bluuebunny/crossref_metadata_2025_split huggingface dataset:
NK Cells Respond to Pulmonary Infection with Mycobacterium tuberculosis, but Play a Minimal Role in Protection
Authors: Junqueira-Kipnis Ana Paula , Kipnis Andre , Jamieson Amanda , Juarrero Mercedes Gonzalez , Diefenbach Andreas , Raulet David H. , Turner Joanne , Orme Ian M. 
Published: April 2014

Abstract
Both innate and adaptive immune systems contribute to host defense against infection with Mycobacterium tuberculosis. NK cells have been associated with early resistance against intracellular pathogens and are known to be potent producers of the cytokine IFN-γ. In C57BL/6 mice infected by aerosol exposure with M. tuberculosis, NK cells increased in the lungs over the first 21 days of infection. Expansion of the NK cell subset was associated with increased expression of activation and maturation markers. In addition, NK cells isolated from the infected lungs were capable of producing IFN-γ and became positive for perforin. In vivo depletion of NK cells using a lytic Ab had no influence on bacterial load within the lungs. These findings indicate that NK cells can become activated during the early response to pulmonary tuberculosis in the mouse model and are a source of IFN-γ, but their removal does not substantially alter the expression of host resistance.
Human C-Reactive Protein Does Not Protect against Acute Lipopolysaccharide Challenge in Mice
Authors: Hirschfield Gideon M. , Herbert Jeff , Kahan Melvyn C. , Pepys Mark B. 
Published: April 2014

AbstractThe physiological and pathophysiological functions of C-reactive protein (CRP), the classical acute-phase protein, are not well established, despite many reports of biological effects of CRP in vitro and in model systems in vivo. Limited, small scale experiments have suggested that rabbit and human CRP may both protect mice against lethal toxicity of Gram-negative bacterial LPS. However, in substantial well-controlled studies in C57BL/6 mice challenged with Escherichia coli O111:B4 LPS, we show in this work that significant protection against lethality was conferred neither by an autologous acute-phase response to sterile inflammatory stimuli given to wild-type mice 24 h before LPS challenge, nor by human CRP, whether passively administered or expressed transgenically. Male mice transgenic for human CRP, which mount a major acute-phase response of human CRP after LPS injection, were also not protected against the lethality of LPS from either E. coli O55:B5 or Salmonella typhimurium. Even when the acute-phase human CRP response was actively stimulated in transgenic mice before LPS challenge, no protection against LPS toxicity was observed. Indeed, male mice transgenic for human CRP that were pretreated with casein to stimulate an acute-phase response 24 h before LPS challenge suffered significantly greater mortality than unstimulated human CRP transgenic controls. Rather than being protective in this situation, human CRP may thus have pathogenic proinflammatory effects in vivo.
IL-1R-Associated Kinase 4 Is Required for Lipopolysaccharide- Induced Activation of APC
Authors: Suzuki Nobutaka , Suzuki Shinobu , Eriksson Urs , Hara Hiromitsu , Mirtosis Christine , Chen Nien-Jung , Wada Teiji , Bouchard Denis , Hwang Irene , Takeda Kiyoshi , Fujita Takashi , Der Sandy , Penninger Josef M. , Akira Shizuo , Saito Takashi , Yeh Wen-Chen 
Published: April 2014

AbstractThe bacterial product LPS is a critical stimulus for the host immune system in the response against the corresponding bacterial infection. LPS provides an activation stimulus for macrophages and a maturation signal for dendritic cells to set up innate and adaptive immune responses, respectively. The signaling cascade of myeloid differentiation factor 88→IL-1R-associated kinase (IRAK)→TNFR-associated factor 6 has been implicated in mediating LPS signaling. In this report, we studied the function of IRAK-4 in various LPS-induced signals. We found that IRAK-4-deficient cells were severely impaired in producing some IFN-regulated genes as well as inflammatory cytokines in response to LPS. Among the critical downstream signaling pathways induced by LPS, NF-κB activation but not IFN regulatory factor 3 or STAT1 activation was defective in cells lacking IRAK-4. IRAK-4 was also required for the proper maturation of dendritic cells by LPS stimulation, particularly in terms of cytokine production and the ability to stimulate Th cell differentiation. Our results demonstrate that IRAK-4 is critical for the LPS-induced activations of APCs.
FcγRIIIb Allele-Sensitive Release of α-Defensins: Anti-Neutrophil Cytoplasmic Antibody-Induced Release of Chemotaxins
Authors: Tanaka Sumiaki , Edberg Jeffrey C. , Chatham Winn , Fassina Giorgio , Kimberly Robert P. 
Published: April 2014

