bluuebunny/crossref_metadata_2025_split huggingface dataset:
Targeting CpG Oligonucleotides to the Lymph Node by Nanoparticles Elicits Efficient Antitumoral Immunity
Authors: Bourquin Carole , Anz David , Zwiorek Klaus , Lanz Anna-Lisa , Fuchs Sebastian , Weigel Sarah , Wurzenberger Cornelia , von der Borch Philip , Golic Michaela , Moder Stefan , Winter Gerhard , Coester Conrad , Endres Stefan 
Published: April 2014

Abstract
Viral nucleic acids are recognized by specific pattern-recognition receptors of the Toll-like and RIG-I-like receptor families. Synthetic DNA and RNA oligonucleotides can activate the immune system through these receptors and potentiate Ab and CD8 cytotoxic responses to Ags. Systemic application of immunostimulatory oligonucleotides however also results in a generalized, non-Ag-specific stimulation of the immune system. In this study, we have dissociated the induction of an Ag-specific response from the systemic immune activation generally associated with immunostimulatory oligonucleotides. Delivery of CpG oligodeoxynucleotides that bind TLR9 by cationized gelatin-based nanoparticles potentiates the in vivo generation of an Ag-specific cytotoxic T cell and Ab response. Furthermore, immunization with CpG-loaded nanoparticles induces a protective antitumoral response in a murine model of melanoma. The systemic release of proinflammatory cytokines and widespread immunostimulation associated with free CpG is however completely abolished. In addition, we show that gelatin nanoparticle formulation prevents the destruction of lymphoid follicles mediated by CpG. Nanoparticle-delivered CpG, in contrast to free CpG, are selectively targeted to APCs in the lymph nodes where they mediate local immune stimulation. We describe a novel strategy to target immunostimulatory oligonucleotides to the initiation site of the immune response while at the same time protecting from an indiscriminate and generalized activation of the immune system.
Critical and Differential Roles of NKp46- and NKp30-Activating Receptors Expressed by Uterine NK Cells in Early Pregnancy
Authors: El Costa Hicham , Casemayou Audrey , Aguerre-Girr Maryse , Rabot Magali , Berrebi Alain , Parant Olivier , Clouet-Delannoy Muriel , Lombardelli Letizia , Jabrane-Ferrat Nabila , Rukavina Daniel , Bensussan Armand , Piccinni Marie-Pierre , Le Bouteiller Philippe , Tabiasco Julie 
Published: April 2014

Abstract
In early human pregnancy, uterine decidual NK cells (dNK) are abundant and considered as cytokine producers but poorly cytotoxic despite their cytolytic granule content, suggesting a negative control of this latter effector function. To investigate the basis of this control, we examined the relative contribution to the cytotoxic function of different activating receptors expressed by dNK. Using a multicolor flow cytometry analysis, we found that freshly isolated dNK exhibit a unique repertoire of activating and inhibitory receptors, identical among all the donors tested. We then demonstrated that in fresh dNK, mAb-specific engagement of NKp46-, and to a lesser extent NKG2C-, but not NKp30-activating receptors induced intracellular calcium mobilization, perforin polarization, granule exocytosis and efficient target cell lysis. NKp46-mediated cytotoxicity is coactivated by CD2 but dramatically blocked by NKG2A coengagement, indicating that the dNK cytotoxic potential could be tightly controlled in vivo. We finally found that in dNK, mAb-specific engagement of NKp30, but not NKp46, triggered the production of IFN-γ, TNF-α, MIP-1α, MIP-1β, and GM-CSF proinflammatory molecules. These data demonstrate a differential, controlled role of NKp46- and NKp30-activating receptors expressed by dNK that could be critical for the outcome of pregnancy and the killing of uterine cells infected by pathogens.
Role of Endogenous Brain-Derived Neurotrophic Factor and Sortilin in B Cell Survival
Authors: Fauchais Anne-Laure , Lalloué Fabrice , Lise Marie-Claude , Boumediene Ahmed , Preud'homme Jean-Louis , Vidal Elisabeth , Jauberteau Marie-Odile 
Published: April 2014

