脂多糖诱导多形核白细胞和肺泡巨噬细胞凋亡异常在急性肺？…

目的：探讨ＰＭＮ和ＡＭ凋亡异常的机制和意义；为适度调控炎性细胞凋亡防治ＡＬＩ提供理论依据。方法：通过建立大鼠外周血多形核白细胞（ＰＭＮ）和肺泡巨噬细胞（ＡＭ）体外培养，采用流式细胞技术观察ＬＰＳ对上述细胞凋亡的影响。结果：ＬＰＳ加入体外培养大鼠外周血ＰＭＮ中，培养２４h，ＰＭＮ的凋亡率明显降低，ＬＰＳ可明显促进体外培养 的大鼠ＡＭ凋亡，并呈剂量、时间信赖关第。结论：ＬＰＳ诱导ＰＭＮ和ＡＭ细胞凋亡异常     

脂多糖诱导多形核白细胞和肺泡巨噬细胞凋亡异常在急性肺损伤发病中的意义

目的：探讨ＰＭＮ 和ＡＭ 凋亡异常的机制和意义;为适度调控炎性细胞凋亡防治ＡＬＩ 提供理论依据。方法：通过建立大鼠外周血多形核白细胞（ＰＭＮ） 和肺泡巨噬细胞（ＡＭ） 体外培养,采用流式细胞技术观察ＬＰＳ 对上述细胞凋亡的影响。结果：ＬＰＳ 加入体外培养大鼠外周血ＰＭＮ 中,培养２４ ｈ ,ＰＭＮ 的凋亡率明显降低,ＬＰＳ 可明显促进体外培养的大鼠ＡＭ 凋亡,并呈剂量、时间依赖关系。结论：ＬＰＳ 诱导ＰＭＮ 和ＡＭ 细胞凋亡异常可能是失控性全身炎症反应持续发展和加重的重要机制之一。     

还原型谷胱苷肽对肺泡巨噬细胞凋亡的影响

肺泡巨噬细胞 (ａｌｖｅｏｌａｒｍａｃｒｏｐｈａｇｅ ,ＡＭ)是肺部防御病原微生物和肺损伤的第一道防线 ,ＡＭ凋亡的异常可影响肺免疫防御的完整性。中性粒细胞(ＰＭＮ)肺内聚集是导致肺损伤的重要因素 ,ＰＭＮ释放介质对ＡＭ有一定的影响。我们采用体外培养细胞方法原代培养大鼠ＡＭ ,分离并激活ＰＭＮ ,收集上清液与ＡＭ共同孵育 ,观察ＡＭ的形态变化 ,测定培养上清液中ＬＤＨ和ＮＯ的释放情况 ,并以原位凋亡检测法和免疫组化测定Ｆａｓ等反映ＡＭ凋亡的变化 ,以期研究还原型谷胱甘肽 (Ｒ ＧＳＨ)对ＡＭ凋亡的影响。材料和方法ＰＭＮ的…     

细胞性一氧化氮供体的建立及其对肿瘤细胞凋亡的诱导效应

目的一氧化氮（ＮＯ）供体细胞系的建立及其对肿瘤细胞凋亡的诱导效应研究。方法采用３Ｈ－胍氨酸转换法进行ＮＯ合成酶（ＮＯＳ）活性测定；亚硝酸盐检测；ＤＮＡ片段的提取及凝胶电泳分析；凋亡细胞的ＤＡＰＩ染色观察；Ｗｅｓｔｅｒｎｂｌｏｔ分析。结果将ｉＮＯＳ真核表达质粒、ｐＣＭＶ／ｉＮＯＳ转染至Ｓｐ２／０骨髓瘤的变异株中，并获得能稳定表达ｉＮＯＳ和合成ＮＯ的重组细胞系（ＳＰｍｔ／ｉＮＯＳ），表达ｉＮＯＳ的效率为每升培养物含４００μｇ蛋白。利用该细胞作ＮＯ细胞性供体，成功地证实ＮＯ能诱导Ｓｐ２／０骨髓瘤细胞发生凋亡。结论所建细胞性ＮＯ供体应用于ＮＯ的生物学功能研究具有ＮＯ合成稳定；更能模拟体内细胞间ＮＯ的信息传递过程；不需任何外源刺激即可合成ＮＯ等独特优点。所建ＮＯ供体细胞可以用于肿瘤细胞凋亡的研究。     

