摘要:

AbstractBasophils and eosinophils can be activated in vitro by several chemokines such as RANTES, monocyte chemotactic and activating factor (MCAF/MCP‐1), macrophage inflammatory peptide‐1α (MIP‐1α), and interleukin‐8 (IL‐8). To explore the clinical relevance of the in vitro observations, we measured here the concentrations of these chemokines in sputa from asthmatic patients during acute attacks. Before the onset of a late‐phase exacerbation, sputum MCAF/MCP‐1, MIP‐1α, and IL‐8 levels transiently but markedly increased from the basal levels in all of the patients with exacerbation, whereas the sputum levels of these chemokines remained unchanged during the course in the patients without a late‐phase exacerbation. These results suggest the involvement of these chemokines in the late‐phase exacerbation of asthma.

ISSN:0741-5400    

DOI:10.1002/jlb.59.3.313

出版商:Wiley    

年代:1996

数据来源: WILEY

摘要:

AbstractPolymorphonuclear leukocytes (PMNs) play an important role in myocardial ischemia/reperfusion (MI/R) injury. We examined the cardioprotective effects ofN,N,N‐trimethylsphingosine (TMS) in a murine model of MI (20 min) and R (24 h) injury in vivo, focusing on leukocyte‐endothelial interactions. TMS is a synthetic N‐methylated sphingosine derivative that has protein kinase C inhibitory activity and has been shown to prevent leukocyte activation. TMS (18 μg/kg), administered intravenously 1 min prior to reperfusion, significantly attenuated myocardial necrotic injury assessed by myocardial creatine kinase loss compared with MI/R rats receiving only vehicle (P<0.001). Cardiac myeloperoxidase activity, an index of PMN accumulation in the ischemic myocardium, was also significantly attenuated by TMS compared with rats receiving vehicle (P<0.001). We further examined whether TMS can attenuate leukocyte‐endothelial interaction by intravital microscopy. TMS significantly attenuatedNG‐nitro‐l‐arginine–methyl ester (l‐NAME)–stimulated PMN rolling and adherence to the rat microvascular endothelium. This action of TMS appears to be mediated by reduction of P‐selectin expression because immunohistochemical analysis demonstrated that TMS significantly attenuated endothelial P‐selectin expression in the l‐NAME‐superfused rat mesenteric microvasculature. Similarly, TMS markedly attenuated rapid P‐selectin expression in rat platelets stimulated with either thrombin or l‐NAME assessed by flow cytometry. In conclusion, TMS seems to be an effective cardioprotective agent by inhibiting early leukocyte‐endothelial interaction, thus preventing leukocyte accumulation in the ischemic reperfused myocardium.

ISSN:0741-5400    

DOI:10.1002/jlb.59.3.317

出版商:Wiley    

年代:1996

数据来源: WILEY

摘要:

AbstractDuring the course of lupus‐like autoimmune disease male BXSB mice develop an increasing monocytosis in the peripheral blood. As we demonstrated previously, this monocytosis is parallelled by an expansion of a strain‐specific high number of macrophage precursor cells (CFU‐M) in the bone marrow of male mice. To test the hypothesis that the expanded mononuclear phagocyte system (MPS) may promote autoimmune disease in these mice the organ‐associated macrophage system was examined. Our latest data show that an unusual expansion of CFU‐M also appears in spleen and liver of male mice 2 weeks after birth. In addition to a morphological alteration of the organs during the course of the disease there is a change in number and distribution of organ‐resident macrophages. Considering these results the possible contribution of the expanded MPS in promoting autoimmune disease is discussed.

