bluuebunny/crossref_metadata_2025 huggingface dataset:
The inflammatory potential of IL-2: local induction of a specific chronic granulomatous lesion in mice
Authors: Dunn Colin J , Hardee Marilyn M , Fidler Stephen F , Shields Sharon K , Chosay John G
Published: January 2018

Subcutaneous injection of recombinant human interleukin-2 (rhuIL-2) at 102-104 U/mouse induced delayed (48 h) accumulation of mononuclear leukocytes with diffuse granulocytes, including eosinophils. Subcutaneous local infusion of rhuIL-2 or recombinant murine IL-2 (102–104 U/mouse) via implanted Alzet miniosmotic pumps in mice induced chronic inflammatory lesions characterized by infiltration of large vacuolated mononuclear leukocytes, lymphoid cells, and eosinophil foci; neovascularization, with high endothelial-like cells, was prominent, exhibiting intravascular trapping and migration of large mononuclear leukocytes. Leukocyte infiltrates comprised T lymphocytes (CD4+; CD8+), B lymphocytes, and macrophages. Control infusions of bovine serum albumin (BSA) induced weak fibrotic lesions with sparse macrophage infiltration and minimal accumulation of lymphocytes; VLA4+ and ICAM-1+ leukocyte infiltrates were significantly greater in IL-2-induced lesions compared with BSA-induced lesions. Quantitative image analysis showed significantly increased lesion size in the IL-2-induced lesions compared with those induced by BSA infusion. The vascularity of IL-2-induced lesions assessed by immunostaining for platelet-endothelial cell adhesion molecule was increased compared with control, BSA-induced lesions mainly due to neovascularization. ICAM-1 and VCAM-1 expression was significantly enhanced in IL-2 lesions. No systemic pathological changes were observed following IL-2 infusion. We conclude that local slow-release of IL-2 causes the evolution and maintenance of a specific chronic inflammatory lesion.
Differential infection of porcine alveolar macrophage subpopulations by nonopsonized Mycobacterium bovis involves CD14 receptors
Authors: Khanna Kristen V , Choi Chang S , Gekker Genya , Peterson Phillip K , Molitor Thomas W
Published: January 2018

The resurgence in mycobacterial infection worldwide has led to renewed attention to the pathogenesis of Mycobacterium species. The purpose of this study was to characterize the infection of alveolar macrophages (AMs) by nonopsonized Mycobacterium bovis, and to elucidate the mechanism by which a differential infection of subpopulations of AM may occur. A difference in susceptiblity to Mycobacterium bovis infection of subpopulations of AMs was observed, such that the least dense cells were the least susceptible (21.4 ± 10.7%) and the most dense cells were the most readily infected (61.8 ± 5.6%). The percentage of AMs staining for CD14 receptors showed a similar differential distribution, with fewer of the least dense cells expressing CD14 and a greater percentage of the most dense cells staining for CD14 receptor expression. To investigate the role of CD14 receptors in the infection of AMs, anti-CD14 antibody was added to the cell cultures. Infection of AM by Mycobacterium bovis was blocked by up to 60.2% by anti-CD14 antibody but not by isotype control antibody. The results of this study suggest that Mycobacterium bovis selectively infects AM subpopulations, specifically those with the greatest expression of CD14, a putative receptor mechanism for Mycobacterium bovis infection of porcine AM.
Hepatic catabolism of intravenously administered pro-macrophage-stimulating protein in mice
Authors: Leonard Edward J , Skeel Alison
Published: January 2018

We injected 125I-pro-macrophage-stimulating protein (pro-MSP) intravenously into normal mice to determine its clearance from the circulation and to test for conversion of pro-MSP to the biologically active heterodimer in the absence of inflammation or tissue injury. Pro-MSP was cleared from the circulation with a half-life of approximately 100 min. This rapid clearance was not peculiar to 125I-pro-MSP, since clearance rates of unlabeled pro-MSP and of 125I-bovine serum albumin were comparable. The liver was the major locus of radioactivity 10–20 min after the intravenous injection of 125I-pro-MSP. By 90 min, over 60% of total recovered radioactivity was in the small intestine. Reflecting gastrointestinal transit, counts decreased in the small intestine and appeared in the colon by 180 min. Essentially all counts in urine and feces obtained at later times were soluble in trichloracetic acid. These findings reflected rapid hepatic proteolysis of pro-MSP to fragments undetectable by antibody to pro-MSP; within 20 min after intravenous administration, immunoprecipitable counts were only 22% of the total liver extract radioactivity. Comparison of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and radioautography data for immunoprecipitated plasma and. liver extract revealed no evidence for hepatic conversion of pro-MSP to MSP. Thus, the hepatic catabolic pathway of pro-MSP is degradative and don not yield mature MSP. The results support our view that MSP is not released into the circulation but is generated at specific extravascular loci by pro-MSP convertases. J.
Mechanisms regulating macrophage-induced nitric oxide production by spontaneously transformed hamster fibroblasts
Authors: Lavnikova Natasha , Prokhorova Svetlana , Burdelia Ludmila , Lakhotia Anand , Laskin Debra L
Published: January 2018