Abstract
Antineutrophil cytoplasmic Abs (ANCA) can activate neutrophils in an FcγR-dependent manner, but the link between this ANCA-induced effect and mononuclear cell activation with the characteristic granuloma formation of Wegener’s granulomatosis is unclear. Human α-defensins, small cationic antimicrobial peptides, are found in neutrophils and have chemotactic activity for T cells, dendritic cells, and monocytes. In this study, we quantitated the release of α-defensins (human neutrophil peptides 1–3) from human neutrophils after targeted FcγR cross-linking (XL). Homotypic XL of FcγRIIa, FcγRIIIb, or heterotypic XL of both receptors resulted in significant release of α-defensins, an effect also induced by both human polyclonal and murine monoclonal cytoplasmic staining ANCA (anti-proteinase 3). This release of α-defensins, as well as of other granule constituents (ANCA targets anti-proteinase 3 and myeloperoxidase and elastase), was significantly greater in donors homozygous for the NA1 allele of FcγRIIIb than in donors homozygous for NA2. Interestingly, the ANCA-induced release was completely inhibited by the IgG Fc-binding peptide TG19320, which blocks the IgG-Fc region from binding to FcγR. Based on their chemotactic properties, α-defensins and their release by ANCA may contribute to modulation of the acquired immune response and to granuloma formation. The greater activity of the FcγRIIIB-NA1 genotype may also explain the greater severity of disease and its flare-ups in patients with this allele.
Activation of Endothelial Extracellular Signal-Regulated Kinase Is Essential for Neutrophil Transmigration: Potential Involvement of a Soluble Neutrophil Factor in Endothelial Activation
Authors: Stein Brian N. , Gamble Jennifer R. , Pitson Stuart M. , Vadas Mathew A. , Khew-Goodall Yeesim 
Published: April 2014

Abstract
During an inflammatory response induced by infection or injury, leukocytes traverse the endothelial barrier into the tissue space. Extravasation of leukocytes is a multistep process involving rolling, tethering, firm adhesion to the endothelium, and finally, transendothelial migration, the least characterized step in the process. The resting endothelium is normally impermeable to leukocytes; thus, during inflammation, intracellular signals that modulate endothelial permeability are activated to facilitate the paracellular passage of leukocytes. Using a static in vitro assay of neutrophil transmigration across human umbilical vein endothelium, a panel of inhibitors of intracellular signaling was screened for their ability to inhibit transmigration. PD98059, a specific inhibitor of extracellular signal-regulated kinase (ERK) 1/2 activation, inhibited both transmigration across TNF-α-activated endothelium and transmigration induced by the chemoattractant fMLP in a dose-dependent manner. PD98059 did not inhibit neutrophil chemotaxis in the absence of an endothelial barrier nor neutrophil adhesion to the endothelium, suggesting that its effect was on the endothelium, and furthermore, that endothelial ERK activation may be important for transmigration. We demonstrate in this study that endothelial ERK is indeed activated during neutrophil transmigration and that its activation is dependent on the addition of neutrophils to the endothelium. Further characterization showed that the trigger for endothelial ERK activation is a soluble protein of molecular mass ∼30 kDa released from neutrophils after activation.
Endothelial Cells Proactively Form Microvilli-Like Membrane Projections upon Intercellular Adhesion Molecule 1 Engagement of Leukocyte LFA-1
Authors: Carman Christopher V. , Jun Chang-Duk , Salas Azucena , Springer Timothy A. 
Published: April 2014

