bluuebunny/crossref_metadata_2025 huggingface dataset:
A recombinant amino terminal fragment of bactericidal/permeability-increasing protein inhibits the induction of leukocyte responses by LPS
Authors: Mészaros Károly , Parent J Brian , Gazzano-Santoro Hélène , Little Roger , Horwitz Arnold , Parsons Thomas , Theofan Georgia , Grinna Lynn , Weickmann Joachim , Elsbach Peter , Weiss Jerrold , Conlon Paul J
Published: January 2018

Bactericidal/permeability-increasing protein (BPI) is a major component of the granules of polymorphonuclear neutrophils (PMNs) and is involved in the killing of gram-negative bacteria. A 23-kd recombinant protein, corresponding to the NH2-terminal fragment of human BPI (rBPI23), has been shown to bind lipid A and antagonize some lipopolysaccharide (LPS)-mediated effects. In this study the ability of rBPI23 to prevent a wide range of cellular responses to LPS was investigated. In vitro assays were carried out using human blood to more closely approximate in vivo conditions. The release of proinflammatory cytokines [tumor necrosis factor (TNF), interleukin-1β (IL-1β), IL-6, IL-8], induced by E. coli 0113 LPS, was markedly reduced by rBPl23 in a concentration-dependent fashion. The production of the anti-inflammatory protein IL-lra (IL-1 receptor antagonist) was triggered by lower LPS concentrations than those necessary for the other cytokines. Furthermore, prevention of IL-lra release required higher rBPl23 concentrations than for other cytokines. The LPS-induced production of oxygen-derived free radicals by phagocytic cells (resulting in chemiluminescence) was also prevented by rBPl23· The inhibition was specific for LPS because the activation of leukocytes by phorbol myristate acetate, zymosan, or TNF was unaffected by BPI. The ability of rBPl23 to antagonize specifically the effects of endotoxin in the complex environment of human blood along with its bactericidal activity suggests that rBPI23 may be a novel therapeutic agent in the treatment of gram-negative infections.
CD18 integrin-dependent endothelial injury: effects of opsonized zymosan and phorbol ester activation
Authors: Lum Hazel , Gibbs Lester , Lai Linda , Malik Asrar B
Published: January 2018

We examined the hypothesis that neutrophil (PMN)-mediated injury of the vascular endothelium is dependent on adhesion of PMNs to endothelial cells via the leukocyte adhesion glycoprotein CD11/CD18. We compared the PMN activation responses [i.e. adhesion to cultured endothelial cells, superoxide (O2-) production, degranulation, and cytosolic [Ca2+] ([Ca2+]i)] and endothelial injury elicited by opsonized zymosan (OZ, which is phagocytosed by PMNs) or phorbol 12-myristate 13-acetate (PMA, a protein kinase C activator). The basal adherence of nonstimulated PMNs to bovine pulmonary artery endothelial cells (BPAEC) was 9.0 ± 1.1 PMN/field. PMA and OZ increased PMN adherence to BPAEC (to 31.1 ± 1.4 and 39.8 ± 3.8 PMN/field, respectively), which in both cases was inhibited by anti-GDI 8 monoclonal antibody (mAb) IB4. Stimulation of PMNs with PMA or OZ produced injury to 73% and 53% of BPAEC examined, respectively, which corresponded to 6.8-fold and 3.5-fold increases in transendothelial 125I-albumin permeability from baseline. Pretreatment of PMNs with mAb IB4 prevented endothelial injury in both cases. Both PMA and OZ increased the production of O2- (by 7.6-fold and 3.1-fold over control, respectively) and promoted the release of myeloperoxidase (5.2-fold and 9.1-fold over control, respectively) (P < .01). IB4 did not inhibit the PMA- or OZ-induced increases in O2-. IB4 did not inhibit the PMA-induced myeloperoxidase release but reduced by 29% the OZ-induced myeloperoxidase release. Stimulation of PMNs layered on BPAEC with OZ (0.5 mg/ml) caused an 7-fold increase in PMN [Ca2+]i over baseline, which decayed to a steady-state level above baseline at 10 min. IB4 (10 μg/ml) alone did not alter baseline [Ca2+]i and did not inhibit the OZ-induced increase in [Ca2+]i. In contrast to OZ, stimulation of PMNs with PMA did not increase [Ca2+]i. The results indicate that the protective effects of the anti-CD18 mAb IB4 were associated predominantly with its antiadherence property. Therefore, CD18 integrin-mediated PMN adhesion to the endothelium is a critical determinant of endothelial injury irrespective of the PMN-activating stimulus. J. Leukoc. Biol. 55: 58–63; 1994.
Induction of osteopontin mRNA expression during activation of murine NK cells
Authors: Pollack Sylvia B , Linnemeyer Paul A , Gill Santokh
Published: January 2018

