bluuebunny/crossref_metadata_2025_split huggingface dataset:
CCR2-Dependent Trafficking of F4/80dim Macrophages and CD11cdim/intermediate Dendritic Cells Is Crucial for T Cell Recruitment to Lungs Infected with Mycobacterium tuberculosis
Authors: Peters Wendy , Cyster Jason G. , Mack Matthias , Schlöndorff Detlef , Wolf Andrea J. , Ernst Joel D. , Charo Israel F. 
Published: April 2014

Abstract
We previously reported that CCR2−/− mice are susceptible to Mycobacterium tuberculosis infection. Susceptibility was associated with an early and sustained macrophage trafficking defect, followed by delayed recruitment of dendritic cells (DCs) and T cells to the lungs. However, the relative importance of the lack of CCR2 expression by macrophages and DCs vs T cells in susceptibility to infection was unclear. In this study, we used mixed bone marrow transplantation to create mice in which the genotype of the T cells was either CCR2+/+ or CCR2−/− while maintaining the genotype of the myeloid cells as CCR2+/+. After infection with M. tuberculosis, we found that the genotype of the macrophages and/or DCs, but not that of the T cells, was critical for both T cell and myeloid cell migration to the lungs. Further investigation revealed a critical role for CCR2 in the recruitment of F4/80dim macrophages and CD11cdim/intermediate DCs to the infected lung.
NK Cells and Polymorphonuclear Neutrophils Are Both Critical for IL-2-Induced Pulmonary Vascular Leak Syndrome
Authors: Assier Eric , Jullien Valérie , Lefort Jean , Moreau Jean-Louis , Di Santo James P. , Vargaftig B. Boris , Lapa e Silva Jose R. , Thèze Jacques 
Published: April 2014

AbstractThe mechanism of IL-2-induced vascular leak syndrome (VLS) is still poorly understood. Cells of both innate and adaptive immune systems have been implicated, but no definitive conclusions have been reached concerning their respective roles. In this study we report a new mouse model of IL-2-induced pulmonary VLS used to obtain a detailed analysis of the early events (sequestration of polymorphonuclear neutrophils and bronchoconstriction) and late events (modifications in the cell and protein content of bronchoalveolar lavages, followed by edema) that characterize this lung injury. This model and knockout animals are used to reconsider the importance of the different leukocyte lineages in early and late events. Recombinase-activating gene 2−/− mice are used to demonstrate that adaptive lymphocytes, including NK T cells, are not required for pulmonary VLS induction. By contrast, results obtained with newly described recombinase-activating gene 2−/−/IL-15−/− mice indicate that NK cells play a key role in both early and late events. In parallel, polymorphonuclear neutrophil depletion is used to evaluate the contributions made by these cells to the late alterations occurring in the lung. Furthermore, when used in combination with inhibition of NO synthase, granulocyte depletion was completely effective in protecting mice from the late events of IL-2-induced pulmonary VLS. Together our results indicate that both NK and PMN cells play a central role in the late events of IL-2-induced VLS.
The Transcriptional Activation Program of Human Neutrophils in Skin Lesions Supports Their Important Role in Wound Healing
Authors: Theilgaard-Mönch Kim , Knudsen Steen , Follin Per , Borregaard Niels 
Published: April 2014

