bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cutting Edge: Histamine Receptor H4 Activation Positively Regulates In Vivo IL-4 and IFN-γ Production by Invariant NKT Cells
Authors: Leite-de-Moraes Maria C. , Diem Séverine , Michel Marie-Laure , Ohtsu Hiroshi , Thurmond Robin L. , Schneider Elke , Dy Michel 
Published: April 2014

Abstract
Histamine (HA) is a biogenic amine with multiple activities in the immune system. In this study we demonstrate that histamine-free histidine decarboxylase-deficient (HDC−/−) mice present a numerical and functional deficit in invariant NK T (iNKT) cells as evidenced by a drastic decrease of IL-4 and IFN-γ production. This deficiency was established both by measuring cytokine levels in the serum and intracellularly among gated iNKT cells. It resulted from the lack of HA, because a single injection of this amine into HDC−/− mice sufficed to restore normal IL-4 and IFN-γ production. HA-induced functional recovery was mediated mainly through the H4 histamine receptor (H4R), as assessed by its abrogation after a single injection of a selective H4R antagonist and the demonstration of a similar iNKT cell deficit in H4R−/− mice. Our findings identify a novel function of HA through its H4R and suggest that it might become instrumental in modulating iNKT cell functions.
Autoimmunity in Dry Eye Is Due to Resistance of Th17 to Treg Suppression
Authors: Chauhan Sunil K. , El Annan Jaafar , Ecoiffier Tatiana , Goyal Sunali , Zhang Qiang , Saban Daniel R. , Dana Reza 
Published: April 2014

Abstract
Dry eye disease (DED), an inflammatory autoimmune disorder affecting the ocular surface, degrades visual performance and the quality of life of &gt;10 million people in the United States alone. The primary limitation in the effective treatment of DED is an incomplete understanding of its specific cellular and molecular pathogenic elements. Using a validated mouse model of DED, herein we functionally characterize the different T cell subsets, including regulatory T cells (Tregs) and pathogenic effector T cells, and determine their contribution to the pathogenesis of DED. Our data demonstrate the presence of dysfunctional Tregs and the resistance of pathogenic T cells, particularly Th17 cells, to Treg suppression in DED. In addition, we clearly show that in vivo blockade of IL-17 significantly reduces the severity and progression of disease, which is paralleled by a reduction in the expansion of Th17 cells and restoration of Treg function. Our findings elucidate involvement of a previously unknown pathogenic T cell subset (Th17) in DED that is associated specifically with Treg dysfunction and disease pathogenesis and suggest a new target for dry eye therapy.
Targeting Antigen to MHC Class II Molecules Promotes Efficient Cross-Presentation and Enhances Immunotherapy
Authors: Dickgreber Nina , Stoitzner Patrizia , Bai Yan , Price Kylie M. , Farrand Kathryn J. , Manning Kristy , Angel Catherine E. , Dunbar P. Rod , Ronchese Franca , Fraser John D. , Bäckström B. Thomas , Hermans Ian F. 
Published: April 2014

Abstract
An efficient pathway of cross-presentation common to a range of dendritic cell (DC) populations was identified by targeting Ag to MHC class II molecules. This finding was achieved by conjugating Ag to M1, which is a modified version of the superantigen streptococcal mitogenic exotoxin Z-2 that binds to MHC class II molecules but cannot directly stimulate T cells. M1 conjugates were efficiently presented to CD4+ and CD8+ T cells by bone marrow-derived DC and Langerhans cells in vitro. Whereas nonconjugated Ag was preferentially cross-presented by splenic CD8α+ DC in vivo, M1-conjugated Ag was cross-presented by all dendritic subtypes assessed. Potent effector T cell responses with antitumor activity were elicited when M1 conjugates were injected together with an adjuvant. This method of Ag delivery has significant potential in therapeutic applications.
Chemokine-Enhanced Chemotaxis of Lymphangioleiomyomatosis Cells with Mutations in the Tumor Suppressor TSC2 Gene
Authors: Pacheco-Rodriguez Gustavo , Kumaki Fumiyuki , Steagall Wendy K. , Zhang Yi , Ikeda Yoshihiko , Lin Jing-Ping , Billings Eric M. , Moss Joel 
Published: April 2014

