bluuebunny/crossref_metadata_2025_split huggingface dataset:
HLA-DQ6 (DQB1*0601)-Restricted T Cells Protect against Experimental Autoimmune Encephalomyelitis in HLA-DR3.DQ6 Double-Transgenic Mice by Generating Anti-Inflammatory IFN-γ
Authors: Mangalam Ashutosh , Luckey David , Basal Eati , Behrens Marshall , Rodriguez Moses , David Chella 
Published: April 2014

AbstractThe human MHC class II genes are associated with genetic susceptibility to multiple sclerosis (MS), a chronic inflammatory demyelinating disease of the CNS of presumed autoimmune origin. These genes encode for proteins responsible for shaping immune response. The exact role of HLA-DQ and -DR genes in disease pathogenesis is not well-understood due to the high polymorphism, linkage disequilibrium, and heterogeneity of human populations. The advent of HLA class II-transgenic (Tg) mice has helped in answering some of these questions. Previously, using single-Tg mice (expressing the HLA-DR or -DQ gene), we showed that proteolipid protein (PLP)91–110 peptide induced classical experimental autoimmune encephalomyelitis only in DR3.Aβ° mice, suggesting that DR3 (DRB1*0301) is a disease susceptible gene in the context of PLP. Human population studies have suggested that HLA-DQ6 (DQB1*0601) may be a protective gene in MS. To test this disease protection in an experimental model, we generated double-Tg mice expressing both HLA-DR3 and -DQ6. Introduction of DQ6 onto DR3-Tg mice led to a decrease in disease incidence on immunization with PLP91–110 peptide indicating a dominant protective role of DQ6. This protective effect is due to high levels of IFN-γ produced by DQ6-restricted T cells, which suppressed proliferation of encephalitogenic DR3-restricted T cells by inducing apoptosis. Our study indicates that DQ6 modifies the PLP91–110-specific T cell response in DR3 through anti-inflammatory effects of IFN-γ, which is protective for experimental autoimmune encephalomyelitis. Thus, our double-Tg mouse provides a novel model in which to study epistatic interactions between HLA class II molecules in MS.
Innate Immunity Mediated by TLR5 as a Novel Antiinflammatory Target for Cystic Fibrosis Lung Disease
Authors: Blohmke Christoph J. , Victor Rachel E. , Hirschfeld Aaron F. , Elias Isaac M. , Hancock David G. , Lane Cheryl R. , Davidson A. George F. , Wilcox Pearce G. , Smith Kelly D. , Overhage Joerg , Hancock Robert E. W. , Turvey Stuart E. 
Published: April 2014

Abstract
Novel therapies to target lung inflammation are predicted to improve the lives of people with cystic fibrosis (CF) but specific antiinflammatory targets have not been identified. The goal of this study was to establish whether TLR5 signaling is the key molecular pathway mediating lung inflammation in CF, and to determine whether strategies to inhibit TLR5 can reduce the damaging inflammatory response. The innate immune responses were analyzed in both airway epithelial cells and primary PBMCs from CF patients and matched controls. Additionally, 151 clinical isolates of Pseudomonas aeruginosa from CF patients were assessed for motility and capacity to activate TLR5. Blood and airway cells from CF patients produced significantly more proinflammatory cytokine than did control cells following exposure to the CF pathogens P. aeruginosa and Burkholderia cepacia complex (p &lt; 0.001). Stimulation with pure TLR ligands demonstrated that TLR signaling appears to mediate the excessive cytokine production occurring in CF. Using complementary approaches involving both neutralizing Ab targeting TLR5 and flagellin-deficient bacteria, we established that inhibition of TLR5 abolished the damaging inflammatory response generated by CF airway cells following exposure to P. aeruginosa (p &lt; 0.01). The potential therapeutic value of TLR5 inhibition was further supported by our demonstration that 75% of clinical isolates of P. aeruginosa retained TLR5 activating capacity during chronic CF lung infection. These studies identify the innate immune receptor TLR5 as a novel antiinflammatory target for reducing damaging lung inflammation in CF.
Noncytotoxic Functions of NK Cells: Direct Pathogen Restriction and Assistance to Adaptive Immunity
Authors: Strowig Till , Brilot Fabienne , Münz Christian 
Published: April 2014

