Vilon(L-Lys-L-Glu)对小鼠腹腔巨噬细胞分泌IL-1β、NO的影响

目的 探讨Vilon(L-Lys-L-Glu)对参与炎症反应的小鼠腹腔巨噬细胞分泌IL-1β、NO的影响.方法 以小鼠原代培养腹腔巨噬细胞为阳性参照,ELISA法检测Vilon及脂多糖(LPS)共刺激的小鼠腹腔巨噬细胞IL-1β的分泌水平;还原酶法分析NO分泌水平;RT-PCR法检测IL-1β和iNOS mRNA的表达.结果 Vilon和LPS共刺激小鼠腹腔巨噬细胞时,Vilon对LPS活化的小鼠腹腔巨噬细胞分泌IL-1β及NO具有明显的促进作用,并且呈剂量依赖关系;同时也促进了IL-1β和iNOS mRNA表达.结论 Vilon对活化的小鼠腹腔巨噬细胞分泌IL-1β、NO具有明显的促进作用.     

淋巴细胞缺陷对内毒素血症小鼠腹腔巨噬细胞活化的影响

目的观察淋巴细胞缺陷对内毒素血症小鼠腹腔巨噬细胞活化的影响。方法采用腹腔注射脂多糖(LPS)建立Balb/c小鼠和T、B细胞缺陷的重症联合免疫缺陷(SCID)小鼠内毒素血症模型,ELISA检测2种小鼠腹腔灌洗液TNF-α和IL-10水平,实时荧光定量PCR检测腹腔巨噬细胞(peritoneal macrophage,PMa)TNF-α、IL-10及丝裂原蛋白激酶磷酸酶-1(mito-gen-activated protein kinase phosphatase-1,MKP-1)mRNA表达;ELISA检测Balb/c及SCID小鼠PMa体外刺激后细胞因子分泌情况。结果 LPS注射后1 h,SCID小鼠腹腔灌洗液TNF-α水平高于Balb/c小鼠,注射后3 h,IL-10水平低于Balb/c小鼠;LPS注射前及注射后,SCID小鼠PMa TNF-αmRNA表达高于Balb/c小鼠PMa,IL-10 mRNA表达低于Balb/c小鼠PMa;体外实验LPS刺激下,SCID小鼠PMa较Balb/c小鼠PMa分泌更多的TNF-α,IL-10的分泌却偏少。LPS注射前及注射后,Balb/c小鼠PMa MKP-1 mRNA表达均明显高于SCID小鼠。结论淋巴细胞缺陷导致内毒素血症小鼠腹腔巨噬细胞活性的增加,淋巴细胞抑制巨噬细胞的活化并可能调控其发育及成熟;MKP-1表达的减少可能是淋巴细胞缺陷导致腹腔巨噬细胞活性增加的分子机制之一。     

阵发性睡眠性血红蛋白尿及再生障碍性贫血造血负调控因子的研究

目的 检测阵发性睡眠性血红蛋白尿(PNH)与再生障碍性贫血(AA)患者外周血血浆中造血负性调控因子IFN-γTNF-α和TGF-β1的表达;研究IFN-γ、TNF-α和TGF-β1表达水平与PNH和AA之间的关系.方法 应用ELISA法检测18例成人PNH与20例从患者外周血血浆中IFN-γ、TNF-α和TGF-β1的表达,并与15例健康体检者对比.结果 AA组的IFN-γ和TNF-α均高于对照组,P<0.05;TGF-β1显著高于对照组,P<0.01.PNH组的IFN-γ、TNF-α和TGF-β1均显著高于对照组,P<0.01.PNH组的TNF-α高于AA组,P<0.05;PNH组IFN-γ和TGF-β1均显著高于AA组,P<0.01.结论 IFN-γ、TNF-α和TGF-β1作为造血负性调控因子在PNH与AA患者体内对造血细胞起抑制作用,反映造血调控因子分泌紊乱可能在PNH与AA的发病中起一定作用.     

