Effects of chlorpromazine on PMN-mediated activities in vivo and in vitro.

Polymorphonuclear neutrophils (PMN) play a central role in the acute inflammatory response and functions associated with phagocytosis and bacterial killing, including lysosomal enzyme release and superoxide anion (O2-) generation, are also implicated in tissue injury. We have studied the modulation by chlorpromazine (CPZ) on the effects of lipopolisaccharide (LPS) in vivo in mice. Pretreatment with CPZ (4 mg/kg) and, to lesser extent, promethazine, inhibited LPS-induced hypoferraemia and lethality in mice. We have also observed that CPZ (1-15 microns) inhibited lactoferrin release by PMN in vitro, suggesting that this effect could be responsible for the inhibition of hypoferraemia. We have also evaluated the effect of CPZ on other PMN functions implicated in tissue damage and inflammation, chemotaxis and O2- production. CPZ inhibited both activities, although it had chemokinetic activity per se. These data indicate that CPZ is a modular of PMN functions in vivo and in vitro and this effect could be directly implicated in the protective action of CPZ against endotoxic shock.     

Novel chemokine responsiveness and mobilization of neutrophils during sepsis

Blood neutrophils (PMN) are usually unresponsive to CC chemokines such as monacyte chemotactic protein-1 and macrophage inflammatory protein-1 alpha. In rodents, the lung buildup of PMN as determined by myeloperoxidase (MPO) activity after airway instillation of bacterial lipopolysaccharide (LPS) was independent of MCP-1 and MIP-1 alpha. In striking contrast, during sepsis following cecal ligation and puncture (CLP), blood PMN demonstrated mRNA for CC chemokine receptors. Furthermore, PMN from CLP, but not from sham rodents, bound MCP-1 and MIP-1 alpha and responded chemotactically in vitro to both MCP-1 and MIP-1 alpha. In CCR2(-/-) mice or WT mice treated in vivo with antibodies to either MCP-1 or MIP-1 alpha, MPO activity was greatly attenuated in CLP animals. In CLP mice, increased serum IL-6 levels were found to be dependent on CCR2, MCP-1, and MIP-1 alpha. When PMN from CLP rodents were incubated in vitro with either MCP-1 or MIP-1 alpha, release of IL-6 was also shown. These findings suggest that sepsis fundamentally alters the trafficking of PMN into the lung in a manner that now engages functional responses to CC chemokines.     

The effect of a selective 5-lipoxygenase inhibitor,zileuton, on tissue damage in acute colonic inflammation in rats

Though the mechanism of tissue damage induced by colonic inflammation in ulcerative colitis is unknown, it has been established that the inflammatory mediator and potent neutrophil (PMN) chemotaxin, leukotriene B4(LTB₄), is present in elevated amounts in the inflamed mucosa. The unique role of 5-lipoxygenase in the production of leukotrienes has made it a target for inhibition. This study used a rat model of acute colonic inflammation induced by a single IP injection of Mitomycin-C to test the efficacy of a specific and potent 5-lipoxygenase inhibitor zileuton in the treatment of colonic inflammation. We hypothesized that after inducing colitis in rats with mitomycin-C, the administration of oral zileuton would inhibit leukotriene production, thus preventing PMN infiltration and subsequent tissue damage. Zileuton decreased colonic tissue damage as measured by Histological score. However, zileuton did not significantly decrease neutrophil infiltration measured by mucosal PMN or myeloperoxidase (MPO) levels. Although zileuton was successful in significantly decreasing the frequency of severe colitis in our model, the fact that the decrease in PMN count and MPO level was not statistically significant suggests that another mechanism may be involved in its anti-inflammatory effect.     

The effect of vasodilator prostaglandins on polymorphonuclear leukocyte infiltration and vascular injury.