Osteopontin (OPN) is an extracellular phosphorylated glycoprotein expressed in bone, kidney, nervous tissue, bone marrow, and granulated metrial gland (GMG) cells in murine decidua. We recently demonstrated that GMG cells are differentiated natural killer (NK) lineage cells that share phenotypic, functional, and morphologic characteristics with adherent interleukin-2 (IL-2)-activated NK cells. We now show that conditions that induce resting splenic NK cells to develop into adherent, activated cells induce the expression of opn mRNA. Nonstimulated NK cells did not express opn mRNA detectable by Northern analysis. However, expression was evident by day 1–2 of culture of NK cells with IL-2, increased to high levels by day 4, and was maintained at high levels thereafter. Thus, expression of mRNA for OPN, a secreted protein associated with cell adhesion, embryonic development, tissue remodeling, and immune regulation, is up-regulated during the activation of NK cells. J. Leukoc. Biol. 55: 398–400; 1994.
Macrophages and angiogenesis
Authors: Sunderkötter Cord , Steinbrink Kerstin , Goebeler Matthias , Bhardwaj Ranjit , Sorg Clemens
Published: January 2018

Macrophages are supposed to play a key role in inflammatory and tumor angiogenesis. Their importance derives from (1) their ubiquitous presence in normal and especially inflamed tissues, (2) their potential to become activated in response to appropriate stimuli, and (3) their repertoire of secretory products. By release of proteases, growth factors (bFGF, GM-CSF, TGF-α, IGF-I, PDGF, VEGF/VPF, TGF-β), and other monokines (IL-1, IL-6, IL-8, TNF-α, substance P, prostaglandins, interferons, thrombospondin 1), activated macrophages have the capability to influence each phase of the angiogenic process, such as alterations of the local extracellular matrix, induction of endothelial cells to migrate or proliferate, and inhibition of vascular growth with formation of differentiated capillaries. This review describes macrophage physiology and the influence of macrophage secretory products on the different phases of angiogenesis in vitro and in vivo. J. Lcukoc. Biol. 55: 410–422; 1994.
Differential expression of CD43 (leukosialin, sialophorin) by mononuclear phagocyte populations
Authors: Howell David N , Ahuja Vinita , Jones Lisa , Blow Osbert , Sanfilippo Fred P
Published: January 2018

CD43 is a hematopoietic cell antigen whose distribution includes T lymphocytes, plasma cells, neutrophils, and platelets. Although it has been detected on peripheral blood monocytes, its expression by other mononuclear phagocytes has not been well documented. Possible changes in monocyte/macrophage CD43 expression in response to inflammation are also poorly defined. To examine these questions, the expression of CD43 by rat peripheral blood monocytes and both resident and elicited peritoneal macrophages was examined. By flow cytometry with two anti-CD43 monoclonal antibodies, blood monocytes were found to express large amounts of surface CD43, whereas surface CD43 expression by resident peritoneal macrophages was negligible. Peritoneal macrophage populations elicited by intraperitoneal injection of thioglycollate were uniformly positive for surface CD43, although the level of expression was lower than that found on monocytes. By labeling resident macrophages with a fluorescent tracer dye, this phenotypic shift was found to reflect an influx of CD43-positive elicited macrophages coupled with a disappearance of CD43-negative resident cells. Evidence from both flow cytometry and Western blotting studies suggests that the CD43 expressed by elicited peritoneal macrophages is less heavily sialylated than that expressed by blood monocytes. These findings, coupled with recent evidence that CD43 influences cellular adhesion, indicate that differential expression of CD43 may play a role in monocyte/macrophage trafficking. J. Leukoc. Biol. 55: 536–544; 1994.
Heterogeneous spontaneous and interleukin-4–induced nitric oxide production by human monocytes
Authors: Mautino Gisèle , Paul-Eugène Nathalie , Chanez Pascal , Vignola Antonio M , Kolb Jean Pierre , Bousquet Jean , Dugas Bernard
Published: January 2018

The generation of nitric oxide by human monocytes has long been a subject of controversy because of the difficulty of rationalizing this production. In this work we evaluated the capacity of human monocytes to produce nitric oxide (NO) as measured by nitrite (NO2-) release. Resting unstimulated monocytes (2 106 cells/ml) were found to produce significant amounts of NO2- after 8 to 12 days in culture. This production appeared to be highly heterogeneous. Indeed, approximatively, 75% of monocytes from the different donors produced up to 10 μM NO2- and were considered low producers; the last 25% produced higher amounts of NO2- (from 10 to 110 μM) and were considered high producers. In any case the spontaneous production of NO2- by monocytes was overcome in the presence of 1 mM Nω-monomethyl-l-arginine (LNMMA). This inhibitory effect was reversed in the presence of an excess of l-arginine (5 mM), indicating that this process is effectively dependent on l-arginine metabolism. Because interleukin-4 (IL-4) is considered an important NO-regulatory cytokine, its regulatory effect on this spontaneous production of NO was also evaluated. In the presence of a defined dose of IL-4 (1 to 100 ng/ml) the spontaneous production of the high-producing population of monocytes was abrogated, whereas IL-4 stimulated the production by the low-producing population of monocytes, which was suppressed in the presence of LNMMA. The present data indicate that NO production by human monocytes is heterogeneous and that IL-4 can be a potent inducer or inhibitor of this production, suggesting a variability in the activation state of these cells. J. Leukoc. Biol. 56: 15–20; 1994.
Cellular and viral determinants that regulate HIV-1 infection in macrophages
Authors: Stevenson Mario , Gendelman Howard E
Published: January 2018