Abstract
Natural killer cells were named after their ability to mediate spontaneous cytotoxicity during innate immune responses. However, it has become clear in recent years that they play an equally important role in restricting infections and assisting the development of adaptive immune responses via their ability to produce cytokines. In humans, a dedicated NK cell subset primarily fulfills these later functions. In this review we discuss the noncytotoxic effector functions of NK cells and how they could be harnessed for immunotherapy and vaccine development.
Spontaneous Development of a Pancreatic Exocrine Disease in CD28-Deficient NOD Mice
Authors: Meagher Craig , Tang Qizhi , Fife Brian T. , Bour-Jordan Helene , Wu Jenny , Pardoux Cecile , Bi Mingying , Melli Kristin , Bluestone Jeffrey A. 
Published: April 2014

AbstractAutoimmune pancreatitis (AIP) is a heterogeneous autoimmune disease in humans characterized by a progressive lymphocytic and plasmacytic infiltrate in the exocrine pancreas. In this study, we report that regulatory T cell-deficient NOD.CD28KO mice spontaneously develop AIP that closely resembles the human disease. NOD mouse AIP was associated with severe periductal and parenchymal inflammation of the exocrine pancreas by CD4+ T cells, CD8+ T cells, and B cells. Spleen CD4+ T cells were found to be both necessary and sufficient for the development of AIP. Autoantibodies and autoreactive T cells from affected mice recognized a ∼50-kDa protein identified as pancreatic amylase. Importantly, administration of tolerogenic amylase-coupled fixed spleen cells significantly ameliorated disease severity, suggesting that this protein functions as a key autoantigen. The establishment and characterization of this spontaneous pancreatic amylase-specific AIP in regulatory T cell-deficient NOD.CD28KO mice provides an excellent model for the study of disease pathogenesis and development of new therapies for human autoimmune pancreatitis.
A Novel Trafficking Signal within the HLA-C Cytoplasmic Tail Allows Regulated Expression upon Differentiation of Macrophages
Authors: Schaefer Malinda R. , Williams Maya , Kulpa Deanna A. , Blakely Pennelope K. , Yaffee Anna Q. , Collins Kathleen L. 
Published: April 2014

AbstractMHC class I molecules (MHC-I) present peptides to CTLs. In addition, HLA-C allotypes are recognized by killer cell Ig-like receptors (KIR) found on NK cells and effector CTLs. Compared with other classical MHC-I allotypes, HLA-C has low cell surface expression and an altered intracellular trafficking pattern. We present evidence that this results from effects of both the extracellular domain and the cytoplasmic tail. Notably, we demonstrate that the cytoplasmic tail contains a dihydrophobic (LI) internalization and lysosomal targeting signal that is partially attenuated by an aspartic acid residue (DXSLI). In addition, we provide evidence that this signal is specifically inhibited by hypophosphorylation of the adjacent serine residue upon macrophage differentiation and that this allows high HLA-C expression in this cell type. We propose that tightly regulated HLA-C surface expression facilitates immune surveillance and allows HLA-C to serve a specialized role in macrophages.
Pulmonary Surfactant Protein A Regulates TLR Expression and Activity in Human Macrophages
Authors: Henning Lisa N. , Azad Abul K. , Parsa Kishore V. L. , Crowther Joy E. , Tridandapani Susheela , Schlesinger Larry S. 
Published: April 2014

