bluuebunny/crossref_metadata_2025_split huggingface dataset:
α-Melanocyte-Stimulating Hormone Suppresses Antigen-Induced Lymphocyte Proliferation in Humans Independently of Melanocortin 1 Receptor Gene Status
Authors: Cooper Ashley , Robinson Samantha J. , Pickard Chris , Jackson Claire L. , Friedmann Peter S. , Healy Eugene 
Published: April 2014

AbstractStudies in mice indicate that α-melanocyte-stimulating hormone (αMSH) is immunosuppressive, but it is not known whether αMSH suppresses human immune responses to exogenous Ags. Human PBMCs, including monocytes, express the melanocortin 1 receptor (MC1R), and it is thought that the ability of αMSH to alter monocyte-costimulatory molecule expression and IL-10 release is mediated by this receptor. However, the MC1R gene is polymorphic, and certain MC1R variants compromise receptor signaling via cAMP, resulting in red hair and fair skin. Here, we have investigated whether αMSH can suppress Ag-induced lymphocyte proliferation in humans and whether these effects are dependent on MC1R genotype. αMSH suppressed streptokinase-streptodornase-induced lymphocyte proliferation, with maximal inhibition at 10−13–10−11 M αMSH. Anti-IL-10 Abs failed to prevent suppression by αMSH, indicating that it was not due to MC1R-mediated IL-10 release by monocytes. Despite variability in the degree of suppression between subjects, similar degrees of αMSH-induced immunosuppression were seen in individuals with wild-type, heterozygous variant, and homozygous/compound heterozygous variant MC1R alleles. RT-PCR of streptokinase-streptodornase-stimulated PBMCs for all five melanocortin receptors demonstrated MC1R expression by monocytes/macrophages, MC1R and MC3R expression by B lymphocytes, but no melanocortin receptor expression by T lymphocytes. In addition, αMSH did not significantly inhibit anti-CD3 Ab-induced lymphocyte proliferation, whereas αMSH and related analogs (SHU9119 and MTII) inhibited Ag-induced lymphocyte proliferation in monocyte-depleted and B lymphocyte-depleted assays. These findings demonstrate that αMSH, acting probably via MC1R on monocytes and B lymphocytes, and possibly also via MC3R on B lymphocytes, has immunosuppressive effects in humans but that suppression of Ag-induced lymphocyte proliferation by αMSH is independent of MC1R gene status.
Gene Family Clustering Identifies Functionally Associated Subsets of Human In Vivo Blood and Tonsillar Dendritic Cells
Authors: Lindstedt Malin , Lundberg Kristina , Borrebaeck Carl A. K. 
Published: April 2014

Abstract
Human dendritic cells (DCs) are a distinct but heterogeneous lineage of APCs operating as the link between innate and adaptive immune responses, with the function to either maintain tolerance or trigger immunity. The DC lineage consists of several subpopulations with unique phenotypes; however, their functional characteristics and transcriptional similarities remain largely unknown. To further characterize the phenotypes and transcriptomes of the subsets, we purified myeloid CD16+, blood DC Ag 1+ (BDCA1+), and BDCA3+ DC populations, as well as plasmacytoid CD123+ DCs, from tonsillar tissue and peripheral blood. Transcriptional profiling and hierarchical clustering visualized that BDCA1+ DCs clustered with BDCA3+ DCs, whereas CD16+ DCs and CD123+ DCs clustered as distinct populations in blood. Differential expression levels of chemokines, ILs, and pattern recognition receptors were demonstrated, which emphasize innate DC subset specialization. Even though highly BDCA1+ and BDCA3+ DC-specific gene expression was identified in blood, the BDCA1+ DCs and BDCA3+ DCs from tonsils displayed similar transcriptional activity, most likely due to the pathogenic or inflammatory maturational signals present in tonsillar tissues. Of note, plasmacytoid DCs displayed less plasticity in their transcriptional activity compared with myeloid DCs. The data demonstrated a functionally distinct association of each of the seven subsets based on their signatures, involving regulatory genes in adaptive and innate immunity.
The CD85J/Leukocyte Inhibitory Receptor-1 Distinguishes between Conformed and β2-Microglobulin-Free HLA-G Molecules
Authors: Gonen-Gross Tsufit , Achdout Hagit , Arnon Tal I. , Gazit Roi , Stern Noam , Hořejší Václav , Goldman-Wohl Debra , Yagel Simcha , Mandelboim Ofer 
Published: April 2014