Some severe acute inflammatory reactions are characterized by polymorphonuclear leukocyte (PMN) infiltration as well as vascular and tissue damage with hemorrhage. Two types of mediators that may be involved in such reactions are chemotactic factors and prostaglandins. The chemotactic factors can induce PMN infiltration, while some types of prostaglandins cause vasodilatation. We reported previously that injection of soluble, nonphagocytosable chemotactic stimuli, zymosan-activated plasma (ZAP), or C5a des Arg into rabbit skin induced PMN-dependent hemorrhage. Here we investigated whether prostaglandins may modulate the rate of PMN infiltration, measured with 51Cr-labeled leukocytes and the degree of hemorrhage, measured with 59Fe-labeled red cells. Prostaglandin (PG) E1 (0.5 microgram) or E2 (1 microgram) increased ZAP-induced PMN accumulation by 81% and hemorrhage by 400%. A similar potentiation by PGE2 was observed when submaximal concentrations of ZAP were injected. Prostaglandin F2 alpha had no such effect. These results indicate that the degree of PMN infiltration of the tissues may be one factor determining the severity of vascular damage. Furthermore, vasodilatory prostaglandins, generated during neutrophilic inflammatory reactions, may enhance chemotactic-factor-mediated PMN infiltration and increase the extent of vascular injury.     

The selective augmentation by recombinant human tumour necrosis factor-alpha of neutrophil responses to pathogenic Escherichia coli.

Endotoxin release may amplify the neutrophil (PMN) responses to bacterial infection through the release of monocyte-derived tumour necrosis factor (TNF). The present study was designed to assess the effect of recombinant human TNF-alpha (rhTNF-alpha) on the in vitro response of human PMN to two defined strains of pathogenic Escherichia coli. In the absence of rhTNF-alpha, a P-fimbriate strain caused significant release of the PMN secondary granule marker vitamin B12-binding protein (B12 BP), and a low level of release of leukotriene B4 (LTB4). Type 1-fimbriate strain 504, however, stimulated the release of the primary granule marker myeloperoxidase (MPO) and PMN chemiluminescence (CL), in addition to B12 BP and LTB4 release. Following rhTNF-alpha (10(-9) M) pretreatment, the release of LTB4 by PMN stimulated with the P-fimbriate strain was synergistically augmented, while B12 BP and MPO release were additively increased. In contrast, rhTNF-alpha did not significantly affect any of the responses by the type 1-fimbriate strain. These results suggest selectivity in the priming of PMN by rhTNF-alpha and confirm the independence of PMN responses to phagocytic stimuli.     

Respiratory burst facilitates the digestion of Escherichia coli killed by polymorphonuclear leukocytes.

We examined factors that may limit degradation of bacterial protein of Escherichia coli S15 killed by polymorphonuclear leukocytes (PMN). Both human and rabbit PMN degraded up to 40% of [14C]amino acid-labeled protein of ingested and killed E. coli in 2 h as determined by loss of acid-precipitable radioactivity. In contrast, equally bactericidal broken-PMN preparations or isolated granules degraded only about 10% of bacterial protein regardless of pH. To determine whether activation of the respiratory burst contributes to digestion, we compared degradation by intact PMN in room air and under N2. Depletion of O2 by N2 flushing had no effect on the bactericidal activity of either human or rabbit PMN but reduced degradation by approximately 50%. Protein degradation during phagocytosis was also reduced in the presence of cyanide or azide, inhibitors of myeloperoxidase (MPO). PMN of two patients with chronic granulomatous disease ingested and killed E. coli S15 as well as did normal PMN but degraded bacterial protein as did normal PMN incubated under N2. The low degradative activity of PMN disrupted by sonication could be raised to nearly the level of intact PMN incubated in room air by preincubation of the PMN with 10(-7) M formyl-methionyl-leucyl-phenylalanine (fMLP) before sonication and by pretreatment of E. coli with MPO. Depletion of O2 or chloride during these preincubations with formyl-methionyl-leucyl-phenylalanine respectively, virtually abolished and markedly diminished stimulation of bacterial protein degradation. We conclude that enhanced MPO-mediated O2 metabolism of intact PMN plays a role in the digestion of killed E. coli.     