ROS对小鼠腹腔巨噬细胞凋亡的影响

目的 探讨ＲＯＳ影响巨噬细胞凋亡的机制。方法 激光扫描共聚集显微术,流式细胞术和荧光标记技术等,结果（１）凋亡巨噬细胞内ＤＡＤＰＨ氧化酶活性急剧降低使得胞内ＲＯＳ水平快速上降;（２）ＲＯＳ清除剂促进地塞米松诱导的巨噬细胞凋亡;（３）ＰＫＣ促进巨细胞凋亡和ＲＯＳ急剧减少;ｃＡＭＰ抑制巨噬细胞凋亡和ＲＯＳ急剧减少。结论 （１）ＲＯＳ抑制地塞米松诱导的巨噬细胞凋亡;（２）ＰＫＣ,ｃＡＭＰ等因素通过影响地     

低浓度H2O2对肺微血管内皮细胞的迟发效应--凋亡

目的和方法：对大鼠肺微血管内皮细胞（ＰＭＶＥＣ）培养、鉴定。观察了低浓度Ｈ２Ｏ２（０￣１００μＭ）对体外培养的ＰＭＶＥＣ的迟发性损伤效应。结果：ＭＩＴ法发现Ｈ２Ｏ２对ＰＭＶＥＣ的增殖代谢活性具有剂量依赖性抑制作用,而且当Ｈ２Ｏ２去除后,此作用仍可进一步发展。形态观察、流式细胞仪ＤＮＡ测定、３’末端标记ＤＮＡ降解片断原位检测（ＴＵＮＥＬ）均表明,细胞凋亡是Ｈ２Ｏ２对ＰＭＶＥＣ迟发性损伤效应的一种重要     

绿脓杆菌外毒素A对人PMN功能的影响

为了证明绿脓杆菌外毒素Ａ（ＰＥＡ）对人中性粒细胞（ＰＭＮ）的破坏以及对ｐＭＮ功能的影响，本文报道用不同剂量的ｐＥＡ和作用时间作用于ＰＭＮ，并用抗ｐＥＡ抗体进行中和保护，分别测定完存的ＰＭＮ数目、超氧（Ｏ２－）水平、特殊颗粒（ＳＧ）数目、胞内杀菌力（ＩＣＢＡ）和吞噬百分数。结果表明，ＰＥＡ４０～１００μｇ／ｍｌ作用１～３ｈ，使ＰＭＮ数目、Ｏ２－水平、ＳＧ数目和ＩＣＢＡ测值明显下降，作用２ｈ以后使其吞噬百分数也明显下降；抗ｐＥＡ抗体能阻止上述指标测值的下降（ｐ＜０．０５）。上述结果证实：ＰＥＡ是造成ＰＭＮ杀菌力和完存ＰＭＮ数目下降的直接原因。     

用CL法和微量MPO法观察人参皂甙对人PMN吞噬杀菌作用

采用化学发光（ＣＬ）法和髓过氧化物酶（ＭＰＯ）微量测定法检测了人参茎叶皂甙对人多形核白细胞（ＰＭＮ）吞噬金黄色葡萄球菌的影响。实验结果表明，人参茎叶皂甙作用过的ＰＭＮ－ＣＬ反应（ＣＬ３０和Ｐｅａｋ）和ＭＰＯ释放水平均增强，对ＣＬ３０与ＣＦＵ、ＭＰＯ与ＣＦＵ行直线相关分析均呈密切相关（ｒ＝０．９５８，ｐ＜０．００１；ｒ＝０．８７５，ｐ＜０．０１）。本实验提示，ＰＭＮ－ＣＬ法和ＭＰＯ微量测定法是研究药物对ＰＭＮ吞噬杀菌功能影响的客观、定量和快速的方法。     