Abstract
Brain-derived neurotrophic factor (BDNF), a major neuronal growth factor, is also known to exert an antiapoptotic effect in myeloma cells. Whereas BDNF secretion was described in B lymphocytes, the ability of B cells to produce sortilin, its transport protein, was not previously reported. We studied BDNF production and the expression of its receptors, tyrosine protein kinase receptor B and p75 neurotrophin receptor in the human pre-B, mature, and plasmacytic malignant B cell lines under normal and stress culture conditions (serum deprivation, Fas activation, or their combination). BDNF secretion was enhanced by serum deprivation and exerted an antiapoptotic effect, as demonstrated by neutralization experiments with antagonistic Ab. The precursor form, pro-BDNF, also secreted by B cells, decreases under stress conditions in contrast to BDNF production. Stress conditions induced the membranous expression of p75 neurotrophin receptor and tyrosine protein kinase receptor B, maximal in mature B cells, contrasting with the sequestration of both receptors in normal culture. By blocking Ab and small interfering RNA, we evidenced that BDNF production and its survival function are depending on sortilin, a protein regulating neurotrophin transport in neurons, which was not previously described in B cells. Therefore, in mature B cell lines, an autocrine BDNF production is up-regulated by stress culture conditions and exerts a modulation of apoptosis through the sortilin pathway. This could be of importance to elucidate certain drug resistances of malignant B cells. In addition, primary B lymphocytes contained sortilin and produced BDNF after mitogenic activation, which suggests that sortilin and BDNF might be implicated in the survival and activation of normal B cells also.
Immunodominance of CD4 T Cells to Foreign Antigens Is Peptide Intrinsic and Independent of Molecular Context: Implications for Vaccine Design
Authors: Weaver Jason M. , Lazarski Christopher A. , Richards Katherine A. , Chaves Francisco A. , Jenks Scott A. , Menges Paula R. , Sant Andrea J. 
Published: April 2014

Abstract
Immunodominance refers to the restricted peptide specificity of T cells that are detectable after an adaptive immune response. For CD4 T cells, many of the mechanisms used to explain this selectivity suggest that events related to Ag processing play a major role in determining a peptide’s ability to recruit CD4 T cells. Implicit in these models is the prediction that the molecular context in which an antigenic peptide is contained will impact significantly on its immunodominance. In this study, we present evidence that the selectivity of CD4 T cell responses to peptides contained within protein Ags is not detectably influenced by the location of the peptide in a given protein or the primary sequence of the protein that bears the test peptide. We have used molecular approaches to change the location of peptides within complex protein Ags and to change the flanking sequences that border the peptide epitope to now include a protease site, and find that immunodominance or crypticity of a peptide observed in its native protein context is preserved. Collectively, these results suggest immunodominance of peptides contained in complex Ags is due to an intrinsic factor of the peptide, based upon the affinity of that peptide for MHC class II molecules. These findings are discussed with regard to implications for vaccine design.
TRIF and IRF-3 Binding to the TNF Promoter Results in Macrophage TNF Dysregulation and Steatosis Induced by Chronic Ethanol
Authors: Zhao Xue-Jun , Dong Qing , Bindas Julie , Piganelli Jon D. , Magill Amy , Reiser Jakob , Kolls Jay K. 
Published: April 2014

Abstract
Chronic ethanol (EtOH) abuse results in the development of steatosis, alcoholic hepatitis, and cirrhosis. Augmented TNF-α production by macrophages and Kupffer cells and signaling via the p55 TNF receptor have been shown to be critical for these effects of chronic EtOH; however, the molecular mechanisms leading to augmented TNF-α production remain unclear. Using cell culture models and in vivo studies we demonstrate that chronic EtOH results in increased TNF-α transcription, which is independent of NF-κB. Using reporter assays and chromatin immunoprecipitation we found that this increased transcription is due to increased IRF-3 binding to and transactivation of the TNF promoter. As IRF-3 is downstream from the TLR4 adaptor TIR-domain-containing adapter-inducing IFN-β (Trif), we demonstrate that macrophages from Trif−/− mice are resistant to this dysregulation of TNF-α transcription by EtOH in vitro as well as EtOH-induced steatosis and TNF dysregulation in vivo. These data demonstrate that the Trif/IRF-3 pathway is a target to ameliorate liver dysfunction associated with chronic EtOH.
Cannabinoids Affect Dendritic Cell (DC) Potassium Channel Function and Modulate DC T Cell Stimulatory Capacity
Authors: Wacnik Paul W. , Luhr Katarina M. , Hill Russell H. , Ljunggren Hans-Gustaf , Kristensson Krister , Svensson Mattias 
Published: April 2014

Abstract
Cannabinoids affect diverse biological processes, including functions of the immune system. With respect to the immune system, anti-inflammatory and immunosuppressive effects of cannabinoids have been reported. Cannabinoids stimulate G protein-coupled cannabinoid receptors CB1 and CB2. These receptors are found primarily on neurons. However, they are also found on dendritic cells (DC), which are recognized for their critical role in initiating and maintaining immune responses. Therefore, DC are potential targets for cannabinoids. We report in this study that cannabinoids reduced the DC surface expression of MHC class II molecules as well as their capacity to stimulate T cells. In the nervous system, CB1 receptor signaling modulates K+ and Ca2+ channels. Interestingly, cannabinoid-treated DC also showed altered voltage-gated potassium (KV) channel function. We speculate that attenuation of KV channel function via CB1 receptor signaling in DC may represent one mechanism by which cannabinoids alter DC function.
A Critical Role for the Proapoptotic Protein Bid in Ultraviolet-Induced Immune Suppression and Cutaneous Apoptosis
Authors: Pradhan Sanjay , Kim Hee Kyung , Thrash Christopher J. , Cox Maureen A. , Mantena Sudheer K. , Wu Jian-He , Athar Mohammad , Katiyar Santosh K. , Elmets Craig A. , Timares Laura 
Published: April 2014