Nitric oxide has been implicated as an important effector molecule involved in tumor cell growth and cytotoxicity. In these studies we examined mechanisms regulating nitric oxide production by hamster tumor cells. Cocultures of hamster alveolar macrophages (HAM) and spontaneously transformed hamster embryonic fibroblasts (STHE cells) produced significant quantities of nitric oxide in response to lipopolysaccharide (LPS). Culture supernatants from HAM treated with LPS also stimulated nitric oxide production by STHE cells, whereas tumor cell culture supernatants had no effect on HAM. These data, together with the findings that paraformaldehyde treatment of STHE cells, but not macrophages, completely abrogated nitric oxide production in the cocultures demonstrate that the tumor cells were the source of this mediator. In contrast to STHE cells, STHE-83/20 cells, a highly malignant variant, did not produce nitric oxide in response to HAM or HAM culture supernatants even in the presence of LPS. Both anti-tumor necrosis factor-α (TNF-α) and antiinterleukin-1α (IL-1α) antibodies inhibited HAM-induced nitric oxide production by STHE cells. However, the kinetics of their effects were different. Moreover, although the nitric oxide stimulating activity in HAM culture supernatants was abrogated by anti-TNF-α antibody, it was only minimally reduced by anti-IL-1α antibody. These data demonstrate that TNF-α and IL-1α play distinct roles in induction of nitric oxide synthesis in STHE cells. HAM were also found to suppress proliferation of STHE cells, an effect that was inhibited by anti-TNF-α antibody, but not NG-monomethyl-l-arginine, which blocks nitric oxide synthase. Abrogation of macrophage-induced cytostasis in STHE cells by anti-TNF-α antibody was associated with decreased nitric oxide production. Thus TNF-α released by macrophages may indirectly activate STHE cells for nitric oxide synthesis by suppressing tumor cell proliferation.
Activation of Src-family tyrosine kinases during Fas-induced apoptosis
Authors: Schlottmann Klaus E , Gulbins Erich , Lau Sey M , Coggeshall K Mark
Published: January 2018

Stimulation of several human and murine hematopoietically derived cell lines with anti-Fas antibodies induced increased tyrosine phosphorylation of a panel of proteins observed in whole-cell lysates. In the human T cell line Jurkat, the activity of a 56-kDa tyrosine kinase was likewise activated by anti-Fas antibodies. Immunoprecipitation studies of anti-Fas-stimulated human Jurkat and murine 2B4.11 T cells revealed activation of the Src-family tyrosine kinases Lck and Fyn. Fas receptor-induced tyrosine phosphorylation of p120 c-cbl proto-oncogene product was observed in Jurkat T cells. Pharmacological experiments demonstrated that pretreatment of Jurkat cells with tyrphostins inhibited Fas-induced apoptosis; likewise, Lck activity was inhibited by tyrphostins in a dose-dependent fashion. Finally, Lck derived from unstimulated Jurkat T cells formed stable complexes with the intracellular domain of the Fas receptor. These data are consistent with the notion that expression and activation of members of the Src-family kinases is required for Fas-induced cell death in T lymphocytes and consistent with recent findings demonstrating decreased Fas-mediated thymocytic death in Fyn-knockout mice.
Pro-inflammatory cytokines in lung and blood during steroid-induced Pneumocystis carinii pneumonia in rats
Authors: Perenboom Roos M , Beckers Pieter , van Der Meer Jos W M , van Schijndel Anita C H W , Oyen Wim J G , Corstens Frans H M , Sauerwein Robert W
Published: January 2018

To gain more insight into the role of cytokines in Pneumocystis carinii pneumonia (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.
Analysis of leukocyte activation during acute rejection of pulmonary allografts in noninfected and cytomegalovirus-infected rats
Authors: Steinmüller Christiane , Steinhoff Gustav , Bauer Dirk , You Xiao-Mang , Denzin Heike , Franke-Ullmann Gabriela , Hausen Bernard , Bruggemann Cathrien , Wagner T O F , Lohmann-Matthes Maria-Luise , Emmendörffer Andreas
Published: January 2018

After human lung transplantation acute rejection and cytomegalovirus (CMV) infections may occur, probably contributing to the development of chronic rejection. We established a model of subacute allograft rejection in rats to analyze leukocyte activation and effects of a CMV infection. Histoincompatible lung transplants (BN/LEW) without immunosuppression (group A) and lungs of initially immunosuppressed animals (group B) were analyzed. The production of inflammatory mediators (interleukin-6, tumor necrosis factor α, nitric oxides) and the expression of MHC class II antigens by alveolar and lung tissue macrophages were significantly enhanced during the alloresponse. In recipients without immunosuppression (group A) allograft necrosis was detected by day 6, whereas group B allografts were fully rejected by day 25. In allografts of immunosuppressed, CMV-infected animals (group C) the CMV infection was clearly aggravated and the number of activated lung tissue macrophages was increased when compared with noninfected allografts or isografts. The subacute model provides the advantage of allowing us to study mechanisms of acute rejection without the effects of reperfusion injury. Furthermore these findings underline the role of inflammatory mediators produced by macrophages during rejection.
Regulation of T cell-dependent and -independent IL-12 production by the three Th2-type cytokines IL-10, IL-6, and IL-4
Authors: Takenaka Hiroshi , Maruo Seiji , Yamamoto Norihiko , Wysocka Maria , Ono Shiro , Kobayashi Michiko , Yagita Hideo , Okumura Ko , Hamaoka Toshiyuki , Trinchieri Giorgio , Fujiwara Hiromi
Published: January 2018

