bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic Protein Associations Define Two Phases of IL-1β Transcriptional Activation
Authors: Zhang Yue , Saccani Simona , Shin Hyunjin , Nikolajczyk Barbara S. 
Published: April 2014

Abstract
IL-1β is a key proinflammatory cytokine with roles in multiple diseases. Monocytes package the IL-1β promoter into a “poised architecture” characterized by a histone-free transcription start site and constitutive transcription factor associations. Upon LPS stimulation, multiple proteins inducibly associate with the IL-1β gene. To understand how the complex combination of constitutive and inducible transcription factors activate the IL-1β gene from a poised structure, we measured temporal changes in NF-κB and IFN regulatory factor (IRF) association with IL-1β regulatory elements. Association of the p65 subunit of NF-κB peaks 30–60 min post-monocyte stimulation, and it shortly precedes IRF-4 recruitment to the IL-1β enhancer and maximal mRNA production. In contrast, IRF-8/enhancer association decreases poststimulation. To test the importance of delayed IRF-4/enhancer association, we introduced a mutated PU.1 protein shown to prevent PU.1-mediated IRF-4 recruitment to the enhancer sequence. Mutated PU.1 initially increased IL-1β mRNA followed by decreased mRNA levels 2–3 h poststimulation. Taken together, these data support a dynamic model of IL-1β transcriptional activation in which a combination of IRF-8 and p65 drives the initial phase of IL-1β transcription, while PU.1-mediated IRF-4 recruitment to the enhancer is important for the second phase. We further demonstrate that activation of both NF-κB and IRF-4 depends on CK2 kinase activity. Because IRF-4/enhancer association requires CK2 but not p65 activation, we conclude that CK2 triggers the IRF-4 and p65 pathways independently to serve as a master regulator of IL-1β transcription.
A Critical Role for Protein Kinase C-θ-Mediated T Cell Survival in Cardiac Allograft Rejection
Authors: Manicassamy Santhakumar , Yin Dengping , Zhang Zheng , Molinero Luciana L. , Alegre Marisa-Luisa , Sun Zuoming 
Published: April 2014

Abstract
Protein kinase C (PKC)-θ mediates the critical TCR signals required for T cell activation. Previously, we have shown that in response to TCR stimulation, PKC-θ−/− T cells undergo apoptosis due to greatly reduced levels of the anti-apoptotic molecule, Bcl-xL. In this study, we demonstrate that PKC-θ-regulated expression of Bcl-xL is essential for T cell-mediated cardiac allograft rejection. Rag1−/− mice reconstituted with wild-type T cells readily rejected fully mismatched cardiac allografts, whereas Rag1−/− mice reconstituted with PKC-θ−/− T cells failed to promote rejection. Transgenic expression of Bcl-xL in PKC-θ−/− T cells was sufficient to restore cardiac allograft rejection, suggesting that PKC-θ-regulated survival is required for T cell-mediated cardiac allograft rejection in this adoptive transfer model. In contrast to adoptive transfer experiments, intact PKC-θ−/− mice displayed delayed, but successful cardiac allograft rejection, suggesting the potential compensation for PKC-θ function. Finally, a subtherapeutic dose of anti-CD154 Ab or CTLA4-Ig, which was not sufficient to prevent cardiac allograft rejection in the wild-type mice, prevented heart rejection in the PKC-θ−/− mice. Thus, in combination with other treatments, inhibition of PKC-θ may facilitate achieving long-term survival of allografts.
Endogenous IL-32 Controls Cytokine and HIV-1 Production
Authors: Nold Marcel F. , Nold-Petry Claudia A. , Pott Gregory B. , Zepp Jarod A. , Saavedra Milene T. , Kim Soo-Hyun , Dinarello Charles A. 
Published: April 2014

