ISSN:0741-5400    

DOI:10.1002/jlb.60.6.675

出版商:Wiley    

年代:1996

数据来源: WILEY

摘要:

AbstractPhagocytes such as neutrophils play a key role in the body's innate immune response to infection. These cells travel throughout the body in search of pathogens and are rapidly mobilized to sites of inflammation where they phagocytose these pathogens and subsequently release a variety of toxic oxygen radical species and proteolytic enzymes to directly destroy the engulfed particle. The generation of microbicidal oxidants by neutrophils results from the action of a multi‐protein enzymatic complex known as the NADPH oxidase. Altogether, there are currently seven proteins reported to be associated with the NADPH oxidase assembly. In resting neutrophils, these NADPH oxidase protein components are segregated into cytoplasmic and plasma membrane compartments. However, during assembly and activation of the NADPH oxidase, the cytosolic protein components translocate to the plasma membrane or phagosomal membrane where they assemble around a central membrane‐bound protein known as flavocytochromeb. This assembly process is highly regulated and involves multiple binding interactions between the individual NADPH oxidase proteins, resulting in an active oxidase complex. Over the past few years, a number of these sites of binding interaction between the oxidase proteins have been identified, leading to a clearer understanding of the intermolecular interactions occurring among protein components during the assembly process. In addition, this information has contributed to our understanding of the roles played by each protein during the activation and assembly process. In this review, we describe the key features of each NADPH oxidase protein and then summarize our current understanding of the specific molecular interactions occurring between these proteins, focusing on the role these protein:protein binding interactions play in the NADPH oxidase assembly process.J. Leukoc. Biol. 60: 677–691; 1996.

ISSN:0741-5400    

DOI:10.1002/jlb.60.6.677

出版商:Wiley    

年代:1996

数据来源: WILEY

摘要:

AbstractActivation of the microvasculature is a major component of the inflammatory response. During inflammation the vascular endothelium not only becomes more permeable to plasma proteins but also develops adhesion molecules that initiate the local immigration of leukocytes. We describe herein the in vivo changes in the three major vascular adhesion molecules during the development and healing of two types of rabbit dermal inflammatory lesions: (1) acute lesions produced in rabbits by the topical application of 1% sulfur mustard (SM, the military irritant/toxicant); and (2) chronic (immune‐mediated) lesions produced in rabbits by intradermal injections ofMycobacterium bovis(BCG), the vaccine strain of tubercle bacillus. In each case, frozen tissue sections were made from lesions of various ages and stained immunohistochemically for von Willebrand (vW) factor to measure the total functional microvasculature. The sections were also stained immunohistochemically for the vascular endothelial adhesion molecules ICAM‐1, ELAM‐1 (E‐selectin), and VCAM‐1, and for the leukocyte ligands for ICAM‐1: LFA‐1 (CDlla/CD18) and Mac‐1 (CD11b/CD18). Infiltrating monocytes and lymphocytes expressed the LFA‐1 ligand and infiltrating PMN expressed the MAC‐1 ligand. The area of stained microvasculature per square millimeter of tissue section was determined with the use of a computerized image analyzer. Edema and cell infiltration spread apart the microvessels, changing the number of microvessels per square millimeter of tissue section. Three methods of assessing such changes are presented. In SM lesions, endothelial ICAM levels were decreased from normal by about 50% at 1 and 2 days (when the lesions reached their peak size) and returned to normal at 3 and 6 days (during the healing process). ELAM rose in peak SM lesions and remained high during healing. VCAM levels, however, were only elevated in the 6‐day (almost healed) lesions. In BCG lesions the levels of endothelial ICAM and VCAM (and to a lesser extent ELAM) were increased at 9 days and remained so as the size of the lesions peaked at 23 days. During the healing phase at 37 days, the elevated ICAM and VCAM levels decreased but the slightly increased ELAM levels persisted. These findings indicate that ELAM plays a major role in acute inflammation and that VCAM and ICAM play major roles in chronic inflammation. VCAM is known to be monocyte and lymphocyte selective.J.Leukoc. Biol. 60: 692–703; 1996.

ISSN:0741-5400    

DOI:10.1002/jlb.60.6.692

出版商:Wiley    

年代:1996

数据来源: WILEY

摘要:

AbstractArachidonic acid (AA), the precursor of eicosanoids, is released from the sn‐2 position of phospholipids by both secretory (8PLA2) and cytosolic phospholipase A2(CPLA2). Eicosanoids have been shown to contribute to bronchospasm in asthma. We measured the enzymatic activity of 8PLA2and CPLA2in the bronchoalveolar lavage fluid and cells, respectively, in male Hartley guinea pigs sensitized with ovalbumin. sPLA2activity was also measured from alveolar macrophages (AM) in culture from unsensitized and sensitized animals. There was an increase in 8PLA2activity and AA content in the lavage fluid following sensitization (18.73 ± 1.33 to 25.74 ± 3.22% hydrolysis and 17.97 ± 12.39 to 44.76 ± 13.37 pmol AA/mL BAL, mean ± SD), which remained elevated but without further increase 4 or 24 h after antigen challenge. AM from unsensitized and sensitized‐unchallenged animals did not secrete 8PLA2 activity in culture for 3 h and therefore do not appear to be the cell source of the sPLA2activity present in the alveolar lavage fluid following OA sensitization. In contrast to the increase in 8PLA2in lung lavage fluid, Western blotting for CPLA2from lung lavage cells showed no increase 4 or 24 h after antigen challenge compared with sensitization alone. CPLA2enzymatic activity of the cytosol fraction of lung lavage cells showed no changes with antigen sensitization or challenge. In summary, intraperitoneal sensitization with ovalbumin in male Hartley guinea pigs caused an increase in both sPLA2and AA in bronchoalveolar lavage fluid without a need for antigen challenge. The increased 8PLA2enzymatic activity following sensitization may be responsible for the elevation of AA in the bronchoalveolar lavage fluid observed after antigen sensitization.J.Leukoc.Biol. 60: 704–709; 1996.

ISSN:0741-5400    

DOI:10.1002/jlb.60.6.704

出版商:Wiley    

年代:1996

数据来源: WILEY

摘要:

AbstractTo gain more insight into the role of cytokines inPneumocystis cariniipneumonia (PCP) we followed pro‐inflammatory cytokine profiles in rats with steroid‐induced PCP at 2‐week intervals. The cytokines measured were immunoreactive interleukin‐1β (IL‐lβ), bioactive interleukin‐6 (IL‐6), and tumor necrosis factor α (TNF‐α). In vivo cytokine concentrations were determined in three compartments, i.e., bronchoalveolar lavage (BAL) fluid, lung homogenatee, and plasma. Lipopotysaccharide (LPS) ‐stimulated cytokine production by alveolar cells and in whole‐blood cultures was measured ex vivo.P.cariniiload and host inflammatory response, as determined by lung/body weight ratio and111indium‐IgG biodistribution were monitored throughout developing PCP. IL‐lβ was elevated in lung homogenatee (600, range<20–1260 pg/mL) and IL‐6 in BAL fluid (48, range<20–115 pg/mL), whereas the pro‐inflammatory cytokine concentrations were not increased in plasma. Thus in rats with PCP elevated pro‐inflammatory cytokine concentrations were found to be restricted to the lung compartments. Corticosteroids did not significantly influence cytokine concentrations, but showed profound inhibitory effects on ex vivo cytokine production. The LPS‐stimulated cytokine production by alveolar cells gradually decreased during the 6 weeks after the start of the steroid injections, whereas the production in whole blood cultures was immediately and completely suppressed.J Leukoc. BioL60: 710–715; 1996.

ISSN:0741-5400    

DOI:10.1002/jlb.60.6.710

出版商:Wiley    

年代:1996

数据来源: WILEY

摘要:

AbstractDaring the international placebo‐controlled trial on the efficacy of interferon‐γ (IFN‐γ) in chronic granulomatous disease (CGD), 19 patients entered the study via our Institute. One patient stopped treatment shortly thereafter. RNA was purified from the mononuclear cells of the remaining 18 CGD patients before and during this placebo‐controlled trial. The mRNA levels for the NADPH oxidase components were subsequently analyzed. Compared with the placebo‐treated CGD patients, the mRNA levels for p4 7‐phoxwere significantly increased in the IFN‐γ‐treated CGD patients (P<0.002). No significant changes were observed in the mRNA levels of the other oxidase components. These findings are in agreement with observations in vitro and indicate that IFN‐γ is active on the NADPH oxidase in vivo as well. However, it remains questionable whether these effects in vivo can explain the observed reduction of infections in these patients.J. Leukoc. Biol. 60: 716–720; 1996.

ISSN:0741-5400    

DOI:10.1002/jlb.60.6.716

出版商:Wiley    

年代:1996

数据来源: WILEY

摘要:

AbstractChimeric receptors that redirect effector cell function to tumor cells or virus‐infected cells have received much attention. Given the high affinity of FcRI for immunoglobulin E (IgE) and low serum IgE levels, redirection of effector cells using Fc receptor may provide a novel, versatile, and effective anti‐tumor strategy. We have used a mouse perforin 5'‐promoter to express a single‐chain human Fc receptor in the mouse cytotoxic T lymphocyte cell line, CTLL‐R8. Upon ligation of the chimeric Fc receptors by IgE, a signal for effector function is transmitted via the intracellular domain of CD3. Selection in G418‐contaming medium produced CTLL‐R8 transfectant clones that: (1) expressed chimeric Fc receptor as determined by flow cytometry; (2) bound human IgE antibodies with high affinity as determined by Scatchard analysis; (3) specifically rosetted IgE‐coated SRBC; (4) lysed target cells in IgE‐mediated ADCC and reverse ADCC assays; and (5) retarded tumor growth in a Winn assay. Therefore these chimeric Fc receptors can effectively redirect cytotoxicity to tumor cells. Future efforts will assess the versatility and efficacy of these IgE‐binding chimeric receptors to redirect killer cell function in animal tumor models.J. Leukoc. Biol. 60: 721–728; 1996.