The production of IL-12 by macrophages/dendritic cells (Mɸ/DC) is mediated either by a T cell-dependent pathway that is induced primarily by the interaction of CD40 ligand (CD40L) on activated T cells with CD40 on IL-12-producing cells or by a T cell-independent pathway that is induced by bacteria or bacterial products and enhanced by interferon-γ (IFN-γ). In this study we investigated the ability of the Th2-type cytokines interleukin (IL) -10, IL-6, and IL-4 to modulate IL-12 production in Mɸ/DC induced through the two pathways. IL-12 production was induced in Mɸ/DC from normal mice by stimulation with the combination of IFN-γ plus lipopolysaccharide (LPS) or Staphylococcus aureus Cowan I (a model for the T cell-independent pathway) or by co-culture with Chinese hamster ovary (CHO) cells transfected with the CD40L (a model for the T cell-dependent pathway). The effects of three Th2-type cytokines on IL-12 production by Mɸ/DC through the two pathways were examined. IL-10 inhibited IL-12 production induced through both pathways, although the inhibitory effect was more potent on the (IFN-γ + LPS)-induced pathway. IL-6 inhibited only (LPS + IFN-γ)-induced IL-12 production. The effect of IL-4 was particularly noteworthy: this cytokme inhibited (LPS + IFN-γ)-induced IL-12 production, whereas it potentiated the production of IL-12 induced by CD40L. Regulation of IL-12 protein production by IL-10 and IL-4 was found to correspond to the levels of mRNA accumulation for the p40 and p35 IL-12 genes, whereas the presence of IL-6 during stimulation decreased IL-12 protein production without affecting steady-state mRNA levels. These results indicate that IL-12 production in Mɸ/DC induced through a T cell-dependent or -independent pathway is positively or negatively regulated by particular cytokines at various control levels.
Development, significance, and heterogeneity of mast cells with particular regard to the mast cell-specific proteases chymase and tryptase
Authors: Welle Monika
Published: January 2018

Mast cells are one of the major effector cells in the pathogenesis of the immediate-type hypersensitivity reaction in a number of non-allergic immune disorders as well as in normal physiological processes. In addition, it has been shown recently that mast cells also play a significant role in a life-saving host response to bacterial reactions. But as much as the immunopathological role of mast cells has been acknowledged, these cells have also aroused much controversy and confusion. By now it is clear that one explanation for the sometimes even contradictory opinions on mast cell function arise from mast cell heterogeneity. This heterogeneity can express itself as differences in histochemical, biochemical, and functional characteristics. In vitro systems provided a powerful tool for the investigation of the basic mechanisms for mast cell development and differentiation and helped to demonstrate that mast cell heterogeneity can be traced back to certain cytokine patterns that are present in different microenvironments. In this context it has also been shown that the growth factors required for human mast cell differentiation are somewhat different than those for rodents. In rodents, the atypical, T cell-dependent mucosal type mast cell can be distinguished from the T cell-independent connective tissue-type mast cell. In humans, the strict classification into mucosal and connective tissue-type mast cells is not possible and the content of mast cell-specific proteases chymase and tryptase is the main criterion for mast cell subtypes in humans. The large quantities of tryptase and chymase that are synthesized by mast cells suggest and emphasize the significance of these proteinases in mast cell function and stimulate d investigations about the biological properties of these mast cell-specific proteases. Comparing their biological activities it becomes clear that they share some activities. On the other hand, tryptase seems to participate in proinflammatory mast cell function, whereas chymase seems to be more involved in inflammatory reactions. This review provides a short overview of the discovery, origin, development, and biological significance of mast cells and will then concentrate on mast cell heterogeneity in rodents and humans with respect to the mast cell proteases tryptase and chymase and their function.
Apoptosis in resolution of inflammation
Authors: Savill John
Published: January 2018

The last few years have seen the accumulation of compelling evidence that apoptosis (programmed cell death) plays a major role in promoting resolution of the acute inflammatory response. Neutrophils are constitutively programmed to undergo apoptosis, which limits their pro-inflammatory potential and leads to rapid, specific, and non-phlogistic recognition by macrophages and semi-professional phagocytes. Similar mechanisms have been implicated in clearance of eosinophils, lymphocytes, and monocytes and apoptosis also plays a role in remodeling the inflamed site by deletion of myofibroblasts. A growing understanding of the mechanisms regulating leukocyte apoptosis and of the molecules mediating safe phagocytic clearance of dying cells may yield new insights into the pathogenesis and therapy of inflammatory diseases.
Different cytokine profiles released by CD4+ and CD8+ tumor-draining lymph node cells involved in mediating tumor regression
Authors: Aruga Atsushi , Aruga Etsuko , Cameron Mark J , Chang Alfred E
Published: January 2018

We have previously demonstrated that the growth of weakly immunogenic murine sarcomas leads to the induction of immunologically specific preeffector cells in tumor-draining lymph nodes (TDLN). The in vitro activation of TDLN cells with anti-CD3 monoclonal antibodies (mAbs) and interleukin-2 (IL-2) resulted in the acquisition of effector function as measured by tumor regression in the adoptive immunotherapy of pulmonary metastases. Further studies were performed to characterize the mechanisms associated with in vivo tumor reactivity mediated by activated TDLN cells. By positive selection, CD4+ and CD8+ T cells were purified and activated by the anti-CD3/IL-2 method. CD8+, but not CD4+, cells manifested tumor-specific granulocyte-macrophage colony-stimulating factor (GM-CSF) and interferon-γ (IFN-γ) release in vitro, and elicited tumor regression in vivo. By contrast, only activated CD4+ were found to release significant amounts of IL-2 in response to tumor antigen but did not mediate tumor regression in vivo. Mixing the two purified populations enhanced the antitumor activity of the CD8+ T cells. In culture, IL-2 was found to augment the relative amount of tumor-specific release of GM-CSF and IFN-γ by activated TDLN cells. We found that the tumor-specific release of GM-CSF and IFN-γ by activated lymphocytes was strongly associated with the in vivo therapeutic efficacy of these cells. Evidence in support of this included the following: (1) cytokine release of TDLN derived after different durations of tumor growth correlated with tumor reactivity in adoptive transfer studies, (2) cytokine release of T cells derived from different lymphoid organs corresponded with tumor reactivity in adoptive transfer, and (3) in vivo administration of neutralizing mAb to IFN-γ and GM-CSF significantly inhibited the antitumor reactivity of TDLN cells. These studies document the contributory roles of IFN-γ, GM-CSF, and IL-2 released by activated CD4+ and CD8+ T cells involved in tumor regression.
IL-15 is chemotactic for natural killer cells and stimulates their adhesion to vascular endothelium
Authors: Allavena P , Giardina G , Bianchi G , Mantovani A
Published: January 2018