Abstract
The pulmonary innate immune system responds to various airborne microbes. Although its specificity is broad and based on the recognition of pathogen-associated molecular patterns, it is uniquely regulated to limit inflammation and thereby prevent damage to the gas-exchanging alveoli. Macrophages, critical cell determinants of this system, recognize microbes through pattern recognition receptors such as TLRs, which typically mediate proinflammatory responses. The lung collectin, surfactant protein A (SP-A), has emerged as an important innate immune determinant that regulates microbe-macrophage interactions in this environment. In this study, we report the basal and SP-A-induced transcriptional and posttranslational regulation of TLR2 and TLR4 expression during the differentiation of primary human monocytes into macrophages. Despite SP-A’s ability to up-regulate TLR2 expression on human macrophages, it dampens TLR2 and TLR4 signaling in these cells. SP-A decreases the phosphorylation of IκBα, a key regulator of NF-κB activity, and nuclear translocation of p65 which result in diminished TNF-α secretion in response to TLR ligands. SP-A also reduces the phosphorylation of TLR signaling proteins upstream of NF-κB, including members of the MAPK family. Finally, we report for the first time that SP-A decreases the phosphorylation of Akt, a major cell regulator of NF-κB and potentially MAPKs. These data identify a critical role for SP-A in modulating the lung inflammatory response by regulating macrophage TLR activity.
Lysine 144, a Ubiquitin Attachment Site in HIV-1 Nef, Is Required for Nef-Mediated CD4 Down-Regulation
Authors: Jin Yong-Jiu , Cai Catherine Yi , Zhang Xiaoping , Burakoff Steven J. 
Published: April 2014

Abstract
Nef is a HIV-1 accessory protein critical for the replication of the virus and the development of AIDS. The major pathological activity of Nef is the down-regulation of CD4, the primary receptor of HIV-1 infection. The mechanism underlying Nef-mediated CD4 endocytosis and degradation remains incompletely understood. Since protein ubiquitination is the predominant sorting signal in receptor endocytosis, we investigated whether Nef is ubiquitinated. The in vivo ubiquitination assay showed that both HIV-1 and SIV Nef proteins expressed in Jurkat T cells and 293T cells were multiple ubiquitinated by ubiquitin-His. The lysine-free HIV-1 Nef mutant (Δ10K) generated by replacing all 10 lysines with arginines was not ubiquitinated and the major ubiquitin-His attachment sites in HIV-1 Nef were determined to be lysine 144 (di-ubiquitinated) and lysine 204 (mono-ubiquitinated). Lysine-free HIV-1 Nef was completely inactive in Nef-mediated CD4 down-regulation, so was the Nef mutant with a single arginine substitution at K144 but not at K204. A mutant HIV-1 provirion NL4–3 with a single arginine substitution in Nef at K144 was also inactive in Nef-mediated CD4 down-regulation. Lysine-free Nef mutant reintroduced with lysine 144 (ΔK10 + K144) was shown active in CD4 down-regulation. These data suggest that ubiquitination of Nef, particularly diubiquitination of the lysine 144, is necessary for Nef-mediated CD4 down-regulation.
Trans-Presentation of IL-15 Dictates IFN-Producing Killer Dendritic Cells Effector Functions
Authors: Ullrich Evelyn , Bonmort Mathieu , Mignot Gregoire , Jacobs Benedikt , Bosisio Daniela , Sozzani Silvano , Jalil Abdelali , Louache Fawzia , Bulanova Elena , Geissman Frederic , Ryffel Bernard , Chaput Nathalie , Bulfone-Paus Silvia , Zitvogel Laurence 
Published: April 2014