Macrophages in brain, lung, and lymphatics constitute a major HIV reservoir during subclinical infection and disease. During HIV transmission macrophages are seemingly one of the first cells infected, being as efficient as T cells in supporting productive viral replication. Macrophages control a myriad of cell-mediated immune responses that regulate the levels of infection and lead to viral persistence. HIV determinants control viral entry and productive replication and, taken together with cellular differentiation factors, decide the outcome of virus-macrophage interactions. Most important, many clinical manifestations of HIV infection such as encephalitis, myelopathy, pneumonitis, and lymphadenopathy are closely linked to viral replication. Indeed, tissue pathology often correlates with viral gene expression in tissue macrophages. Taken together, these observations provide strong support for a central role of macrophages in progressive HIV infection and its clinical manifestations. J. Leukoc. Biol. 56: 278–288; 1994.
Brain macrophages: neurotoxic or neurotrophic effector cells?
Authors: Mallat M , Chamak B
Published: January 2018

The development of the central nervous system and various pathological contexts imply remodeling or alteration of neuronal networks associated with tissue recruitment of mononuclear phagocytes. Purification and culture of brain macrophages have provided a tool for investigating the functions of these cells. We discuss different mechanisms whereby macrophages could directly influence the survival of neurons and the growth of their processes. J. Leukoc. Biol. 56: 416–422; 1994.
The IL-1 receptor signaling pathway
Authors: Kuno Kouji , Matsushima Kouji
Published: January 2018

Interleukin-1 (IL-1) exerts pleiotropic effects on a variety of tissues through binding to its receptor. Two distinct types of receptors for IL-1 have been characterized in mouse and human. Most of the IL-1 signal has been shown to be transmitted through type I IL-1R (80 kDa) in T lymphocytes as well as B lymphocytes and monocytes. Type II receptor may act as a suppressor of IL-1 biological activities by competing in binding with type I receptors on the cell surface. Functional studies of the type I IL-1R demonstrated that the cytoplasmic segments, possessing a sequence similarity with the Drosophila Toll gene product or IL-6R β chain, gpl30, are important for transmitting activity that induces cytokine genes. In the past three years, several groups reported that IL-1 and tumor necrosis factor (TNF) rapidly induce sphingomyelin turnover in various types of cells, producing ceramide, which may act as a second messenger molecule in an intracellular signaling cascade. Activation of both acid and neutral sphingomyelinases (SMases) has been suggested, and Schutz et al. proposed that the phosphatidylcholine–phospholipase C/acid SMase pathway is involved in TNF-induced NF-xB activation. However, our recent study showed that the NF-xB activation is induced by IL-1/TNF in fibroblasts from patients with type A Niemann-Pick disease, with acid SMase deficiency. This finding implies that acid SMase activity is not essential for the activation of NF-xB by IL-1/TNF at least in fibroblasts. Other signaling pathways including neutral SMase and unidentified protein kinases may be important for NF-xB–mediated cytokine gene activation. J. Leukoc. Biol. 56: 542–547; 1994.
Macrophages derived from C3H/HeJ (Lpsd) mice respond to bacterial lipopolysaccharide by activating NF-χB
Authors: Ding Aihao , Hwang Sonya , Lander Harry M , Xie Qiao-wen
Published: January 2018

The effects of bacterial lipopolysaccharide (LPS) on macrophage gene expression are mediated in part by its ability to induce activation of transcription factor NF-χB. We compared the ability of LPS-treated macrophages from Lpsn (LPS-responsive) C3H/HeN and Lpsd (LPS-hyporesponsive) C3H/HeJ mice to mobilize NF-χB by electrophoretic mobility shift assays with oligonucleotide probes containing a unique NF-χB sequence from the promoter of inducible nitric oxide synthase (iNOS). In response to ng/ml concentrations of LPS, this probe bound proteins that appeared rapidly in the nuclei of thioglycollate-elicited macrophages and bone marrow–derived macrophage cell lines from both Lpsn and Lpsd mice. Only in macrophages from Lpsn mice, however, was LPS able to induce iNOS or tumor necrosis factor α. NF-χB-containing DNA-protein complexes from Lpsd macrophages were formed in lesser amounts than from Lpsn macrophages but shared the same composition, insofar as they displayed the same electrophoretic mobilities and content of heterodimers of p50/RelA (p65) and p50/c-rel. Two conclusions emerge from these findings: (1) NF-χB activity alone is not sufficient for induction of certain LPS-responsive genes and (2) An LPS-response pathway involving activation of NF-χB is preserved in Lpsd mice. The inability of cells from Lpsd mice to induce gene expression in response to LPS thus cannot be attributed to inability to activate NF-χB. J. Leukoc. Biol. 57: 174–179; 1995.
Cellular localization and hormonal regulation of inducible nitric oxide synthase in cycling mouse uterus
Authors: Huang Jian , Roby Katherine F , Pace Judith L , Russell Stephen W , Hunt Joan S
Published: January 2018