Interleukin-15 (IL-15) is a recently described cytokine with IL-2-like stimulating activities on T lymphocytes and natural killer (NK) cells. IL-15 mediates its function through the β- and γ-chains of the IL-2 receptor. In this work, we have investigated the effect of IL-15 on the directional migration of NK cells in chemotaxis assays and on the ability of NK cells to bind to vascular endothelium. IL-15 (10–20 ng/mL) had chemotactic effects on freshly isolated resting NK cells as well as on long-termed IL-2-cultured NK cells. A checkerboard experiment demonstrated that migration in response to IL-15 was observed only in the presence of a positive gradient (chemotaxis). Overnight treatment of freshly isolated NK cells with IL-15 (10–20 ng/mL) augmented their binding to cultured endothelial cells (EC) in vitro, especially to resting EC. IL-15-activated NK cells bound to resting and tumor necrosis factor-activated EC by use of LFA-1/ICAM-1 and VLA-4/VCAM-1 adhesion pathways, essentially as untreated NK cells do. The fact that IL-15 increased NK cell binding to ICAM-1-transfected NIH-3T3 fibroblasts, together with the finding that IL-15 did not increase binding to extracellular matrix proteins, where the major molecules involved are VLA proteins, indicated that IL-15 primarily stimulates LFA-1-dependent adhesion. By increasing NK cell adhesion to vascular endothelium and migratory response, IL-15 is an important determinant of NK cell recruitment in tissues.
Increased mortality, blunted production of nitric oxide, and increased production of TNF-α in endotoxemic TGF-β1 transgenic mice
Authors: Vodovotz Yoram , Kopp Jeffrey B , Takeguchi Heather , Shrivastav Shashi , Coffin Deborah , Lucia M Scott , Mitchell James B , Webber Robert , Letterio John , Wink David , Roberts Anita B
Published: January 2018

The expression of the inducible isoform of nitric oxide synthase (NOS2, iNOS) is increased in patients undergoing sepsis as well as in animal models in which septic shock is induced by injection of bacterial lipopolysaccharide (LPS). Transforming growth factor-β1 (TGF-β1) potently suppresses NO production both in vitro and in vivo. After intraperitoneal injection of LPS, mice over-expressing a cDNA coding for active TGF-β1 in the liver (Alb/ TGF-β1) exhibited reduced serum levels of the NO reaction products NO2– + NO3– compared with controls. Paradoxically, while endotoxemic Alb/ TGF-β1 mice expressed much less NOS2 protein in peritoneal exudate cells than did endotoxemic wild-type mice, Alb/TGF-β1 mice expressed more NOS2 mRNA and protein in both liver and kidney. Alb/ TGF-β1 mice treated with LPS had eightfold higher serum tumor necrosis factor α (TNF-α) levels and experienced increased mortality compared with wild-type mice, which was associated with renal insufficiency. These results suggest that renal dysfunction, decreased production of NO, and/or increased production of TNF-α are associated with increased mortality of endotoxemic Alb/TGF-β1 mice.
G-CSF instillation into rat lungs mediates neutrophil recruitment, pulmonary edema, and hypoxia
Authors: Hierholzer Christian , Kelly Edward , Lyons Valerie , Roedling Eva , Davies Paul , Billiar Timothy R , Tweardy David J
Published: January 2018

Activated neutrophils (PMN) have been implicated in the pathogenesis of adult respiratory distress syndrome (ARDS). Granulocyte colony-stimulating factor (G-CSF) is essential for PMN production and activation of PMN functions. We have recently shown that levels of G-CSF mRNA in a rat model of hemorrhagic shock correlated with severity of shock, PMN infiltration, pulmonary edema, and hypoxia. To determine whether increased tissue levels of G-CSF contribute to PMN recruitment and PMN-mediated injury, we instilled G-CSF into the lungs by intratracheal injection. Animals treated with G-CSF became hypoxic, hypocapnic, and alkalotic and demonstrated increased BAL fluid cellularity compared with control animals. The wet-to-dry ratio increased significantly after G-CSF instillation and peaked at 12 h. Histological examination of the lungs from G-CSF-treated rats revealed marked edema and increased PMN within the interstitium and alveoli. These results indicate that the presence of G-CSF alone in the lung can lead to recruitment of PMN, lung injury, and impaired pulmonary function, suggesting that local production of G-CSF may contribute to the development of lung damage and possibly ARDS in the setting of resuscitated hemorrhagic shock.
Impairment of human neutrophil oxidative burst by polychlorinated biphenyls: inhibition of superoxide dismutase activity
Authors: Narayanan P K , Carter W O , Ganey P E , Roth R A , Voytik-Harbin S L , Robinson J P
Published: January 2018