ISSN:0741-5400    

DOI:10.1002/jlb.59.3.325

出版商:Wiley    

年代:1996

数据来源: WILEY

摘要:

AbstractA murine anti‐rat intercellular adhesion molecule 1 (ICAM‐1) monoclonal antibody (mAb), 1A29, was used to investigate the importance of blood leukocyte‐associated β2‐integrin (CD11/CD18)/vascular endothelmm‐associated ICAM‐1 adhesive interactions in the reversed passive Arthus reaction (RPAR) in rats. An Arthus pleurisy reaction (4 h) was employed in these studies because it permits the accurate quantitation of polymorphonuclear neutrophil (PMN) influx into the pleural space and fluid accumulation. 1A29, which localized within Arthus lung lesions, caused a dose‐dependent (0.5–2.0 mg/kg, i.v.) inhibition of PMN influx (19–56%) and exudate volume (9–55%) in the Arthus pleurisy reaction. P7 (2 mg/kg, i.V.), a murine anti‐human P‐selectin mAb used as an isotype‐matched control tor 1A29, did not localize at the lung lesion site and was inactive. Immunohisto‐chemical analysis of lung tissue from 1A29‐treated rats demonstrated increased granulocyte accumulation in the alveolar capillaries compared with more extensive granulocyte emigration into the lung tissue and pleural space in P7‐treated rats and Arthus control rats; however, quantitative image analysis revealed increased numbers of lung granulocytes in 1A29‐treated rats compared with controls. Neither ICAM‐1 mRNA nor expression, assessed by immunocytochemistry, was increased above control levels in rats during the pleural Arthus reaction. Neutropenia was not observed in either 1A29‐ or P7‐treated rats.

ISSN:0741-5400    

DOI:10.1002/jlb.59.3.333

出版商:Wiley    

年代:1996

数据来源: WILEY

摘要:

AbstractIn a parallel study in 10 individual rats, three time series of plasma concentrations of ACTH, corticosterone (CORT), and interleukin‐1β (IL‐1β) were measured before (time 0) and at intervals between 15 and 480 min following intra‐arterial (i.a.) infusions of 25μg/kg lipopolysaccharide (LPS). All LPS injections were given at 9 AM. The first time series was performed on naive rats (day 1). A sequence of six daily injections (days 3–8) of the same dose of LPS followed. The post‐LPS time course of the plasma ACTH, CORT and IL‐1β levels were studied on days 3 (second injection) and 8 (seventh injection). The first LPS injection induced a rapid (30 min) eightfold rise in plasma ACTH and CORT, culminating in concentrations 30 times the baseline at 60 min (ACTH) and 15 times baseline at 120 min (CORT). Both hormones receded back to the initial basal level at 480 min. On the other hand, IL‐1β increased slowly to peak at 13 times baseline 120 min before declining to minimal seven‐ to ninefold basal levels, 480 min and even 48 h post‐LPS. During the second phase of the experiment starting 48 h after the initial LPS priming sequence, the ACTH and CORT responses to daily recurrent LPS injections again differed from those of IL‐1β. The post‐LPS time courses of the ACTH and CORT reaction displayed a typical pattern of a progressive attenuation studied at days 3 and 8. The peak amplitudes at days 3 and 8 were reduced to 60 and 10%, respectively, for ACTH, and to 85 and 45% for CORT of those observed at the first LPS test. The duration of the response (both) was also shortened from 480 min (first LPS test) to 300 min at days 3 and 8. The post‐LPS patterns of the IL‐1β responses were characterized, first by basal levels seven to nine times higher than the initial baseline values (day 1), and by a rapid suppression of the post‐LPS response, with only a slight (30%) increase at day 3 and no increase at day 8. Thus, after both acute and recurrent LPS administration, ACTH/CORT and IL‐1β reacted differently to the endotoxin challenge. The two LPS reactive systems were not correlated. This is inconsistent with the often proposed role of increased plasma IL‐1β release as an intermediary factor in the LPS‐induced recruitment of the corticotropic axis in general infections.