Nitric oxide (NO), a potent and versatile free radical, is synthesized in macrophages and mast cells as well as in other types of cells by the inducible form of nitric oxide synthase (iNOS). In this study, cells containing iNOS were identified in the uteri of cycling mice by using a rabbit antibody generated to an iNOS-specific peptide. Macrophages were identified in semiserial sections of the same tissues with the monoclonal antibody, F4/80, and mast cells were identified by toluidine blue staining. In tissue sections of uteri obtained from mice in the four stages of the estrous cycle (8 to 11 mice per stage), iNOS immunoreactivity was strongest in diestrus-I uteri and weakest in diestrus-II uteri. Myometrial mast cells and endometrial epithelial cells were prominent locations of iNOS, and specific protein was also present in myometrial smooth muscle and macrophage-like cells in the endometrial stroma. Because cyclic variations suggested regulation of iNOS expression by ovarian steroid hormones, studies were done using ovariectomized mice. Seven days after ovariectomy, immunoreactive iNOS was low but detectable in mast cells and luminal epithelial cells. In the uteri of ovariectomized, estradiol-17β (E2)–treated mice, mast cells were iNOS+ after 24 h whereas epithelial cells were negative; the reverse was observed in progesterone (P4)-treated mice. Both mast cells and epithelial cells were iNOS+ in the uteri of mice that had received a combination of E2 + P4. These results indicate that several types of uterine cells produce iNOS and that expression of this enzyme in specific cell lineages is governed by ovarian steroid hormones. The data are consistent with the postulate that NO derived from uterine leukocytes and other types of cells plays a role in uterine cyclicity and preparation for pregnancy. J. Leukoc. Biol. 57: 27–35; 1995.
Immunocytochemical localization of granulin-1 to mononuclear phagocytic cells of the teleost fish Cyprinus carpio and Carassius auratus
Authors: Belcourt Daniel R , Okawara Yuji , Fryer James N , Bennett Hugh P J
Published: January 2018

A new class of low-molecular-weight cysteine-rich regulatory growth factors, designated granulins, has been isolated from hematopoietic tissues of a teleost fish (Cyprinus carpio) and structurally characterized. Granulin-1, the predominant form found in carp spleen, was used to raise polyclonal antibodies in rabbits and to establish a radioimmunoassay. This permitted preliminary tissue distribution studies of granulin-1 to be undertaken in carp (Cyprinus carpio) and goldfish (Carassius auratus). Granulin-1 immunoreactivity was found in the melanomacrophage centers of the spleen and head kidney. Carp tissues anatomically involved in the first line of defense against infection, including skin, gills, gut, and also heart, showed intense granulin-1 immunoreactive staining within presumptive macrophage cells. Granulin-1 immunoreactive macrophages prepared from goldfish spleen and head kidney adhered to glass slides, actively phagocytosed carbon particles, and contained granulin-1 immunoreactivity as well as abundant endogenous peroxidase activity. This study demonstrates that granulin-1 is synthesized and stored in macrophages/monocytes of spleen, head kidney, and peripheral tissues of teleost fish. J. Lcukoc. Biol. 57: 94–100; 1995.
Intercellular adhesion molecule 1 (ICAM-1) expression and its role in neutrophil-induced ischemia-reperfusion injury in rat liver
Authors: Farhood Anwar , McGuire Gerald M , Manning Anthony M , Miyasaka Masayuki , Smith C Wayne , Jaeschke Hartmut
Published: January 2018

The potential role of intercellular adhesion molecule-1 (ICAM-1) in the pathogenesis of reperfusion injury was investigated in male Fischer rats subjected to 45 min of hepatic ischemia and 24 h of reperfusion. ICAM-1 mRNA levels increased during ischemia in the ischemic liver lobes; however, during reperfusion mRNA levels increased in both the ischemic and nonischemic lobes. Immunohistochemical evaluation indicated ICAM-1 expression only on sinusoidal lining cells in controls; ischemia-reperfusion enhanced ICAM-1 expression in the sinusoids and induced some expression on hepatocytes. The monoclonal anti–ICAM-1 antibody 1A29, but not an immunoglobulin G control antibody, administered at 1 h and 8 h of reperfusion (2 mg/kg) significantly attenuated liver injury as indicated by 51% lower plasma alanine aminotransferase activities and 32–36% less hepatic necrosis at 24 h without affecting reactive oxygen formation by Kupffer cells and hepatic neutrophils. Although 1A29 reduced neutrophil extravasation in a glycogen peritonitis by 60%, the antibody had no significant effect on hepatic neutrophil infiltration during reperfusion. These data suggest that ICAM-1 plays a significant role during the neutrophil-dependent injury phase after hepatic ischemia and reperfusion and therefore blocking this adhesion molecule may have therapeutic potential against postischemic acute liver failure. J. Leukoc. Biol. 57: 368–374; 1995.
Mature polymorphonuclear leukocytes express high-affinity receptors for IgG (FcγRI) after stimulation with granulocyte colony-stimulating factor (G-CSF)
Authors: Gericke Germo H , Ericson Solveig G , Pan Luying , Mills Letha E , Guyre Paul M , Ely Pamela
Published: January 2018