Abstract
To investigate the cellular fate and function of polymorphonuclear neutrophilic granulocytes (PMNs) attracted to skin wounds, we used a human skin-wounding model and microarray technology to define differentially expressed genes in PMNs from peripheral blood, and PMNs that had transmigrated to skin lesions. After migration to skin lesions, PMNs demonstrated a significant transcriptional response including genes from several different functional categories. The up-regulation of anti-apoptotic genes concomitant with the down-regulation of proapoptotic genes suggested a transient anti-apoptotic priming of PMNs. Among the up-regulated genes were cytokines and chemokines critical for chemotaxis of macrophages, T cells, and PMNs, and for the modulation of their inflammatory responses. PMNs in skin lesions down-regulated receptors mediating chemotaxis and anti-microbial activity, but up-regulated other receptors involved in inflammatory responses. These findings indicate a change of responsiveness to chemotactic and immunoregulatory mediators once PMNs have migrated to skin lesions and have been activated. Other effects of the up-regulated cytokines/chemokines/enzymes were critical for wound healing. These included the breakdown of fibrin clots and degradation of extracellular matrix, the promotion of angiogenesis, the migration and proliferation of keratinocytes and fibroblasts, the adhesion of keratinocytes to the dermal layer, and finally, the induction of anti-microbial gene expression in keratinocytes. Notably, the up-regulation of genes, which activate lysosomal proteases, indicate a priming of skin lesion-PMNs for degradation of phagocytosed material. These findings demonstrate that migration of PMNs to skin lesions induces a transcriptional activation program, which regulates cellular fate and function, and promotes wound healing.
IL-16 Is Constitutively Present in Peripheral Blood Monocytes and Spontaneously Released During Apoptosis
Authors: Elssner Andreas , Doseff Andrea I. , Duncan Michelle , Kotur Mark , Wewers Mark D. 
Published: April 2014

AbstractConstitutive expression of the pro-molecule of IL-16 has been found in T cells, mast cells, eosinophils, epithelial cells, fibroblasts, and dendritic cells. Here we show that IL-16 is also constitutively present in &gt;98% of freshly isolated human CD14-positive peripheral blood monocytes when analyzed by flow cytometry. Because pro-IL-16 is cleaved to its bioactive mature form by caspase-3, and caspase-3 is also the pivotal effector of apoptosis in monocytes, we asked whether IL-16 release occurs in monocytes that undergo spontaneous apoptosis. As expected, freshly isolated, unstimulated monocytes underwent spontaneous caspase-3 activation. This apoptosis was paralleled by the loss of intracellular IL-16, as detected by flow cytometry, and the concurrent release of IL-16, as detected by ELISA. In contrast, stimulation with bacterial LPS inhibited caspase-3 activation and significantly inhibited the release of IL-16. As a specificity control, IL-1β and IL-8 were not released during spontaneous monocyte apoptosis. In summary, our data demonstrate that monocytes contain IL-16 that is released during spontaneous apoptosis.
Adenosine-Activated Mast Cells Induce IgE Synthesis by B Lymphocytes: An A2B-Mediated Process Involving Th2 Cytokines IL-4 and IL-13 with Implications for Asthma
Authors: Ryzhov Sergey , Goldstein Anna E. , Matafonov Anton , Zeng Dewan , Biaggioni Italo , Feoktistov Igor 
Published: April 2014

Abstract
Adenosine provokes bronchoconstriction in asthmatics through acute activation of mast cells, but its potential role in chronic inflammation has not been adequately characterized. We hypothesized that adenosine up-regulates Th2 cytokines in mast cells, thus promoting IgE synthesis by B lymphocytes. We tested this hypothesis in human mast cells (HMC-1) expressing A2A, A2B, and A3 adenosine receptors. The adenosine analog 5′-N-ethylcarboxamidoadenosine (NECA) (10 μM) increased mRNA expression of IL-1β, IL-3, IL-4, IL-8, and IL-13, but not IL-2 and IFN-γ. Up-regulation of IL-4 and IL-13 was verified using RT-PCR and ELISA; 10 μM NECA increased IL-13 concentrations in HMC-1 conditioned medium 28-fold, from 7.6 ± 0.3 to 215 ± 4 pg/ml, and increased IL-4 concentrations 6-fold, from 19.2 ± 0.1 to 117 ± 2 pg/ml. This effect was mediated by A2B receptors because neither the selective A2A agonist 2-p-(2-carboxyethyl)phenethylamino-NECA nor the selective A3 agonist N6-(3-iodobenzyl)-N-methyl-5′-carbamoyladenosine reproduced it, and the selective A2B antagonist 3-isobutyl-8-pyrrolidinoxanthine prevented it. Constitutive expression of CD40 ligand on HMC-1 surface was not altered by NECA. Human B lymphocytes cocultured for 12 days with NECA-stimulated HMC-1 produced 870 ± 33 pg IgE per 106 B cells, whereas lymphocytes cocultured with nonstimulated HMC-1, or cultured alone in the absence or in the presence of NECA, produced no IgE. Thus, we demonstrated induction of IgE synthesis by the interaction between adenosine-stimulated mast cells and B lymphocytes, and suggest that this mechanism is involved in the amplification of the allergic inflammatory responses associated with asthma.
Labile Zinc and Zinc Transporter ZnT4 in Mast Cell Granules: Role in Regulation of Caspase Activation and NF-κB Translocation
Authors: Ho Lien H. , Ruffin Richard E. , Murgia Chiara , Li Lixin , Krilis Steven A. , Zalewski Peter D. 
Published: April 2014

