼠腹腔巨噬细胞为靶细胞,通过＾３Ｈ－尿嘧啶（＾３Ｈ－Ｕ）特异性标记的弓形虫在ＭＰＭ内的增殖实验,研究了ＩＬ－４,ＩＬ－６对ＩＦＮ－γ诱导的ＭＰＭ扩弓形虫作用的影响。     

肺结核患者抗原特异性IFN-γ+ TNF-α+T细胞的检测分析

目的 研究肺结核患者与健康对照外周血T淋巴细胞中γ干扰素(IFN-γ)和肿瘤坏死因子α(TNF-α)的表达情况,初步探讨多功能性T细胞在结核发病中的作用.方法 分离外周血单个核细胞(PBMCs),与特异性结核抗原共培养后,用流式细胞仪检测外周血CD8+、CD4+T细胞以及CD3-CD8+细胞中抗原特异性IFN-γ和TNF-α的表达情况.通过非参数检验比较患者与PPD阳性健康对照者之间的表达差异.结果 根据细胞因子分泌的类型将每群细胞分成3个亚群,分别为两个单阳性细胞亚群(IFN-γ+ TNF-α-或IFN-γ-TNF-α+)和一个双阳性细胞亚群(IFN-γ+ TNF-α+)即多功能性细胞亚群.经统计学分析,肺结核患者三群细胞中抗原特异性多功能性细胞的比例均高于PPD阳性健康对照者(P=0.001,0.001和0.014),且对照组该亚群的比例大部分均在结核病患者均值以下.结论 多功能性T细胞很可能在结核的疾病进展过程中发挥重要作用.     

IL-6对弓形虫增殖的影响

目的：观察白细胞介素－６（ＩＬ－６）对弓形虫增殖的影响。方法：以Ｃ５７ＢＬ／６小鼠腹腔巨噬细胞为靶细胞,采用３Ｈ－尿嘧啶（３Ｈ－Ｕ）特异性标记的弓形虫在ＭΦ内的增殖实验。结果：单独应用ＩＬ－６处理ＭΦ,可以促进弓形虫在ＭΦ内的增殖,α肿瘤坏死因子（ＴＮＦα）的影响不明显;而在ＩＬ－６逆转γ干扰素（ＩＦＮγ）诱导的ＭΦ抗弓形虫效应的实验中发现,加入抗ＴＮＦα抗体可增加ＩＬ－６对ＩＦＮγ诱导ＭΦ抗弓形虫效应的逆转作用。结论：体外应用ＩＬ－６可促进弓形虫在小鼠腹腔ＭΦ内的增殖作用,并能部分逆转ＩＦＮγ的抗弓形虫效应。     

帕金森病患者肠道菌群、血清IFN-γ、TNF-α水平变化及临床检测价值

目的 探究帕金森病(PD)患者肠道菌群、血清干扰素(IFN)-γ、肿瘤坏死因子(TNF)-α水平变化及临床检测价值。方法 选取100例PD患者作为研究组,100例健康志愿者作为对照组,比较两组一般资料、疣状菌属丰度、血清IFN-γ、TNF-α水平,通过Spearman/Pearson相关系数模型分析疣状菌属丰度与PD患者临床症状[统一PD评定量表第三部分(UPDRSⅢ)评分、Hoehn-Yahr分期、非运动症状评定量表(NMSS)评分]及血清IFN-γ、TNF-α水平的相关性。研究组均行对症治疗3个月,比较不同预后患者治疗前疣状菌属丰度、血清IFN-γ、TNF-α水平,采用受试者工作特征(ROC)曲线分析疣状菌属丰度、血清IFN-γ、TNF-α水平预测短期预后的价值。结果 研究组疣状菌属丰度、血清IFN-γ、TNF-α水平均显著高于对照组(P<0.05);PD患者疣状菌属丰度与UPDRSⅢ评分、Hoehn-Yahr分期、NMSS评分及血清IFN-γ、TNF-α水平均呈正相关(P<0.05);预后不良患者疣状菌属丰度、血清IFN-γ、TNF-α水平均显著高于预后良好患者(P&...     