Abstract
For a proper development of the placenta, maternal NK cells should not attack the fetal extravillous cytotrophoblast cells. This inhibition of maternal NK cells is partially mediated via the nonclassical MHC class I molecule HLA-G. Recently, we demonstrated that HLA-G forms disulfide-linked high molecular complexes on the surface of transfected cells. In the present study, we demonstrate that HLA-G must associate with β2m for its interaction with CD85J/leukocyte Ig-like receptor-1 (LIR-1). Although HLA-G free H chain complexes are expressed on the surface, they are not recognized and possibly interfere with CD85J/LIR-1 and HLA-G interaction. The formation of these complexes on the cell surface might represent a novel mechanism developed specifically by the HLA-G protein aimed to control the efficiency of the CD85J/LIR-1-mediated inhibition. We also show that endogenous HLA-G complexes are expressed on the cell surface. These findings provide novel insights into the delicate interaction between extravillous cytotrophoblast cells and NK cells in the decidua.
Engagement of 4-1BB Inhibits the Development of Experimental Allergic Conjunctivitis in Mice
Authors: Fukushima Atsuki , Yamaguchi Tomoko , Ishida Waka , Fukata Kazuyo , Mittler Robert S. , Yagita Hideo , Ueno Hisayuki 
Published: April 2014

Abstract
The 4-1BB receptor acts as a costimulator in CD8+ T cell activation. Agonistic stimulation through this molecule by treatment with anti-4-1BB Abs has been demonstrated to inhibit various experimentally induced diseases in animals. However, the effect of anti-4-1BB Abs on experimental allergic diseases has not been reported. We investigated the effect of anti-4-1BB Abs on the development and progression of experimental allergic conjunctivitis in mice. To examine the effects of Abs during the induction or effector phase, actively immunized mice or passively immunized mice by splenocyte transfer were treated with agonistic anti-4-1BB Abs, blocking anti-4-1BB ligand Abs, or normal rat IgG. Eosinophil infiltration into the conjunctiva was significantly reduced in wild-type mice by the anti-4-1BB Ab treatment during either induction or effector phase. Th2 cytokine production by splenocytes and total serum IgE were significantly reduced by the anti-4-1BB Ab treatment, while IFN-γ production was increased. The anti-4-1BB Ab treatment induced a relative increase of CD8-positive cell numbers in the spleens. Moreover, inhibition of eosinophil infiltration by the treatment with anti-4-1BB Abs was also noted in actively immunized IFN-γ knockout mice. Taken altogether, in vivo treatment with agonistic anti-4-1BB Abs in either induction or effector phase inhibits the development of experimental allergic conjunctivitis, and this inhibition is likely to be mediated by suppression of Th2 immune responses rather than up-regulation of IFN-γ.
Vα24-Invariant NKT Cells from Patients with Allergic Asthma Express CCR9 at High Frequency and Induce Th2 Bias of CD3+ T Cells upon CD226 Engagement
Authors: Sen Yang , Yongyi Bi , Yuling He , Luokun Xie , Li He , Jie Xiong , Tao Deng , Gang Zhou , Junyan Liu , Chunsong Hu , Zhang Xuejun , Youxin Jin , Feili Gong , Boquan Jin , Jinquan Tan 
Published: April 2014