Abstract
Lymphangioleiomyomatosis (LAM) is characterized by cystic lung destruction caused by LAM cells (smooth-muscle-like cells) that have mutations in the tumor suppressor genes tuberous sclerosis complex (TSC) 1 or 2 and have the capacity to metastasize. Since chemokines and their receptors function in chemotaxis of metastatic cells, we hypothesized that LAM cells may be recruited by chemokine(s) in the lung. Quantification of 25 chemokines in bronchoalveolar lavage fluid from LAM patients and healthy volunteers revealed that concentrations of CCL2, CXCL1, and CXCL5 were significantly higher in samples from LAM patients than those from healthy volunteers. In vitro, CCL2 or MCP-1 induced selective migration of cells, showing loss of heterozygosity of TSC2 from a heterogeneous population of cells grown from explanted LAM lungs. Additionally, the frequencies of single-nucleotide polymorphisms in the CCL2 gene promoter region differed significantly in LAM patients and healthy volunteers (p = 0.018), and one polymorphism was associated significantly more frequently with the decline of lung function. The presence (i.e., potential functionality) of chemokine receptors was evaluated using immunohistochemistry in lung sections from 30 LAM patients. Expression of chemokines and these receptors varied among LAM patients and differed from that seen in some cancers (e.g., breast cancer and melanoma cells). These observations are consistent with the notion that chemokines such as CCL2 may serve to determine mobility and specify the site of metastasis of the LAM cell.
Differentiated Human Alveolar Type II Cells Secrete Antiviral IL-29 (IFN-λ1) in Response to Influenza A Infection
Authors: Wang Jieru , Oberley-Deegan Rebecca , Wang Shuanglin , Nikrad Mrinalini , Funk C. Joel , Hartshorn Kevan L. , Mason Robert J. 
Published: April 2014

Abstract
Alveolar type II epithelial cells (ATIIs) are one of the primary targets for influenza A pneumonia. The lack of a culture system for maintaining differentiated ATIIs hinders our understanding of pulmonary innate immunity during viral infection. We studied influenza A virus (IAV)-induced innate immune responses in differentiated primary human ATIIs and alveolar macrophages (AMs). Our results indicate that ATIIs, but not AMs, support productive IAV infection. Viral infection elicited strong inflammatory chemokine and cytokine responses in ATIIs, including secretion of IL-8, IL-6, MCP-1, RANTES, and MIP-1β, but not TNF-α, whereas AMs secreted TNF-α as well as other cytokines in response to infection. Wild-type virus A/PR/8/34 induced a greater cytokine response than reassortant PR/8 virus, A/Phil/82, despite similar levels of replication. IAV infection increased mRNA expression of IFN genes IFN-β, IL-29 (IFN-λ1), and IL-28A (IFN-λ2). The major IFN protein secreted by type II cells was IL-29 and ATIIs appear to be a major resource for production of IL-29. Administration of IL-29 and IFN-β before infection significantly reduced the release of infectious viral particles and CXC and CC chemokines. IL-29 treatment of type II cells induced mRNA expression of antiviral genes MX1, OAS, and ISG56 but not IFN-β. IL-29 induced a dose-dependent decrease of viral nucleoprotein and an increase of antiviral genes but not IFN-β. These results suggest that IL-29 exerts IFN-β-independent protection in type II cells through direct activation of antiviral genes during IAV infection.
Scrapie Pathogenesis: The Role of Complement C1q in Scrapie Agent Uptake by Conventional Dendritic Cells
Authors: Flores-Langarica Adriana , Sebti Yasmine , Mitchell Daniel A. , Sim Robert B. , MacPherson Gordon G. 
Published: April 2014