The differential release of eosinophil granule proteins. Studies on patients with acute bacterial and viral infections

Background: Harlier in vitro studies have suggested that the eosinophil may release its granule proteins selectively depending on the stimulus to which the cell is exposed. Objective: The object of the present study was to study the question of selective release in vivo by means of serum measurements of the two eosinophil granule proteins eosinophil cationic protein (ECP) and eosinophil peroxidase (EPO) in acute infections. Methods: Fourty-six subjects with acute infections were studied before treatment, 20 with bacterial infections and 26 with viral infections. Serum ECP, EPO and MPO were measured by specific RIA. Results: In acute bacterial infections ECP, but not EPO. was significantly raised in serum (P < 0.0001) compared with non-infected healthy subjects. In acute bacterial infections ECP was significantly correlated to the levels of the neutrophil marker myeloperoxidase (MPO) (r_s= 0.96, P < 0.0001) but not to EPO. In acute viral infections neither ECP nor EPO were on average raised. However, almost 20% the patients had elevated levels of both proteins. In the viral infections the serum-levels of ECP and EPO were correlated (r_s= 0.63, P < 0.001), but no correlation was found with MPO Conclusion: It is concluded that eosinophils are activated during acute bacterial infections and that this activation results in the preferential mobilisation of ECP. The simultaneous assay of the two eosinophil proteins, ECP and EPO. may give new insight into the role of the eosinophil in disease.     

Protective effect of dapsone against renal ischemia-reperfusion injury in rat

Abstract

Background: Ischemia/reperfusion can cause injury to tissues and compromise functionality of organs due to inflammatory processes. Significantly, development of these effects in kidney tissue has been a challenging issue that leads to acute renal injury. In this study, anti-inflammatory, anti-oxidative, and protective features of dapsone on kidney ischemia/reperfusion injury were investigated.

Material and methods: Renal ischemia was induced in rats by bilateral renal arteries clamping for 45?min followed by 24?h reperfusion phase. The effects of different doses of dapsone (1, 3, 10?mg/kg) on ischemia/reperfusion injury in kidney tissue were investigated by targeting BUN, Creatinine, LDH, MDA, MPO, IL-1β, TNF-α, and NFκB. In addition histopathological examination was performed by H&E staining method.

Results and discussion: Comparing the findings of this study showed significant reduction in BUN and LDH in 10?mg/kg dapsone received groups, and Cr, MDA, and MPO in 3?mg/kg dapsone received groups. The serum level of TNF-α was significantly decreased with both doses of 3 and 10?mg/kg dapsone. The same results were observed in the serum level of IL-1β and NFκB. Besides, remarkable improvement in histological damages was also observed with dapsone treatment.

Conclusion: These results support the hypothesis that the positive effects of dapsone on the renal ischemia/reperfusion injury are mediated by modulating inflammatory cascades.     

Alpha-hemolysin of uropathogenic Escherichia coli induces GM-CSF-mediated acute kidney injury

Uropathogenic Escherichia coli (UPEC) is the leading cause of urinary tract infections (UTIs), inducing acute pyelonephritis and may result in permanent renal scarring and failure. Alpha-hemolysin (HlyA), a key UPEC toxin, causes serious tissue damage; however, the mechanism through which HlyA induces kidney injury remains unclear. In the present study, granulocyte-macrophage colony-stimulating factor (GM-CSF) secreted by renal epithelial cells was upregulated by HlyA in vitro and in vivo, which induced M1 macrophage accumulation in kidney, and ADAM10 was found involved in HlyA-induced GM-CSF. Macrophage elimination or GM-CSF neutralization protected against acute kidney injury in mice, and increased GM-CSF was detected in urine of patients infected by hlyA-positive UPEC. In addition, HlyA was found to promote UPEC invasion into renal epithelial cells by interacting with Nectin-2 in vitro. However, HlyA did not affect bacterial titers during acute kidney infections, and HlyA-induced invasion did not contribute to GM-CSF upregulation in vitro, which indicate that HlyA-induced GM-CSF is independent of bacteria invasion. The role of GM-CSF in HlyA-mediated kidney injury may lead to novel strategies to treat acute pyelonephritis.     