约氏疟原虫感染早期抵抗和易感小鼠Th1反应特点的实验研究

为探讨疟原虫感染早期抵抗和易感小鼠Th1反应特点,以约氏疟原虫腹腔感染DBA/2和BALB/c小鼠为材料,用ELISA试剂盒和Griess实验分别检测感染第3天小鼠脾细胞、悬浮细胞以及巨噬细胞培养上清液中IFN-γ和NO水平。结果表明以PRBC或LPS刺激后,DBA/2小鼠脾细胞上清液中IFN-γ和NO水平随培养时间的延长均有不同程度的提高,但BALB/c小鼠48h培养组的IFN-γ和NO水平仅比24h培养组略有升高。两种小鼠单纯悬浮细胞或巨噬细胞上清液中IFN-γ或NO水平均明显低于其脾细胞上清液中的水平。这表明,约氏疟原虫感染早期,抵抗宿主对特异性或非特异性因子刺激的应答能力明显强于易感宿主,在相同因子刺激下前者建立的Th1反应可进一步被强化;巨噬细胞分泌NO明显依赖于IFN-γ的诱导效应。     

黑大蒜提取物对小鼠细胞免疫应答影响的初步探讨

目的:探讨黑大蒜提取物对BALB/c小鼠细胞免疫功能的影响。方法:连续5天给予小鼠腹腔注射黑大蒜提取物溶液。从第6天开始处死鼠,分离培养脾细胞,生物学方法检测自然杀伤(NK)细胞杀伤活性,Griess法检测脾细胞培养上清一氧化氮(NO)的分泌水平,ELISA法检测脾细胞培养上清IL-2、IL-4、IFN-γ和TNF-α的水平,RT-PCR方法检测脾细胞FasLmRNA的表达水平。结果:黑大蒜提取物能显著增强NK细胞杀伤活性,促进NO和Th1型细胞因子IL-2、IFN-γ和TNF-α的分泌,IL-4水平略有降低,脾细胞FasLmRNA的表达水平未见明显变化。结论:黑大蒜提取物对小鼠细胞免疫应答具有一定的促进效应。     

表没食子儿茶素没食子酸酯对IFN-γ/LPS刺激的小鼠髓源性巨噬细胞极化的影响

目的:探讨表没食子儿茶素没食子酸酯(EGCG)对IFN-γ/LPS刺激的小鼠髓源性巨噬细胞促炎细胞因子表达的影响。方法:取6~8周龄C57BL/6小鼠骨髓细胞,经100 ng/ml巨噬细胞集落刺激因子(M-CSF)体外诱导分化为骨髓巨噬细胞(BMDM),加入50 ng/ml干扰素γ(IFN-γ)和1μg/ml细菌脂多糖(LPS)刺激,并同时暴露于12.5~50μmol/L EGCG处理48 h,利用实时荧光定量PCR(qRT-PCR)和酶联免疫吸附试验(ELISA)检测巨噬细胞促炎细胞因子IL-1β、TNF-α和i NOS的mRNA表达水平和蛋白含量。结果:IFN-γ和LPS处理可刺激巨噬细胞IL-1β、TNF-α和i NOS表达显著上调,而EGCG则能抑制IFN-γ和LPS刺激的IL-1β、TNF-α和i NOS表达,且存在剂量依赖性。结论:EGCG能够减弱IFN-γ和LPS刺激的髓源性巨噬细胞的促炎作用。     

