bluuebunny/crossref_metadata_2025_split huggingface dataset:
Leptospira interrogansActivation of Human Peripheral Blood Mononuclear Cells: Preferential Expansion of TCRγδ+ T Cells vs TCRαβ+ T Cells
Authors: Klimpel Gary R. , Matthias Michael A. , Vinetz Joseph M. 
Published: April 2014

AbstractInnate and adaptive immune responses induced by leptospirosis have not been well characterized. In this study we show that in vitro exposure of naive human PBMC to Leptospira interrogans results in cell proliferation and the production of IFN-γ, IL-12, and TNF-α. Cell proliferation was highest when using high numbers of Leptospira. Optimal cell proliferation occurred at 6–8 days, and the majority of cells contained in these cultures were γ/δ T cells. These cultures showed a 10- to 50-fold expansion of γ/δ T cells compared with the initial cellular input. Additionally, these cultures contained elevated numbers of NK cells. In contrast, exposure of PBMC to low numbers of Leptospira failed to induce γδ T cell or NK cell expansion, but induced significant αβ T cell expansion. Vγ9/Vδ2 were expressed on all γ/δ T cells expanded by exposure of PBMC to Leptospira. Leptospira stimulation of purified TCRγδ+ T cells, obtained from 8-day cultures of Leptorspira-stimulated PBMC, induced high levels of IFN-γ production, but no cell proliferation, suggesting that such stimulation of γδ T cells did not depend on specialized accessory cells or Ag processing. Finally, in patients with acute leptospirosis, there was a significant (4- to 5-fold) increase in the number of peripheral blood TCRγδ+ T cells. These results indicate that Leptospira can activate γδ T cells and αβ T cells and will guide further investigations into the roles of these T cell populations in host defense and/or the pathology of leptospirosis.
Inhibition of a p38/Stress-Activated Protein Kinase-2-Dependent Phosphatase Restores Function of IL-1 Receptor-Associated Kinase-1 and Reverses Toll-Like Receptor 2- and 4-Dependent Tolerance of Macrophages
Authors: Ropert Catherine , Closel Meire , Chaves Andréa C. L. , Gazzinelli Ricardo T. 
Published: April 2014

AbstractPretreatment of macrophages with Toll-like receptor (TLR)2 or TLR4 agonists leads to a stage of cell hyporesponsiveness to a second stimulation with TLR agonists. This tolerance state is accompanied by the repression of IL-1 receptor-associated kinase-1, mitogen-activated protein kinases, and IκB phosphorylation and expression of genes encoding proinflammatory cytokines, like IL-1β and TNF-α. In this report, we demonstrated that mucin-like glycoprotein (tGPI-mucin) of Trypanosoma cruzi trypomastigotes (TLR2 agonist) and LPS (TLR4 agonist) induce cross-tolerance in macrophages and we addressed the role of phosphatase activity in this process. Analysis of the kinetic of phosphatase activity induced by tGPI-mucin or LPS revealed maximum levels between 12 and 24 h, which correlate with the macrophage hyporesponsiveness stage. The addition of okadaic acid, an inhibitor of phosphatase activity, reversed macrophage hyporesponsiveness after exposure to either LPS or tGPI-mucin, allowing phosphorylation of IL-1R-associated kinase-1, mitogen-activated protein kinases, and ΙκB and leading to TNF-α gene transcription and cytokine production. Furthermore, pretreatment with either the specific p38/stress-activated protein kinase-2 inhibitor (SB203580) or the NF-κB translocation inhibitor (SN50) prevented the induction of phosphatase activity and hyporesponsiveness in macrophage, permitting cytokine production after restimulation with LPS. These results indicate a critical role of p38/stress-activated protein kinase-2 and NF-κB-dependent phosphatase in macrophage hyporesponsiveness induced by microbial products that activate TLR2 and TLR4.
Human Mast Cell β-Tryptase Is a Gelatinase
Authors: Fajardo Ignacio , Pejler Gunnar 
Published: April 2014

AbstractRemodeling of extracellular matrix is an important component in a variety of inflammatory disorders as well as in normal physiological processes such as wound healing and angiogenesis. Previous investigations have identified the various matrix metalloproteases, e.g., gelatinases A and B, as key players in the degradation of extracellular matrix under such conditions. Here we show that an additional enzyme, human mast cell β-tryptase, has potent gelatin-degrading properties, indicating a potential contribution of this protease to matrix degradation. Human β-tryptase was shown to degrade gelatin both in solution and during gelatin zymographic analysis. Further, β-tryptase was shown to degrade partially denatured collagen type I. β-Tryptase bound strongly to gelatin, forming high molecular weight complexes that were stable during SDS-PAGE. Mast cells store large amounts of preformed, active tryptase in their secretory granules. Considering the location of mast cells in connective tissues and the recently recognized role of mast cells in disorders in which connective tissue degradation is a key event, e.g., rheumatoid arthritis, it is thus likely that tryptase may contribute to extracellular matrix-degrading processes in vivo.
Pellino3, a Novel Member of the Pellino Protein Family, Promotes Activation of c-Jun and Elk-1 and May Act as a Scaffolding Protein
Authors: Jensen Liselotte E. , Whitehead Alexander S. 
Published: April 2014

