ISSN:0741-5400    

DOI:10.1002/jlb.52.1.1

出版商:Wiley    

年代:1992

数据来源: WILEY

ISSN:0741-5400    

DOI:10.1002/jlb.52.1.2

出版商:Wiley    

年代:1992

数据来源: WILEY

摘要:

AbstractWheat germ agglutinin (WGA) has been shown to inhibit the interaction of C5a with the C5a receptor on both polymorphonuclear neutrophils (PMNs) and the histiocytic cell line U937. The level of inhibition with isolated receptor preparations is 100%, and on intact cells 10 to 20% of the receptor population appear to retain their ability to bind C5a in the presence of WGA. In contrast, this lectin completely inhibits the C5a‐mediated degranulation of PMN primary and secondary granules, suggesting that the population of C5a receptors responsible for mediating degranulation is also recognized by WGA. More than 50% of the receptors appear to be blocked before an effect on degranulation occurs. This inhibition by WGA does not appear to be due to down‐regulation of C5a receptors from the cell surface, excessive aggregation of receptor sites, or interaction of WGA with the carbohydrate portion of the C5a molecule. The inhibition is reversed byN‐acetylglucosamine but not by sialic acid. This effect appears to be specific for WGA because various other lectins do not inhibit the C5a receptor interaction. That the inhibition by WGA is due to direct binding of the lectin toN‐acetylglucosamine residues on the C5a receptor is strongly supported by the ability of the cross‐linked C5a‐receptor complex to bind to and be specifically eluted from a WGA‐Affigel affinity matrix. These observations are consistent with hypothesis that the population of C5a receptors on leukocytes exhibits microheterogeneity with respect to structure (carbohydrate content) and/or function.J. Leukoc. Biol.52: 3–10; 1992.

ISSN:0741-5400    

DOI:10.1002/jlb.52.1.3

出版商:Wiley    

年代:1992

数据来源: WILEY

摘要:

AbstractCD66 and CD67 are granulocyte‐specific activation antigens; their surface expression is up‐regulated when neutrophils are activated. CD66 antibodies recognize an ~180‐kd neutrophil surface protein that is also recognized by anti–carcinoembryonic antigen (CEA) antibodies and is therefore a nonspecific cross‐reacting antigen (NCA). CD67 antibodies recognize an ~100‐kd neutrophil surface protein that is attached to the membrane via a glycosyl‐phosphatidylinositol anchor. To identify an intracellular pool from which CD66 and CD67 could be up‐regulated, the subcellular distribution of proteins recognized by CD66 and CD67 monoclonal antibodies and polyclonal anti‐CEA was studied. Neutrophil plasma membranes, granules, and cytoplasm were prepared by nitrogen cavitation and differential centrifugation and then analyzed by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis and immunoblotting. Most of the 180‐kd protein recognized by CD66 antibodies and the 100‐kd protein recognized by CD67 antibodies were located in the secondary granule fraction, with lesser amounts detectable in the plasma membrane fraction. Several NCA species ranging from ~40 to 200 kd were identified, and the distribution of these NCAs was different in the primary granules, secondary granules, and plasma membrane fractions. The major NCAs in the plasma membrane fraction were of ~95 to 100 and ~180 to 200 kd; the secondary granule fraction contained major NCAs of ~42, 85, 95 to 100, and 180 to 200 kd. NCAs were also detected in the primary granule fraction, the most prominent being of ~90–100 kd; no NCA of ~180 to 200 kd was detected in the primary granules. The presence of CD66, CD67, and NCAs in the secondary granules suggests secondary granules as a likely source from which these antigens could be recruited to the cell surface with activation. The potential role for NCAs in the primary granules is unknown.

ISSN:0741-5400    

DOI:10.1002/jlb.52.1.11

出版商:Wiley    

年代:1992

数据来源: WILEY

摘要:

AbstractRecombinant human monocyte–derived interleukin‐8 (IL‐8M), recombinant human endotheliumderived IL‐8 (IL‐8E), and a recombinant human truncated form of IL‐8 (IL‐8T) stimulated a time‐dependent (t1/2~ 2–3 s) and concentration‐dependent (0.1–100 nM) release of azurophil (myeloperoxidase) and specific (vitamin B12binding protein, gelatinase) granule constituents from cytochalasin B–treated human neutrophils (HNs) wherein IL‐8T = IL‐8M>IL‐8E. An increase in the cytosolic free calcium concentration ([Ca2+]i) was greater in IL‐8T– than in IL‐8M– or IL‐8E–activated HNs, and IL‐8T was more potent than either IL‐8M or IL‐8E in sequentially desensitizing the HNs to the effects of the other IL‐8 forms. IL‐8 induced a time‐ and concentration‐dependent (0.1–100 nM) increase in the production of inositol 1,4,5‐trisphosphate (IP3) in HNs. U‐73122 (1‐[6‐[[17β‐3‐methoxyestra‐1,3,5(10)‐trien‐17‐yl]amino]hexyl]‐1H‐pyrrole‐2,5‐dione), a potent inhibitor of phospholipase C–catalyzed events in HNs, suppressed IL‐8–triggered IP3production, increased [Ca2+]iand granule exocytosis in HNs. The membrane‐associated activity of the α and β subtypes of protein kinase C was significantly enhanced in IL‐8–activated cells.

ISSN:0741-5400    

DOI:10.1002/jlb.52.1.17

出版商:Wiley    

年代:1992

数据来源: WILEY

摘要:

AbstractWe have examined the tissue distribution of 10‐kd inflammatory protein (IP‐10) mRNA expression in C57Bl/6 mice injected intravenously (i.v.) with various inflammatory stimuli. IP‐10 mRNA was strongly induced by interferon‐γ (IFN‐γ) in liver and kidney but only poorly in skin, heart, and lung. IFN‐γ had nearly equivalent access to these tissues as indicated by the distribution of radiolabeled recombinant IFN‐γ 1 h after injection. The time course of IP‐10 mRNA appearance was rapid and transient in both liver and kidney; maximal expression in the liver (2 h) preceded that in the kidney (3 h) and declined rapidly thereafter in both tissues. Expression of IP‐10 mRNA in the liver and kidney was highly sensitive to IFN‐γ treatment; nearly maximal stimulation occurred with injection of 500 U of IFN‐γ per mouse. Comparable stimulation of IP‐10 mRNA expression in splenic macrophages required 10,000 U of IFN‐γ administered i.v., indicating that liver and kidney responses are 10‐ to 20‐fold more sensitive. IP‐10 mRNA expression in both tissues was not restricted to stimulation by IFN‐γ but was also seen with injection of lipopolysaccharide (LPS) (25 μg/mouse) or IFN‐β (100,000 U/mouse). Two other members of the IP‐10 gene family, KC (gro) and JE (MCP‐1), were expressed at lower levels under similar treatment conditions. Analysis of IP‐10 mRNA distribution in the liver and kidney by in situ hybridization indicated that expression in both tissues was most prominent in the reticuloendothelial cell system, particularly in the endothelial lining of the microvascular circulation. Although the function of the IP‐10 gene product has not been defined, these results suggest that it may play an important role in the response of both the liver and kidney to systemic inflammation.

ISSN:0741-5400    

DOI:10.1002/jlb.52.1.27

出版商:Wiley    

年代:1992

数据来源: WILEY

摘要:

AbstractA monoclonal has been isolated that labels an intracellular antigen in dendritic cells and some B cells. The M342 hamster immunoglobulin was selected because it stained cells in the periarterial sheaths of spleen, the deep cortex of lymph node, and the thymic medulla –‐ the same regions in which one finds interdigitating cells, the presumptive in situ counterparts of isolated lymphoid dendritic cells. M342 labeled an antigen within granules of isolated dendritic cells, but only in cells that had been cultured for a day and not in fresh isolates. This extends recent findings that most freshly isolated spleen dendritic cells are located in the periphery of the white pulp nodule and may serve as precursors for the periarterial pool of interdigitating cells, the site for M342 staining in situ. By electron microscopic immunolabeling, the M342 antigen was found exclusively in a type of multivesicular body. M342 staining was not found in mononuclear phagocytes from blood and peritoneal cavity. Peritoneal B cells expressed M342+granules, and upon appropriate stimulation splenic B cells developed reactive granules as well. We conclude that M342 is a strong marker for interdigitating cells. Its existence reveals intracellular specializations in the vacuolar system of antigen‐presenting cells including subsets of dendritic cells.