Abstract
Specific leukocyte/endothelial interactions are critical for immunity and inflammation, yet the molecular details of this interaction interface remain poorly understood. Thus, we investigated, with confocal microscopy, the distribution dynamics of the central adhesion molecules ICAM-1 and LFA-1 in this context. Monolayers of activated HUVECs stained with fluorescent anti-ICAM-1 Fabs or Chinese hamster ovary-K1 cells expressing ICAM-1-green fluorescent protein were allowed to bind LFA-1-bearing monocytes, neutrophils, or K562 LFA-1 transfectants. ICAM-1 was rapidly relocalized to newly formed microvilli-like membrane projections in response to binding LFA-1 on leukocytes. These ICAM-1-enriched projections encircled the leukocytes extending up their sides and clustered LFA-1 underneath into linear tracks. Projections formed independently of VCAM-1/very late Ag 4 interactions, shear, and proactive contributions from the LFA-1-bearing cells. In the ICAM-1-bearing endothelial cells, projections were enriched in actin but not microtubules, required intracellular calcium, and intact microfilament and microtubule cytoskeletons and were independent of Rho/Rho kinase signaling. Disruption of these projections with cytochalasin D, colchicine, or BAPTA-AM had no affect on firm adhesion. These data show that in response to LFA-1 engagement the endothelium proactively forms an ICAM-1-enriched cup-like structure that surrounds adherent leukocytes but is not important for firm adhesion. This finding leaves open a possible role in leukocyte transendothelial migration, which would be consistent with the geometry and kinetics of formation of the cup-like structure.
Toll-Like Receptor 2 Pathway Drives Streptococcal Cell Wall-Induced Joint Inflammation: Critical Role of Myeloid Differentiation Factor 88
Authors: Joosten Leo A. B. , Koenders Marije I. , Smeets Ruben L. , Heuvelmans-Jacobs Marleen , Helsen Monique M. A. , Takeda Kiyoshi , Akira Shizuo , Lubberts Erik , van de Loo Fons A. J. , van den Berg Wim B. 
Published: April 2014

Abstract
The IL-1R/Toll-like receptor (TLR) superfamily of receptors has a key role in innate immunity and inflammation. In this study, we report that streptococcal cell wall (SCW)-induced joint inflammation is predominantly dependent on TLR-2 signaling, since TLR-2-deficient mice were unable to develop either joint swelling or inhibition of cartilage matrix synthesis. Myeloid differentiation factor 88 (MyD88) is a Toll/IL-1R domain containing adaptor molecule known to have a central role in both IL-1R/IL-18R and TLR signaling. Mice deficient for MyD88 did not develop SCW-induced arthritis; both joint swelling and disturbance of cartilage chondrocyte anabolic function was completely abolished. Local levels of proinflammatory cytokines and chemokines in synovial tissue washouts were strongly reduced in MyD88-deficient mice. Histology confirmed the pivotal role of MyD88 in acute joint inflammation. TLR-2-deficient mice still allow influx of inflammatory cells into the joint cavity, although the number of cells was markedly reduced. No influx of inflammatory cells was seen in joints of MyD88-deficient mice. In addition, cartilage matrix proteoglycan loss was completely absent in MyD88 knockout mice. These findings clearly demonstrated that MyD88 is a key component in SCW-induced joint inflammation. Since agonists of the Toll-like pathway are abundantly involved in both septic and rheumatoid arthritis, targeting of MyD88 may be a novel therapy in inflammatory joint diseases.
Apoptosis-Associated Speck-Like Protein Containing a Caspase Recruitment Domain Is a Regulator of Procaspase-1 Activation
Authors: Stehlik Christian , Lee Sug Hyung , Dorfleutner Andrea , Stassinopoulos Angela , Sagara Junji , Reed John C. 
Published: April 2014

Abstract
Apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC)/target of methylation-induced silencing/PYCARD represents one of only two proteins encoded in the human genome that contains a caspase recruitment domain (CARD) together with a pyrin, AIM, ASC, and death domain-like (PAAD)/PYRIN/DAPIN domain. CARDs regulate caspase family proteases. We show here that ASC binds by its CARD to procaspase-1 and to adapter proteins involved in caspase-1 activation, thereby regulating cytokine pro-IL-1β activation by this protease in THP-1 monocytes. ASC enhances IL-1β secretion into the cell culture supernatants, at low concentrations, while suppressing at high concentrations. When expressed in HEK293 cells, ASC interferes with Cardiak/Rip2/Rick-mediated oligomerization of procaspase-1 and suppresses activation this protease, as measured by protease activity assays. Moreover, ASC also recruits procaspase-1 into ASC-formed cytosolic specks, separating it from Cardiak. We also show that expression of the PAAD/PYRIN family proteins pyrin or cryopyrin/PYPAF1/NALP3 individually inhibits IL-1β secretion but that coexpression of ASC with these proteins results in enhanced IL-1β secretion. However, expression of ASC uniformly interferes with caspase-1 activation and IL-1β secretion induced by proinflammatory stimuli such as LPS and TNF, suggesting pathway competition. Moreover, LPS and TNF induce increases in ASC mRNA and protein expression in cells of myeloid/monocytic origin, revealing another level of cross-talk of cytokine-signaling pathways with the ASC-controlled pathway. Thus, our results suggest a complex interplay of the bipartite adapter protein ASC with PAAD/PYRIN family proteins, LPS (Toll family receptors), and TNF in the regulation of procaspase-1 activation, cytokine production, and control of inflammatory responses.
Alterations in Granule Matrix and Cell Surface of Focal Adhesion Kinase-Deficient Mast Cells
Authors: Vial Daniel , Oliver Constance , Jamur Maria Célia , Pastor Maria Verônica Dávila , da Silva Trindade Edvaldo , Berenstein Elsa , Zhang Juan , Siraganian Reuben P. 
Published: April 2014