ISSN:0741-5400    

DOI:10.1002/jlb.59.3.341

出版商:Wiley    

年代:1996

数据来源: WILEY

摘要:

AbstractEosinophils play an important role in the pathogenesis of allergic diseases such as allergic asthma. Eosinophil migration in vitro can be divided into directed migration, or Chemotaxis, and random migration, or chemokinesis. Here, we studied intracellular signals involved in eosinophil migration in vitro induced by platelet‐activating factor (PAF) and interleukin‐5 (IL‐5), applying a Boyden chamber assay. Migration induced by PAF (10‐11‐10‐6M) largely consisted of Chemotaxis with some chemokinesis, whereas IL‐5 (10‐12‐10‐8M) induced chemokinesis only. Eosinophils were depleted from intracellular and extracellular Ca2+to study the role of Ca2+as a second messenger. Ca2+depletion did not change PAF‐induced Chemotaxis, however, IL‐5‐induced chemokinesis was inhibited. Interestingly, PAF, but not IL‐5, induced changes in [Ca2+]i. This rise originated mainly from internal stores. Inhibition of protein kinase A by H‐89 and protein kinase C by GF 109203X had no effect on both forms of eosinophil migration. Addition of the protein kinase inhibitor staurosporine significantly inhibited IL‐5‐induced chemokinesis. Inhibition of tyrosine kinases by herbimycin A completely blocked IL‐5‐induced chemokinesis. PAF and IL‐5‐induced actin polymerization was studied to compare migratory responses with a migration‐associated intracellular response. Ca2+depletion significantly enhanced PAF‐induced (10‐8M) actin polymerization, whereas IL‐5‐induced actin polymerization was not influenced. Addition of staurosporine led to an increase in F‐actin. Subsequent addition of PAF or IL‐5 resulted in an additive increase in F‐actin content. In summary, both forms of eosinophil migration are protein kinase A and protein kinase C independent. In contrast to PAF‐induced Chemotaxis, IL‐5‐induced chemokinesis was found to be completely Ca2+and tyrosine kinase dependent.

ISSN:0741-5400    

DOI:10.1002/jlb.59.3.347

出版商:Wiley    

年代:1996

数据来源: WILEY

摘要:

AbstractThe phagocytosis of erythrocytes may contribute to the increased susceptibility to life‐threatening infections in patients with burn injury, sickle cell anemia, and malaria. The phagocytosis of Immunoglobulin G–coated erythrocytes (EIgG) is followed by a transient depression of several macrophage functions including phagocytosis, respiratory burst capacity, and killing of bacteria. The present study suggests the possibility that after erythrophagocytosis hemoglobin‐derived iron conspires with reactive oxygen products of the macrophage respiratory burst to cause oxidant damage to the phagocyte. Challenge of elicited peritoneal macrophages with EIgG phagocytosis was followed by an increase in lipid peroxidation as assessed by thiobarbituric acid–reactive substances (TBARS). Doses of EIgG associated with increased TBARS also caused a depression of Fc receptor–mediated phagocytosis and phorbol myristate acetate (PMA)–stimulated hydrogen peroxide production. Time course experiments demonstrated that the increase in TBARS coincided with the depression of macrophage function. There was no increase in TBARS following the phagocytosis of IgG‐coated erythrocyte ghosts, suggesting that hemoglobin iron is involved in the generation of TBARS. The phagocytosis of erythrocyte ghosts did not depress macrophage function. Since complement receptor–mediated phagocytosis does not stimulate the respiratory burst, the role of the respiratory burst in causing lipid peroxidation was assessed using the phagocytosis of complement‐coated erythrocytes. Phagocytic challenge with complement‐coated erythrocytes caused neither an increase in TBARS nor a depression of macrophage function. However, there was an increase in TBARS when the respiratory burst was stimulated with PMA following complement receptor–mediated phagocytosis of erythrocytes. These results suggest that hemoglobin iron and phagocyte‐generated oxidants collaborate to cause the depression of macrophage function following EIgG phagocytosis.

ISSN:0741-5400    

DOI:10.1002/jlb.59.3.357

出版商:Wiley    

年代:1996

数据来源: WILEY

摘要:

AbstractWe investigated the presence of a galectin‐like protein in rat mononuclear cells using a polyclonal antibody raised against a soluble lactose‐binding lectin purified from adult chicken liver that immunoreacted strongly with a broad protein band of about 16 kd in Western blot assays. Immunochemical studies revealed a constitutive expression of this protein in mononuclear cells mainly in the macrophage (Mφ) population. Subcellular localization was assessed by Western blot assays of the cytosolic and membrane fractions of different cell populations studied: (1) spleen mononuclear cells, (2) T cell‐enriched, (3) B cell‐ and Mφ‐enriched populations, and (4) peritoneal cells, processed in the presence of lactose. In broad agreement with immunocytochemical studies of nonpermeabilized and permeabilized cells, Western blot assays suggest that this protein is localized mainly in the cytoplasmic compartment but also associated with the cell surface. By flow cytometric analyses we detected about a 14% of ED1 double‐positive cells corresponding to Mφs that constitutively express this galectin‐like protein associated with their cell surface. The cytosolic fraction obtained from the Mφ‐enriched cell population showed hemagglutinating activity specifically inhibited by β‐galactoside–related sugars. Moreover, this galectin‐like protein was retained in a lactosyl‐Sepharose matrix and specifically eluted with lactose. In this work, evidence is also provided to show that different stimuli are able to modulate the expression of the galectin‐like protein. Expression was upregulated in inflammatory and activated Mφs, revealing a significant increase in phorbol ester– and formylmethionine oligopeptide–treated cells. Both stimuli involving protein kinase C activation pathway have been able not only to up‐regulate the total expression of this protein but also to modulate its subcellular localization.

ISSN:0741-5400    

DOI:10.1002/jlb.59.3.363

出版商:Wiley    

年代:1996

数据来源: WILEY

摘要:

AbstractGangliosides have diverse immunoregulatory properties. The gangliosides endogenous to macrophages may have immunoregulatory properties that distinguish them from other gangliosides. Gangliosides have been indirectly implicated in macrophage migration as putative cell surface receptors for migration inhibitory factor (MIF). In this study, a monoclonal antibody to human macrophage gangliosides (antibody 25F4) was developed and characterized. This is the first report of the development of monoclonal antibodies to gangliosides of macrophages of any species. Thin‐layer chromatographic immunostaining indicated that antibody 25F4 recognized major gangliosides of human macrophages but did not recognize those previously identified as containing fucose. Immunofluorescent surface labeling of viable human macrophages indicated that antibody 25F4 recognized a surface‐accessible epitope, present on all cells, and that this was abolished with lipid depletion of macrophage membranes. This epitope was not present on several human nonmacrophage cells. Finally, human macrophages pretreated with antibody 25F4 demonstrated striking inhibition of migration in an agarose droplet assay, whereas an irrelevant monoclonal antibody or monoclonal antibodies to nonganglioside surface epitopes of human macrophages had no effect on migration. Migration inhibition occurred even though antibody 25F4 was removed from the extracellular milieu and was not due to formation of cellular aggregates. These studies support a role for human macrophage gangliosides in macrophage migration.

ISSN:0741-5400    

DOI:10.1002/jlb.59.3.371

出版商:Wiley    

年代:1996

数据来源: WILEY

摘要:

AbstractWe tested the hypothesis that apoptosis contributes to the depletion of macrophages expressing the ED1 or ED2 antigen during the resolution of rat muscle inflammation. Muscle inflammation was induced by subjecting rat soleus muscle to 10 days of unloading followed by periods of muscle reloading. Terminal deoxynucleotidyl transferase‐ mediated deoxyuridine triphosphate (dUTP) labeling of apoptotic nuclei showed that apoptotic inflammatory cells increase in concentration within necrotic fibers and in the connective tissue at 2 days following muscle injury caused by increased loading. Four days following injury, the apoptotic cells within damaged fibers returned to control levels, and at 7 days following injury apoptotic cells in the connective tissue returned to control concentrations. No preferential, internucleosomal cleavage of DNA from inflamed muscle was observed, although there was greater fragmentation of DNA in inflamed muscle than in controls. Double labeling studies show that cells expressing either ED1 or ED2 antigen can undergo apoptosis in vivo. The time course of apoptosis and concentration of apoptotic cells within damaged muscle fibers indicates that apoptosis contributes to returning ED1+cells to control concentration during the resolution of inflammation. However, apoptosis of ED2+cells during the first week following injury is not sufficient to return ED2+cell concentrations to control values.

ISSN:0741-5400    

DOI:10.1002/jlb.59.3.380

出版商:Wiley    

年代:1996

数据来源: WILEY