Cellular basis of host defence in pyelonephritis. III. Deletion of individual components.

Hosts were depleted of individual cellular components to determine the effects of these manipulations on cellular defence mechanisms in acute and chronic pyelonephritis. T-lymphocytes were found to have little or no involvement in host protection but cyclosporin A administration had a dramatic effect on the gross pathology and bacteriological status of experimentally induced pyelonephritis. This change represented a major depression of host defence status. Cyclosporin A also activated resolved lesions in chronic pyelonephritis, associated with an increase in bacterial numbers. Administration of antineutrophil serum also led to a 1000-fold increase in bacterial numbers in the acute phase but had little effect on the host-parasite balance in chronic pyelonephritis. Macrophage blockade, on the other hand, did not affect the course of either acute or chronic infection. These studies have provided additional information on the immunobiology of experimental pyelonephritis and have focussed attention on the role of neutrophils, and an unidentified mechanism, affected by cyclosporin A, in host defence to renal infection.     

Cellular basis of host defence in pyelonephritis. III. Deletion of individual components

Hosts were depleted of individual cellular components to determine the effects of these manipulations on cellular defence mechanisms in acute and chronic pyelonephritis. T-lymphocytes were found to have little or no involvement in host protection but cyclosporin A administration had a dramatic effect on the gross pathology and bacteriological status of experimentally induced pyelonephritis. This change represented a major depression of host defence status. Cyclosporin A also activated resolved lesions in chronic pyelonephritis, associated with an increase in bacterial numbers. Administration of antineutrophil serum also led to a 1000-fold increase in bacterial numbers in the acute phase but had little effect on the host-parasite balance in chronic pyelonephritis. Macrophage blockade, on the other hand, did not affect the course of either acute or chronic infection. These studies have provided additional information on the immunobiology of experimental pyelonephritis and have focussed attention on the role of neutrophils, and an unidentified mechanism, affected by cyclosporin A, in host defence to renal infection.     

In vivo gene silencing (with siRNA) of pulmonary expression of MIP-2 versus KC results in divergent effects on hemorrhage-induced, neutrophil-mediated septic acute lung injury

Lung injury in trauma patients exposed to a secondary infectious/septic challenge contributes to the high morbidity/mortality observed in this population. Associated pathology involves a dys-regulation of immune function, specifically, sequestration of activated polymorphonuclear neutrophils (PMN) in the lungs. The targeting of PMN is thought to involve the release of chemokines from cells within the local environment, creating a concentration gradient along which PMN migrate to the focus of inflammation. Keratinocyte-derived chemokine (KC) and macrophage-inflammatory protein-2 (MIP-2) are murine neutrophil chemokines identified as playing significant but potentially divergent roles in the pathogenesis of acute lung injury (ALI). In the current study, we examined the contribution of local pulmonary cells to the production of KC and MIP-2 and the pathogenesis of ALI. We hypothesized that local silencing of KC or MIP-2, via the local administration of small interference RNA (siRNA) against KC or MIP-2, following traumatic shock/hemorrhage (Hem), would suppress signaling for PMN influx to the lung, thereby reducing ALI associated with a secondary septic challenge (cecal ligation and puncture). Assessment of siRNA local gene silencing was done in green fluorescent protein (GFP)-transgenic, overexpressing mice. A marked suppression of GFP expression was observed in the lung 24 h following intratracheal (i.t.) instillation of GFP siRNA, which was not observed in the liver. To test our hypothesis, siRNA against KC or MIP-2 (75 ug/C3H/Hen mouse) was instilled (i.t.) 2 h post-Hem (35 mm Hg for 90 min, 4x LRS Rx.). Twenty-four hours after, mice were subjected to septic challenge and then killed 24 h later. i.t. MIP-2 siRNA significantly (P < 0.05, ANOVA-Tukey's test, n = 5-6/group) reduced tissue and plasma interleukin (IL)-6, tissue MIP-2 (enzyme-linked immunosorbent assay), as well as neutrophil influx [myeloperoxidase (MPO) activity]. In contrast, KC siRNA treatment reduced plasma KC, tissue KC, and IL-6 but produced no significant reduction in plasma IL-6 or MPO. Neither treatment reduced tissue or plasma levels of tumor necrosis factor alpha compared with vehicle. These data support not only our hypothesis that local pulmonary chemokine production of MIP-2, to a greater extent than KC, contributes to the pathogenesis of PMN-associated ALI following Hem but also the use of siRNA as a potential therapeutic.     