AbstractIFN-producing killer dendritic cells (IKDC) were initially described as B220+CD11c+CD3−NK1.1+ tumor-infiltrating cells that mediated part of the antitumor effects of the combination therapy with imatinib mesylate and IL-2. In this study, we show their functional dependency on IL-15 during homeostasis and inflammatory processes. Trans-presentation of IL-15 by IL-15Rα allows dramatic expansion of IKDC in vitro and in vivo, licenses IKDC for TRAIL-dependent killing and endows IKDC with immunizing potential, all three biological attributes not shared by B220−NK cells. However, IL-15 down-regulates the capacity of IKDC to induce MHC class I- or II-restricted T cell activation in vitro. Trans-presentation of IL-15 by IL-15Rα allows IKDC to respond to TLR3 and TLR4 ligands for the production of CCL2, a chemokine that is critical for IKDC trafficking into tumor beds (as described recently). We conclude that IKDC represent a unique subset of innate effectors functionally distinguishable from conventional NK cells in their ability to promptly respond to IL-15-driven inflammatory processes.
Inhibition of Dendritic Cell Maturation and Function Is Independent of Heme Oxygenase 1 but Requires the Activation of STAT3
Authors: Mashreghi Mir-Farzin , Klemz Roman , Knosalla Isabela Schmitt , Gerstmayer Bernhard , Janssen Uwe , Buelow Roland , Jozkowicz Alicja , Dulak Jozef , Volk Hans-Dieter , Kotsch Katja 
Published: April 2014

Abstract
The induction of heme oxygenase 1 (HO-1) by a single treatment with cobalt protoporphyrin (CoPPIX) protects against inflammatory liver failure and ischemia reperfusion injury after allotransplantation. In this context, the HO-1-mediated inhibition of donor-derived dendritic cell maturation and migration is discussed as one of the key events of graft protection. To investigate the poorly understood mechanism of CoPPIX-induced HO-1 activity in more detail, we performed gene expression analysis in murine liver, revealing the up-regulation of STAT3 after CoPPIX treatment. By using wild-type and HO-1-deficient dendritic cells we demonstrated that LPS-induced maturation is dependent on STAT3 phosphorylation and independent of HO-1 activity. In summary, our observations revise our understanding of the anti-inflammatory properties of HO-1 and highlight the immunomodulatory capacity of STAT3, which might be of further interest for targeting undesired immune responses, including ischemia reperfusion injury.
Regulation of IL-17 in Human CCR6+ Effector Memory T Cells
Authors: Liu Hong , Rohowsky-Kochan Christine 
Published: April 2014

Abstract
IL-17–secreting T cells represent a distinct CD4+ effector T cell lineage (Th17) that appears to be essential in the pathogenesis of numerous inflammatory and autoimmune diseases. Although extensively studied in the murine system, human Th17 cells have not been well characterized. In this study, we identify CD4+CD45RO+CCR7−CCR6+ effector memory T cells as the principal IL-17-secreting T cells. Human Th17 cells have a unique cytokine profile because the majority coexpress TNF-α but not IL-6 and a minor subset express IL-17 with IL-22 or IL-17 and IFN-γ. We demonstrate that the cytokines that promote the differentiation of human naive T cells into IL-17-secreting cells regulate IL-17 production by memory T cells. IL-1β alone or in association with IL-23 and IL-6 markedly increase IL-17+ CCR6+ memory T cells and induce IL-17 production in CCR6− memory T cells. We also show that T cell activation induces Foxp3 expression in T cells and that the balance between the percentage of Foxp3+ and IL-17+ T cells is inversely influenced by the cytokine environment. These studies suggest that the cytokine environment may play a critical role in the expansion of memory T cells in chronic autoimmune diseases.
IL-6, in Synergy with IL-7 or IL-15, Stimulates TCR-Independent Proliferation and Functional Differentiation of CD8+ T Lymphocytes
Authors: Gagnon Julien , Ramanathan Sheela , Leblanc Chantal , Cloutier Alexandre , McDonald Patrick P. , Ilangumaran Subburaj 
Published: April 2014