Abstract
We have demonstrated that Vα24+Vβ11+ invariant (Vα24+i) NKT cells from patients with allergic asthma express CCR9 at high frequency. CCR9 ligand CCL25 induces chemotaxis of asthmatic Vα24+i NKT cells but not the normal cells. A large number of CCR9-positive Vα24+i NKT cells are found in asthmatic bronchi mucosa, where high levels of Th2 cytokines are detected. Asthmatic Vα24+i NKT cells, themselves Th1 biased, induce CD3+ T cells into an expression of Th2 cytokines (IL-4 and IL-13) in cell-cell contact manner in vitro. CD226 are overexpressed on asthmatic Vα24+i NKT cells. CCL25/CCR9 ligation causes directly phosphorylation of CD226, indicating that CCL25/CCR9 signals can cross-talk with CD226 signals to activate Vα24+i NKT cells. Prestimulation with immobilized CD226 mAb does not change ability of asthmatic Vα24+i NKT cells to induce Th2-cytokine production, whereas soluble CD226 mAb or short hairpin RNA of CD226 inhibits Vα24+i NKT cells to induce Th2-cytokine production by CD3+ T cells, indicating that CD226 engagement is necessary for Vα24+i NKT cells to induce Th2 bias of CD3+ T cells. Our results are providing with direct evidence that aberration of CCR9 expression on asthmatic Vα24+i NKT cells. CCL25 is first time shown promoting the recruitment of CCR9-expressing Vα24+i NKT cells into the lung to promote other T cells to produce Th2 cytokines to establish and develop allergic asthma. Our findings provide evidence that abnormal asthmatic Vα24+i NKT cells induce systemically and locally a Th2 bias in T cells that is at least partially critical for the pathogenesis of allergic asthma.
Early Presence of Regulatory Cells in Transplanted Rats Rendered Tolerant by Donor-Specific Blood Transfusion
Authors: Kitade Hiroaki , Kawai Masaru , Rutgeerts Omer , Landuyt Willy , Waer Mark , Mathieu Chantal , Pirenne Jacques 
Published: April 2014

Abstract
Mechanisms by which donor-specific blood transfusion (DSBT) promotes organ allograft acceptance are unclear. In a rat fully mismatched cardiac allograft model, we found that DSBT alone (without immunotherapy) induces the development of regulatory T cells (DSBT-Tregs) posttransplant, thereby shedding new light in the mechanisms of the transfusion effect. Compartments and timing of expansion, requirements, and phenotype of DSBT-Tregs are unknown. It is generally assumed that some time is necessary before Tregs develop. However, we show—by adoptive transfer from DSBT—tolerant into naive recipients: 1) the presence of DSBT-Tregs at 5 days posttransplant in spleen and lymph nodes; 2) their gradual expansion in these compartments; and 3) their presence in the graft 14 of 30 days posttransplant. DSBT-Tregs are donor specific and do not protect third-party allografts. Splenocytes from DSBT-treated nontransplanted recipients or from transplanted DSBT-untreated (rejecting) recipients do not transfer tolerance, indicating that both DSBT and graft are required for sufficient numbers of DSBT-Tregs to develop. Thymectomy (or splenectomy) before DSBT (not at transplantation) abrogate DSBT-Tregs generation and tolerance, showing that thymus (and spleen) are required for DSBT-Tregs generation (not for expansion/maintenance). In contrast with other Tregs models, DSBT-Tregs activity is not restricted to CD4+CD25+ but to CD4+CD45RC− cells, whereas CD4+CD45RC+ cells act as effector cells and accelerate rejection. In conclusion, DSBT alone induces—rapidly posttransplant—the development of alloantigen-specific Tregs in lymphoid tissues and in the graft. DSBT, graft, thymus, and spleen are required for DSBT-Tregs generation. DSBT-Tregs in this model are CD4+CD45RC− (identical to Tregs protecting from autoimmunity in rats).
Mechanisms of Hypotonicity-Induced Calcium Signaling and Integrin Activation by Arachidonic Acid-Derived Inflammatory Mediators in B Cells
Authors: Zhu Peimin , Liu Xiaohong , Labelle Edward F. , Freedman Bruce D. 
Published: April 2014