PMN degranulation in relation to CD63 expression and genetic polymorphisms in healthy individuals and COPD patients

Polymorphonuclear neutrophils (PMNs) play an important role in chronic obstructive pulmonary disease (COPD) pathogenesis. The tetraspanin CD63 is a membrane marker of azurophilic granules and is actively involved in the process of PMN endocytosis and azurophilic granule exocytosis. In this study, we investigated genetic polymorphisms of the CD63 gene, quantified CD63 expression and PMN myeloperoxidase (MPO) release in healthy individuals and COPD patients. We evaluated the potential correlations between genetic polymorphisms and gene expression and MPO release. COPD patients had significantly lower CD63 expression and released less MPO upon chemokine stimulation compared with the healthy individuals. Eleven putative polymorphisms in the CD63 gene were investigated but only three were polymorphic in our study subjects. None of the polymorphisms was associated with CD63 expression in either the healthy subjects or the COPD patients. However, the 8041C/G polymorphism, which is located 3' to the CD63 gene, was associated with MPO release in the healthy subjects. The CC genotype was associated with greater MPO release than the GG genotype (P=0.007). These results suggest that COPD patients have different patterns of CD63 expression and PMN mediator release than healthy individuals. It is likely that genetic variants have limited effect on CD63 expression and MPO release in the context of COPD but their role in other diseases has yet to be determined.     

髓过氧化物酶在大鼠哮喘中的作用及地塞米松对其的影响

目的：观察大鼠哮喘中性粒细胞（PMN）及其髓过氧化物酶（MPO）的表达水平及地塞米松（DM）对其的影响。方法：采用大鼠哮喘模型，随机分成哮喘组（A组）、正常对照组（C组）、地塞米松治疗组（D组），对血PMN进行分离纯化和支气管肺泡灌洗液（BALF）进行细胞计数，免疫组化和比色法测定MPO的表达水平。结果：（1）A组血PMN和支气管壁中MPO的表达水平均显著高于C组（P〈0．01）；D组血PMN中其表达水平显著低于A组（P〈0．01），而在支气管壁两者没有显著性差异（P〉0．05）。A组肺组织和BALF中MPO的活性均显著高于C组（P〈0．01，P〈0．05），D组肺组织中其活性显著性低于A组（P〈0．01），而在BALF中两者没有显著性差异（P〉0．05）。（2）A组BALF、肺组织中PMN的计数均显著高于C组（P〈0．01）；D组肺组织中其计数显著高于A组（P〈0．01），而两组BALF中PMN占细胞总数的百分比无显著性差异（P〉0．05）。结论：PMN及其MPO的表达水平在哮喘时增加，PMN可能通过合成MPO参与了哮喘的炎症过程，DM对其合成功能有抑制作用，但加剧PMN在肺组织中聚集。MPO与气道中PMN的浸润密切相关。     

Effect of ingested pentoxifylline on neutrophil superoxide anion production.