AbstractIL-32, a proinflammatory cytokine that activates the p38MAPK and NF-κB pathways, induces other cytokines, for example, IL-1β, IL-6, and TNF-α. This study investigated the role of endogenous IL-32 in HIV-1 infection by reducing IL-32 with small interfering (si)RNA in freshly infected PBMC and in the latently infected U1 macrophage cell line. When PBMC were pretreated with siRNA to IL-32 (siIL-32), IL-6, IFN-γ, and TNF-α were reduced by 57, 51, and 36%, respectively, compared with scrambled siRNA. Cotransfection of NF-κB and AP-1 reporter constructs with siIL-32 decreased DNA binding of these transcription factors by 42 and 46%, respectively. Cytokine protein array analysis revealed that the inhibitory activity of siIL-32 primarily targeted Th1 and proinflammatory cytokines and chemokines, e.g., MIP-1α/β. Unexpectedly, HIV-1 production (as measured by p24) increased 4-fold in these same PBMC when endogenous IL-32 was reduced. Because IFN-γ was lower in siIL-32-treated PBMC, we blocked IFN-γ bioactivity, which enhanced the augmentation of p24 by siIL-32. Furthermore, siIL-32 reduced the natural ligands of the HIV-1 coreceptors CCR5 (MIP-1α/β and RANTES) and CXCR4 (SDF-1). Inhibition of endogenous IL-32 in U1 macrophages also increased HIV-1. When rhIL-32γ was added to these cells, p24 levels fell by 72%; however, in the same cultures IFN-α increased 4-fold. Blockade of IFN-α/β bioactivity in IL-32γ-stimulated U1 cells revealed that IFN-α conveys the anti-HIV-1 effect of rhIL-32γ. In summary, depletion of endogenous IL-32 reduced the levels of Th1 and proinflammatory cytokines but paradoxically increased p24, proposing IL-32 as a natural inhibitor of HIV-1.
Control of Pseudomonas aeruginosa in the Lung Requires the Recognition of Either Lipopolysaccharide or Flagellin
Authors: Ramphal Reuben , Balloy Viviane , Jyot Jeevan , Verma Amrisha , Si-Tahar Mustapha , Chignard Michel 
Published: April 2014

Abstract
Acute lung infection due to Pseudomonas aeruginosa is an increasingly serious problem that results in high mortality especially in the compromised host. In this study, we set out to ascertain what components of the TLR system are most important for innate immunity to this microorganism. We previously demonstrated that TLR2,4−/− mice were not hypersusceptible to infection by a wild-type P. aeruginosa strain. However, we now find that mice lacking both TLR2 and TLR4 (TLR2,4−/− mice) are hypersusceptible to infection following challenge with a P. aeruginosa mutant devoid of flagellin production. We demonstrate that this hypersusceptibilty is largely due to a lack of innate defense by the host that fails to control bacterial replication in the lung. Further evidence that a response to flagellin is a key factor in the failure of TLR2,4−/− mice to control the infection with the mutant strain was obtained by demonstrating that the intrapulmonary administration of flagellin over a 18 h period following infection, saved 100% of TLR2,4−/− mice from death. We conclude that the interactions of either TLR4 with LPS or TLR5 with flagellin can effectively defend the lung from P. aeruginosa infection and the absence of a response by both results in hypersusceptibility to this infection.
CCR2 Mediates Conventional Dendritic Cell Recruitment and the Formation of Bronchovascular Mononuclear Cell Infiltrates in the Lungs of Mice Infected withCryptococcus neoformans
Authors: Osterholzer John J. , Curtis Jeffrey L. , Polak Timothy , Ames Theresa , Chen Gwo-Hsiao , McDonald Rod , Huffnagle Gary B. , Toews Galen B. 
Published: April 2014

AbstractPulmonary clearance of the encapsulated yeast Cryptococcus neoformans requires the development of T1-type immunity. CCR2-deficient mice infected with C. neoformans develop a non-protective T2 immune response and persistent infection. The mechanisms responsible for this aberrant response are unknown. The objective of this study was to define the number, phenotype, and microanatomic location of dendritic cells (DC) residing within the lung of CCR2+/+ or CCR2−/− mice throughout a time course following infection with C. neoformans. Results demonstrate the CCR2-mediated recruitment of conventional DC expressing modest amounts of costimulatory molecules. DC recruitment was preceded by the up-regulation in the lung of the CCR2 ligands CCL2 and CCL7. Colocalization of numerous DC and CD4+ T cells within bronchovascular infiltrates coincided with increased expression of IL-12 and IFN-γ. By contrast, in the absence of CCR2, DC recruitment was markedly impaired, bronchovascular infiltrates were diminished, and mice developed features of T2 responses, including bronchovascular collagen deposition and IL-4 production. Our results demonstrate that CCR2 is required for the recruitment of large numbers of conventional DC to bronchovascular infiltrates in mice mounting a T1 immune response against a fungal pathogen. These findings shed new insight into the mechanism(s) by which DC recruitment alters T cell polarization in response to an infectious challenge within the lung.
Sequential Binding of Cytosolic Phox Complex to Phagosomes through Regulated Adaptor Proteins: Evaluation Using the Novel Monomeric Kusabira-Green System and Live Imaging of Phagocytosis
Authors: Ueyama Takehiko , Kusakabe Tomoko , Karasawa Satoshi , Kawasaki Takumi , Shimizu Aya , Son Jeonghyun , Leto Thomas L. , Miyawaki Atsushi , Saito Naoaki 
Published: April 2014