Abstract
Toll-like receptors and the IL-1R are part of the innate immune response aimed at mobilizing defense mechanisms in response to infections or injury. These receptors can initiate common intracellular signaling cascades. One intermediate component in these signaling cascades is Pellino, which was first identified in Drosophila and shown to interact with IL-1R-associated kinase. Two homologues, Pellino1 and Pellino2, have been identified in mammals. A novel member of the Pellino protein family has been identified and named Pellino3. Pellino3 shares 84 and 85% amino acid identity with Pellino1 and Pellino2, respectively. Two alternatively spliced Pellino3 mRNAs, Pellino3a and Pellino3b, are widely expressed. Pellino3 physically interacts with IL-1R-associated kinase-1, TNF receptor-associated factor-6, TGF-β-activated kinase-1, and NF-κB-inducing kinase in an IL-1-dependent manner, suggesting that it plays a role as a scaffolding protein. In reporter assays Pellino3 leads to activation of c-Jun and Elk-1, but not NF-κB. Pellino3 also leads to activation of c-Jun N-terminal kinase. These data suggest that Pellino3 plays an important role in the innate immune response.
The Proteasome as a Lipopolysaccharide-Binding Protein in Macrophages: Differential Effects of Proteasome Inhibition on Lipopolysaccharide-Induced Signaling Events
Authors: Qureshi Nilofer , Perera Pin-Yu , Shen Jing , Zhang Guochi , Lenschat Arnd , Splitter Gary , Morrison David C. , Vogel Stefanie N. 
Published: April 2014

AbstractWe have developed a novel LPS probe using a highly purified and homogenous preparation of [3H] Escherichia coli LPS from the deep rough mutant, which contains a covalently linked, photoactivable 4-p-(azidosalicylamido)-butylamine group. This cross-linker was used to identify the LPS-binding proteins in membranes of the murine-macrophage-like cell line RAW 264.7. The α-subunit (PSMA1 C2, 29.5 kDa) and the β-subunit (PSMB4 N3, 24.36 kDa) of the 20S proteasome complex were identified as LPS-binding proteins. This is the first report demonstrating LPS binding to enzymes such as the proteasome subunits. Functionally, LPS enhanced the chymotrypsin-like activity of the proteasome to degrade synthetic peptides in vitro and, conversely, the proteasome inhibitor lactacystin completely blocked the LPS-induced proteasome’s chymotrypsin activity as well as macrophage TNF-α secretion and the expression of multiple inflammatory mediator genes. Lactacystin also completely blocked the LPS-induced expression of Toll-like receptor 2 mRNA. In addition, lactacystin dysregulated mitogen-activated protein kinase phosphorylation in LPS-stimulated macrophages, but failed to inhibit IL-1 receptor-associated kinase-1 activity. Importantly, lactacystin also prevented LPS-induced shock in mice. These data strongly suggest that the proteasome complex regulates the LPS-induced signal transduction and that it may be an important therapeutic target in Gram-negative sepsis.
TRAIL Induces Apoptosis and Inflammatory Gene Expression in Human Endothelial Cells
Authors: Li Jie Hui , Kirkiles-Smith Nancy C. , McNiff Jennifer M. , Pober Jordan S. 
Published: April 2014

AbstractHuman TRAIL can efficiently kill tumor cells in vitro and kill human tumor xenografts in mice with little effect on normal mouse cells or tissues. The effects of TRAIL on normal human tissues have not been described. In this study, we report that endothelial cells (EC), isolated from human umbilical veins or human dermal microvessels, express death domain-containing TRAIL-R1 and -R2. Incubation with TRAIL for 15 h causes ∼30% of cultured EC to die, as assessed by propidium iodide uptake. Death is apoptotic, as assessed by Annexin V staining, 4′,6′-diamidino-2-phenylindole staining, and DNA fragment ELISA. EC death is increased by cotreatment with cycloheximide but significantly reduced by caspase inhibitors or transduced dominant-negative Fas-associated death domain protein. In surviving cells, TRAIL activates NF-κB, induces expression of E-selectin, ICAM-1, and IL-8, and promotes adhesion of leukocytes. Injection of TRAIL into human skin xenografts promotes focal EC injury accompanied by limited neutrophil infiltration. These data suggest that TRAIL is an inducer of tissue injury in humans, an outcome that may influence antitumor therapy with TRAIL.
Proangiogenic Function of CD40 Ligand-CD40 Interactions
Authors: Reinders Marlies E. J. , Sho Masayuki , Robertson Stuart W. , Geehan Christopher S. , Briscoe David M. 
Published: April 2014