We report evidence of a novel mechanism by which polychlorinated biphenyls might act as potent inducers of inflammation. Aroclor 1242 (A1242), a polychlorinated biphenyl mixture, and 2,2′,4,4′-tetrachlorobiphenyl (PCB47), a constituent of A1242 that produces the same patterns of effects, impaired the oxidative burst of human neutrophils by inhibiting the antioxidant enzyme superoxide dismutase, which converts O2–to H2O2. Pre-incubation of neutrophils with A1242 or PCB47 before stimulation with phorbol 12-myristate 13-acetate heightened the respiratory burst, producing a significant increase in intracellular O2- production along with a significant decrease in H2O2 production compared with unexposed agonist-stimulated neutrophils. This was also evident in a physiologically relevant situation in which neutrophils pre-incubated with A1242 were subsequently stimulated with a combination of N-formyl-L-methionyl-L-leucyl-L-phenylalanine and tumor necrosis factor-α. Incubation of bovine copper-zinc superoxide dismutase (EC 1.15.1.1) with A1242 or PCB47 in a cell-free system reversed the enzyme-mediated inhibition of 6-hydroxydopamine autoxidation, indicating that polychlorinated biphenyls inhibited superoxide dismutase activity. Low superoxide dismutase activity in neutrophils leads to imbalances between production of free radicals and antioxidant defense mechanisms, which can in turn induce tissue damage and hasten the onset of neutrophil apoptosis.
Increased P-selectin gene expression in the liver vasculature and its role in the pathophysiology of neutrophil-induced liver injury in murine endotoxin shock
Authors: Essani Naeem A , Fisher Michael A , Simmons Carol A , Hoover Jennifer L , Farhood Anwar , Jaeschke Hartmut
Published: January 2018

We studied the role of P-selectin, an adhesion molecule known to be important for neutrophil localization to sites of inflammation, in a model of inflammatory liver injury. Male C3Heb/ FeJ (ET-sensitive) mice treated with 700 mg/kg galactosamine and 100 μg/kg Salmonella abortus equi endotoxin (Gal/ET), murine tumor necrosis factor α (TNF-α,15 μg/kg), or interleukin-1 (IL-1, 13–23 μg/kg), showed increased P-selectin mRNA levels in the liver. In contrast, C3H/HeJ (ET-resistant) mice responded only to cytokines with P-selectin mRNA formation. Whereas no P-selectin expression was detectable in control livers, there was temporary staining of endothelium in large blood vessels but not in sinusoids between 3 and 5 h after ET, TNF-α, or IL-1 treatment. Severe liver injury induced by Gal/ET at 7 h was not inhibited by an anti-P-selectin antibody in C3Heb/FeJ mice or in P-selectin-deficient animals. Sequestration of neutrophils in sinusoids, i.e. those neutrophils that have been identified as critical for the injury, was not affected by the antibody or in P-selectin-deficient mice. However, the temporary margination in portal and postsinusoidal venules was reduced by 75% in anti-P-selectin antibody-treated animals and by 51% in P-selectin-deficient mice. We conclude that hepatic P-selectin gene transcription in vivo involves cytokines. However, blocking P-selectin neither attenuated sinusoidal neutrophil sequestration nor prevented neutrophil-induced liver injury during endotoxin shock but attenuated neutrophil margination in larger vessels. Thus, our data demonstrate similarities and fundamental differences in the requirement for adhesion molecules to localize neutrophils in the liver vasculature compared to other organs during an inflammatory response.
Activated T lymphocytes induce degranulation and cytokine production by human mast cells following cell-to-cell contact
Authors: Bhattacharyya Siba P , Drucker llana , Reshef Tamar , Kirshenbaum Arnold S , Metcalfe Dean D , Mekori Yoseph A
Published: January 2018

Activated mast cells reside in close apposition to T cells in some inflammatory processes. In this study, we analyzed whether this close physical proximity affects human mast cell degranulation and cytokine release. Thus HMC-1 human mast cells or primary bone marrow-derived human mast cells were cocultured with activated and with resting T cells. Mast cells cocultured with activated T cells released histamine and β-hexosaminidase and produced tumor necrosis factor α (TNF-α), an effect that peaked at 20 h. Kinetics of histamine release paralleled the formation of heterotypic aggregates. Separation of the two cell populations with a porous membrane prevented mediator release and TNF-α production. Addition of the PI3-kinase inhibitor, wortmannin, inhibited the heterotypic adhesion-associated degranulation but not TNF-α production. These data thus indicate a novel pathway through which human mast cells are activated to both release granule-associated mediators and to produce cytokines in association with heterotypic adhesion to activated human T cells.
Transduction of recombinant human erythropoietin receptor cDNA into daughter progenitors derived from single CD343+ cord blood cells changes the differentiation profile of daughter progenitors
Authors: Lu Li , Li Zhi-Hua , He Jie , Ge Yue , Rice Susan , Broxmeyer Hal E
Published: January 2018

In this study, we tested the capacity to change the differentiation profile of progenitor cells by retroviral-mediated transduction of EpoR cDNA into one of the paired daughter cells derived from single CD343+ CB cells. Our results show that for the non-viral-treated daughter cells, the majority (99.6%) formed the same colony type. However, with cells transduced with viral vectors, 7.1% of the daughter cells transduced with the EpoR cDNA formed either a burst forming unit-erythroid (BFU-E) or a colony-forming unit-granulocyte, macrophage, erythroid, megakaryocyte (CFU-GEMM) colony compared to the other daughter cell transduced with viral supernatant lacking EpoR cDNA, which formed either a colony-forming unit granulocyte-macrophage (CFU-GM) or a high proliferative potential-colony forming cell (HPP-CFC) colony. Expression of the transduced EpoR cDNA was confirmed in individual colonies by RT-PCR analysis. These results substantiate in a more rigorous fashion our previous results that it is possible to change the Epo-responsive differentiation profile of progenitor cells by transduction into these cells of an EpoR cDNA and this change was apparent only in daughter cells derived from single CD343+ kit+ cells transduced with EpoR cDNA.
Suppressed PHA activation of T lymphocytes in simulated microgravity is restored by direct activation of protein kinase C
Authors: Cooper David , Pellis Neal R
Published: January 2018