Abstract
Mice lacking complement components show delayed development of prion disease following peripheral inoculation. The delay could relate to reduced scrapie prion protein (PrPSc) accumulation on follicular dendritic cells (DCs). However conventional DCs (cDCs) play a crucial role in the early pathogenesis of prion diseases and complement deficiency could result in decreased PrPSc uptake by cDCs in the periphery. To explore this possibility, we cultured murine splenic or gut-associated lymph node cDCs with scrapie-infected whole brain homogenate in the presence or absence of complement. Uptake decreased significantly if the serum in the cultures was heat-inactivated. Because heat inactivation primarily denatures C1q, we used serum from C1q−/− mice and showed that PrPSc uptake was markedly decreased. PrPSc internalization was saturable and temperature-dependent, suggesting receptor-mediated uptake. Furthermore, uptake characteristics differed from fluid-phase endocytosis. Immunofluorescence showed colocalization of C1q and PrPSc, suggesting interaction between these molecules. We evaluated the expression of several complement receptors on cDCs and confirmed that cDCs that take up PrPSc express one of the C1q receptors, calreticulin. Our results show that C1q participates in PrPSc uptake by cDCs, revealing a critical role for cDCs in initial prion capture, an event that takes place before the PrPSc accumulation within the follicular DC network.
IL-12 Enhances CTL Synapse Formation and Induces Self-Reactivity
Authors: Markiewicz Mary A. , Wise Erica L. , Buchwald Zachary S. , Cheney Elizabeth E. , Hansen Ted H. , Suri Anish , Cemerski Saso , Allen Paul M. , Shaw Andrey S. 
Published: April 2014

Abstract
Immunological synapse formation between T cells and target cells can affect the functional outcome of TCR ligation by a given MHC-peptide complex. Although synapse formation is usually induced by TCR signaling, it is not clear whether other factors can affect the efficiency of synapse formation. Here, we tested whether cytokines could influence synapse formation between murine CTLs and target cells. We found that IL-12 enhanced synapse formation, whereas TGFβ decreased synapse formation. The enhanced synapse formation induced by IL-12 appeared to be functional, given that IL-12-treated cells could respond to weak peptides, including self-peptides, to which the T cells were normally unresponsive. These responses correlated with expression of functionally higher avidity LFA-1 on IL-12-treated CTLs. These findings have implications for the function of IL-12 in T cell-mediated autoimmunity.
The Epigenetic Profile of Ig Genes Is Dynamically Regulated during B Cell Differentiation and Is Modulated by Pre-B Cell Receptor Signaling
Authors: Xu Cheng-Ran , Feeney Ann J. 
Published: April 2014

Abstract
Ag receptor loci poised for V(D)J rearrangement undergo germline transcription (GT) of unrearranged genes, and the accessible gene segments are associated with posttranslational modifications (PTM) on histones. In this study, we performed a comprehensive analysis of the dynamic changes of four PTM throughout B and T cell differentiation in freshly isolated ex vivo cells. Methylation of lysines 4 and 79 of histone H3, and acetylation of H3, demonstrated stage and lineage specificity, and were most pronounced at the J segments of loci poised for, or undergoing, rearrangement, except for dimethylation of H3K4, which was more equally distributed on V, D, and J genes. Focusing on the IgL loci, we demonstrated there are no active PTM in the absence of pre-BCR signaling. The κ locus GT and PTM on Jκ genes are rapidly induced following pre-BCR signaling in large pre-B cells. In contrast, the λ locus shows greatly delayed onset of GT and PTM, which do not reach high levels until the immature B cell compartment, the stage at which receptor editing is initiated. Analysis of MiEκ−/− mice shows that this enhancer plays a key role in inducing not only GT, but PTM. Using an inducible pre-B cell line, we demonstrate that active PTM on Jκ genes occur after GT is initiated, indicating that histone PTM do not make the Jκ region accessible, but conversely, GT may play a role in adding PTM. Our data indicate that the epigenetic profile of IgL genes is dramatically modulated by pre-BCR signaling and B cell differentiation status.
Tim-1 Signaling Substitutes for Conventional Signal 1 and Requires Costimulation to Induce T Cell Proliferation
Authors: Mariat Christophe , Degauque Nicolas , Balasubramanian Savithri , Kenny James , DeKruyff Rosemarie H. , Umetsu Dale T. , Kuchroo Vijay , Zheng Xin Xiao , Strom Terry B. 
Published: April 2014