ISSN:0741-5400    

DOI:10.1002/jlb.60.6.721

出版商:Wiley    

年代:1996

数据来源: WILEY

摘要:

AbstractThe aim of this work was to study in vivo and in vitro the involvement of macrophages and interleukin‐1β (IL‐lβ) in the necrosis of encapsulated islets during xenograft and to evaluate the immuno‐protective efficiency of the AN69 membrane. In vivo, 6 days after implantation, 65% of the membrane surface of the devices containing the islets was colonized with macrophages compared with only 5% of the surface of the empty control devices. The morphological aspect of implanted islets was altered and their insulin release decreased significantly compared with freshly isolated ones (265 ± 50 vs. 507 ± 81 μU/mL). In vitro, the insulin release of encapsulated islets cultured for 2 days decreased to 32 and 28%, respectively, in the presence of IL‐1β and macrophages. The addition of anti‐IL‐1β antibody to the co‐culture of macrophages and islets did not modify this loss of functional activity. Furthermore, IL‐1β passed through the AN69 membrane. In conclusion, macrophages are involved in damaging encapsulated pancreatic islets and are probably partly responsible for islet transplantation failure.J. Leukoc.Biol. 60: 729–736; 1996.

ISSN:0741-5400    

DOI:10.1002/jlb.60.6.729

出版商:Wiley    

年代:1996

数据来源: WILEY

摘要:

AbstractInfectious microorganisms can differently induce or Inhibit apoptosis of immunocompetent effector and host cells. In this study we examined the influence of an infection byCandida albicans(C.albicans) on programmed cell death of monocytic U937 cells and human monocytes. Basal and tumor necrosis factor α (TNF‐α)‐induced DNA fragmentation of U937 cells was significantly inhibited by an infection with C.albicans. Enhanced apoptosis of U937 cells, induced by TNF‐α, caused a diminished candidacidal activity of the effector cells, whereas inhibition of apoptosis by granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) was paralleled by an intensified host defense. Pretreatment of U937 cells or monocytes with the cyclooxygenase blocker indomethacin completely abolished the reduction of DNA fragmentation induced by the yeast. Studying the underlying mechanisms we found that C.albicansinduced formation of prostaglandin E2(PGE2) by U937. Exogenous administration of PGE2down‐regulated apoptosis of U937 or human monocytes to a similar extent as did fungal infection. Activation of protein kinase A by the cAMP analogue 8‐bromo‐cAMP inhibited U937 apoptosis, as did PGE2On the other hand, rp‐cAMP, a blocker of the cAMP‐dependent signal transduction, restored and elevated DNA fragmentation levels down‐regulated by C.albicans. U937 cells expressed the bcl‐2 protein but the infection with fungi or PGE2 treatment did not increase proto‐oncogene expression. Monocytic effector cells may therefore strengthen the defense againstC.albicansby an autocrine feedback regulation via a PGE2‐dependent, cAMP‐transduced inhibition of apoptosis.J. Leukoc. Biol. 60: 737–743; 1996.

ISSN:0741-5400    

DOI:10.1002/jlb.60.6.737

出版商:Wiley    

年代:1996

数据来源: WILEY

摘要:

AbstractVascular endothelial cell addressins play an important role in lymphocyte homing in secondary lymphoid organs and in chronic inflammatory areas. A SV40 large T antigen‐immortalized cell line from peripheral lymph nodes, HECa10 [Bizouarne et al., 1993a], was used to characterize the location of addressing with regard to environmental factors and cytokines. For this purpose, two monoclonal antibodies, MECA 79 and MECA 367, specific for peripheral lymph node vascular addressin and for mucosal addressin (Peyer's patches), respectively, were bound to unstimulated HECa10 cells. Both mucosal and peripheral addressins were detected inside the cells and in cellular extracts of the resting cells. On the cell surface, both addressins could be evidenced on the same cells at a moderate level of expression. They partly mediate the EL4/EL4IL2 lymphoma cells9adhesion to HECa10 cells. Supernatants of cultured peripheral lymph node or Peyers' patch cells induced expression of MECA 79 or MECA 367 antigens, respectively, on the surface of HECa10 cells. Interleukins, IL‐7, IL‐3, and IL‐8, induced the cell‐surface appearance of MECA 79 but not of MECA 367 antigen. Therefore, the same cell type synthesizes both antigens, but the expression of these antigens on the cell surface is independently regulated, thus uncovering a characteristic tissue type‐specific as well as environment‐sensitive properties of microvascular endothelial cells.J. Leukoc. Biol. 60: 744–752; 1996.

ISSN:0741-5400    

DOI:10.1002/jlb.60.6.744

出版商:Wiley    

年代:1996

数据来源: WILEY