Abstract
We engineered a method for detecting intramolecular and intermolecular phox protein interactions in cells by fluorescence microscopy using fusion proteins of complementary fragments of a coral fluorescent reporter protein (monomeric Kusabira-Green). We confirmed the efficacy of the monomeric Kusabira-Green system by showing that the PX and PB1 domains of p40phox interact in intact cells, which we suggested maintains this protein in an inactive closed conformation. Using this system, we also explored intramolecular interactions within p47phox and showed that the PX domain interacts with the autoinhibited tandem Src homology 3 domains maintained in contact with the autoinhibitory region, along with residues 341–360. Furthermore, we demonstrated sequential interactions of p67phox with phagosomes involving adaptor proteins, p47phox and p40phox, during FcγR-mediated phagocytosis. Although p67phox is not targeted to phagosomes by itself, p47phox functions as an adaptor for the ternary complex (p47phox-p67phox-p40phox) in early stages of phagocytosis before phagosome closure, while p40phox functions in later stages after phagosomal closure. Interestingly, a mutated “open” form of p40phox linked p47phox to closed phagosomes and prolonged p47phox and p67phox retention on phagosomes. These results indicate that binding of the ternary complex to phagosomes can be temporally regulated by switching between adaptor proteins that have PX domains with distinct lipid-binding specificities.
Chronic Alcohol Consumption Increases the Severity of Murine Influenza Virus Infections
Authors: Meyerholz David K. , Edsen-Moore Michelle , McGill Jodi , Coleman Ruth A. , Cook Robert T. , Legge Kevin L. 
Published: April 2014

AbstractRespiratory infections with both seasonal as well as potential pandemic Influenza viruses represent a significant burden on human health. Furthermore, viruses such as Influenza are increasingly recognized as important etiologic agents in community acquired pneumonia. Within the U.S. alone, ∼12.9 million people are heavy drinkers and chronic abuse of alcohol is known to increase the risk and severity of community acquired pneumonia. Given the lack of knowledge regarding Influenza disease in this population, we determined the effects of chronic alcohol consumption on Influenza virus infection. Herein, we report that mice exposed to chronic ethanol have sharp increases in morbidity, mortality, and pulmonary virus titers relative to controls. These increases in influenza severity correspond with inhibited pulmonary influenza-specific CD8 T cell responses. Further, chronic ethanol consumption results in an enhanced pulmonary lesion severity, similar to that recently described for pandemic influenzas. Together, our results suggest that chronic alcohol consumption may increase the risk for severe influenza virus infections by altering the pulmonary inflammatory environment and CD8 T cell response.
Cathepsin B Is Involved in the Trafficking of TNF-α-Containing Vesicles to the Plasma Membrane in Macrophages
Authors: Ha Soon-Duck , Martins Andrew , Khazaie Khashayarsha , Han Jiahuai , Chan Bosco M. C. , Kim Sung Ouk 
Published: April 2014

Abstract
TNF-α is a potent proinflammatory cytokine, essential for initiating innate immune responses against invading microbes and a key mediator involved in the pathogenesis of acute and chronic inflammatory diseases. To identify molecules involved in the production of TNF-α, we used a functional gene identification method using retroviral integration-mediated mutagenesis, followed by LPS-stimulated TNF-α production analysis in macrophages. We found that cathepsin B, a lysosomal cysteine proteinase, was required for optimal posttranslational processing of TNF-α in response to the bacterial cell wall component LPS. Mouse bone marrow-derived macrophages from cathepsin B-deficient mice and macrophages treated with the cathepsin B-specific chemical inhibitor CA074 methyl ester or small interfering RNA against cathepsin B secreted significantly less TNF-α than wild-type or nontreated macrophages. We further showed that the inhibition of cathepsin B caused accumulation of 26-kDa pro-TNF-containing vesicles. Ectopic expression of GFP-conjugated pro-TNF further suggests that pro-TNF failed to reach the plasma membrane without intracellular cathepsin B activity. Altogether, these data suggest that intracellular cathepsin B activity is involved in the TNF-α-containing vesicle trafficking to the plasma membrane.
In Vitro Differentiation of Dendritic Cells in the Presence of Prostaglandin E2 Alters the IL-12/IL-23 Balance and Promotes Differentiation of Th17 Cells
Authors: Khayrullina Tanzilya , Yen Jui-Hung , Jing Huie , Ganea Doina 
Published: April 2014