红景天苷对小鼠腹腔巨噬细胞体外增殖、凋亡、吞噬、ROS和NO产生的影响

目的:研究红景天苷(Sal)对小鼠腹腔巨噬细胞体外增殖、凋亡、吞噬、胞内活性氧簇(ROS)及分泌一氧化氮(NO)的影响,初步探讨其对小鼠腹腔巨噬细胞的免疫调节作用。方法:无菌分离小鼠腹腔巨噬细胞,并制备单细胞悬液,以不同终浓度(80μmol/L、160μmol/L及320μmol/L)的Sal和巨噬细胞共培养4 h,再以脂多糖(LPS)和γ-干扰素(IFN-γ)进行共刺激。利用MTT比色法检测Sal对巨噬细胞体外增殖的影响。用放线菌酮(CHX)诱导巨噬细胞凋亡,用Sytox G reen染色结合荧光酶标仪检测Sal对CHX诱导巨噬细胞凋亡的影响。用流式细胞术(FCM)检测Sal对巨噬细胞吞噬功能的影响。用2-7-二氯氢化荧光素乙二脂(H2DCFDA)染色法结合荧光酶标仪检测Sal对胞内ROS产生的影响;用G riess反应检测Sal对巨噬细胞分泌NO的影响。结果:MTT比色法检测显示,终浓度为80、160、320μmol/L的Sal均可显著促进LPS+IFN-γ刺激巨噬细胞增殖(P<0.05)。荧光酶标仪检测Syto xG reen染色法的结果显示,160μmol/L的Sal可抑制CHX诱导的巨噬细胞凋亡(P<0.01)。FCM结果显示,各浓度的Sal均能促进单纯药物组和实验药物组LPS+IFN-γ刺激巨噬细胞的吞噬功能(P<0.05)。用荧光酶标仪检测DH2DCFDA染色结果表明,各浓度的Sal对LPS+IFN-γ刺激的巨噬细胞胞内ROS的产生均具有显著的抑制作用(P<0.01)。Griess反应检测NO含量的结果显示,各浓度的Sal对LPS+IFN-γ刺激巨噬细胞产生NO均具有促进作用(P<0.05)。结论:Sal对LPS和IFN-γ刺激的巨噬细胞增殖具有显著的促进作用,对CHX诱导的巨噬细胞凋亡具有显著的抑制作用,对静息态和活化态的巨噬细胞的吞噬功能均有增强作用,并能减少LPS和IFN-γ活化的巨噬细胞胞内ROS的产生;但能促进LPS和IFN-γ活化的巨噬细胞NO的分泌。     

激活素A对RAW264.7巨噬细胞活性的调节作用

目的探讨激活素A对参与炎症反应的小鼠巨噬细胞活性调节作用。方法以LPS刺激活化的小鼠巨噬细胞系RAW264．7细胞作为阳性参照，ELISA法检测激活素A及LPS刺激的小鼠腹腔巨噬细胞系RAW264．7细胞IL-1β分泌水平，还原酶法分析NO分泌水平，RT-PCR检测IL-1β和iNOS mRNA的表达，瑞氏染色检测RAW264．7细胞吞噬活性。结果在激活素A刺激下RAW264．7细胞IL-1β和NO分泌水平均明显升高，IL-1β和iNOS mRNA表达亦增加，巨噬细胞吞噬活性增强；激活素A和LPS共刺激RAW264．7细胞时，激活素A明显抑制LPS刺激的RAW264．7细胞IL-1β和NO产生水平，以及IL-1β和iNOS mRNA表达，巨噬细胞吞噬活性也明显低于LPS单独刺激组。结论激活素对巨噬细胞的活性调节具有双重作用，这种作用与巨噬细胞的激活状态有关。     

小鼠腹腔巨噬细胞诱生一氧化氮的实验研究

应用细胞因子,细菌内毒素和甲醛固定的细菌刺激小鼠腹腔巨噬细胞观察其诱生一氧化氮(NO)的能力,结果发现LPS,IFN-γ+IL-2能够诱生NO,IFN-γ和高浓度的M-CSF与LPS具有协同作用。细菌和BCG也具有诱生NO的能力。还观察了巨噬细胞诱生NO的动力学变化。     