Abstract
The granules of mast cells and other inflammatory cells are known to be rich in zinc (Zn), a potent caspase inhibitor. The functions of granular Zn, its mechanism of uptake, and its relationship to caspase activation in apoptosis are unclear. The granules of a variety of mast cell types fluoresced intensely with the Zn-specific fluorophore Zinquin, and fluorescence was quenched by functional depletion of Zn using a membrane-permeable Zn chelator N, N, N′, N′-tetrakis (2-pyridyl-methyl)ethylenediamine (TPEN). Zn levels were also depleted by various mast cell activators, including IgE/anti-IgE, and Zn was rapidly replenished during subsequent culture, suggesting an active uptake mechanism. In support of the latter, mast cells contained high levels of the vesicular Zn transporter ZnT4, especially in the more apical granules. Immunofluorescence and immunogold labeling studies revealed significant pools of procaspase-3 and -4 in mast cell granules and their release during degranulation. Functional depletion of Zn by chelation with TPEN, but not by degranulation, resulted in greatly increased susceptibility of mast cells to toxin-induced caspase activation, as detected using a fluorogenic substrate assay. Release of caspases during degranulation was accompanied by a decreased susceptibility to toxins. Zn depletion by chelation, but not by degranulation, also resulted in nuclear translocation of the antiapoptotic, proinflammatory transcription factor NF-κB. These findings implicate a role for ZnT4 in mast cell Zn homeostasis and suggest that granule pools of Zn may be distinct from those regulating activation of procaspase-3 and NF-κB.
An In Vitro Model for the Lepromatous Leprosy Granuloma: Fate ofMycobacterium lepraefrom Target Macrophages after Interaction with Normal and Activated Effector Macrophages
Authors: Hagge Deanna A. , Ray Nashone A. , Krahenbuhl James L. , Adams Linda B. 
Published: April 2014