Abstract
PGE2, an endogenous lipid mediator released in inflammatory conditions, affects both dendritic cell (DC) differentiation and maturation. Whereas the effect of PGE2 on fully differentiated DC was studied extensively, little is known about its effects on DC differentiation. In this study, we show that bone marrow-derived DC generated in the presence of PGE2 (DCp) acquire a proinflammatory profile; produce higher levels of proinflammatory cytokines/chemokines; express higher levels of MHC class II, costimulatory molecules, and TLRs; and exhibit increased activation of the NF-κB-signaling pathway. In addition, DCp exhibit a different IL-12/IL-23 profile than DC generated in the absence of PGE2. The low IL-12 and high IL-23 production in LPS-stimulated DCp is associated with the down-regulation of p35 and the up-regulation of p19 expression, respectively. In agreement with the DCp proinflammatory phenotype and especially with the altered IL-12/IL-23 balance which strongly favors IL-23, DCp also affect T cell differentiation. In contrast to DC which favor Th1 differentiation, DCp promote Th17 and inhibit Th1/Th2 differentiation, in vitro and in vivo. Previous in vivo studies indicated that PGE2 had a proinflammatory effect, especially in models of autoimmune diseases. Our results suggest that the proinflammatory effects of PGE2 could be mediated, at least partially, through effects on differentiating DC and subsequent alterations in CD4+ T cell differentiation, resulting in the preferential development of pathogenic autoimmune Th17 cells.
Contribution of Antibody and T Cell-Specific Responses to the Progression of 139A-Scrapie in C57BL/6 Mice Immunized with Prion Protein Peptides
Authors: Sacquin Antoine , Bergot Anne Sophie , Aucouturier Pierre , Bruley-Rosset Martine 
Published: April 2014

Abstract
Prion diseases are associated with the conversion of the normal host cellular prion protein to an abnormal protease-resistant (PrPres) associated with infectivity. No specific immune response against prions develops during infection due to the strong tolerance to cellular prion protein. We examined the protective potential on prion diseases of immune responses elicited in C57BL/6 mice with PrP peptides 98–127 (P5) or 158–187 (P9) with CpG. After immunization, P5-treated mice developed high titer and long-lasting Abs, and P9-treated mice developed transient IFN-γ secreting T cells and poor and variable Ab responses. Both treatments impaired early accumulation of PrPres in the spleen and prolonged survival of mice infected with 139A scrapie. Additional P9 boosts after 139A infection sustained the T cell response and partially inhibited PrPres early accumulation but did not improve the survival. Surprisingly, when P9 injections were started 1 mo after infection and repeated subsequently, specific T cell and Ab responses were impaired and no beneficial effect on prion disease was observed. After a single injection of P9, the number of IFN-γ secreting CD4+ T cells was also reduced in mice 8- to 10-wk postinfection compared with healthy mice. In vivo and in vitro removal of CD4+CD25+ T cells restored the T cell response to P9 in infected mice. In conclusion, CD4+ T cells as well as Abs might participate to the protection against scrapie. Of importance, the peripheral accumulation of PrPres during infection negatively interferes with the development of T and B cell responses to PrP and regulatory T cells might contribute to this phenomenon.
Immunization of Malignant Melanoma Patients with Full-Length NY-ESO-1 Protein Using TLR7 Agonist Imiquimod as Vaccine Adjuvant
Authors: Adams Sylvia , O'Neill David W. , Nonaka Daisuke , Hardin Elizabeth , Chiriboga Luis , Siu Kimberly , Cruz Crystal M. , Angiulli Angelica , Angiulli Francesca , Ritter Erika , Holman Rose Marie , Shapiro Richard L. , Berman Russell S. , Berner Natalie , Shao Yongzhao , Manches Olivier , Pan Linda , Venhaus Ralph R. , Hoffman Eric W. , Jungbluth Achim , Gnjatic Sacha , Old Lloyd , Pavlick Anna C. , Bhardwaj Nina 
Published: April 2014