The high-affinity receptor for the constant region of immunoglobulin G IgG (FcγRI; CD64) is virtually undetectable on mature polymorphonuclear neutrophils (PMNs) in healthy individuals but is expressed on PMNs in patients with certain infections and in patients treated with recombinant human granulocyte colony-stimulating factor (rhG-CSF). The induction of FcγRI by rhG-CSF has previously been reported to result from effects on immature granulocyte progenitors. To evaluate the G-CSF effect on mature PMNs, we studied the correlation between G-CSF plasma concentration and expression of FcγRI on PMNs in vivo as well as the effect of G-CSF on FcγRI expression on mature PMNs in vitro. FcγRI expression on PMNs correlated (R = 0.79; p < .001) with plasma concentrations of endogenous or recombinant G-CSF in healthy volunteers and in patients undergoing high-dose chemotherapy and autologous bone marrow transplantation. PMNs exhibited a unimodal distribution for elevated FcγRI expression, suggesting that G-CSF induced increased expression of FcγRI on mature as well as on immature PMNs. In vitro, incubation of mature PMNs with G-CSF induced mRNA for FcγRI. Significant FcγRI surface expression was induced in a time- and dose-dependent manner. Thus, G-CSF can act on mature PMNs to increase FcγRI expression and may be useful for stimulating antibody mediated immune functions of PMNs in vivo. J. Leukoc. Biol. 57: 455–461; 1995.
The role of PECAM-1 (CD31) in leukocyte emigration: studies in vitro and in vivo
Authors: Muller William A
Published: January 2018

Platelet/endothelial cell adhesion molecule-1 (PECAM-1, CD31) is a molecule capable of mediating both homophilic and heterophilic adhesion. It is constitu tively expressed and concentrated in the lateral borders between endothelial cells and expressed on the surfaces of neutrophils, monocytes, and some T cell subsets, as well as on platelets. In a quantitative in vitro assay, monoclonal antibody against PECAM-1 or soluble recombinant PECAM-1 selectively blocked passage of both neutrophils and monocytes across the endothelial monolayer by 70–90% without interfering with the ability of these cells to bind to the apical endothelial cell surface. These rea gents worked whether directed against leukocyte PECAM-1 or against endothelial cell PECAM-1 and were not additive, suggesting that a homophilic interaction was occurring. In a murine model of acute inflammation, thioglycollate-induced peritonitis, a monoclonal anti body against mouse PECAM-1 blocked emigration of leu kocytes into the peritoneal cavity down to background levels. Examination of peritoneal venules in these mice revealed many leukocytes in apparent contact with the endothelial surface but unable to cross the intima. Thus, PECAM-1 has a distinct role in the transendothelial migration phase of leukocyte emigration, independent of the adhesion events on the apical surface. J. Leukoc. Biol. 57: 523–528; 1995.
Localization of cyclic GMP-dependent protein kinase in human mononuclear phagocytes
Authors: Pryzwansky Katherine B , Kidao Sudha , Wyatt Todd A , Reed William , Lincoln Thomas M
Published: January 2018

The presence and physiological role of cGMP-dependent protein kinase (G-kinase) was investigated in human mononuclear phagocytes. Western blots of mono cyte extracts revealed a single polypeptide band that comigrated with purified bovine lung G-kinase. G-kinase was localized by immunofluorescence microscopy in freshly isolated adherent human monocytes, monocyte-derived macrophages cultured from 4 to 14 days, and al veolar macrophages. In monocytes, G-kinase was local ized in granules or vesicles in the cytoplasm, at the microtubule organizing center, on filaments, and in the nucleus. In monocyte-derived macrophages, intense staining for G-kinase was found in the vicinity of the Golgi, in vesicles throughout the cytoplasm, and diffusely in the nucleus. Dual-label confocal laser scanning microscopy demonstrated that G-kinase was colocalized with the endoplasmic reticulum. For comparison, G-kinase was localized in alveolar macrophages that were adhered from 3 to 30 min. In these cells, G-kinase was prominent within the organelle-rich area pericortical to the nucleus. However, a well-defined area of intense staining was also observed at the cell periphery at early time points during adherence and spreading. Rhodamine-labeled phalloidin showed that this peripheral area was rich in F-actin. Cytochalasin D, but not nocodazole, in hibited G-kinase targeting to the cell margin. Further more, the guanylate cyclase inhibitor LY83583 inhibited alveolar macrophage spreading and staining for G-kinase at the cell periphery. These data suggest that G-kinase may play an important role in cGMP-mediated regulation involved in protein processing and cell motility. J. Leukoc. Biol. 57: 670–678; 1995.
Priming of tyrosine phosphorylation in GM-CSF-stimulated adherent neutrophils
Authors: Johnson George M , Gomez-Cambronero Julian
Published: January 2018