Abstract
We previously characterized the initial steps in the activation of novel (calcium-permeant) nonselective cation channels (NSCCs) and calcium release-activated calcium channels in primary murine B lymphocytes. Phospholipase C products, namely diacylglycerol and d-myo-inositol 1,4,5-trisphosphate, were identified as proximal intracellular agonists of these respective channels following mechanical stimulation of B cells. However, neither the distal steps in NSCC activation nor the contribution of these channels to sustained mechanical signaling were defined in these previous studies. In this study, single cell measurements of intracellular Ca2+ were used to define the mechanisms of NSCC activation and demonstrate a requirement for arachidonic acid liberated from diacylglycerol. Several arachidonic acid-derived derivatives were identified that trigger Ca2+ entry into B cells, including the lipoxygenase product 5-hydroperoxyeicosatetranenoic acid and the cytochrome P450 hydroxylase product 20-hydroxyeicosatetraenoic; however, the cytochrome P450 epoxygenase product 5,6-epoxyeicosatrienoic acid is primarily responsible for hypotonicity-induced responses. In addition to regulating calcium entry, our data suggest that eicosanoid-activated NSCCs have a separate and direct role in regulating the avidity of integrins on B cells for extracellular matrix proteins, including ICAM-1 and VCAM-1. Thus, in addition to defining a novel osmotically activated signal transduction pathway in B cells, our results have broad implications for understanding how inflammatory mediators dynamically and rapidly regulate B cell adhesion and trafficking.
Chronic Morphine Treatment Promotes Specific Th2 Cytokine Production by Murine T Cells In Vitro via a Fas/Fas Ligand-Dependent Mechanism
Authors: Greeneltch Kristy M. , Kelly-Welch Ann E. , Shi Yufang , Keegan Achsah D. 
Published: April 2014

Abstract
Improper homeostasis of Th1 and Th2 cell differentiation can promote pathological immune responses such as autoimmunity and asthma. A number of factors govern the development of these cells including TCR ligation, costimulation, death effector expression, and activation-induced cell death (AICD). Although chronic morphine administration has been shown to selectively promote Th2 development in unpurified T cell populations, the direct effects of chronic morphine on Th cell skewing and cytokine production by CD4+ T cells have not been elucidated. We previously showed that morphine enhances Fas death receptor expression in a T cell hybridoma and human PBL. In addition, we have demonstrated a role for Fas, Fas ligand (FasL), and TRAIL in promoting Th2 development via killing of Th1 cells. Therefore, we analyzed whether the ability of morphine to affect Th2 cytokine production was mediated by regulation of Fas, FasL, and TRAIL expression and AICD directly in purified Th cells. We found that morphine significantly promoted IL-4 and IL-13 production but did not alter IL-5 or IFN-γ. Furthermore, morphine enhanced the mRNA expression of Fas, FasL and TRAIL and promoted Fas-mediated AICD of CD4+ T cells. Additionally, blockade of Fas/FasL interaction by anti-FasL inhibited the morphine-induced production of IL-4 and IL-13 and AICD of CD4+ T cells. These results suggest that morphine preferentially enhances Th2 cell differentiation via killing of Th1 cells in a Fas/FasL-dependent manner.
Paradoxical Anti-Inflammatory Actions of TNF-α: Inhibition of IL-12 and IL-23 via TNF Receptor 1 in Macrophages and Dendritic Cells
Authors: Zakharova Maria , Ziegler H. Kirk 
Published: April 2014