P物质对人多形核白细胞功能的影响

目的研究Ｐ物质（ＳＰ）对人多形核白细胞（ＰＭＮ）有关方面作用及可能的意义。方法应用硝基四氮唑蓝（ＮＢＴ）还原法，荧光法和Ｇｒｉｅｓｓ反应等测定不同浓度ＳＰ单独或在细菌衍生肽类似物ＦＭＬＰ甲酯存在下对ＰＭＮ产生超氧阴离子（Ｏ－２，）过氧化氢（Ｈ２Ｏ２），一氧化氮（ＮＯ）和ＰＭＮ膜上一功能酶中性内肽酶（ＮＥＰ）活性及膜流动性的影响。结果ＳＰ（≥１０－５ｍｏｌ／Ｌ）可剌激ＰＭＮ显著产生Ｏ－２，Ｈ２Ｏ２和ＮＯ，后者被Ｌ－单甲基精氨酸（ＮＭＭＡ）所抑制；ＳＰ（１０－８～１０－４ｍｏｌ／Ｌ）能显著增加ＦＭＬＰ甲酯剌激ＰＭＮ产生Ｈ２Ｏ２，并显浓度递增依赖性；ＳＰ与ＦＭＬＰ甲酯协同可下调ＮＥＰ活性；ＳＰ能提高ＰＭＮ膜流动性。结论ＳＰ可通过ＰＭＮ介导调节炎症反应，对ＰＭＮ的杀菌功能有增强作用，ＳＰ对ＰＭＮ的这些影响可能是神经系统参与炎症和免疫调节的途径之一。     

多形核白细胞在内毒素休克时肝组织损伤中的作用

家兔输注内毒素０．３ｍｇ／ｋｇ复制内毒素休克模型。输注４ｈｒ以后ＰＭＮ吞噬发光和Ｏ＾－２生成呈持续升高（Ｐ＜０．０５～０．０１），同时激活的ＰＭＮ释放氧自由基损伤肝细胞，引起肝细胞内ＭＤＡ含量和培养上清ＬＤＨ活性升高（Ｐ＞０．０５～０．０１）。体外内毒素与ＰＭＮ共孵，ＰＭＮ吞噬发光和Ｏ＾－２生成呈先升高后回降的变化，经内毒素在体外激活的ＰＭＮ也能明显引起肝细胞内ＭＤＡ含量和上清ＬＤＨ活性升高（Ｐ＜     

Concurrent lipopolysaccharide enhances chemotactic response of human polymorphonuclear leukocytes to bacterial chemotaxin

Polymorphonuclear neutrophil (PMN) function is thought to be critical in resistance to infectious agents and this implies that the PMN must be able to migrate into, and to function in, environments that may have high levels of bacterial lipopolysaccharide (LPS). Therefore, we have evaluated the effect of LPS on the in vitro migration of PMNs. Our data reveal that the human PMN is resistant to the deleterious effects of high levels of LPS, that in high concentrations LPS is, itself, a direct chemoattractant for PMNs, and that PMN migration toward a bacterial chemotaxin is enhanced if LPS is also present. Such capabilities suggest that the PMN may be uniquely qualified to migrate into microenvironments that are rich in LPS.     

Effects of Aspergillus fumigatus gliotoxin and methylprednisolone on human neutrophils: implications for the pathogenesis of invasive aspergillosis

Aspergillus fumigatus (AF) is a ubiquitous mold and the most common cause of invasive aspergillosis (IA) in immunocompromised patients. In stem cell transplant recipients, IA now occurs most frequently in the setting of therapy with corticosteroids, including methylprednisolone (MP). We showed previously that gliotoxin (GT), an AF-derived mycotoxin, induces apoptosis in monocytes and dendritic cells, resulting in the suppression of AF-specific T cell responses. We examined the ability of GT to induce apoptosis in polymorphonuclear leukocytes (PMN) and assessed GT effects on important neutrophil functions, including phagocytic function, degranulation, myeloperoxidase activity, and the production of reactive oxygen species (ROS). In contrast to its effects on monocytes, PMN remained resistant to GT-mediated apoptosis. Although many essential neutrophil functions were unaffected, GT inhibited phagocytosis and also induced a decrease in ROS generation by PMN. In contrast, MP therapy potentiated ROS production, suggesting a mechanism that may facilitate tissue injury in IA. Distinct from its effects on untreated PMN, GT augmented ROS production in MP-treated PMN. Our results suggest that although GT may suppress the adaptive immune response, GT may also serve to increase PMN-mediated inflammation, which is likely to play an important role in tissue destruction in the setting of IA.     