AbstractThe lepromatous leprosy granuloma is a dynamic entity requiring a steady influx of macrophages (Mφ) for its maintenance. We have developed an in vitro model to study the fate of Mycobacterium leprae in a LL lesion, with and without immunotherapeutic intervention. Target cells, consisting of granuloma Mφ harvested from the footpads of M. leprae-infected athymic nu/nu mice, were cocultured with normal or IFN-γ-activated (ACT) effector Mφ. The bacilli were recovered and assessed for viability by radiorespirometry. M. leprae recovered from target Mφ possessed high metabolic activity, indicating a viable state in this uncultivable organism. M. leprae recovered from target Mφ incubated with normal effector Mφ exhibited significantly higher metabolism. In contrast, bacilli recovered from target Mφ cocultured with ACT effector Μφ displayed a markedly decreased metabolic activity. Inhibition by ACT Mφ required an E:T ratio of at least 5:1, a coculture incubation period of 3–5 days, and the production of reactive nitrogen intermediates, but not reactive oxygen intermediates. Neither IFN-γ nor TNF-α were required during the cocultivation period. However, cell-to-cell contact between the target and effector Mφ was necessary for augmentation of M. leprae metabolism by normal effector Mφ as well as for inhibition of M. leprae by ACT effector Mφ. Conventional fluorescence microscopy and confocal fluorescence microscopy revealed that the bacilli from the target Mφ were acquired by the effector Mφ. Thus, the state of Mφ infiltrating the granuloma may markedly affect the viability of M. leprae residing in Mφ in the lepromatous lesion.
Shear-Dependent Capping of L-Selectin and P-Selectin Glycoprotein Ligand 1 by E-Selectin Signals Activation of High-Avidity β2-Integrin on Neutrophils
Authors: Green Chad E. , Pearson David N. , Camphausen Raymond T. , Staunton Donald E. , Simon Scott I. 
Published: April 2014

AbstractTwo adhesive events critical to efficient recruitment of neutrophils at vascular sites of inflammation are up-regulation of endothelial selectins that bind sialyl Lewisx ligands and activation of β2-integrins that support neutrophil arrest by binding ICAM-1. We have previously reported that neutrophils rolling on E-selectin are sufficient for signaling cell arrest through β2-integrin binding of ICAM-1 in a process dependent upon ligation of L-selectin and P-selectin glycoprotein ligand 1 (PSGL-1). Unresolved are the spatial and temporal events that occur as E-selectin binds to human neutrophils and dynamically signals the transition from neutrophil rolling to arrest. Here we show that binding of E-selectin to sialyl Lewisx on L-selectin and PSGL-1 drives their colocalization into membrane caps at the trailing edge of neutrophils rolling on HUVECs and on an L-cell monolayer coexpressing E-selectin and ICAM-1. Likewise, binding of recombinant E-selectin to PMNs in suspension also elicited coclustering of L-selectin and PSGL-1 that was signaled via mitogen-activated protein kinase. Binding of recombinant E-selectin signaled activation of β2-integrin to high-avidity clusters and elicited efficient neutrophil capture of β2-integrin ligands in shear flow. Inhibition of p38 and p42/44 mitogen-activated protein kinase blocked the cocapping of L-selectin and PSGL-1 and the subsequent clustering of high-affinity β2-integrin. Taken together, the data suggest that E-selectin is unique among selectins in its capacity for clustering sialylated ligands and transducing signals leading to neutrophil arrest in shear flow.
Membrane-Bound Matrix Metalloproteinase-8 on Activated Polymorphonuclear Cells Is a Potent, Tissue Inhibitor of Metalloproteinase-Resistant Collagenase and Serpinase
Authors: Owen Caroline A. , Hu Zhuma , Lopez-Otin Carlos , Shapiro Steven D. 
Published: April 2014