Superoxide and other oxygen radicals produced by activated polymorphonuclear leukocytes (PMN) may be important causes of tissue damage in a number of inflammatory conditions. Therefore, a drug which suppresses PMN responses in vivo is potentially important. In vitro, pentoxifylline (PTOX) inhibits superoxide anion production when PMN are stimulated with an activated complement component (C5a Des Arg) or formyl peptides but only at concentrations not achieved in the circulation. The aim of this study was to determine whether PTOX has an effect on PMN responses in vivo. Superoxide anion production, monitored by lucigenin-enhanced chemiluminescence, was inhibited by 40.5% +/- 8.0% (n = 8, P < 0.009) for C5a Des Arg and 47.7% +/- 9.6% (n = 8, P < 0.009) for formyl-methionylleucylphenylalanine stimulation 1.5 h after ingestion of 400 mg of PTOX in a slow-release tablet, with some inhibitory effects persisting at 5 h. There was a strong correlation between reduced PMN response to activated complement and plasma concentrations of three PTOX metabolites (P < 0.05), but not with plasma concentrations of the parent drug. In vitro investigations with each of the four methylxanthines showed two of these metabolites to be most effective at reducing PMN respiratory burst activity, lactoferrin release, and the expression of CD11b and CD18 molecules. Furthermore, this in vitro inhibitory activity was achieved at concentrations of metabolites achievable in vivo. The results suggest that PTOX reduces oxygen radical production and protects against unwanted tissue damage in vivo by the action of its metabolites.     

Interaction of inflammatory cells and oral microorganisms. II. Modulation of rabbit polymorphonuclear leukocyte hydrolase release by polysaccharides in response to Streptococcus mutans and Streptococcus sanguis.

The release of lysosomal hydrolases from polymorphonuclear leukocytes (PMNs) has been postulated in the pathogenesis of tissue injury in periodontal disease. In the present study, lysosomal enzyme release was monitored from rabbit peritoneal exudate PMNs exposed to Streptocccus mutans or Streptococcus sanguis. S. mutans grown in brain heart infusion (BHI) broth failed to promote significant PMN enzyme release. S. sanguis grown in BHI broth, although more effective than S. mutants, was a weak stimulus for promotion of PMN hydrolase release. Preincubation of washed, viable S. mutans in sucrose or in different-molecular-weight dextrans resulted in the ability of the organisms to provoke PMN release reactions. This effect could bot be demonstrated with boiled or trypsinized S. mutans or with viable S. sanguis. However, when grown in BHI broth supplemented with sucrose, but not with glucose, both S. mutans and S. sanguis triggered discharge of PMN enzymes. The mechanism(s) whereby dextran or sucrose modulates PMN-bacterial interaction may in some manner be related to promotion of microbial adhesiveness or aggregation by dextran and by bacterial synthesis of glucans from sucrose.     

Effects of mercury on human polymorphonuclear leukocyte function in vitro.

A variety of heavy metals are recognized as environmental pollutants, and although a significant body of literature exists on the acute toxicity of these metals in various tissues, little is known about the effects of metals such as mercury on host defense. Therefore, the effect of mercuric chloride (HgCl2) on human polymorphonuclear leukocytes (PMN) function in vitro was evaluated. The acute toxicity of HgCl2 for human PMN was calculated initially using vital dye exclusion (trypan blue), and lactate dehydrogenase (LDH) release. Concentrations of HgCl2 less than or equal to 10(-6) M did not induce significant LDH release, or uptake of trypan blue. Additionally, HgCl2 at less than or equal to 10(-7) M produced no ultrastructural alterations in the PMN. The effects of HgCl2 on human PMN functions involved in host defense were evaluated next. HgCl2 consistently suppressed human PMN adherence, polarization, chemotaxis, and erythrophagocytosis at concentrations between 10(-6) and 10(-17) M. Because of the established role of oxygen metabolites in host defense, the effects of HgCl2 on human PMN chemiluminescence and H2O2 production were evaluated next. These studies demonstrated that low concentrations of HgCl2 (ie, 10(-9)-10(-15) M) significantly enhanced chemiluminescence, as well as stimulated H2O2 production by the PMN. These studies clearly demonstrate the ability of extremely low levels of HgCl2 not only to suppress various PMN functions involved in host defense, but also to stimulate oxygen metabolism. In vivo, these HgCl2 effects would not only compromise host defense but also promote tissue injury via the local production of oxygen metabolites.     