Leukotriene B4 receptor (BLT-1) modulates neutrophil influx into the peritoneum but not the lung and liver during surgically induced bacterial peritonitis in mice

Leukotriene B4 (LTB4) is a rapidly synthesized, early neutrophil chemoattractant that signals via its cell surface receptor, BLT-1, to attract and activate neutrophils during peritonitis. BLT-1-deficient (BLT-1(-/-)) mice were used to determine the effects of LTB4 on neutrophil migration and activation, bacterial levels, and survival after cecal ligation and puncture (CLP). Male BLT-1(-/-) or wild-type (WT) BALB/c mice underwent CLP. Tissues were harvested for determination of levels of bacteria, myeloperoxidase (MPO), LTB4, macrophage inflammatory protein 2 (MIP-2), and neutrophil (polymorphonuclear leukocyte [PMN]) numbers at 4 and 18 h after CLP. PMN activation was determined by an assessment of phagocytosis ability and CD11b expression. Survival was also determined. BLT-1(-/-) mice had decreased numbers of PMNs in the peritoneum at both 4 and 18 h after CLP but increased numbers of PMNs in the blood at 18 h compared with WT mice. Liver and lung MPO levels were significantly higher in BLT-1(-/-) mice at both 4 and 18 h after CLP, with increased bacterial levels in the blood, the liver, and peritoneal fluid at 4 h. Bacterial levels remained higher in peritoneal fluid at 18 h, but blood and liver bacterial levels at 18 h were not different from levels at 4 h. PMN phagocytosis and CD11b levels were decreased in BLT-1(-/-) mice. LTB4 levels were similar between the groups before and after CLP, but MIP-2 levels were decreased both locally and systemically in BLT-1(-/-) mice. Survival was significantly improved in BLT-1(-/-) mice (71%) compared with WT mice (14%) at 48 h post-CLP. Thus, LTB4 modulates neutrophil migration into the mouse peritoneum, but not the lung or liver, after CLP. Despite higher bacterial and PMN levels at remote sites, there was increased survival in BLT-1(-/-) mice compared to WT mice. Decreased PMN activation may result in less remote organ dysfunction and improved survival.     

Leukocyte spreading behavior on vascular biomaterial surfaces: consequences of chemoattractant stimulation

Chemoattractant-induced phenomena of polarity and migration of polymorphonuclear leukocytes (PMN) are believed to play a key physiological role in controlling bacterial infections on implantable vascular biomaterials. Our study targeted the spreading behavior of human PMN adherent to expanded polytetrafluoroethylene (ePTFE), pretreated with various plasma proteins, in response to the chemoattractant, N-formyl-methionyl-leucyl-phenylalanine (fMLP). To this end, a novel imaging configuration was developed to allow in situ reconstructive analysis of PMN 3-D morphology on opaque ePTFE surfaces, using optical sectioning confocal microscopy. Following fMLP stimulation, PMN morphological polarity was enhanced on all substrates studied except fibrinogen treated ePTFE. 3-D PMN morphometry revealed that in the absence of fMLP, overall cell spreading was minimized on albumin-treated ePTFE and maximized on fibrinogen and immunoglobulin-G-treated ePTFE. Following fMLP stimulation, overall PMN spreading increased markedly on untreated and albumin-coated ePTFE, while it stayed invariant on IgG and plasma treated ePTFE, and decreased on fibrinogen-treated ePTFE. Spatial analysis of PMN spreading following fMLP stimulation revealed enhanced PMN attachment on untreated and albumin treated ePTFE and diminished attachment on fibrinogen and plasma treated ePTFE. Thus, chemoattractant stimulation altered a wide range of PMN spreading attributes on ePTFE, including morphological polarity, substrate attachment, and 3-D membrane spreading, in a substrate dependent manner. These chemoattractant-induced spreading responses may also have important consequences for PMN phagocytosis. We report that fMLP stimulation led to enhanced unopsonized particulate phagocytosis on untreated and albumin treated ePTFE, but caused no discernible change in phagocytosis on other protein substrates. Thus, chemoattractant modulation of PMN spreading on ePTFE is highly substrate-regulated, and manifests in concerted effects on PMN phagocytosis.     