AbstractRecent reports have shown that IL-21, in synergy with IL-15, stimulates proliferation of CD8+ T lymphocytes in the absence of signaling via the TCR. In this study, we show that IL-6, which induces phosphorylation of STAT3 similarly to IL-21, also can stimulate proliferation of CD8+ T cells in synergy with IL-7 or IL-15. IL-6 displays a stronger synergy with IL-7 than with IL-15 to stimulate naive CD8+ T cells. Concomitant stimulation by IL-6 or IL-21 augments phosphorylation and DNA-binding activity of STAT5 induced by IL-7 or IL-15. Like IL-21, IL-6 reduces the TCR signaling threshold required to stimulate CD8+ T cells. Prior culture of P14 TCR transgenic CD8 T cells with IL-6 or IL-21 in the presence of IL-7 or IL-15 augments their proliferation and cytolytic activity upon subsequent stimulation by Ag. Furthermore, cytokine stimulation induces quantitatively and qualitatively distinct phenotypic changes on CD8+ T cells compared with those induced by TCR signaling. We propose that the ability of IL-6 to induce TCR-independent activation of CD8+ T cells in synergy with IL-7 or IL-15 may play an important role in the transition from innate to adaptive immunity.
Retinoic Acid-Inducible Gene-I Mediates Late Phase Induction of TNF-α by Lipopolysaccharide
Authors: Wang Jing , Wu Su , Jin Xin , Li Mingtao , Chen Shiyong , Teeling Jessica L. , Perry V. Hugh , Gu Jun 
Published: April 2014

Abstract
LPS is the known component of bacterial pathogens that stimulates a number of proinflammatory factors. However, the mechanism of the induction of these factors by LPS has not been fully elucidated. We show here that LPS induces retinoic acid-inducible gene-I (RIG-I) in vitro and in vivo as a result from autocrine secretion of IFN-β in macrophages. TIR-domain-containing adapter-inducing IFN-β-deficient mouse embryo fibroblast (trif−/−) fail to show expression of RIG-I following LPS stimulation. Interference of RIG-I expression short interfering RNA represses the expression of LPS-induced TNF-α, whereas over-expression of RIG-I leads to the activation of TNF-α promoter and the induction of TNF-α expression. LPS- and IFN-β-induced TNF-α are suppressed in RIG-I-deficient mouse embryo fibroblasts (rig−/−). Thus, RIG-I plays a key role in the expression of TNF-α in macrophages in response to LPS stimulation, mainly for the late phase LPS-induced expression of TNF-α.
Proteasome Inhibitors Enhance TRAIL-Induced Apoptosis through the Intronic Regulation of DR5: Involvement of NF-κB and Reactive Oxygen Species-Mediated p53 Activation
Authors: Chen Jun-Jie , Chou Chia-Wei , Chang Yu-Fan , Chen Ching-Chow 
Published: April 2014

Abstract
Manipulation of TRAIL receptor 2 (DR5) pathway is a promising therapeutic strategy to overcome TRAIL-resistant lung cancer cells. Preclinical studies have shown that proteasome inhibitors enhance TRAIL-induced apoptosis in lung cancer cells, but the underlying mechanism has not been fully elucidated. In this study, we demonstrated the enhancement of TRAIL-mediated apoptosis in human alveolar epithelial cells by proteasome inhibitors that up-regulate DR5 expression. This effect was blocked by DR5-neutralizing Ab. Using reporter assay, we demonstrated that the p53 and NF-κB elements on the DR5 first intron region were involved in proteasome inhibitor-induced DR5 expression. Both p53 small interfering RNA and NF-κB inhibitor suppressed DR5 expression, strengthening the significance of p53 and NF-κB in DR5 transcription. The protein stability, Ser392 phosphorylation and Lys373/Lys382 acetylation of p53 were enhanced by MG132. In addition to p53, IκBα degradation and NF-κB translocation was also observed. Moreover, the binding of p53 and p65 to the first intron of DR5 was demonstrated by DNA affinity protein-binding and chromatin immunoprecipitation assays. Intracellular reactive oxygen species (ROS) generation after MG132 treatment contributed to p53, but not p65 nuclear translocation and DNA-binding activity. ROS scavenger dramatically inhibited the apoptosis induced by proteasome inhibitors plus TRAIL. The p53-null H1299 cells were resistant to proteasome inhibitor-induced DR5 up-regulation and enhancement of TRAIL-induced apoptosis. These findings reveal that proteasome inhibitor-mediated NF-κB and ROS-dependent p53 activation are contributed to intronic regulation of DR5 transcription, and resulted in the subsequent enhancement of TRAIL-induced apoptosis in human lung cancer cells.
ERK-Dependent Bim Modulation Downstream of the 4-1BB-TRAF1 Signaling Axis Is a Critical Mediator of CD8 T Cell Survival In Vivo
Authors: Sabbagh Laurent , Pulle Gayle , Liu Yuanqing , Tsitsikov Erdyni N. , Watts Tania H. 
Published: April 2014