Utilizing clinostatic rotating wall vessel (RWV) bioreactors that simulate aspects of microgravity, we found phytohemagglutinin (PHA) responsiveness to be almost completely diminished. Activation marker expression was significantly reduced in RWV cultures. Furthermore, cytokine secretion profiles suggested that monocytes are not as adversely affected by simulated microgravity as T cells. Reduced cell-cell and cell-substratum interactions may play a role in the loss of PHA responsiveness because placing peripheral blood mononuclear cells (PBMC) within small collagen beads did partially restore PHA responsiveness. However, activation of purified T cells with cross-linked CD2/CD28 and CD3/CD28 antibody pairs was completely suppressed in the RWV, suggesting a defect in signal transduction. Activation of purified T cells with PMA and ionomycin was unaffected by RWV culture. Furthermore, sub-mitogenic doses of PMA alone but not ionomycin alone restored PHA responsiveness of PBMC in RWV culture. Thus our data indicate that during polyclonal activation the signaling pathways upstream of PKC activation are sensitive to simulated microgravity.
A novel cell surface proliferation-associated marker expressed on T cells and up-regulated on germinal center B cells
Authors: Campbell J D M , Hopkins J , Howie S E M , Oliver R A , Nichani A K , Goel P , Spooner R L , Glass E J
Published: January 2018

In this study we present data on a novel cell surface antigen recognized by monoclonal antibody (mAb) VPM30, originally thought to recognize only bovine and ovine sIg+ B cells from peripheral blood. Here we show that the antigen, molecular mass 28 kDa, is not only found in B cell follicles in frozen sections, but when used on paraffin sections VPM30 specifically stains B cells in the light zone of germinal centers but not in the mantle or dark zones. In addition we show that the antigen is also expressed by 90% of T cells after activation, with kinetics of antigen expression mirroring those of proliferation. By both size and distribution, the antigen appears to be novel, corresponding to no known cluster of differentiation, and will be of great use in the study of ruminant cellular immune responses.
Th1 and Th2 cytokines cooperate to stimulate mannose-receptor-mediated phagocytosis
Authors: Raveh David , Kruskal Benjamin A , Farland Julien , Ezekowitz R Alan B
Published: January 2018

The mannose receptor is a macrophage surface receptor that mediates both endocytosis and phagocytosis. Previous work has demonstrated that the prototypical Th2 cytokine, interleukin-4 (IL-4), increases both cell-surface receptor expression and mannose receptor-mediated endocytosis, whereas the prototypical Th1 cytokine, interferon-γ (IFN-γ), decreases both surface expression and endocytosis. In many aspects of the immune response, Th1 and Th2 cytokines oppose each others’ actions. We demonstrate that IL-4 and IFN-γ alone and together enhance mannose receptor-mediated phagocytosis, despite opposing effects on cell-surface mannose receptor expression and endocytosis. Thus these usually antagonistic cytokines cooperate in increasing mannose receptor phagocytic function. The cooperative effect of these cytokines is not observed for Fc receptor-mediated phagocytosis. The Th2 cytokine IL-13 exerts similar effects to IL-4. Our results suggest that Th1 and Th2 cytokines may act in concert at sites of inflammation to enhance mannose receptor-mediated phagocytosis of microorganisms. J. Leukoc. Biol. 64: 108–113; 1998.
LPS-binding proteins and receptors
Authors: Fenton Matthew J , Golenbock Douglas T
Published: January 2018

Macrophage activation by Gram-negative lipopolysaccharide (LPS) has been extensively studied in an attempt to define the mechanisms that underlie innate immunity against bacterial pathogens. Dysregulation of these same mechanisms contributes to the pathophysiological consequences of bacterial sepsis. The biological actions of LPS are mediated, at least in part, by both LPS-binding proteins and LPS receptors. Several LPS receptors (CD14, the macrophage scavenger receptor, and the β2 integrins), as well as the serum LPS-binding protein LBP, have been cloned and studied in detail. In addition, insights gained through the use of LPS antagonists have led to a better understanding of a molecule believed to function in conjunction with LPS receptors to transduce signals from the membrane to the cytosol. More recently, the use of knockout mice has greatly expanded our knowledge of the biology of LPS receptors and binding proteins. This review will summarize various phenotypes of mice that lack genes encoding CD14, the scavenger receptor, and LBP. These knockout mice have revealed several unexpected features of LPS action in vivo. Together, these animal models may provide a means to develop and evaluate novel therapeutic approaches to the control of endotoxin shock. J. Leukoc. Biol. 64: 25–32; 1998.
Antioxidants attenuate anthralin-induced skin inflammation in BALB/c mice: role of specific proinflammatory cytokines
Authors: Lange Robert W , Germolec Dori R , Foley Julie F , Luster Michael I
Published: January 2018

Anthralin is the most common therapeutic agent among a small number of pro-oxidant, 9-anthrones effective in the topical treatment of psoriasis. However, the usefulness of this drug is diminished by toxic side effects, including skin irritation and inflammation. The activities of anthralin are believed to be mediated by the generation of reactive oxygen intermediates and anthrone radicals produced in the skin. In this study, the dermal inflammatory response to anthralin was determined using a mouse ear swelling test. Maximum ear swelling induced by anthralin coincided with the elevation of cytokine mRNA expression in the skin, including interleukin-6, granulocyte-macrophage colony-stimulating factor, macrophage inflammatory protein-2, and tumor necrosis factor α at 24 h post challenge. The role of free radical generation in ear swelling and cytokine modulation were examined by systemic administration of cell permeable and impermeable antioxidants before anthralin challenge. Superoxide dismutase and α-tocopherol acetate, but not the glutathione precursor N-acetyl cysteine, were effective inhibitors of anthralin-induced ear swelling and cytokine elevation. Maximum inflammatory cell infiltration occurred 72–96 h post anthralin challenge and was also reduced by antioxidants. These data suggest that oxidative stress, generated at the site of anthralin treatment, alters the expression of dermal chemokines and other cytokines resulting in the recruitment of inflammatory cells. Systemic antioxidant administration may provide opportunities for therapeutic intervention against anthralin-associated toxicities. J. Leukoc. Biol. 64: 170–176; 1998.
Effect of trifluoromethyl ketone-based elastase inhibitors on neutrophil function in vitro
Authors: Huang Yu-Ing , Surichamorn Wanida , Cao Guan-Liang , Meng Min , Pou Sovitj , Rosen Gerald M , Salcedo Theodora W , Strimpler Anne , Veale Chris , Bernstein Peter R , Bonuccelli Catherine M
Published: January 2018