TNF—α对IFN—γ抗弓形虫效应中的作用的影响

应用＾３Ｈ－尿嘧啶（＾３Ｈ－Ｕ）特异性标记弓形虫在小鼠腹腔巨噬细胞（ＭＰＭ）内的增殖实验，观察了ＴＮＦ－α及ＴＮＦ－α在ＴＮＦ－γ诱导的ＭＰＭ抗弓形虫效应中的作用。结果表明：单独用高浓度ＴＮＦ－α只能诱导ＭＰＭ轻微的抗弓形虫效应（１９％左右），而与亚刺激量的ＴＮＦ－γ相结合几乎可以完全抑制弓形虫的增殖；抗ＴＮＦ－α可消除ＴＮＦ－γ诱导的ＭＰＭ的抗弓形虫的效应，其作用只发生在ＴＮＦ－γ诱导ＭＰＭ的最     

Toxoplasma gondii infection induces apoptosis in noninfected macrophages: role of nitric oxide and other soluble factors

Apoptosis has been found to help in the defence against pathogens. Infection with the obligate intracellular parasite Toxoplasma gondii is known to trigger host-cell apoptosis. When using a T. gondii-infected macrophage cell line, J774A.1, treatment with IFN-gamma significantly enhanced apoptosis in noninfected bystander cells while parasitized cells became relatively resistant. Infection and IFN-gamma treatment activated the expression of inducible nitric oxide synthase (iNOS), and the production of nitric oxide (NO) and treatment of cells with an iNOS inhibitor, N(G)-monomethlyl-L-arginine acetate (L-NMMA) reduced the apoptosis frequency. However, the reversal was only partial suggesting that not only NO, but also other, as of yet, unknown factors are induced. Finally, we studied the effect in vivo by infecting mice with either a virulent or an avirulent strain. Challenge with the virulent strain lead to a higher parasite burden, induced host-cell apoptosis in peritoneal cells, and produced higher levels of IFN-gamma and NO. Moreover, treatment of mice with a NO synthase inhibitor, aminoguanidine, partially inhibited the host-cell apoptosis induced by the parasite infection. Altogether, our findings indicate that apoptosis in bystander host cells is due to the secretion of NO and other soluble factors released by parasite-infected cells.     

Effect of hepatocyte apoptosis induced by TNF-alpha on acute severe hepatitis in mouse models

AIM:To study the effect of hepatocyte apoptosis and necrosis induced by TNF-alpha on the pathogenesis of acute severe hepatitis (ASH).METHODS:The model of ASH was prepared in D-galactosamine (GalN) sensitized BALB/c mice by injection of either endotoxin (ET) or tumor necrosis factor-alpha(TNF-alpha. Morphological changes of apoptotic hepatocytes were studied by both light and electron microscope and in site end labeling method (ISEL). Molecular biological changes of DNA ladder were observed by electrophoresis of extract from liver tissues. Biochemical changes were measured by alanine aminotransferase (ALT), aspartic aminotransferase (AST) and TNF-alpha. The relation between apoptosis and necrosis was evaluated simultaneously.RESULTS:The sequence of hepatocyte apoptosis, necrosis, and final death from ASH was observed both in GalN/ET and GalN/TNF-alpha group. Apoptosis was prominent at 3.5h and 6h after injection of inducer, while necrosis became dominant at 9h after challenge. The appearance of apoptosis was earlier in GalN/TNF-alpha group than that in GalN/ET group. Pretreatment of mice with antiTNF IgG1 may completely prevent the liver injury induced by GalN/ET.CONCLUSION:TNF-alpha can cause liver amage by inducing hepatic apoptosis and necrosis in mice with endotoxemia.     