Abstract
Differentiation and clonal expansion of Ag-activated naive T cells play a pivotal role in the adaptive immune response. T cell Ig mucin (Tim) proteins influence the activation and differentiation of T cells. Tim-3 and Tim-2 clearly regulate Th1 and Th2 responses, respectively, but the precise influence of Tim-1 on T cell activation remains to be determined. We now show that Tim-1 stimulation in vivo and in vitro induces polyclonal activation of T cells despite absence of a conventional TCR-dependent signal 1. In this model, Tim-1-induced proliferation is dependent on strong signal 2 costimulation provided by mature dendritic cells. Ligation of Tim-1 upon CD4+ T cells with an agonist anti-Tim-1 mAb elicits a rise in free cytosolic calcium, calcineurin-dependent nuclear translocation of NF-AT, and transcription of IL-2. Because Tim-4, the Tim-1 ligand, is expressed by mature dendritic cells, we propose that interaction between Tim-1+ T cells and Tim-4+ dendritic cells might ensure optimal stimulation of T cells, when TCR-derived signals originating within an inflamed environment are weak or waning.
Macrophages Activated by C-Reactive Protein through FcγRI Transfer Suppression of Immune Thrombocytopenia
Authors: Marjon Kristopher D. , Marnell Lorraine L. , Mold Carolyn , Du Clos Terry W. 
Published: April 2014

Abstract
C-reactive protein (CRP) is an acute-phase protein with therapeutic activity in mouse models of systemic lupus erythematosus and other inflammatory and autoimmune diseases. To determine the mechanism by which CRP suppresses immune complex disease, an adoptive transfer system was developed in a model of immune thrombocytopenic purpura (ITP). Injection of 200 μg of CRP 24 h before induction of ITP markedly decreased thrombocytopenia induced by anti-CD41. CRP-treated splenocytes also provided protection from ITP in adoptive transfer. Splenocytes from C57BL/6 mice were treated with 200 μg/ml CRP for 30 min, washed, and injected into mice 24 h before induction of ITP. Injection of 106 CRP-treated splenocytes protected mice from thrombocytopenia, as did i.v. Ig-treated but not BSA-treated splenocytes. The suppressive cell induced by CRP was found to be a macrophage by depletion, enrichment, and the use of purified bone marrow-derived macrophages. The induction of protection by CRP-treated cells was dependent on FcRγ-chain and Syk activation, indicating an activating effect of CRP on the donor cell. Suppression of ITP by CRP-treated splenocytes required FcγRI on the donor cell and FcγRIIb in the recipient mice. These findings suggest that CRP generates suppressive macrophages through FcγRI, which then act through an FcγRIIb-dependent pathway in the recipient to decrease platelet clearance. These results provide insight into the mechanism of CRP regulatory activity in autoimmunity and suggest a potential new therapeutic approach to ITP.
B7RP-1 Blockade Ameliorates Autoimmunity through Regulation of Follicular Helper T Cells
Authors: Hu Yi-Ling , Metz Daniela P. , Chung James , Siu Gerald , Zhang Ming 
Published: April 2014