Abstract
Little is known about the cell biology or the biologic roles of polymorphonuclear cell (PMN)-derived matrix metalloproteinase-8 (MMP-8). When activated with proinflammatory mediators, human PMN release only ∼15–20% of their content of MMP-8 (∼60 ng/106 cells) exclusively as latent pro-MMP-8. However, activated PMN incubated on type I collagen are associated with pericellular collagenase activity even when bathed in serum. PMN pericellular collagenase activity is attributable to membrane-bound MMP-8 because: 1) MMP-8 is expressed in an inducible manner in both pro- and active forms on the surface of human PMN; 2) studies of activated PMN from mice genetically deficient in MMP-8 (MMP-8−/−) vs wild-type (WT) mice show that membrane-bound MMP-8 accounts for 92% of the MMP-mediated, PMN surface type I collagenase activity; and 3) human membrane-bound MMP-8 on PMN cleaves types I and II collagens, and α1-proteinase inhibitor, but is substantially resistant to inhibition by tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2. Binding of MMP-8 to the PMN surface promotes its stability because soluble MMP-8 has t1/2 = 7.5 h at 37°C, but membrane-bound MMP-8 retains &gt;80% of its activity after incubation at 37°C for 18 h. Studies of MMP-8−/− vs WT mice given intratracheal LPS demonstrate that 24 h after intratracheal LPS, MMP-8−/− mice have 2-fold greater accumulation of PMN in the alveolar space than WT mice. Thus, MMP-8 has an unexpected, anti-inflammatory role during acute lung injury in mice. TIMP-resistant, active MMP-8 expressed on the surface of activated PMN is likely to be an important form of MMP-8, regulating lung inflammation and collagen turnover in vivo.
Defective Dendritic Cell Function in HIV-Infected Patients Receiving Effective Highly Active Antiretroviral Therapy: Neutralization of IL-10 Production and Depletion of CD4+CD25+ T Cells Restore High Levels of HIV-Specific CD4+ T Cell Responses Induced by Dendritic Cells Generated in the Presence of IFN-α
Authors: Carbonneil Cédric , Donkova-Petrini Vladimira , Aouba Albertine , Weiss Laurence 
Published: April 2014

Abstract
We previously demonstrated that GM-CSF/IFN-α combination allowed the differentiation of monocytes from HIV-infected patients into dendritic cells (DCs) exhibiting high CD8+ T cell stimulating abilities. The present study was aimed at characterizing the ability of DCs generated in the presence of GM-CSF and IFN-α to induce CD4 T cell responses. DCs were generated from monocytes of HIV-infected patients in the presence of GM-CSF with either IFN-α (IFN-DCs) or IL-4 (IL-4-DCs) for 7 days. Eleven patients receiving highly active antiretroviral therapy and exhibiting CD4 cell counts above 400/mm3 and plasma HIV-RNA &lt;50 copies/ml for at least 1 year were included in the study. Both DC populations were found to be defective in inducing autologous (in response to tuberculin or HIV-p24) or allogeneic CD4 T cell proliferation. Neutralization of IL-10 during the differentiation of IFN-DCs, but not during the DC-T cell coculture, significantly increased their ability to stimulate autologous CD4 T cell proliferation in response to tuberculin and allogeneic CD4 T cell proliferation (4.1-fold and 3.0-fold increases, respectively, at the DC to T cell ratio of 1:10). Moreover, IL-10 neutralization and CD4+CD25+ T cell depletion synergistically act to dramatically increase HIV-p24-specific CD4 T cell responses induced by IFN-DCs (31.7-fold increase) but not responses induced by IL-4-DCs. Taken together, our results indicate that IFN-DCs are more efficient than IL-4-DCs to stimulate CD4+ T cell proliferation, further supporting their use for immune-based therapy in HIV infection.
Development of Antigen-Specific CD8+ CTL in MHC Class I-Deficient Mice through CD4 to CD8 Conversion
Authors: Tanaka Yasuhiro , Koido Shigeo , Xia Jianchuan , Ohana Masaya , Liu Chunlei , Cote Gregory M. , Sawyer Douglas B. , Calderwood Stuart , Gong Jianlin 
Published: April 2014

Abstract
CD8+ CTL are the predominant tumoricidal effector cells. We find, however, that MHC class I-deficient mice depleted of CD8+ T cells are able to mount an effective antitumor immunity after immunization with fused dendritic/tumor cells. Such immunity appears to be mediated by the generation of phenotypic and functional CD8+ CTL through CD4+ to CD8+ conversion, which we have demonstrated at the single cell level. CD4+ to CD8+ conversion depends on effective in vivo activation and is promoted by CD4+ T cell proliferation. The effectiveness of this process is shown by the generation of antitumor immunity through adoptive transfer of primed CD4 T cells to provide protection against tumor cell challenge and to eliminate established pulmonary metastases.
Cutting Edge: Neutrophil Granulocyte Serves as a Vector forLeishmaniaEntry into Macrophages
Authors: van Zandbergen Ger , Klinger Matthias , Mueller Antje , Dannenberg Sonja , Gebert Andreas , Solbach Werner , Laskay Tamás 
Published: April 2014