Relationship between granulocyte macrophage-colony stimulating factor, tumour necrosis factor-α and Trypanosoma cruzi infection of murine macrophages

Gamma interferon (IFN-γ)-activated macrophages control Trypanosoma cruzi infection via nitric oxide (NO), recently recognized as a major effector molecule. Granulocyte macrophage-colony stimulating factor (GM-CSF) is a multipotent cytokine secreted by macrophages and many other cells. It induces the production of tumour necrosis factor alpha (TNF-α), another cytokine also secreted by macrophages and involved in the control of T. cruzi infection. However, no data are available on the relationship between GM-CSF, TNF-a and NO produced by macrophages activated by IFN-γ and infected with T. cruzi. To highlight this relationship, mouse peritoneal macrophages (MPM) and two c-myc retrovirus-induced macrophage cell lines (9.1.1 and BMM8), respectively characterized by a constitutive and an inducible production of GM-CSF, were activated with I FN–γ and/or GM-CSF and infected with T. cruzi. Our results indicate that T. cruzi upregulates GM-CSF release from MPM and from the two macrophage cell lines, activated (or not) by IFN-γ. A high autocrine production of GM-CSF or an exogenous supply of GM-CSF is correlated with an enhanced release of TNF-α and NO, inducing an improved control of T. cruzi infection by IFN-γ-activated MPM.     

TNF-α, nitric oxide and IFN-γ are all critical for development of necrosis in the small intestine and early mortality in genetically susceptible mice infected perorally with Toxoplasma gondii

We previously reported that genetic susceptibility of mice to peroral infection with T. gondii is associated with CD4+ T cell-dependent, interferon (IFN)-gamma-mediated necrosis of their small intestine. We examined the role of tumour necrosis factor (TNF)-alpha and nitric oxide (NO), in addition to IFN-gamma. At 7 days after infection, a marked increase in CD4+ T cells was observed in lamina propria mononuclear cells (LPC) of the small intestine as compared with normal mice, and significantly greater amounts of mRNA for IFN-gamma, TNF-alpha, and inducible NO synthase (iNOS) were detected in LPC of the small intestine of infected than uninfected animals. Treatment of infected mice with anti-TNF-alpha monoclonal antibody (mAb) or the iNOS inhibitor, aminoguanidine, prevented necrosis and prolonged time to death. Infected iNOS-targeted mutant mice did not develop the disease whereas infected, control mice did. Treatment with anti-TNF-alpha mAb did not affect the expression of IFN-gamma in the LPC but inhibited expression of iNOS in the infected mice, indicating the role of TNF-alpha in the induction of iNOS. These results suggest that NO induced by a combination of IFN-gamma and TNF-alpha through activation of iNOS is a critical mediator of intestinal pathology and contributes to early mortality in genetically susceptible mice.     

In-vivo treatment with benznidazole enhances phagocytosis, parasite destruction and cytokine release by macrophages during infection with a drug-susceptible but not with a derived drug-resistant Trypansoma cruzi population

To stuck the effect of chemotherapy on parasite-macrophage interaction we used the wild-type Y strain (drug-susceptible) of Trypanosoma cruzi and a drug-resistant parasite population derived from the same strain. Trypomastigotes isolated from untreated infected mice, as well as, 3 h after treatment with BZ were incubated with inflammatory macrophages and used to study phagocytosis, parasite destruction, cytokine release and reactive nitrogen intermediates (RN!) synthesis. Phagocytosis and destruction of the drug-susceptible parasites were significant/v enhanced by drug treatment. These enhancements were accompanied by an increase in cytokines [interleukin (IL)-12 and tumour necrosis factor (TNF)alpha] and RNI release by murine inflammatory macrophages primed with IFN-gamma. In contrast, BZ treatment of mice infected with drug-resistant T. cruzi population showed no effect whatsoever. The synthesis of IFN-gamma and RNI by splenocytes of mice infected with either susceptible and drug-resistant parasite populations, before and after treatment with BZ were also studied. On/v the splenocytes from mice infected with the drug-susceptible parasites treated with BZ produced high levels of IFN-gamma and RNI. Our findings indicate that BZ acts on the drug-susceptible T. cruzi parasites by enhancing the phagocytosis and the production of cytokines and RN!, thus, favouring the destruction of the intracellular parasites by the cellular compartment of the immune system.     