Identification of antigen-specific neutrophils in the tonsils with recurrent acute inflammation

Abstract

The pathogenesis of recurrent acute tonsillitis (Rtn) is to be further investigated. Polymorphonuclear neutrophils (PMN) often associate with the pathogenesis of acute and chronic inflammation. This study aims to identify the antigen-specific PMNs (sPMNs) isolated from the tonsillar tissues with recurrent acute inflammation. In this study, CD66b⁺ PMNs were isolated from surgically removed tonsils (40 tonsils were from 20 Rtn patients; 24 tonsils were from 12 tonsil tumour patients) by flow cytometry cell sorting. sPMNs were identified through immunological approaches. We found that compared with the control tonsil samples (from marginal non-tumour tissues of tonsil cancer), Rtn samples showed higher PMN frequency, higher levels of myeloperoxidase (MPO) and neutrophil elastase (NE), in which positive correlation was detected between the inflammatory scores in the Rtn tissues and PMN counts (r?=?.7352; p?=?.0002), or MPO (r?=?.6565, p?=?.0017), or NE (r?=?.6687, p?=?.0013). Upon exposure to tonsillar tissue protein extracts in the culture, a portion of Rtn PMNs was activated and released inflammatory mediators. A complex of tonsillar tissue-specific IgG and FcγRI was observed on the surface of Rtn PMNs; these PMNs could specifically recognize the Rtn tissue extracts and were designated the tonsillar antigen-specific PMNs (sPMNs). A signal transduction pathway of mitogen-activated protein kinase (MAPK)-nuclear factor of T cell activation (NFAT) was activated in sPMNs after exposure to Rtn tissue extracts. In summary, a fraction of sPMN in the Rtn tonsillar tissues was identified and characterized. The sPMNs can be activated upon exposure to tonsil-specific antigens. These sPMNs may contribute to the Rtn pathogenesis.     

Expression of the CXCR6 on polymorphonuclear neutrophils in pancreatic carcinoma and in acute, localized bacterial infections

The chemokine receptor CXCR6 has been described on lymphoid cells and is thought to participate in the homing of activated T-cells to non-lymphoid tissue. We now provide evidence that the chemokine receptor CXCR6 is also expressed by activated polymorphonuclear neutrophils (PMN) in vivo: Examination of biopsies derived from patients with pancreatic carcinoma by confocal laser scan microscopy revealed a massive infiltration of PMN that expressed CXCR6, while PMN of the peripheral blood of these patients did not. To answer the question whether CXCR6 expression is a property of infiltrated and activated PMN, leucocytes were collected from patients with localized soft tissue infections in the course of the wound debridement. By cytofluorometry, the majority of these cells were identified as PMN. Up to 50% of these PMN were also positive for CXCR6. Again, PMN from the peripheral blood of these patients were nearly negative for CXCR6, as were PMN of healthy donors. In a series of in vitro experiments, up-regulation of CXCR6 on PMN of healthy donors by a variety of cytokines was tested. So far, a minor, although reproducible, effect of tumour necrosis factor (TNFalpha) was seen: brief exposure with low-dose TNFalpha induced expression of CXCR6 on the surface of PMN. Furthermore, we could show an increased migration of PMN induced by the axis CXCL16 and CXCR6. In summary, our data provide evidence that CXCR6 is not constitutively expressed on PMN, but is up-regulated under inflammatory conditions and mediates migration of CXCR6-positive PMN.     

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。