Adherence of human neutrophils to plastic, fibronectin, or collagen-coated surfaces modifies their response to several agonists including granulocyte-macrophage colony-stimulating factor (GM-CSF), tumor necrosis factor α (TNF-α), and fMet-Leu-Phe, permitting them to trigger superoxide anion (O2-) release, which they are unable to do as cells in suspension. Adherence of neu trophils causes a slight decrease in the basal level of tyro sine phosphorylation compared with that of suspended cells. The addition of GM-CSF, however, brings all pro teins to a level of phosphorylation at least equal to that seen in suspended cells. In the case of a 130-kDa (pl30) and a 42-kDa (p42) protein, the increase in tyrosyl phos phorylation in response to GM-CSF challenge is clearly larger in adherent than in suspended cells (6- and 4-fold increases for p130 and p42, respectively, in adherent cells vs. 1.7- and 2.1-fold in suspended cells). This is even more patent in the case of collagen-coated plates (9.4-fold in crease for p42). Therefore, once neutrophils attach to sur faces, they become primed and respond to GM-CSF with greater potency than when they are in suspension. By Western blot analysis with anti-MAP kinase antibodies, we demonstrate that p42 is one member of the mitogenactivating protein kinase, namely the p42MAPK. The tyrosyl phosphorylation of p42MAPK is elevated in GM-CSF-treated adherent neutrophils in a time-dependent fashion as measured by the formation of a doublet com posed of the phospho (or activated) form and the dephospho (or inactive) form of MAP kinase. MAP kinase activation and tyrosine phosphorylation are in hibited by tyrosine kinase inhibitors genistein and tyrphostin-23. Our results indicate that adherence acts to prime neutrophils for enhanced functionality and that tyrosine phosphorylation is involved in this process. J. Leukoc. Biol. 57: 692–698; 1995.
Dietary modulation of Kupffer cell and splenocyte function during a Salmonella typhimurium challenge in mice
Authors: Eicher Susan D , McVey D Scott
Published: January 2018

Oils from cold-water fish are rich in (n-3) polyunsaturated fatty acids, in particular eicosapentaenoic acid (20:5) and docosahexaenoic acid (22:6). Although those fatty acids are beneficial in the prevention of carliac disease and have anti-inflammatory properties, they can also decrease survival rates of mice during challenges with food-borne pathogens. This study was designed to determine dietary fat effects on Kupffer cells and splenocytes during a Salmonella typhimurium challenge. Mice were fed a low corn oil diet (3%, control), high corn oil diet (20%, HCO), or a menhaden fish oil diet (17% + 3% corn oil, FO) for 28 days and then orally given 3.1 108 colony-forming units of S. typhimurium. Kupffer cells and splenocytes were separated immediately prior to and on days 6, 10, and 14 postchallenge. Fish oil decreased Kupffer cell phagocytosis and oxidative burst early in the infection and adhesion molecule (CD 18) expression at the end of the infection. In splenocytes, fish oil affected la expression prior to and late in the infection and depressed CD18 expression late in the infection. These data suggest that the diet affected Kupffer cells most early in the infection but affected splenocytes primarily later in the infection. Therefore, because the greatest death rate during an S. typhimurium infection occurs early, the reduced function of the Kupffer cells is probably a major factor. J. Leukoc. Biol. 58: 32–39; 1995.
Graded changes in the response of individual human basophils to stimulation: distributional behavior of events temporally coincident with degranulation
Authors: MacGlashan Donald W
Published: January 2018

Human basophils, stimulated with either anti-IgE antibody or formyl-methionine-leucine-phenylalanine, were examined by two measures of the cell response that may reflect degranulation. Flow cytometric measurement of either of these two measures, changes in forward scatter intensity (an indirect measure of the basophil size) or changes in the intensity of acridine orange-loaded cells (which labels basophil granules), allowed an assessment of the distribution of single cell responses. With regard to the latter technique, structures that appeared to be basophil granules were shown to metachromatically label with low concentrations of acridine orange, which has little or no effect on histamine release. During stimulation these labeled granules were lost, leading to decreased fluorescence. Changes in either the forward scatter parameter or acridine orange labeling occurred on the same time scale as histamine release, differentiating these measures of the basophil response from early signal transduction events. Challenging basophils with a combination of phorbol myristate acetate and ionomycin caused 100% histamine release and allowed a measurement of the maximum change in forward scatter intensity or loss of acridine orange labeling. The flow cytometric distributions after this treatment were then compared with the distributions obtained by challenging cells with several concentrations of anti-IgE antibody or formyl-methionine-leucine-phenyialanine, which induced various submaximal responses. These flow cytometric distributions demonstrated that single cells could be found in intermediate states of activation, i.e., the response of all cells was graded according to the strength of the stimulus. These studies lead to the general conclusion that all aspects of the basophil response, including those late events in the basophil response we have studied here, as well as early events that we have studied previously, are graded in a continuous manner, according to the magnitude of the stimulus. J. Leukoc. Biol. 58: 177–188; 1995.
Role of interferon-γ in immune cell regulation
Authors: Young Howard A , Hardy Kenneth J
Published: January 2018

In 1965 Wheelock reported that phytohemagglutinin could induce from human leukocytes an interferon-like virus inhibitor [1]. This substance, which turned out to be interferon-γ (IFN-γ), has been the subject, directly or indirectly, of thousands of scientific publications since that initial report. Past research has led to the general conclusion that IFN-γ is much more than an interferon in that it has broader effects on the various arms of the immune system than most any other lymphokine or cytokine. In this review we discuss the effects of IFN-γ on the various cell lineages of the immune system, focusing on the biology of its actions. In addition, we summarize research focused on the consequences of introducing IFN-γ cDNA into tumor cells, aberrant IFN-γ production in transgenic animals, and inhibition of IFN-γ effects by knocking out either the IFN-γ gene itself or the IFN-γ receptor gene.
Colony-stimulating factor-1 expression in the human fetus and newborn
Authors: Roth Philip , Stanley E Richard
Published: January 2018