Activation of JNK and xanthine oxidase by TNF-alpha impairs nitric oxide-mediated dilation of coronary arterioles

Elevated levels of tumor necrosis factor-alpha (TNF), a proinflammatory cytokine, are associated with coronary artery disease. However, it is unclear whether vasodilator function of coronary resistance arterioles is susceptible to TNF. Herein, we examined whether TNF can affect endothelium-dependent nitric oxide (NO)-mediated dilation of coronary arterioles to adenosine and whether inflammatory signaling pathways such as mitogen-activated protein kinases, ceramide sphingolipids, and oxidative stress are involved in the TNF-mediated effect. To eliminate confounding influences associated with in vivo preparations, coronary arterioles from porcine heart were isolated and pressurized without flow for in vitro study. Intraluminal treatment with TNF (1 ng/ml, 90 min) significantly attenuated the NO release and vasodilation to adenosine. This inhibitory effect was not observed in denuded vessels or in the presence of NO synthase inhibitor l-NMMA. Histochemical data showed that superoxide production and JNK phosphorylation in arteriolar endothelial cells was enhanced by TNF. Administration of superoxide scavenger or inhibitors of ceramide-activated protein kinase (dimethylaminopurine), JNK (SP600125 and dicumarol), and xanthine oxidase (allopurinol) reduced superoxide production as well as restored NO release and vasodilation to adenosine. Conversely, the effects of TNF were insensitive to inhibitors of p38 (SB203580), ERK (PD98059), NAD(P)H oxidase (apocynin), or mitochondrial respiratory chain (rotenone). These data indicate that TNF inhibits endothelium-dependent NO-mediated dilation of coronary arterioles by ceramide-induced activation of JNK and subsequent production of superoxide via xanthine oxidase. Because myocardial ischemia augments adenosine production and elevates TNF level, inhibiting adenosine-stimulated endothelial release of NO by TNF could contribute to inadequate regulation of coronary blood flow during the development of ischemic heart disease.     

Heterogeneity in secretory responses of rat liver macrophages of different size

Abstract: Four subpopulations of hepatic macrophages, differing in size, were isolated from rat liver. The secretion of nitric oxide (NO), tumor necrosis factor-α (TNF-α), prostaglandin E (PGE) and interleukin-1 (IL-1) by freshly isolated as well as cultured cells was studied after in vitro stimulation with the immunomodulator muramyl dipeptide (MDP) in free or liposome-encapsulated form. Freshly isolated liver macrophages could be induced to secrete significant levels of NO, TNF-α, PGE and IL-1. The extent of secretion, however, varied substantially between macrophages of different size. The highest levels of secretion of TNF-α, PGE and IL-1 were observed in the fraction containing the large-size macrophages, while progressively lower levels of secretion were observed with decreasing size. In constrast, the highest levels of NO secretion were observed by small macrophages and steadily decreased with increasing size. Hepatic macrophages of different size displayed differences in secretory potential during in vitro culture. The ability of small liver macrophages to secrete NO, TNF-α, or PGE, following activation with MDP, gradually increased with time in culture. In contrast, large liver macrophages gradually lost their secretory ability after 1–2 days and the intermedicate-size cells after 2–3 days in culture. This functional heterogeneity in secretory properties among rat liver macrophages of different size is discussed with reference to their potential role and significance in host defense against metastatic tumor growth in the liver.     

人可溶性肿瘤坏死因子受体1基因转染对肿瘤坏死因子α诱导肝细胞凋亡的影响

TNFα能诱导肝细胞凋亡,其过度表达是肝衰竭发生发展过程中的一个重要因素。可溶性TNFα受体1（sTNFR1）可中和TNFα的部分毒性作用。为有效抑制TNFα诱导的细胞凋亡以及治疗肝衰竭,我们拟构建sTNFR1的真核表达载体,并将重组质粒pcDNA3-1（-）sTNFR 1瞬时转染QSG7701细胞,研究其对TNFα诱导细胞凋亡的抑制作用。[第一段]