LPSp辅佐HBsAg诱导机体产生特异性抗体的机制

目的:研究革兰阴性非致病性成团泛菌脂多糖(LPSp)作为佐剂促进乙型肝炎表面抗原蛋白(HBsAg)诱导小鼠产生抗-HBs抗体的作用机制。方法:在体外用LPSp HBsAg、HBsAg、LPSp、生理盐水分别致敏小鼠腹腔巨噬细胞,观察致敏细胞回输体内后诱导HBs抗体产生水平,检测巨噬细胞培养上清中TNF-α活性和NO浓度;观察4组巨噬细胞吞噬功能变化,并检测致敏巨噬细胞诱导局部淋巴结细胞分泌IL-4和IFN-γ的能力。结果:HBsAg LPSp致敏巨噬细胞促进小鼠HBs抗体产生,LPSp致敏的巨噬细胞的吞噬能力显著增强(P<0.05),释放TNF-α和NO水平增加(P<0.05)。LPSp HBsAg致敏巨噬细胞诱导局部淋巴结细胞释放IL-4水平升高(P<0.05),诱导IFN-γ水平与单纯HBsAg致敏组差异无统计学意义(P>0.05)。结论:LPSp的佐剂机制为参与活化巨噬细胞,增强巨噬细胞对抗原的吞噬、消化和处理能力;同时促进HBsAg致敏的巨噬细胞诱导淋巴结内淋巴细胞释放IL-4,增强HBsAg致敏的巨噬细胞诱导Th2淋巴细胞活化,促进B细胞产生抗体。     

Pre-exposure of murine macrophages to lipopolysaccharide inhibits the induction of nitric oxide synthase and reduces leishmanicidal activity

Murine macrophages produce nitric oxide (NO) from L-arginine on stimulation with lipopolysaccharide (LPS), alone or with interferon-γ (IFN-γ). The effect of incubation of macrophages with low concentrations of LPS on NO synthesis on subsequent stimulation was investigated, using a murine macrophage cell line, J774, and peritoneal macrophages from CBA mice. Cells which had been incubated with LPS produced significantly lower amounts of NO, and expressed lower levels of NO synthase activity, following stimulation with IFN-γ and LPS, or with a high concentration of LPS. This effect was not reversed by tumor necrosis factor-α. The ability of CBA macrophages to kill the intracellular parasite Leishmania major was markedly reduced by pre-incubation with LPS. Reduced NO production by macrophages previously exposed to LPS is a manifestation of endotoxin tolerance, and may represent an important means of regulation of NO synthesis and thus a survival mechanism for intracellular parasites.     

NITRIC OXIDE PREVENTS THE IFN-γ/LPS-INDUCED HEPATOTOXICITY IN A PROTEIN KINASE G-INDEPENDENT MANNER

Although it has been well known that the role of LPS on hepatotoxicity is mediated through TNF-α, the direct cytotoxic effect of LPS on IFN-γ-primed hepatocytes has not yet been clearly demonstrated. Here, we demonstrate that the IFN-γ-mediated death of murine embryonic liver BNL CL2 cells is potentiated by LPS (0.5 μg/ml). In addition, an exogenous NO donor, sodium nitroprusside (SNP) significantly prevents cell death induced by IFN-γ alone or IFN-γ plus LPS (IFN-γ/LPS) in a dose-dependent manner over 25 μM. SNP significantly blocked the death of BNL CL2 cells only when it was added within 12 hr after treatment of IFN-γ and IFN-γ/LPS. The preventive effect of SNP occurred in parallel with the suppression of caspase 3-like protease activation. We have also demonstrated that a relatively high concentration as well as an appropriate period of exposure to NO may be critical to maintain cell viability from the cytotoxic effect of IFN-γ and IFN-γ/LPS. Furthermore, the preventive effect of SNP on IFN-γ/LPS-induced cell death is mediated by a protein kinase G (PKG)-independent manner.     