Abstract
Focal adhesion kinase (FAK) is a nonreceptor protein tyrosine kinase that plays an important role in many cellular processes and is tyrosine phosphorylated after FcεRI aggregation in mast cells. In mice, null mutation of the fak gene results in a lethal phenotype in which the embryos fail to develop past day 8.5 of gestation. To study the role of FAK in these mast cells, 8.5-day embryos were isolated and placed in culture with IL-3 and stem cell factor (SCF). Although FAK was not required for the development of mast cells in culture, the FAK−/− embryo-derived mast cells had several distinct characteristics. Compared with the controls, the mast cells that lack FAK were less metachromatic and by electron microscopy had granules that appeared largely electron lucid, although their histamine content was unchanged. The FAK-deficient mast cells had a reduction in the content of chondroitin/dermatan sulfate, the major glycosaminoglycan component of the granular matrix. The FAK-deficient cells had fewer microvilli that were fused with each other, giving the cell surface a ruffled appearance. There was also a 3-fold increase in the number of cells highly expressing β7 integrin. However, signal transduction from the high affinity IgE receptor for the secretion of histamine was similar in the wild-type, heterozygote, and the FAK-deficient cells. The FcεRI-induced tyrosine phosphorylation of paxillin, Crk-associated tyrosine kinase substrate (CAS), and mitogen-activated protein kinase proteins was independent of FAK. These results indicate that FAK plays a role in regulating the glycosaminoglycan content of the secretory granules and influences the cell surface morphology of mast cells.
B-1 B Cells Mediate Required Early T Cell Recruitment to Elicit Protein-Induced Delayed-Type Hypersensitivity
Authors: Szczepanik Marian , Akahira-Azuma Moe , Bryniarski Krzysztof , Tsuji Ryohei F. , Kawikova Ivana , Ptak Wlodzimierz , Kiener Claudia , Campos Regis A. , Askenase Philip W. 
Published: April 2014

AbstractWe define the initiation of elicited delayed-type hypersensitivity (DTH) as a series of processes leading to local extravascular recruitment of effector T cells. Responses thus have two sequential phases: 1) 2-h peaking initiation required for subsequent recruitment of T cells, and 2) the late classical 24-h component mediated by the recruited T cells. We analyzed DTH initiation to protein Ags induced by intradermal immunization without adjuvants. Ag-spceific initiating cells are present by 1 day in spleen and lymph nodes. Their phenotypes, determined by depletion of cell transfers by mAb and complement, are CD5+, CD19+, CD22+, B220+, Thy1+, and Mac1+, suggesting that they are B-1 B cells. DTH initiation is absent in μMT B cell and xid B-1 cell deficient mice, is impaired in mice unable to secrete IgM, and is reconstituted with 1 day immune serum, suggesting that early B-1 cell-derived IgM is responsible. Study of complement C5a receptor-deficient mice, anti-C5 mAb neutralization, or mast cell deficiency suggests that DTH initiation depends on complement and mast cells. ELISPOT assay confirmed production of Ag-specific IgM Abs at days 1 and 4 in wild-type mice, but not in B-1 cell-deficient xid mice. We conclude that rapidly activated B-1 cells produce specific IgM Abs which, after local secondary skin challenge, form Ag-Ab complexes that activate complement to generate C5a. This stimulates C5a receptors on mast cells to release vasoactive substances, leading to endothelial activation for the 2-h DTH-initiating response, allowing local recruitment of DTH-effector T cells.
Mechanisms of Spontaneous Resolution versus Fibrosis in Granulomatous Experimental Autoimmune Thyroiditis
Authors: Chen Kemin , Wei Yongzhong , Sharp Gordon C. , Braley-Mullen Helen 
Published: April 2014