Colony-stimulating factor-1 (CSF-1) is a hematopoietic growth factor that regulates the survival, proliferation, and differentiation of mononuclear phagocytes. Because this cellular compartment undergoes major changes during fetal and neonatal life, we examined concurrent CSF-1 expression during human development. While levels increased dramatically after full-term birth, CSF-1 concentrations steadily declined in the preterm circulation from 2.7 to 1.9 times adult values as gestational age increased. CSF-1 was already detectable at 10 weeks gestation in spleen, intestine, lung, kidney, heart, and liver in order of decreasing concentration, but a positive correlation with gestational age was seen only in lung and intestine. Although a 4.4-kb CSF-1 mRNA was detectable in all tissues at all gestational ages, increased expression with advancing gestational age was observed in lung and kidney, whereas a rise and fall was observed in spleen. We conclude that CSF-1 concentration in the human circulation is developmentally regulated and that its expression in fetal tissues is compatible with its role in regulating the development of tissue mononuclear phagocytes.
Protein kinase C and intracellular pH regulate zymosan-induced lysosomal enzyme secretion in macrophages
Authors: Tapper Hans , Sundler Roger
Published: January 2018

Binding of zymosan particles to macrophage β-glucan receptors has previously been shown to trigger exocytosis of preformed lysosomal contents. In the present study, the involvement of Ca2+-, PKC-, and pH-dependent processes in the signaling to macrophage lysosomal secretion by zymosan was investigated. Also, the PKC dependence of lysosomal secretion in response to some soluble agents that directly alters intracellular pH was considered. Signaling to macrophage lysosomal secretion differs from that of many other secretory systems, because an elevation of cytosolic Ca2+ did not trigger a large secretory response, nor did attempts to reduce cytosolic Ca2+ affect the lysosomal secretory response to other stimuli. PKC activation by phorbol diester was also a poor stimulus of lysosomal secretion. However, when triggered by zymosan or by soluble stimuli raising lysosomal pH, the secretory response could be down-regulated by a prior prolonged incubation with phorbol diester. Such treatment also had marked effects on the binding and uptake of zymosan particles, the study of which was made possible by a novel approach. Furthermore, a synergistic effect on lysosomal secretion was obtained when stimuli that elevated lysosomal pH and stimuli that activated PKC were combined. This is of likely relevance for the secretory response to zymosan particles, a stimulus that both activates PKC and elevates lysosomal pH. The secretory response to zymosan was furthermore shown to be inhibited by a reduction of extracellular pH or [Na+], conditions that impair macrophage extrusion of acid equivalents. Earlier studies using soluble stimuli have shown a sensitivity of the secretory response to changes in cytosolic pH. We suggest a model in which the lysosomal secretory response to an elevation of lysosomal pH (1) is dependent on basal PKC activity and (2) can be enhanced further by activation of PKC. We consider PKC activity and elevation of lysosomal pH as independent and necessary signals, while cytosolic pH has a modulatory effect on some component(s) in the signal transduction pathway or in the secretory apparatus itself.
The vesiculo-vacuolar organelle (VVO): a distinct endothelial cell structure that provides a transcellular pathway for macromolecular extravasation
Authors: Dvorak A M , Kohn Sarah , Morgan Ellen S , Fox Patricia , Nagy Janice A , Dvorak Harold F
Published: January 2018

The vesiculo-vacuolar organelle (VVO) is a recently described organelle found in the cytoplasm of endothelial cells that line tumor microvessels and normal venules. VVOs are grape-like clusters of interconnecting uncoated vesicles and vacuoles, bounded by trilaminar unit membranes, that span the entire thickness of vascular endothelium, thereby providing a potential transendothelial connection between the vascular lumen and the extravascular space. Macromolecular tracers preferentially cross hyperpermeable tumor microvessels through VVOs. The present investigation was undertaken to elucidate further the ultrastructure and function of VVOs in a murine ovarian carcinoma (MOT) and in normal venules. Morphometry revealed that VVOs were enormous cytoplasmic structures (median area, 0.12–0.14 μm2 in single electron micrographs). Moreover, the individual vesicles and vacuoles that comprised VVOs were on average substantially larger than capillary caveolae and followed a non-normal distribution that was skewed to the right. Specimen tilting provided conclusive evidence that individual VVO vesicles and vacuoles communicated with each other and with the endothelial cells’ plasma membranes by stomata, some of which were closed by diaphragms composed of a single membrane. Studies with two tracers, ferritin (FE, diameter ~ 11 nm) and horseradish peroxidase (HRP, diameter ~ 5 nm), revealed that passage of macromolecules through VVOs was regulated at the level of stomatal diaphragms, thereby demonstrating a mechanism for controlling the passage of macromolecules across endothelial cells. Thus, compared with tumor microvessels, little circulating FE and HRP entered the VVOs of normal venular endothelium because stomata joining vesicles and vacuoles to each other and to the lumen and ablumen were closed. VVOs and their component vesicles/vacuoles were readily distinguished from endosomal organelles such as coated vesicles and multivesicular bodies, which also accumulated FE and HRP. Our findings indicate that VVOs provide a major pathway for the extravasation of circulating macromolecules across endothelia taller than capillary endothelium and suggest that upregulated VVO function accounts for the well-known hyperpermeability of tumor blood vessels.
Regulation and expression of chemokines: potential role in glomerulonephritis
Authors: Brown Zarin , Robson Rachel L , Westwick John
Published: January 2018