Abstract
Autoimmune diseases are marked by the presence of class-switched, high-affinity autoantibodies with pathogenic potential. Costimulation plays an important role in the activation of T cells and the development of T cell-dependent B cell responses. ICOS plays an indispensable role in the development of follicular helper T cells (TFH cells), which provide cognate help to germinal center (GC) B cells. We show that the levels of TFH cells and GC B cells in two different models of autoimmunity, the New Zealand Black/New Zealand White (NZB/NZW) F1 mouse model of systemic lupus erythematosus and the collagen-induced arthritis model of rheumatoid arthritis, are dependent on the maintenance of the ICOS/B7RP-1 pathway. Treatment with an anti-B7RP-1 Ab ameliorates disease manifestations and leads to a decrease in TFH cells and GC B cells as well as an overall decrease in the frequency of ICOS+ T cells. Coculture experiments of Ag-primed B cells with CXCR5+ or CXCR5− T cells show that blocking B7RP-1 does not directly impact the production of IgG by B cells. These findings further support the role of ICOS in autoimmunity and suggest that the expansion of the TFH cell pool is an important mechanism by which ICOS regulates Ab production.
Heat Shock Protein 70, Released from Heat-Stressed Tumor Cells, Initiates Antitumor Immunity by Inducing Tumor Cell Chemokine Production and Activating Dendritic Cells via TLR4 Pathway
Authors: Chen Taoyong , Guo Jun , Han Chaofeng , Yang Mingjin , Cao Xuetao 
Published: April 2014

Abstract
Extracellular heat shock proteins (HSP) can activate dendritic cells (DC) and monocytes/macrophages, and HSP derived from tumor cells have been regarded as potent adjuvant facilitating presentation of tumor Ags and induction of antitumor immunity. However, the roles and the underlying mechanisms of releasable HSP in the induction of antitumor immunity have not been fully elucidated. In this study, we report that heat stress can induce the release of various HSP from tumor cells, which, in turn, activate tumor cells to produce chemokines for chemoattraction of DC and T cells via TLR4 signaling pathway. In vivo, we find that the infiltration and function of DC and T cells within tumor after local hyperthermia are increased significantly. We also provide evidence that HSP70 proteins released by tumor cells and TLR4 expressed by tumor cells/DC are essential for the chemoattraction of DC/T cells and for the subsequent induction of tumor-specific antitumor immunity. Therefore, our study suggests that heat stress-induced releasable HSP70 proteins from tumor cells play important roles in the initiation of antitumor immunity by inducing tumor cell production of chemokines and by activating the chemoattracted DC via TLR4 pathway.
T Cell Leukemia/Lymphoma 1 and Galectin-1 Regulate Survival/Cell Death Pathways in Human Naive and IgM+ Memory B Cells through Altering Balances in Bcl-2 Family Proteins
Authors: Tabrizi Siamak Jabbarzadeh , Niiro Hiroaki , Masui Mariko , Yoshimoto Goichi , Iino Tadafumi , Kikushige Yoshikane , Wakasaki Takahiro , Baba Eishi , Shimoda Shinji , Miyamoto Toshihiro , Hara Toshiro , Akashi Koichi 
Published: April 2014

Abstract
BCR signaling plays a critical role in purging the self-reactive repertoire, or in rendering it anergic to establish self-tolerance in the periphery. Differences in self-reactivity between human naive and IgM+ memory B cells may reflect distinct mechanisms by which BCR signaling dictates their survival and death. Here we demonstrate that BCR stimulation protected naive B cells from apoptosis with induction of prosurvival Bcl-2 family proteins, Bcl-xL and Mcl-1, whereas it rather accelerated apoptosis of IgM+ memory B cells by inducing proapoptotic BH3-only protein Bim. We found that BCR-mediated PI3K activation induced the expression of Mcl-1, whereas it inhibited Bim expression in B cells. Phosphorylation of Akt, a downstream molecule of PI3K, was more sustained in naive than IgM+ memory B cells. Abundant expression of T cell leukemia/lymphoma 1 (Tcl1), an Akt coactivator, was found in naive B cells, and enforced expression of Tcl1 induced a high level of Mcl-1 expression, resulting in prolonged B cell survival. In contrast, Galectin-1 (Gal-1) was abundantly expressed in IgM+ memory B cells, and inhibited Akt phosphorylation, leading to Bim up-regulation. Enforced expression of Gal-1 induced accelerated apoptosis in B cells. These results suggest that a unique set of molecules, Tcl1 and Gal-1, defines distinct BCR signaling cascades, dictating survival and death of human naive and IgM+ memory B cells.
Methylation Status of CpG Islands Flanking a cAMP Response Element Motif on the Protein Phosphatase 2Acα Promoter Determines CREB Binding and Activity
Authors: Sunahori Katsue , Juang Yuang-Taung , Tsokos George C. 
Published: April 2014