AbstractDuring an acute immune response, CD8 T cells undergo rapid expansion followed by a contraction phase during which the majority of activated T cells die, leaving a few survivors to persist as memory cells. The regulation of T cell survival is critical at each stage of this response. 4-1BB, a TNFR family member, has been implicated in prolonging the survival of activated and memory CD8 T cells; however, the precise mechanisms by which 4-1BB sustains T cell survival are incompletely understood. Upon aggregation on T cells, 4-1BB associates with two TNFR-associated factors (TRAF), TRAF1 and TRAF2. TRAF2 is essential for downstream signaling from 4-1BB; however, the role of TRAF1 in 4-1BB signaling has not been elucidated and there have been conflicting data as to whether TRAF1 provides a positive or a negative signal in T cells. In this study, we report that TRAF1 plays a critical role in survival signaling downstream of 4-1BB during CD8 T cell expansion in response to viral infection in vivo. Further analysis reveals that TRAF1-deficient cells are impaired in their ability to up-regulate the prosurvival Bcl-2 family member Bcl-xL and show increased levels of the proapoptotic Bcl-2 family member Bim following 4-1BB signaling. TRAF1-deficient CD8 T cells fail to activate ERK in response to 4-1BB ligation and inhibition of ERK signaling downstream of 4-1BB in wild-type cells leads to increased Bim levels. Thus, TRAF1 has a prosurvival effect in CD8 T cells via the 4-1BB-mediated up-regulation of Bcl-xL and ERK-dependent Bim down-modulation.
Histone Acetylation Facilitates Rapid and Robust Memory CD8 T Cell Response through Differential Expression of Effector Molecules (Eomesodermin and Its Targets: Perforin and Granzyme B)
Authors: Araki Yasuto , Fann Monchou , Wersto Robert , Weng Nan-ping 
Published: April 2014

Abstract
To understand the mechanism regulating the effector function of memory CD8 T cells, we examined expression and chromatin state of a key transcription factor (eomesodermin, EOMES) and two of its targets: perforin (PRF1) and granzyme B (GZMB). Accessible chromatin associated histone 3 lysine 9 acetylation (H3K9Ac) was found significantly higher at the proximal promoter and the first exon region of all three genes in memory CD8 T cells than in naive CD8 T cells. Correspondingly, EOMES and PRF1 were constitutively higher expressed in memory CD8 T cells than in naive CD8 T cells at resting and activated states. In contrast, higher expression of GZMB was induced in memory CD8 T cells than in naive CD8 T cells only after activation. Regardless of their constitutive or inducible expression, decreased H3K9Ac levels after treatment with a histone acetyltransferase inhibitor (Curcumin) led to decreased expression of all three genes in activated memory CD8 T cells. These findings suggest that H3K9Ac associated accessible chromatin state serves as a corner stone for the differentially high expression of these effector genes in memory CD8 T cells. Thus, epigenetic changes mediated via histone acetylation may provide a chromatin “memory” for the rapid and robust transcriptional response of memory CD8 T cells.