Increased Escherichia coli phagocytosis in neutrophils that have transmigrated across a cultured intestinal epithelium

The functionality of polymorphonuclear leukocytes (PMNs) once they migrate into the digestive lumen is still ill defined. More specifically, phagocytic function and bactericidal action of PMNs after transepithelial migration have not received much attention. The aim of the present study is to compare PMN behavior before and after transepithelial migration, in particular (i) phagocytosis and bactericidal activity; (ii) expression of surface molecules, particularly those involved in phagocytosis; and (iii) apoptosis. Cultured human intestinal epithelial T84 cell monolayers were used. The effect of transepithelial migration on phagocytosis was evaluated by immunofluorescence and electron microscopy and by flow cytometric assessment of the engulfment of a strain of Escherichia coli transfected with the green fluorescent protein. Superoxide production by PMNs was investigated by luminol-mediated chemiluminescence. Expression of various surface molecules on PMNs was evaluated by flow cytometry, while PMN apoptosis was assayed by morphologic changes and DNA fragmentation. E. coli phagocytosis by the PMNs was markedly increased after transepithelial migration without modification of superoxide production. CD11b/CD18 and CD47 expression was increased upon PMN transmigration, whereas CD16 expression was decreased and CD29, CD46, CD49e, CD49f, CD55, CD59, CD61, CD95 levels remained unchanged. Apoptosis in transmigrated PMNs was slightly advanced and was observed after 12 h compared to 16 h for nontransmigrated PMNs. In conclusion, the phagocytic capacity of the PMNs is augmented after transepithelial migration, with a dramatic increase in the level of CD11b/CD18 and preservation of the superoxide production. These results suggest a higher bactericidal activity of the PMNs once they have translocated into the digestive lumen.     

Fas activation reduces neutrophil adhesion to endothelial cells

Polymorphonuclear neutrophils (PMN) express apoptotic markers and lose effector functions including adhesion, chemotaxis, and phagocytosis when cultured overnight. Although the loss of function correlates with apoptosis, it is not clear if functions are lost before an early marker of apoptosis, the display of phosphatidylserine (PS), targets PMN for removal by phagocytic cells. To address this question, freshly isolated PMN were treated with Fas-activating antibodies to induce apoptosis rapidly. Early markers of apoptosis and PMA-stimulated adhesion to endothelial cells were measured. After 1 h of Fas exposure, only 16% PMN had externalized PS. In contrast, Fas activation reduced PMA-stimulated adhesion between 68 and 27% depending on PMA concentration. The loss of adhesion was accompanied by a reduction in beta2 integrin expression and receptor clustering. These results indicate that the Fas-induced loss of adhesion may precede PS externalization and could limit participation in the inflammatory response before PS externalization targets PMN for removal.     

Induction of necrosis and apoptosis of neutrophil granulocytes by Streptococcus pneumoniae

Apoptosis followed by macrophage phagocytosis is the principal mechanism by which neutrophil granulocytes (PMN) are removed from the site of inflammation. To investigate whether Streptococcus pneumoniae causes apoptosis of PMN, we exposed PMN to viable and heat-killed pneumococci and purified pneumococcal cell walls (PCW). The occurrence of PMN cell death was quantified by flow cytometry using annexin V/propidium iodide labelling of the cells. Intracellular histone-associated DNA fragments were quantified by ELISA. The presence of apoptosis was confirmed by in situ tailing. Exposure of PMN to viable pneumococci caused necrosis of the cells. The pneumococcal cytotoxin pneumolysin, the bacterial production of hydrogen peroxide, and PCW contributed to necrosis. Heat-killed pneumococci accelerated the process of apoptosis observed in cultivated non-stimulated PMN in vitro. These results demonstrated that pneumococci induce PMN cell death. Depending on the intensity of the stimulus, PMN necrosis and apoptosis were observed.     