Glomerular diseases represent the major cause of renal failure. Despite decades of research our understanding of the mechanism(s) associated with immune-mediated glomerular injury remains poor. Consequently most of the therapies that are used are nonspecific with major side effects and offer minimal therapeutic benefits for the patient. The need for new strategies for therapy is clear. The drawing of leukocytes from the circulation into the inflamed glomerulus, accompanied by proliferation of resident mesangial cells and expansion of the mesangial matrix are key processes in the pathogenesis of glomerulonephritis (GN). The migration of inflammatory cells into an extravascular site requires a series of coordinated signals including the generation of a chemotactic gradient by the cells of the extravascular compartment. The nature of the stimulus and the subsequent spectrum of chemotactic factors produced determine the specific leukocyte population recruited to the inflammatory site. Members of the chemokine family play a central role in this process by attracting and stimulating specific subsets of leukocytes. Our hypothesis is that mesangial cell-derived chemokines are responsible for the initiation and maintenance of glomerular inflammation; in this review we discuss our recent findings supporting this theory. Increasing our understanding of the intracellular pathways that regulate chemokine production in human mesangial cells may provide leads to the design of more effective therapies for the prevention and treatment of glomerular inflammation.
Development, differentiation, and phenotypic heterogeneity of murine tissue macrophages
Authors: Naito Makoto , Umeda Syuji , Yamamoto Takashi , Moriyama Hiroshi , Umezu Hajime , Hasegawa Go , Usuda Hiroyuki , Shultz Leonard D , Takahashi Kiyoshi
Published: January 2018

In murine ontogeny, macrophage precursor cells develop in the yolk sac and fetal liver. Primitive macrophages also appear in the yolk sac, migrate to various tissues, and differentiate into several fetal macrophage populations. Because the development of the monocytic cell lineage is incomplete in the early stage of fetal hematopoiesis, primitive/fetal macrophages are considered to originate from granulocyte-macrophage colony-forming cells or earlier macrophage precursors, bypassing the early monocytic cell series. In adult mice rendered severely monocytopenic by administration of strontium-89, resident macrophages are maintained by self-renewal. In contrast, administration of liposome-encapsulated dichloromethylene diphosphonate (clodronate) results in the elimination of various tissue macrophage populations. The repopulation of affected macrophages is dependent on the increase of precursors in the liver and spleen during the period of macrophage depletion. Such precursors reconstitute heterogeneous macrophage subpopulations. In mice homozygous for the osteopetrosis (op) mutation, the absence of macrophage colony-stimulating factor (M-CSF) activity results in a deficiency of monocytes and monocyte-derived macrophages. However, immature macrophages are present in various tissues. Administration of M-CSF to op/op mice induces the increased proliferative capacity and the morphological maturation of macrophages. However, the responses of individual tissue macrophage subpopulations to M-CSF are different. These results indicate that macrophage development, differentiation, and proliferation are regulated by the tissue microenvironment including the in situ production of macrophage growth factors in both fetal and adult life.
Increase of chemokine levels in sputum precedes exacerbation of acute asthma attacks
Authors: Kurashima Kazuyoshi , Mukaida Naofumi , Fujimura Masaki , Schröder Jens-M , Matsuda Tamotsu , Matsushima Kouji
Published: January 2018

Basophils 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.
Regulated expression of a 16-kd galectin-like protein in activated rat macrophages
Authors: Rabinovich Gabriel , Castagna Leonardo , Landa Carlos , Riera Clelia M , Sotomayor Claudia
Published: January 2018

We 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.
Ceramide selectively inhibits early events in the response of human neutrophils to tumor necrosis factor
Authors: Fuortes Michele , Jin Wen-wen , Nathan Carl
Published: January 2018

Cell spreading and the respiratory burst of neutrophils responding to soluble, physiological agents and adherent to model biological surfaces are typically delayed in onset by 15 min or more. The lag period may be a physiologically important feature of the action of such agents on neutrophils in that it may allow for migration before secretion. However, the mechanism that interposes such a long delay between stimulus and response is unknown. Tumor necrosis factor α (TNF-α) mediates some of its actions by triggering sphingomyelinase to generate ceramide. In adherent human neutrophils, however, exogenous ceramide did not mimic TNF-α’s ability to stimulate cell spreading, paxillin tyrosine phosphorylation, or the respiratory burst. On the contrary, ceramide suppressed each such response. Ceramide did so by extending the lag period in the cells’ response to TNF-α. Ceramide extended the lag period whether it was added exogenously or generated endogenously by sphingomyelinase, and the effect was reversible. Remarkably, however, ceramide inhibited cell spreading or the respiratory burst only if added together with TNF-α or within the next few minutes. Neutrophils ignored ceramide if it was added later, even if the TNF-α-triggered respiratory burst had not yet commenced. These features suggest that an early, brief elevation of ceramide in response to TNF-α could mediate the lag period. By temporarily inhibiting tyrosine phosphorylation, cell spreading, and the respiratory burst, ceramide or a functionally similar mediator could serve as a phase coordinator of the neutrophil’s response to soluble agonists.