AbstractMacrophages (MF) are the final host cells for multiplication of the intracellular parasite Leishmania major (L. major). However, polymorphonuclear neutrophil granulocytes (PMN), not MF, are the first leukocytes that migrate to the site of infection and encounter the parasites. Our previous studies indicated that PMN phagocytose but do not kill L. major. Upon infection with Leishmania, apoptosis of human PMN is delayed and takes 2 days to occur. Infected PMN were found to secrete high levels of the chemokine MIP-1β, which attracts MF. In this study, we investigated whether MF can ingest parasite-infected PMN. We observed that MF readily phagocytosed infected apoptotic PMN. Leishmania internalized by this indirect way survived and multiplied in MF. Moreover, ingestion of apoptotic infected PMN resulted in release of the anti-inflammatory cytokine TGF-β by MF. These data indicate that Leishmania can misuse granulocytes as a “Trojan horse” to enter their final host cells “silently” and unrecognized.
Cutting Edge: Transpresentation of IL-15 by Bone Marrow-Derived Cells Necessitates Expression of IL-15 and IL-15Rα by the Same Cells
Authors: Sandau Michelle M. , Schluns Kimberly S. , Lefrancois Leo , Jameson Stephen C. 
Published: April 2014

AbstractIL-15 is critical for generation of multiple lymphoid subsets. Recent data have demonstrated a unique aspect of responses to IL-15, in that cells bearing the IL-15Rα chain can bind soluble IL-15 and “transpresent” the cytokine to other cells, allowing the latter to respond to IL-15. However, it is unclear whether IL-15 is normally secreted and then becomes bound to surface IL-15Rα on bystander cells, or whether transpresentation is mediated by the same cells which synthesize IL-15. Using mixed bone marrow chimeric mice, we present evidence for the latter model, showing that development of NK cells and memory phenotype CD8 T cells necessitates that both IL-15 and IL-15Rα be expressed by the same population of cells. These data argue that soluble forms of IL-15 are irrelevant for physiological responses to this cytokine, and the implications of this finding are discussed.
Novel Insights on Human NK Cells’ Immunological Modalities Revealed by Gene Expression Profiling
Authors: Hanna Jacob , Bechtel Pamela , Zhai Yufeng , Youssef Fadi , McLachlan Karen , Mandelboim Ofer 
Published: April 2014

Abstract
As part of the innate immune system, human NK cells play a critical role early in the systemic host defense against pathogens and tumor cells. Recent studies suggest a more complex view of NK cell behavior, as different functions and tissue localizing capabilities seem to be preferentially assigned to distinct subpopulations of NK cells, CD56dimCD16+ or CD56brightCD16−. In this study, we used oligonucleotide microarrays to compare the expression profile of ∼20,000 genes in three NK cell subpopulations: peripheral blood-derived CD56dimCD16+, CD56brightCD16−, and in vitro-activated CD16+ NK cells. The differential expression of selected genes was verified by flow cytometry and functional assays. When comparing CD56dimCD16+ and CD56brightCD16− subsets, a new heterogeneous molecular basis for the functional and developmental differences between these two subsets was revealed. Furthermore, systematic analysis of transcriptional changes in activated CD16+ NK cells provided us with a better understanding of NK function in inflamed tissues. We highlight a number of genes that were overexpressed upon activation (e.g., OX40 ligand, CD86, Tim3, galectins, etc.), that enable these cells to directly cross-talk with other innate and adaptive immune effectors. The overexpressed genes assign novel intriguing immunomodulatory functions to activated NK cells, in addition to their potent cytotoxic abilities.