AbstractAngiogenesis is a characteristic component of cell-mediated immune inflammation. However, little is known of the immunologic mediators of angiogenesis factor production. Interactions between CD40 ligand (CD40L) and CD40 have been shown to have pluripotent functions in inflammation, including the production of cytokines, chemokines, as well as the angiogenesis factor, vascular endothelial growth factor (VEGF), by endothelial cells. In this study we found that treatment of cultured human endothelial cells with an anti-CD40 Ab (to ligate CD40) resulted in the expression of several other angiogenesis factors, including fibroblast growth factor-2 and the receptors Flt-1 and Flt-4. To determine the proangiogenic effect of CD40L in vivo, human skin was allowed to engraft on SCID mice for 6 wk. These healed human skins express CD40 on resident endothelial cells and monocyte/macrophages, but not on CD20-expressing B cells. Skins were injected with saline, untransfected murine fibroblasts, or murine fibroblasts stably transfected with human CD40L. We found that the injection of CD40L-expressing cells, but not control cells, resulted in the in vivo expression of several angiogenesis factors (including VEGF and fibroblast growth factor) and a marked angiogenesis reaction. Mice treated with anti-VEGF failed to elicit an angiogenesis reaction in response to injection of CD40L-expressing cells, suggesting that the proangiogenic effect of CD40L in vivo is VEGF dependent. These observations imply that ligation of CD40 at a peripheral inflammatory site is of pathophysiological importance as a mediator of both angiogenesis and inflammation.
Role of Regulator of G Protein Signaling 16 in Inflammation- Induced T Lymphocyte Migration and Activation
Authors: Lippert Eric , Yowe David L. , Gonzalo Jose-Angel , Justice J. Paul , Webster Jeremy M. , Fedyk Eric R. , Hodge Martin , Miller Cheryl , Gutierrez-Ramos Jose-Carlos , Borrego Francisco , Keane-Myers Andrea , Druey Kirk M. 
Published: April 2014

AbstractChemokine-induced T lymphocyte recruitment to the lung is critical for allergic inflammation, but chemokine signaling pathways are incompletely understood. Regulator of G protein signaling (RGS)16, a GTPase accelerator (GTPase-activating protein) for Gα subunits, attenuates signaling by chemokine receptors in T lymphocytes, suggesting a role in the regulation of lymphocyte trafficking. To explore the role of RGS16 in T lymphocyte-dependent immune responses in a whole-organism model, we generated transgenic (Tg) mice expressing RGS16 in CD4+ and CD8+ cells. rgs16 Tg T lymphocytes migrated to CC chemokine ligand 21 or CC chemokine ligand 12 injection sites in the peritoneum, but not to CXC chemokine ligand 12. In a Th2-dependent model of allergic pulmonary inflammation, CD4+ lymphocytes bearing CCR3, CCR5, and CXCR4 trafficked in reduced numbers to the lung after acute inhalation challenge with allergen (OVA). In contrast, spleens of sensitized and challenged Tg mice contained increased numbers of CD4+CCR3+ cells producing more Th2-type cytokines (IL-4, IL-5, and IL-13), which were associated with increased airway hyperreactivity. Migration of Tg lymphocytes to the lung parenchyma after adoptive transfer was significantly reduced compared with wild-type lymphocytes. Naive lymphocytes displayed normal CCR3 and CXCR4 expression and cytokine responses, and compartmentation in secondary lymphoid organs was normal without allergen challenge. These results suggest that RGS16 may regulate T lymphocyte activation in response to inflammatory stimuli and migration induced by CXCR4, CCR3, and CCR5, but not CCR2 or CCR7.
Complement Activation Determines the Therapeutic Activity of Rituximab In Vivo
Authors: Di Gaetano Nicola , Cittera Elena , Nota Rachele , Vecchi Annunciata , Grieco Valeria , Scanziani Eugenio , Botto Marina , Introna Martino , Golay Josée 
Published: April 2014