ISSN:0741-5400    

DOI:10.1002/jlb.52.1.34

出版商:Wiley    

年代:1992

数据来源: WILEY

摘要:

AbstractInterleukin‐8 (IL‐8) induces diverse biological responses in neutrophils, including inhibition of adhesion to cytokine‐activated endothelium, which we have termed the leukocyte adhesion inhibition (LAI) effect. Pretreatment of neutrophils with cytochalasin B abolished the LAI effect of IL‐8, suggesting a microfilament‐dependent mechanism. Interleukin‐8 induced a rapid increase (≤ 15 s) in the polymerization of actin filaments in human neutrophils that was blocked by pretreatment with cytochalasin B. F‐actin depolymerization occurred gradually at a rate inversely proportional to IL‐8 concentration. This temporal pattern of actin polymerization‐depolymerization was similar to that induced by other chemotactic factors such as C5a andN‐formylmethionyl‐leucyl‐phenylalanine, which also exhibit a marked LAI effect, but the lipid mediators, leu‐kotriene B4and platelet‐activating factor, lack any significant LAI effect. Scanning confocal microscopy demonstrated that neutrophil actin microfilaments undergo a dramatic rearrangement prior to detachment of the neutrophil from a surface. We suggest that the ability of IL‐8 and certain other leukocyte agonists to regulate the actin polymer network of neutrophils may play an important role in adhesive interactions with the vascular endothelium.

ISSN:0741-5400    

DOI:10.1002/jlb.52.1.43

出版商:Wiley    

年代:1992

数据来源: WILEY

摘要:

AbstractAn antirat monoclonal antibody (mAb) against nonlymphoid dendritic cells, RED‐1, was produced using epidermal Langerhans cells (LCs) as the immunogen. This mAb reacted mainly with the LCs and indeterminate dendritic cells (ICs), interdigitating cells in the T cell areas of lymphoid tissues, and monocyte/macrophages in various organs and tissues of adult rats. In the epidermal sheets prepared from adult rats, it specifically recognized the cell surface antigen(s) present on LCs and ICs. In the fetal rat skin, primitive or fetal macrophages migrated into the epidermis and expressed RED‐1 at fetal day 17. With advance of gestation, RED‐1–positive cells increased, started expressing Ia antigens at fetal day 18, and subsequently differentiated into dendritic cells. Most of them showed Ia expression by fetal day 20 and differentiated into LCs within a few days after birth. The labeling index of 5‐bromo‐2′‐deoxyuridine in RED‐1–positive cells was 18% at fetal day 17 and decreased to 5 to 6% in the postnatal period. These results imply that proliferative capacity of RED‐1–positive cells is important for the formation and expansion of the IC population in the fetal stage and for the survival of LCs in the postnatal period.

ISSN:0741-5400    

DOI:10.1002/jlb.52.1.52

出版商:Wiley    

年代:1992

数据来源: WILEY

摘要:

AbstractMonocytes express cell surface receptors for extracellular matrix (ECM) proteins of basement membranes. These receptors are engaged during extravasation of cells through capillary endothelium into tissue. The number of human immunodeficiency virus (HIV)‐infected monocytes that adhered to ECM over 2 h was threefold higher than that of uninfected control cells. This difference was ECM specific and was not observed with a bovine serum albumin substrate. Enhanced adhesion to ECM was evident in monocytes by 4 days after HIV infection and increased through 10 days. Monocytes exposed to a T cell–tropic HIV strain that binds to but does not replicate in monocytes showed no changes in adherence to ECM. Thus, productive infection of monocytes by HIV induces a significant increase in the capacity of these cells to interact with ECM. Enhanced adhesion of HIV‐infected monocytes to ECM was associated with increased spreading: at 12 h, sixfold more HIV‐infected monocytes were spread on ECM than were uninfected control cells. Cell processes of HIV‐infected monocytes formed a complex network on ECM: many of these cells expressed HIV proteins as detected by indirect immunofluorescence. HIV‐associated cytopathic effects and levels of virion‐associated reverse transcriptase activity depended on the substrate to which monocytes were attached. Virus replication and cytopathic effects in monocytes adhered to ECM, fibronectin, or plastic alone were comparable. In contrast, HIV‐infected monocytes attached to laminin showed a significant increase in virus replication and in extent of cytopathic effects through 2 weeks after infection. The lowest levels of HIV replication and cytopathic effects were in monocytes attached to collagen IV. Interactions between monocytes and ECM profoundly affect the manner in which these cells control HIV infection: HIV infection changes the capacity of infected monocytes to attach and spread on ECM; attachment to ECM alters the extent of virus replication in infected cells.

ISSN:0741-5400    

DOI:10.1002/jlb.52.1.62

出版商:Wiley    

年代:1992

数据来源: WILEY