小鼠IFN-γ真核表达载体的构建及其抗肿瘤效应研究

目的：构建小鼠IFN-γ的真核表达载体，将载体在体外转染小鼠腹腔MΦ，观察MΦ的抗肿瘤效应。在荷瘤小鼠腹腔内注射重组表达载体，观察抗肿瘤效应。 方法： RT-PCR扩增小鼠IFN-γ mRNA，将扩增的cDNA通过亚克隆重组到表达载体pcDNA3.1上。体外转染小鼠的腹腔MΦ，RT-PCR检测小鼠IFN-γ mRNA的表达，用转染的MΦ的培养上清培养另一组MΦ，MTT法检测MΦ对肿瘤细胞的杀伤活性。将重组质粒注射到荷瘤小鼠腹腔，观察小鼠腹水出现时间和存活时间。 结果: 将小鼠基因的开放阅读框（ORF）重组到真核表达载体pcDNA3.1内，测序证实和GenBank所公布序列相符。体外将IFN-γ基因导入MΦ内并表达，其培养上清对MΦ有激活作用，杀伤肿瘤细胞活性增强。腹腔内注射重组表达载体，荷瘤小鼠的腹水增长延迟、荷瘤生存时间延长。 结论： 构建的小鼠pcDNA3.1-IFN-γ表达载体体外转染腹腔MΦ并获表达，体内外实验显示有抗肿瘤细胞活性。     

IFN-γ-induced TNF-α is a prerequisite for in vitro production of nitric oxide generated in murine peritoneal macrophages by IFN-γ

The effect of IFN-γ to stimulate formation of nitric oxide (NO) by normal murine peritoneal macrophages (Mϕ) has been found to be completely dependent on the ability of IFN-γ to activate secretion of TNF-α. The NO-stimulatory effect of IFN-γ was abolished by anti-TNF-α antibodies, the inhibitory intervention of which could be fully reversed by exogenously supplied TNF-α. Accordingly, the failure of Mϕ from C3H/HeJ mice to secrete TNF-α upon stimulation with IFN-γ was associated with their complete incapability to generate NO, unless they were simultaneously treated with IFN-γ + TNF-α. Collectively, the data document that similar to the NO up-regulatory action of other cytokines, the effect of IFN-γ is not independent, but depends on a synergistic cooperation with the self-produced TNF-α. The findings thus indicate that a widespread opinion claiming that IFN-γ per se is able to stimulate biosynthesis of NO needs revision.     

Interferon-Gamma Alone Triggers the Production of Nitric Oxide from Serum-Starved BNL CL.2, Murine Embryonic Liver Cells

A previous study has demonstrated that both interferon-gamma (IFN-γ) and lipopolysaccharide (LPS) were needed to induce the production of nitric oxide (NO) in BNL CL.2 cells, murine embryonic liver cells. We here demonstrate that when BNL CL.2 cells were cultured with serum-free medium, they were induced to produce NO by the stimulation of IFN-γ alone. BNL CL.2 cells were cultured with serum-free or serum-containing medium for 1-3 days and then stimulated to synthesize NO by IFN-γ. Surprisingly, only serum-starved cells showed significant amount of nitrite accumulation and iNOS protein expression in response to IFN-γ in dose- and time-dependent manners, but serum-supplied cells did not. When the cells were stimulated with IFN-γ- tumor necrosis factor-α (TNF-α), or LPS in combinations, only the combination of IFN-γ and LPS produced more NO than that produced by IFN-γ alone. The production of NO by the cells stimulated with IFN-γ or IFN-γ plus LPS was blocked by the addition of N^G-monomethyl-L-arginine (N^GMMA), a NO synthesis inhibitor. To address the intracellular signal pathway responsible for the production of NO by the cells stimulated with IFN-γ alone or IFN-γ plus LPS, we examined the effects of several protein kinase inhibitors on the production of NO from the cells. The production of NO was significantly inhibited by protein tyrosine kinase (PTK) inhibitors, genistein and herbimycin A, but not by protein kinase A or C inhibitors. These results suggest that the deprivation of serum from BNL CL.2 cell culture medium might prime the cells to induce NO synthesis when the cells are triggered by IFN-γ and the involvement of PTK signal transduction pathway in the expression of inducible NO synthase gene in murine hepatoma cells.     