AbstractRituximab is an anti-CD20 chimeric mAb effective for the treatment of B-NHL. It can lyse lymphoma cells in vitro through both C- and Ab-dependent cellular cytotoxicity. The mechanism of action of rituximab in vivo is however still unclear. We have set up a new in vivo model in nonimmunodeficient mice by stable transduction of the human CD20 cDNA in the murine lymphoma line EL4. Animals injected i.v. with the EL4-CD20+ lymphoma cells died within 30 days with evident liver, spleen, and bone marrow involvement, confirmed by immunohistochemistry and PCR analysis. A single injection of rituximab or the murine anti-CD20 Ab 1F5, given i.p. 1 day after the tumor, cured 100% of the animals. Indeed, at week 4 after tumor cell inoculation, CD20+ cells were undetectable in all organs analyzed in rituximab-treated animals, as determined by immunohistochemistry and PCR. Rituximab had no direct effect on tumor growth in vitro. Depletion of either NK cells or neutrophils or both in tumor-injected animals did not affect the therapeutic activity of the drug. Similarly, rituximab was able to eradicate tumor cells in athymic nude mice, suggesting that its activity is T cell independent. In contrast, the protective activity of rituximab or the 1F5 Ab was completely abolished in syngeneic knockout animals lacking C1q, the first component of the classical pathway of C (C1qa−/−). These data demonstrate that C activation is fundamental for rituximab therapeutic activity in vivo.
HER-2 DNA and Protein Vaccines Containing Potent Th Cell Epitopes Induce Distinct Protective and Therapeutic Antitumor Responses in HER-2 Transgenic Mice
Authors: Renard Valéry , Sonderbye Lene , Ebbehøj Kirsten , Rasmussen Peter Birk , Gregorius Klaus , Gottschalk Tine , Mouritsen Søren , Gautam Anand , Leach Dana R. 
Published: April 2014

AbstractOverexpression of the growth factor receptor HER-2 (c-erbB-2, neu) has transforming potential and occurs in ∼20–30% of breast and ovarian cancers. HER-2 is a self Ag, but Abs and T cells specific for HER-2 have been isolated from cancer patients, suggesting HER-2 may be a good target for active immunotherapy. We constructed rat HER-2 DNA and protein vaccines containing potent Th cell epitopes derived from tetanus toxin and studied their potency in two strains of mice transgenic for the rat HER-2 molecule. Vaccination with HER-2 DNA protected nontransgenic mice from tumor challenge, but induced only moderate protection in one of the tumor models. However, vaccination with the modified HER-2 protein resulted in almost complete protection from tumor challenge in both tumor models. This protection could be mediated by Abs alone. In addition, protein vaccination efficiently eliminated pre-established tumors in both models, even when vaccination occurred 9 days after tumor implantation. These data demonstrate the potential of HER-2-based vaccines as therapeutic agents for the treatment of cancers overexpressing HER-2.
Microglia-Mediated Nitric Oxide Cytotoxicity of T Cells Following Amyloid β-Peptide Presentation to Th1 Cells
Authors: Monsonego Alon , Imitola Jaime , Zota Victor , Oida Takatoku , Weiner Howard L. 
Published: April 2014

AbstractAlzheimer’s disease is marked by progressive accumulation of amyloid β-peptide (Aβ) which appears to trigger neurotoxic and inflammatory cascades. Substantial activation of microglia as part of a local innate immune response is prominent at sites of Aβ plaques in the CNS. However, the role of activated microglia as Aβ APCs and the induction of adaptive immune responses has not been investigated. We have used primary microglial cultures to characterize Aβ-Ag presentation and interaction with Aβ-specific T cells. We found that IFN-γ-treated microglia serve as efficient Aβ APCs of both Aβ1–40 and Aβ1–42, mediating CD86-dependent proliferation of Aβ-reactive T cells. When cultured with Th1 and Th2 subsets of Aβ-reactive T cells, Th1, but not Th2, cells, underwent apoptosis after stimulation, which was accompanied by increased levels of IFN-γ, NO, and caspase-3. T cell apoptosis was prevented in the presence of an inducible NO synthase type 2 inhibitor. Microglia-mediated proliferation of Aβ-reactive Th2 cells was associated with expression of the Th2 cytokines IL-4 and IL-10, which counterbalanced the toxic levels of NO induced by Aβ. Our results demonstrate NO-dependent apoptosis of T cells by Aβ-stimulated microglia which may enhance CNS innate immune responses and neurotoxicity in Alzheimer’s disease. Secretion of NO by stimulated microglia may underlie a more general pathway of T cell death in the CNS seen in neurodegenerative diseases. Furthermore, Th2 type T cell responses may have a beneficial effect on this process by down-regulation of NO and the proinflammatory environment.
Rapid High Efficiency Sensitization of CD8+ T Cells to Tumor Antigens by Dendritic Cells Leads to Enhanced Functional Avidity and Direct Tumor Recognition Through an IL-12-Dependent Mechanism
Authors: Xu Shuwen , Koski Gary K. , Faries Mark , Bedrosian Isabelle , Mick Rosemarie , Maeurer Markus , Cheever Martin A. , Cohen Peter A. , Czerniecki Brian J. 
Published: April 2014