Neutrophils release elastase, which is known secondarily to cause tissue damage. However, it is rapidly inactivated by the endogenous α1-proteinase inhibitor (α1Pi). Nevertheless, under pathological conditions, α1Pi is inactivated by oxidants released from neutrophils, resulting in an excess of elastase at the site of inflammation. This elastase/α1Pi imbalance has been implicated as a pathogenic factor in cystic fibrosis, acute respiratory distress syndrome, and emphysema. Elastase inhibitors, which do not interfere with the microbicidal activity of neutrophils and are resistant to neutrophil-released oxidants, would undoubtedly represent an important advance in the management of neutrophil-mediated tissue injury. We report that a new family of elastase inhibitors ICI200355 and ZD0892 was found to be resistant toward superoxide, hypochlorous acid, hydrogen peroxide, hydroxyl radical, and peroxynitrite mediated degradation as well as having no effect on the formation of these oxidants by activated neutrophils. More importantly, we found that these inhibitors did not interfere with the ability of human neutrophils to phagocytose and to kill Staphylococcus aureus. In conclusion, a new potent class of elastase inhibitors, while blocking the effects of neutrophil elastase, was found not to impede various physiological functions of human neutrophils, in particular the ability of these phagocytic cells to phagocytose and kill bacteria. J. Leukoc. Biol. 64: 322–330; 1998.
Expression of functional major histocompatility complex class II molecules on HMC-1 human mast cells
Authors: Dimitriadou Violetta , Mécheri Salaheddine , Koutsilieris Michael , Fraser William , Al-Daccak Reem , Mourad Walid
Published: January 2018

Mast cells hold a key position in the defensive mechanisms against exogenous intruders. In this study, we investigated whether human mast cells express functional major histocompatibility complex (MHC) class II molecules that can transduce endogenous signals and present staphylococcal enterotoxin A (SEA) to T cells. Similar to HMC-1 human mast cell line, umbilical cord blood-derived mast cells express HLA-DR, -DP and -DQ molecules on their surface. MHC class II molecules expressed on HMC-1 cells bind significantly the SEA (a natural MHC class II ligand), and their ligation with specific mAbs or with SEA, leads ultrastructural chages, suggesting their degranulation. Recognition of SEA-bound MHC class II molecules on HMC-1 mast cells by the T cell receptor of K25 cells, an SEA-specific murine T cell hybridoma, triggers significant IL-2 secretion by these T cell hybridomas. Hence, our data point out the expression of functional MHC class II molecules on human mast cells, reinforcing the implication of these cells in the defense mechanisms of acquired immunity. J. Leukoc. Biol. 64: 791–799; 1998.
Different in vivo tolerogenicity of MHC class I peptides
Authors: Fändrich Fred , Zhu Xiaofung , Schröder Jörg , Dresske Bettina , Henne-Bruns Doris , Oswald Hanno , Zavazava Nicholaus
Published: January 2018

The efficacy of MHC class I-derived peptides to induce tolerance was tested in a cardiac transplantation model. Two 25-mer peptides from the polymorphic region of the DA class I molecule (RT1.Aa) were synthesized by F-moc chemistry and injected intrathymically or intraperitoneally into LEW (RT1.1) responder animals. Intrathymic treatment of the recipient animals with peptide 1 (residues 56–80) accompanied by intraperitoneal treatment with peptide 4 (residues 96–120) led to indefinite survival of allogeneic DA cardiac allografts (n = 7; >100 days). The tolerogenicity of both peptides differed according to the site of inoculation, as donor-specific tolerance was only observed after administration of peptide 1 into the thymus and injection of peptide 2 into the abdominal cavity of LEW recipients, but not vice versa. Donor-specific tolerance was confirmed in vivo by grafting of full-thickness skin and in vitro by appropriate proliferation and cytotoxicity assays using donor and third-party rats. Donor-specific tolerance was associated with up-regulation of interleukin-4, transforming growth factor β, and interleukin-10 gene expression within cardiac allografts, thus suggesting intrathymic clonal deletion and external suppression with expansion of T-helper 2-type lymphocytes as the underlying mechanisms of tolerance induction. J. Leukoc. Biol. 65: 16-27; 1999.
Disparities in the respiratory burst between human and rat neutrophils
Authors: Johnson Jeffrey L , Moore Ernest E , Hiester Andrew A , Tamura Douglas Y , Zallen Garret , Silliman Christopher C
Published: January 2018