巨噬细胞NO_2~－释放法检测小鼠IFN－γ

本文建立了一种新的ＩＦＮ－γ检测方法。此方法利用ＩＦＮ－γ能够诱导ＭΦ产生并释放ＮＯ的原理，用微量显色技术对其衍生物亚硝酸盐ＮＯ进行定量测定。结果表明，样品中ＩＦＮ－γ的含量与ＭΦ释放ＮＯ的量有很好的相关性，抑制试验证实这种方法具有特异性。与ＩＦＮ－γ一起加入少量ＬＰＳ可以提高方法的敏感性和特异性。其它细胞因子，如ＩＬ－１、ＩＬ－２、ＴＮＦ、ＩＦＮ－β，对ＮＯ释放量的影响较小，可以忽略不计。此方法可供检测实验动物的ＩＦＮ－γ之用，有较高实用价值。     

Interleukin-12 is required for interferon-γ production and lethality in lipopolysaccharide-induced shock in mice

Several cytokines, in particular tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), have been shown to be responsible for pathological reactions which may lead to shock and death observed in infection with Gram-negative bacteria and in response to endotoxins (lipopolysaccharides, LPS). Priming of mice with the avirulent Bacille Calmette Guérin (BCG) vaccine strain of Mycobacterium bovis increases the sensitivity of mice to the lethal effect of LPS and results in an efficient priming for cytokine production. In response to low doses (1 γg/mouse) of LPS, BCG-primed mice produce interleukin-12 (IL-12) which controls IFN-γ production, as demonstrated by the ability of neutralizing anti-IL-12 antibodies to suppress IFN-γ production. However, the concentration of the biologically active IL-12 p70 heterodimer is similar in the serum of both BCG-primed or unprimed mice, reaching levels of 1–3 ng/ml at 3–6 h after LPS injection, whereas IFN-γ production was observed only in BCG-primed mice. The priming effect of BCG on IFN-γ production appears to be mostly due to its ability to increase TNF-α production, which acts as cofactor with LPS-induced IL-12 in inducing IFN-γ production, as shown by the ability of injection of TNF-α and LPS (1 γg/mouse), but not LPS alone, to induce IFN-γ production. However, in addition to TNF-α, other LPS-induced cofactor(s) are required in cooperation with IL-12 to induce optimal IFN-γ production, because co-injection of TNF-α and IL-12, sufficient to induce serum concentrations of both cytokines higher and more persistent than those obtained by injection of LPS, was not sufficient to induce IFN-γ production in vivo. Neutralizing anti-IL-12 antibodies, in addition to inhibiting the in vivo LPS-induced IFN-γ production, also completely protect BCG-primed mice injected with up to 10 μg of LPS from shock-induced death. Thus, IL-12 is required for IFN-γ production and lethality in an endotoxic shock model in mice.     

IFN-γ inhibits the production of latent transforming growth factor-β1 by mouse inflammatory macrophages

Transforming growth factor (TGF)-β is a multifunctional cytokine, which in mammals exists in three isoforms (TGF-β1, 2 and 3). It is synthesized by a variety of cells including macrophages, and exerts potent immunoregulatory effects such as the inhibition of Th1 development and the suppression or reversal of IFN-γ-induced macrophage activation. In this study we analyzed the effect of IFN-γ on the production of TGF-β1 by thioglycolate-elicited mouse peritoneal macrophages under serum-free conditions. Untreated macrophages released TGF-β1 in its latent form, which became detectable in a capture ELISA specific for active TGF-β1 after acid activation of the culture supernatants. Treatment with IFN-γ reduced the amount of latent TGF-β1 in the culture supernatants in a dose-dependent fashion. The effect of IFN-γ was confirmed by a newly developed Western blot system for the detection of mouse TGF-β1 protein. IFN-γ only weakly (16 – 24 %) reduced the levels TGF-β1 mRNA at early and late time points of stimulation, and no evidence was obtained that IFN-γ suppresses the secretion of latent TGF-β1. Thus, inhibition of TGF-β1 production by IFN-γ is most likely due to decreased synthesis and/or stability of the TGF-β1 protein, and might be important for the generation of fully activated macrophages and a Th1 response.