Abstract
IL-12 and TNF-α are central proinflammatory cytokines produced by macrophages and dendritic cells. Disregulation of TNF-α is associated with sepsis and autoimmune diseases such as rheumatoid arthritis. However, new evidence suggests an anti-inflammatory role for TNF-α. TNF-α-treated murine macrophages produced less IL-12p70 and IL-23, after stimulation with IFN-γ and LPS. Frequency of IL-12p40-producing macrophages correspondingly decreased as measured by intracellular cytokine staining. IL-12p40 production was also inhibited in dendritic cells. TNFR1 was established as the main receptor involved in IL-12p40 regulation, because IL-12p40 levels were not affected by TNF-α in TNFR1−/−-derived macrophages. Macrophages activated during Listeria monocytogenes infection were more susceptible to inhibition by TNF-α than cells from naive animals, which suggests a regulatory role for TNF-α in later stages of infection. This nonapoptotic anti-inflammatory regulation of IL-12 and IL-23 is an important addition to the multitude of TNF-α-induced responses determined by cell-specific receptor signaling.
Tight Regulation of IFN-γ Transcription and Secretion in Immature and Mature B cells by the Inhibitory MHC Class I Receptor, Ly49G2
Authors: Hart Gili , Flaishon Liat , Becker-Herman Shirly , Shachar Idit 
Published: April 2014

Abstract
To complete their maturation and to participate in the humoral immune response, immature B cells that leave the bone marrow are targeted to specific areas in the spleen, where they differentiate into mature cells. Previously, we showed that immature B cells actively down-regulate their integrin-mediated migration to lymph nodes or sites of inflammation, enabling their targeting to the spleen to allow their final maturation. This inhibition is mediated by IFN-γ, which is transcribed and secreted at low levels by these immature B cells and is down-regulated at the mature stage. The activating MHC class I receptor, Ly49D, which is expressed at high levels on immature B cells, stimulates this IFN-γ secretion. In this study we show that B cells coexpress the inhibitory MHC class I receptor, Ly49G2. In addition, we demonstrate a tight regulation in the expression of the Ly49 family members on B cells that depends on their cell surface levels. High levels of Ly49G2 have a dominant inhibitory effect on Ly49D expressed at low levels on immature bone marrow and mature B cells, resulting in inhibition of IFN-γ secretion. However, low levels of the inhibitory receptor, Ly49G2, coexpressed with high levels of the activating receptor, Ly49D, on the immigrating immature B cells enable the secretion of specific low levels of IFN-γ. This expression pattern insures the inhibitory control of peripheral immature B cell to prevent premature encounter with an Ag while enabling entry to the lymph nodes during the mature stage.
Estrogen Enhances Susceptibility to Experimental Autoimmune Myasthenia Gravis by Promoting Type 1-Polarized Immune Responses
Authors: Delpy Laurent , Douin-Echinard Victorine , Garidou Lucile , Bruand Corinne , Saoudi Abdelhadi , Guéry Jean-Charles 
Published: April 2014

Abstract
Myasthenia gravis (MG) is an organ-specific autoimmune disease caused in most cases by autoantibodies against the nicotinic acetylcholine receptor (AChR). It is now well documented that many autoimmune diseases, including MG, are more prevalent in women than in men, and that fluctuations in disease severity occur during pregnancy. These observations raise the question of the potential role of sex hormones, such as estrogens, as mediators of sex differences in autoimmunity. In the present study, we have analyzed the effect of 17β-estradiol (E2) on the pathogenesis of experimental autoimmune myasthenia gravis (EAMG), an animal model of MG. We show that treatment with E2 before Ag priming is necessary and sufficient to promote AChR-specific Th1 cell expansion in vivo. This time-limited exposure to E2 enhances the production of anti-AChR IgG2ab (specific for b allotype; e.g., B6) and IgG2b, but not IgG1, and significantly increases the severity of EAMG in mice. Interestingly, the E2-mediated augmentation in AChR-specific Th1 response correlates with an enhanced production of IL-12 by splenic APCs through the recruitment of CD8α+ dendritic cells. These data provide the first evidence that estrogen enhances EAMG, and sheds some light on the role of sex hormones in immune responses and susceptibility to autoimmune disease in women.
Human Embryonic Stem Cell-Derived NK Cells Acquire Functional Receptors and Cytolytic Activity
Authors: Woll Petter S. , Martin Colin H. , Miller Jeffrey S. , Kaufman Dan S. 
Published: April 2014