The importance of reactive oxygen species (ROS) in neutrophil (PMN)-mediated injury to host tissues has been strongly implicated in a number of animal models. Peculiarities of the laboratory rat PMN, including an apparent paucity of superoxide release, prompted us to examine disparities in the respiratory burst between human and rat PMNs. Using isolated PMNs, we examined oxygen consumption, superoxide release, nitrate/nitrite release, and dihydrorhodamine (DHR) oxidation in response to an array of soluble stimuli. Our findings confirm that intact rat PMNs release little superoxide in comparison to human PMNs when primed and activated by soluble stimuli. For example, PMA-activated human PMNs released superoxide at 10.1 ± 2.7 times the rate of rat PMNs (P < 0.01). However, measurements of oxygen consumption, cell-associated oxidant production (by DHR oxidation) and release of superoxide from electroporated cells suggests that rat PMNs generate oxidants at rates equivalent to human PMNs but preferentially release them in an intracellular compartment. Implications for the study of PMN- mediated oxidant injury in animal models are discussed. J. Leukoc. Biol. 65: 211–216; 1999.
Lineage-specific activation of STAT3 by interferon-γ in human neutrophils
Authors: Caldenhoven Eric , Buitenhuis Miranda , van Djk Thamar B , Raaijmakers Jan A M , Lammers Jan-Willem J , Koenderman Leo , de Groot Rolf P
Published: January 2018

Binding of interferon-γ (IFN-γ) to its heterodimeric receptor induces activation of the tyrosine kinases JAK1 and JAK2 followed by tyrosine phosphorylation of STAT1α. Selective activation of STAT1α at the IFN-γ receptor is achieved by specific interaction between a cytosolic tyrosine motif including Y440 in the IFN-γ receptor α-chain and the SH2 domain of STAT1α. We demonstrate that, in addition to STAT1α, STAT3 is also activated by IFN-γ in human neutrophils. The activation of STAT3 was not found in human eosinophils, monocytes, and HL-60 cells, although the STAT3 protein was expressed in these cells. The cell type-specific activation of STAT3 by IFN-γ was also observed in neutrophils that are differentiated in vitro from human CD34+ hematopoietic stem cells. These results indicate that a single cytokine receptor can activate different STAT family members in a cell-specific manner, which might result in cell-specific gene transcription. J. Leukoc. Biol. 65: 391–396; 1999.
Mucosal and systemic candidiasis in IL-8Rh−/− BALB/c mice
Authors: Balish Edward , Wagner R Doug , Vazquez-Torres Andres , Jones-Carson Jessica , Pierson Carey , Warner Thomas
Published: January 2018

Germ-free BALB/c mice, genetically engineered to be deficient for interleukin-8 (IL-8) receptor homolog (IL-8Rh−/−), were more susceptible to gastric candidiasis after oral challenge and to acute systemic candidiasis after intravenous challenge than IL-8Rh+/+ controls. In comparison to IL-8Rh+/+ mice, the IL-8Rh−/− mice had slower influx of polymorphonuclear neutrophils (PMN) into Candida albicans-infected tissues and a lower percentage of PMN in peritoneal exudate cells (PEC) elicited with heat-killed C. albicans. PEC from IL-8Rh−/− mice exhibited less luminol-dependent chemiluminescence in response to C. albicans and did not kill C. albicans hyphae as well as PEC from IL-8Rh+/+ mice. C. albicans-colonized IL-8Rh−/− mice showed no histological evidence of systemic candidiasis. These results suggest a role for the IL-8Rh in murine resistance to gastric and acute systemic candidiasis, but not in resistance to systemic candidiasis of endogenous origin. J. Leukoc. Biol. 66: 144–150; 1999.
Induction of CC chemokines in human peripheral blood mononuclear cells by staphylococcal exotoxins and its prevention by pentoxifylline
Authors: Krakauer Teresa
Published: January 2018

We investigated the inflammatory processes that might be associated with the arthrogenic activity of Staphylococcus aureus, the principal causative agent of bacterial arthritis. Human peripheral blood mononuclear cells (PBMC) were stimulated with the staphylococcal toxic shock syndrome toxin-1 (TSST-1) or enterotoxin B (SEB) and the production of chemokines was examined. Both TSST-1 and SEB induced high levels (ng/mL) of MIP-1α, MIP-1β, and MCP-1. The induction of these chemokines occurred mostly by direct stimulation of PBMC with staphylococcal exotoxins (SE), without requiring the intervention of IL-1 and TNF-α. The production of SE-induced chemokines was blocked partially by anti-DR and anti-CD2 antibodies. Cell separation revealed monocytes as the cell source of these chemokines. However, addition of purified T cells amplified the levels of chemokine produced, suggesting that cognate interaction of SE bound on antigen-presenting cells with T cells also contributes to chemokine production. The activation and recruitment of leukocytes by these chemokines may contribute to the pathophysiology of septic arthritis caused by staphylococci in humans through tissue injury and the recruitment of T lymphocytes, perhaps also initiating autoimmune responses. Pentoxifylline, an anti-inflammatory agent, completely inhibited the production of these chemokines. J. Leukoc. Biol. 66: 158–164; 1999.
Dendritic cells/chimerism/alleviation of chronic allograft rejection
Authors: Murase Noriko , Ichikawa Naoya , Ye Qing , Chun Hyo Jin , Okuda Toyokazu , Demetris Anthony J
Published: January 2018

Chronic rejection (CR) is the major obstacle of long-term successful organ transplantation. Using a recently developed rat model of CR, we found that heart allografts susceptible to development of CR showed an early (<10 days) dramatic disappearance of donor MHC class II+ cells, including ED2+ tissue macrophages, and an influx of recipient ED1+ macrophages intermixed with small numbers of recipient ED2+ and OX62+ cells. In contrast, donor MHC class II+ cells persisted in allografts resistant to CR with a small influx of recipient macrophages. MHC class II+ cells function as potent modulators of the immune system and may mediate both stimulatory and tolerogenic immune reactions after transplantation. Persistence of donor MHC class II+ antigen-presenting cells (APC) in CR-free graft acceptance suggests that transplantation tolerance is an active immune response requiring antigen presentation to the recipient immune system in the proper context by dendritic cells and other APC. J. Leukoc. Biol. 66: 297–300; 1999.