Abstract
Protein phosphatase 2A (PP2A) is a major serine/threonine protein phosphatase in eukaryotic cells and is involved in many essential aspects of cell function. The catalytic subunit of the enzyme (PP2Ac), a part of the core enzyme, has two isoforms, α (PP2Acα) and β (PP2Acβ), of which PP2Acα is the major form expressed in vivo. Deregulation of PP2A expression has been linked to several diseases, but the mechanisms that control the expression of this enzyme are still unclear. We conducted experiments to decipher molecular mechanisms involved in the regulation of the PP2Acα promoter in human primary T cells. After preparing serially truncated PP2Acα promoter luciferase constructs, we found that the region stretching around 240 bases upstream from the translation initiation site was of functional significance and included a cAMP response element motif flanked by three GC boxes. Shift assays revealed that CREB/phosphorylated CREB and stable protein 1 could bind to the region. Furthermore, we demonstrated that methylation of deoxycytosine in the CpG islands limited binding of phosphorylated CREB and the activity of the PP2Acα promoter. In contrast, the binding of stable protein 1 to a GC box within the core promoter region was not affected by DNA methylation. Primary T cells treated with 5-azacitidine, a DNA methyltransferase inhibitor, showed increased expression of PP2Acα mRNA. We propose that conditions associated with hypomethylation of CpG islands, such as drug-induced lupus, permit increased PP2Ac expression.
A Novel Activating Chicken IgY FcR Is Related to Leukocyte Receptor Complex (LRC) Genes but Is Located on a Chromosomal Region Distinct from the LRC and FcR Gene Clusters
Authors: Viertlboeck Birgit C. , Schmitt Ramona , Hanczaruk Matthias A. , Crooijmans Richard P. M. A. , Groenen Martien A. M. , Göbel Thomas W. 
Published: April 2014

Abstract
FcRs have multifaceted roles in the immune system. Chicken FcRs were demonstrated on macrophages decades ago; however, only recently the chicken Ig-like receptor AB1, encoded in the leukocyte receptor complex, was molecularly identified as a high-affinity FcR. The present study was initiated to identify additional receptors with the capability to bind chicken immunoglobulins. Based on database searches, we cloned a novel chicken FcR, designated gallus gallus FcR (ggFcR), which was shown to bind selectively chicken IgY. The receptor consists of four extracellular C2-set Ig domains, followed by a transmembrane region containing arginine as a positively charged amino acid and a short cytoplasmic tail. ggFcR associates with the common γ-chain, indicative for an activating receptor, and real-time RT-PCR revealed high expression on PBMC, thrombocytes, and macrophages. The genomic organization is similar to most Ig-like receptor genes, where each Ig domain is encoded by a separate exon. Additionally, the ggFcR signal peptide is encoded by two exons, the second of which is 36 bp, a hallmark for genes encoded in the leukocyte receptor complex. Phylogenetic analysis also showed a relationship to genes encoded in the leukocyte receptor complex. Surprisingly, ggFcR is not encoded in the leukocyte receptor complex, but it is located as a single isolated gene at the extremity of chicken chromosome 20.