Recognition of apoptotic cells by human peripheral blood monocytes does not alter their ability to phagocytize and kill Staphylococcus aureus

INTRODUCTION: During acute inflammation, leukocyte infiltration is mostly neutrophilic, but later monocytes prevail. The majority of inflammatory cells, particularly neutrophilic polymorphonuclear leukocytes (PMNs), become apoptotic at later stages of inflammation and are phagocytosed by neighboring cells, mostly by macrophages. Recently, it has been found that human peripheral blood monocytes also recognize apoptotic cells, which primes them to increased production of interleukin (IL)-10--a cytokine known to reduce phagocytes' ability to engulf and kill pathogens. Based on the above, we studied monocytes' ability to phagocytose and kill Staphylococcus aureus while in contact with apoptotic cells. MATERIALS AND METHODS: Monocytes isolated by elutriation were co-cultured with apoptotic PMNs or Jurkat cells and exposed to viable, human serum-opsonized S. aureus. To induce apoptosis PMNs were cultured overnight while Jurkat cells were UV-treated. Apoptosis, phagocytosis of bacteria and intracellular superoxide production were measured by flow cytometry. Production of reactive oxygen species was also followed by measurement of chemiluminescence. The bactericidal effect was determined by standard colony forming units method. RESULTS: Data presented show that contact of monocytes with apoptotic neutrophils and Jurkat cells had no influence on monocyte phagocytosis of S. aureus, the generation of reactive oxygen species, or the killing of bacteria. CONCLUSION: The data obtained suggest that monocytes attracted to the inflammatory site are not deficient in their ability to cope with pathogens after contact with apoptotic cells despite increased production of IL-10.     

Endomorphins delay constitutive apoptosis and alter the innate host defense functions of neutrophils

Recent studies have shown that opioid peptides are released from cells of the immune system during inflammation and stress, and are associated with altered immune responses. Moreover, concentrations of opioid peptides are increased in peripheral blood and at the sites of inflammatory reactions. The aim of this study was to evaluate immunological effects of opioid peptides endomorphins 1 and 2 on constitutive apoptosis, superoxide anion production, hydrogen peroxide production, adhesion, phagocytosis, and chemotaxis of neutrophils. Neutrophils were isolated by peritoneal lavage from rats. Endomorphins 1 and 2 significantly delayed constitutive neutrophil apoptosis. The delay of neutrophil apoptosis was markedly attenuated by LY294002, a phosphoinositide 3-kinase inhibitor. Moreover, endomorphins 1 and 2 activated the phosphoinositide 3-kinase pathway as determined by phosphorylation of BAD. In contrast, endomorphins 1 and 2 blocked the production of superoxide anion and hydrogen peroxide by PMA-stimulated neutrophils. In addition, endomorphins 1 and 2 inhibited neutrophil adhesion to fibronectin. Moreover, endomorphins 1 and 2 potentiated neutrophil chemotaxis toward zymosan-activated serum and IL-8, respectively. However, endomorphins 1 and 2 did not alter phagocytosis of Escherichia coli by neutrophils. These results suggest that endomorphins 1 and 2 may act to delay neutrophil apoptosis and alter the natural immune functions of neutrophils.     

Direct effect of human immunodeficiency virus protease inhibitors on neutrophil function and apoptosis via calpain inhibition

Impairment of neutrophil functions and high levels of apoptotic neutrophils have been reported in human immunodeficiency virus (HIV) patients. The aim of the present study was to investigate the direct in vitro effects of the different HIV protease inhibitors (PIs) on neutrophil functions and apoptosis and to explore their mechanisms of action. The effects of nelfinavir (NFV), saquinavir (SQV), lopinavir (LPV), ritonavir (RTV), and amprenavir (APV) in the range of 5 to 100 microg/ml on neutrophil function, apoptosis, and mu-calpain activity were studied. The neutrophil functions studied included superoxide production stimulated by 5 ng/ml phorbol myristate acetate, 5 x 10(-7) M N-formyl-methionyl-leucyl-phenylalanine, and 1 mg/ml opsonized zymosan; specific chemotaxis; random migration; and phagocytosis. Apoptosis was determined by DNA fragmentation, fluorescein isothiocyanate-annexin V binding, and nuclear morphology. All three neutrophil functions, as well as apoptosis, were similarly affected by the PIs. SQV and NFV caused marked inhibition and LPV and RTV caused moderate inhibition, while APV had a minor effect. mu-Calpain activity was not affected by the PIs in neutrophil lysate but was inhibited after its translocation to the membranes after cell stimulation. SQV, which was the most potent inhibitor of neutrophil functions and apoptosis, caused significant inhibition of calpain activity, while APV had no effect. The similar patterns of inhibition of neutrophil functions and apoptosis by the PIs, which coincided with inhibition of calpain activity, suggest the involvement of calpain activity in the regulation of these processes.