Abstract
Myeloid-origin dendritic cells (DCs) can develop into IL-12-secreting DC1 or non-IL-12-secreting DC2 depending on signals received during maturation. Through rapid culture techniques that prepared either mature, CD83+ DC1 or DC2 from CD14+ monocytes in only 2 days followed by a single 6–7 day DC-T cell coculture, we sensitized normal donor CD8+ T cells to tumor Ags (HER-2/neu, MART-1, and gp100) such that peptide Ag-specific lymphocytes constituted up to 16% of the total CD8+ population. Both DC1 and DC2 could sensitize CD8+ T cells that recognized peptide-pulsed target cells. However, with DC2, a general decoupling was observed between recognition of peptide-pulsed T2 target cells and recognition of Ag-expressing tumor cells, with peptide-sensitized T cells responding to tumor only about 15% of the time. In contrast, direct recognition of tumor by T cells was dramatically increased (to 85%) when DC1 were used for sensitization. Enhanced tumor recognition was accompanied by 10- to 100-fold increases in peptide sensitivity and elevated expression of CD8β, characteristic of high functional avidity T cells. Both of these properties were IL-12-dependent. These results demonstrate the utility of rapid DC culture methods for high efficiency in vitro T cell sensitization that achieves robust priming and expansion of Ag-specific populations in 6 days. They also demonstrate a novel function of IL-12, which is enhancement of CD8+ T cell functional avidity. A new approach to DC-based vaccines that emphasizes IL-12 secretion to enhance functional avidity and concomitant tumor recognition by CD8+ T cells is indicated.
TNF Skews Monocyte Differentiation from Macrophages to Dendritic Cells
Authors: Chomarat Pascale , Dantin Carole , Bennett Lynda , Banchereau Jacques , Palucka A. Karolina 
Published: April 2014

AbstractMonocytes represent a large pool of circulating precursors of APCs, both macrophages and dendritic cells (DCs). It is thus important to identify the mechanisms by which microenvironment regulates monocyte differentiation. We have previously shown that, upon contact with resting stromal cells such as fibroblasts, monocytes differentiate into macrophages in an IL-6/M-CSF-dependent fashion. Yet, in the inflamed tissue, monocytes need to yield DCs for the adaptive immunity to be induced. Inasmuch as TNF and IL-1 are present at the site of inflammation, we tested their capacity to modulate monocyte differentiation into either macrophages or DCs. TNF, but not IL-1, induce monocytes to become DCs despite the presence of fibroblasts. TNF-induced DCs contain Langerin-positive cells and are able to induce allogenic T cell proliferation. Then, TNF was found to decrease the expression and internalization of the M-CSF receptor, thus overriding the IL-6/M-CSF pathway. Thus, TNF facilitates the induction of adaptive immunity by promoting DC differentiation not only from CD34+ progenitors but also from CD14+ blood precursors.
CD4+ Th Cells Resembling Regulatory T Cells That Inhibit Chronic Colitis Differentiate in the Absence of Interactions Between CD4 and Class II MHC
Authors: Denning Timothy L. , Qi Hai , König Rolf , Scott Kevin G. , Naganuma Makoto , Ernst Peter B. 
Published: April 2014

AbstractRegulatory CD4+ Th cells can prevent many autoimmune diseases; however, the factors selecting for these cells remain poorly defined. In transgenic mice with a mutation in the CD4 binding region on class II MHC, the disruption of CD4-class II interactions selected for CD4+ Th cells that expressed surface markers and cytokines associated with regulatory Th cells. Th cells from these mice were enriched for CD45RBlow as well as CD25+, while they expressed high levels of the transcription factor associated with regulatory T cells, Foxp3, and cytokines, including IL-4, IL-10, and IFN-γ mRNA and protein. These regulatory Th cells inhibited the function of APCs via IL-10 production, and adoptive transfer of these cells prevented weight loss and inflammation in a model of colitis. CD4+ regulatory Th cells emerged only when interactions between CD4 and class II MHC were deficient on cells of nonhemopoietic origin. These data support a novel model controlling the differentiation of regulatory Th cells and suggest that interactions between CD4 and class II MHC may a useful target for re-educating T cells as a treatment for inflammatory diseases.