Abstract
T cell-mediated immunity to microbes and to cancer can be enhanced by the activation of dendritic cells (DCs) via TLRs. In this study, we evaluated the safety and feasibility of topical imiquimod, a TLR7 agonist, in a series of vaccinations against the cancer/testis Ag NY-ESO-1 in patients with malignant melanoma. Recombinant, full-length NY-ESO-1 protein was administered intradermally into imiquimod preconditioned sites followed by additional topical applications of imiquimod. The regimen was very well tolerated with only mild and transient local reactions and constitutional symptoms. Secondarily, we examined the systemic immune response induced by the imiquimod/NY-ESO-1 combination, and show that it elicited both humoral and cellular responses in a significant fraction of patients. Skin biopsies were assessed for imiquimod’s in situ immunomodulatory effects. Compared with untreated skin, topical imiquimod induced dermal mononuclear cell infiltrates in all patients composed primarily of T cells, monocytes, macrophages, myeloid DCs, NK cells, and, to a lesser extent, plasmacytoid DCs. DC activation was evident. This study demonstrates the feasibility and excellent safety profile of a topically applied TLR7 agonist used as a vaccine adjuvant in cancer patients. Imiquimod’s adjuvant effects require further evaluation and likely need optimization of parameters such as formulation, dose, and timing relative to Ag exposure for maximal immunogenicity.
Thyroglobulin Peptides Associate In Vivo to HLA-DR in Autoimmune Thyroid Glands
Authors: Muixí Laia , Carrascal Montserrat , Alvarez Iñaki , Daura Xavier , Martí Mercè , Armengol Maria Pilar , Pinilla Clemencia , Abian Joaquín , Pujol-Borrell Ricardo , Jaraquemada Dolores 
Published: April 2014

Abstract
Endocrine epithelial cells, targets of the autoimmune response in thyroid and other organ-specific autoimmune diseases, express HLA class II (HLA-II) molecules that are presumably involved in the maintenance and regulation of the in situ autoimmune response. HLA-II molecules thus expressed by thyroid cells have the “compact” conformation and are therefore expected to stably bind autologous peptides. Using a new approach to study in situ T cell responses without the characterization of self-reactive T cells and their specificity, we have identified natural HLA-DR-associated peptides in autoimmune organs that will allow finding peptide-specific T cells in situ. This study reports a first analysis of HLA-DR natural ligands from ex vivo Graves’ disease-affected thyroid tissue. Using mass spectrometry, we identified 162 autologous peptides from HLA-DR-expressing cells, including thyroid follicular cells, with some corresponding to predominant molecules of the thyroid colloid. Most interestingly, eight of the peptides were derived from a major autoantigen, thyroglobulin. In vitro binding identified HLA-DR3 as the allele to which one of these peptides likely associates in vivo. Computer modeling and bioinformatics analysis suggested other HLA-DR alleles for binding of other thyroglobulin peptides. Our data demonstrate that although the HLA-DR-associated peptide pool in autoimmune tissue mostly belongs to abundant ubiquitous proteins, peptides from autoantigens are also associated to HLA-DR in vivo and therefore may well be involved in the maintenance and the regulation of the autoimmune response.
Critical Role for the Chemokine Receptor CXCR6 in Homeostasis and Activation of CD1d-Restricted NKT Cells
Authors: Germanov Elitza , Veinotte Linnea , Cullen Robyn , Chamberlain Erin , Butcher Eugene C. , Johnston Brent 
Published: April 2014

Abstract
NK T (NKT) cells play important roles in the regulation of diverse immune responses. However, little is known about the mechanisms that regulate homeostasis and activation of these cells. Thymic NKT cells up-regulated the chemokine receptor CXCR6 following positive selection and migrated toward CXCL16 in vitro. However, CXCR6 was not essential for thymic development or maturation. In contrast, liver and lung NKT cells were depleted in CXCR6+/− and CXCR6−/− mice. The reduction in liver and lung NKT cells coincided with an increase in bone marrow NKT cells, suggesting a redistribution of NKT cells in CXCR6−/− animals. In wild-type mice, CXCL16 neutralization reduced accumulation of mature NK1.1+, but not immature NK1.1− NKT cell recent thymic emigrants in the liver. Given that thymic NKT cells are preferentially exported as NK1.1− cells, this suggests an additional role for CXCR6/CXCL16 in maturation or survival of immature liver NKT cells. CXCL16 blockade did not deplete resident NK1.1+ NKT cells, indicating that CXCR6/CXCL16 are not required to retain mature NKT cells in the liver. Cytokine production by liver and spleen NKT cells was impaired in CXCR6−/− mice following in vivo stimulation with α-galactosylceramide, implicating a novel role for CXCR6 in NKT cell activation. Reduced IFN-γ production was not due to an intrinsic defect as production was normal following PMA and ionomycin stimulation. Preformed transcripts for IL-4, but not IFN-γ, were reduced in CXCR6−/− liver NKT cells. These data identify critical roles for CXCR6/CXCL16 in NKT cell activation and the regulation of NKT cell homeostasis.