Abstract
Human embryonic stem cells (hESCs) provide a unique resource to analyze early stages of human hematopoiesis. However, little is known about the ability to use hESCs to evaluate lymphocyte development. In the present study, we use a two-step culture method to demonstrate efficient generation of functional NK cells from hESCs. The CD56+CD45+ hESC-derived lymphocytes express inhibitory and activating receptors typical of mature NK cells, including killer cell Ig-like receptors, natural cytotoxicity receptors, and CD16. Limiting dilution analysis suggests that these cells can be produced from hESC-derived hemopoietic progenitors at a clonal frequency similar to CD34+ cells isolated from cord blood. The hESC-derived NK cells acquire the ability to lyse human tumor cells by both direct cell-mediated cytotoxicity and Ab-dependent cellular cytotoxicity. Additionally, activated hESC-derived NK cells up-regulate cytokine production. hESC-derived lymphoid progenitors provide a novel means to characterize specific cellular and molecular mechanisms that lead to development of specific human lymphocyte populations. These cells may also provide a source for innovative cellular immune therapies.
Critical Role for the Tapasin-Docking Site of TAP2 in the Functional Integrity of the MHC Class I-Peptide-Loading Complex
Authors: Leonhardt Ralf M. , Keusekotten Kirstin , Bekpen Cemalettin , Knittler Michael R. 
Published: April 2014

Abstract
The transporter associated with Ag processing (TAP) translocates antigenic peptides into the endoplasmic reticulum for binding onto MHC class I (MHC I) molecules. Tapasin organizes a peptide-loading complex (PLC) by recruiting MHC I and accessory chaperones to the N-terminal regions (N domains) of the TAP subunits TAP1 and TAP2. To investigate the function of the tapasin-docking sites of TAP in MHC I processing, we expressed N-terminally truncated variants of TAP1 and TAP2 in combination with wild-type chains, as fusion proteins or as single subunits. Strikingly, TAP variants lacking the N domain in TAP2, but not in TAP1, build PLCs that fail to generate stable MHC I-peptide complexes. This correlates with a substantially reduced recruitment of accessory chaperones into the PLC demonstrating their important role in the quality control of MHC I loading. However, stable surface expression of MHC I can be rescued in post-endoplasmic reticulum compartments by a proprotein convertase-dependent mechanism.
Attenuation of Th1 Response in Decoy Receptor 3 Transgenic Mice
Authors: Hsu Tsui-Ling , Wu Ying-Yu , Chang Yung-Chi , Yang Chih-Ya , Lai Ming-Zong , Su Wenlynn B. , Hsieh Shie-Liang 
Published: April 2014

Abstract
The soluble decoy receptor 3 (DcR3) is a member of the TNFR superfamily. Because DcR3 is up-regulated in tumor tissues and is detectable in the sera of cancer patients, it is regarded as an immunosuppressor to down-regulate immune responses. To understand the function of DcR3 in vivo, we generated transgenic mice overexpressing DcR3 systemically. In comparison with HNT-TCR (HNT) transgenic mice, up-regulation of IL-4 and IL-10 and down-regulation of IFN-γ, IL-12, and TNF-α were observed in the influenza hemagglutinin126–138 peptide-stimulated splenocytes of HNT-DcR3 double-transgenic mice. When infected with Listeria monocytogenes, DcR3 transgenic mice show attenuated expression of IFN-γ as well as increased susceptibility to infection. The Th2 cell-biased phenotype in DcR3 transgenic mice is attributed to decreased IL-2 secretion by T cells, resulting in the suppression of IL-2 dependent CD4+ T cell proliferation. This suggests that DcR3 might help tumor growth by attenuating the Th1 response and suppressing cell-mediated immunity.