AbstractWhen granulomatous experimental autoimmune thyroiditis (G-EAT) was induced in CBA/J or DBA/1 mice, thyroid lesions resolved in less severe (3+) G-EAT in wild-type mice or severe (5+) G-EAT in IFN-γ−/− mice, but progressed to fibrosis in 5+ G-EAT in wild-type mice. To define the mechanisms leading to these distinct outcomes, the expression of inflammatory and apoptotic molecules and infiltrating cells was evaluated using immunohistochemistry, RT-PCR, and confocal microscopy. The ratio of CD4+/CD8+ T cells in thyroid infiltrates was one factor that predicted G-EAT outcome. CD4+ T cells outnumbered CD8+ T cells when lesions progressed to fibrosis, while CD8+ T cells outnumbered CD4+ T cells in thyroids that resolved. Fas, Fas ligand, FLIP, TNF-α, inducible NO synthase, TGF-β, and IFN-γ were highly expressed by infiltrating cells when G-EAT progressed to fibrosis. The expression of active caspase-3 was low, possibly contributing to the persistence of CD4+ T cells in fibrosis. In contrast, FLIP was mainly expressed by thyrocytes in resolving G-EAT, the expression of active caspase-3 was high, and resolution correlated with apoptosis of infiltrating cells. There was also relatively less expression of TGF-β, IFN-γ, TNF-α, and inducible NO synthase and higher expression of IL-10 in resolving G-EAT than in G-EAT that progressed to fibrosis. These differences were particularly striking when comparing IFN-γ−/− vs wild-type mice. These results suggest that several opposing biological mechanisms contribute to the outcome of an ongoing autoimmune response. These include differential expression of pro- and antiapoptotic molecules, cytokines, and the ratio of CD4+ vs CD8+ T cells.
Injection of Immature Dendritic Cells into Adjuvant-Treated Skin Obviates the Need for Ex Vivo Maturation
Authors: Nair Smita , McLaughlin Catherine , Weizer Alon , Su Zhen , Boczkowski David , Dannull Jens , Vieweg Johannes , Gilboa Eli 
Published: April 2014

AbstractA key and limiting step in the process of generating human monocyte-derived dendritic cells (DC) for clinical applications is maturation. In the setting of immunotherapy, DC are matured ex vivo by culturing them with various agents that mimic the conditions encountered at a site of inflammation. This study examined whether the ex vivo DC maturation step could be replaced by maturing DC in situ by injecting immature DC into sites pre-exposed to agents that induce a microenvironment conducive to in situ maturation of the injected DC. The hypothesis was that recapitulation of the physiological conditions occurring during pathogen infection would lead to optimal conditions for DC maturation, migration, and function. Murine immature DC injected into adjuvant (Adjuprime, poly-arginine, or Imiquimod)-pretreated skin exhibited lymph node migratory capacity comparable to and immunostimulatory capacity equal to or exceeding that of ex vivo matured DC. Acquisition of migratory capacity did not always correlate with enhanced immunostimulatory capacity. Immunostimulatory capacity was not enhanced when mature DC were injected into adjuvant-pretreated sites and remained below that seen with immature DC matured in situ. Immature DC injected into adjuvant-pretreated sites were more effective than mature DC in stimulating antitumor immunity in mice. 111Indium-labeled human monocyte-derived immature DC injected into adjuvant (Imiquimod)-pretreated sites in cancer patients acquired lymph node migratory capacity comparable to ex vivo matured DC. This study shows that in situ maturation offers a simpler and potentially superior method to generate potent immunostimulatory DC for clinical immunotherapy.
Cutting Edge: CIAS1/Cryopyrin/PYPAF1/NALP3/ CATERPILLER 1.1 Is an Inducible Inflammatory Mediator with NF-κB Suppressive Properties
Authors: O’Connor William , Harton Jonathan A. , Zhu Xinsheng , Linhoff Michael W. , Ting Jenny P.-Y. 
Published: April 2014

Abstract
Mutations in the cold-induced autoinflammatory syndrome 1 (CIAS1) gene have been recently linked to three chronic autoinflammatory disorders. These observations point to an important role for CIAS1 in regulating inflammatory processes. We report that TNF-α and ligands recognized by multiple Toll-like receptors rapidly induce CIAS1 gene expression in primary human monocytes. Transfection of full-length CIAS1 or either of two shorter, naturally occurring isoforms dramatically inhibited TNF-α-induced activation of NF-κB reporter activity. Furthermore, CIAS1 suppressed TNF-α-induced nuclear translocation of endogenous p65. Transcriptional activity of exogenous NF-κB p65 was also blocked by CIAS1. The nucleotide-binding and leucine-rich repeat regions, but not the pyrin domain of CIAS1, are responsible for this inhibition. These data suggest CIAS1/cryopyrin may act as a key regulator of inflammation, induced to dampen NF-κB-dependent proinflammatory signals.