AbstractApoptosis plays an important role in eliminating UV-damaged keratinocytes, but its role in UV-induced immune suppression is not clear. Langerhans cells (LCs) may function as inducers of immune suppression. We have shown that LCs derived from mice deficient in the proapoptotic Bid (BH3-interacting death domain protein) gene (Bid KO) resist apoptosis and induce amplified immune responses. In this report, we examined responses in Bid KO mice to UVB exposure. Acute UV exposure led Bid KO mice to develop fewer apoptotic cells and retain a greater fraction of LCs in the epidermal layer of skin in comparison to wild-type mice. Bid KO mice were also markedly resistant to local and systemic UV tolerance induction to hapten sensitization and contact hypersensitivity responses. Elicitation responses and inflammation at skin sensitization sites in UV-treated Bid KO mice were equal to or greater than nonsuppressed control responses. In Bid KO mice, LCs accumulated in lymph nodes to greater numbers, demonstrated longer lifespans, and contained fewer DNA-damaged cells. These studies provide evidence that Bid activation is a critical upstream mediator in UV-induced keratinocyte and LC apoptosis and that its absence abrogates UV-induced immune tolerance.
OK432-Activated Human Dendritic Cells Kill Tumor Cells via CD40/CD40 Ligand Interactions
Authors: Hill Katy S. , Errington Fiona , Steele Lynette P. , Merrick Alison , Morgan Ruth , Selby Peter J. , Georgopoulos Nikolaos T. , O'Donnell Dearbhaile M. , Melcher Alan A. 
Published: April 2014

Abstract
In vivo, dendritic cells (DC) are programmed to orchestrate innate and adaptive immunity in response to pathogen-derived “danger” signals. Under particular circumstances, DC can also be directly cytotoxic against tumor cells, potentially allowing them to release tumor associated Ags from dying cells and then prime antitumor immunity against them. In this study, we describe the innate characteristics of DC (OK-DC) generated in vitro after exposure of immature human myeloid-derived DC to OK432, a penicillin-inactivated and lyophilized preparation of Streptococcus pyrogenes. OK-DC produced proinflammatory cytokines, stimulated autologous T cell proliferation and IFN-γ secretion, expressed CCR7, and migrated in response to MIP-3β. Moreover, OK-DC displayed strong, specific cytotoxicity toward tumor cell targets. This cytotoxicity was associated with novel, OK432-induced up-regulation of CD40L on the cell surface of OK-DC, and was absolutely dependent on expression of CD40 on the tumor targets. These data demonstrate that maturation of human DC with OK432, an adjuvant suitable for clinical use, induces direct tumor cell killing by DC, and describes a novel CD40/CD40L-mediated mechanism for specific DC antitumor cytotoxicity.
The C-Type Lectin Macrophage Galactose-Type Lectin Impedes Migration of Immature APCs
Authors: van Vliet Sandra J. , Paessens Lutz C. , Broks-van den Berg Venice C. M. , Geijtenbeek Teunis B. H. , van Kooyk Yvette 
Published: April 2014

Abstract
Dendritic cells (DCs) are the most potent APCs of the immune system that seed the peripheral tissues and lymphoid organs. In an immature state, DCs sample their surroundings for incoming pathogens. Upon Ag encounter, DCs mature and migrate to the lymph node to induce adaptive immune responses. The C-type macrophage galactose-type lectin (MGL), expressed in immature DCs, mediates binding to glycoproteins carrying GalNAc moieties. In the present study, we demonstrate that MGL ligands are present on the sinusoidal and lymphatic endothelium of lymph node and thymus, respectively. MGL binding strongly correlated with the expression of the preferred MGL ligand, α-GalNAc-containing glycan structures, as visualized by staining with the α-GalNAc-specific snail lectin Helix pomatia agglutinin. MGL+ cells were localized in close proximity of the endothelial structures that express the MGL ligand. Strikingly, instead of inducing migration, MGL mediated retention of human immature DCs, as blockade of MGL interactions enhanced DC trafficking and migration. Thus, MGL+ DCs are hampered in their migratory responses and only upon maturation, when MGL expression is abolished; these DCs will be released from their MGL-mediated restraints.
Mononuclear Phagocyte-Derived IL-10 Suppresses the Innate IL-12/IFN-γ Axis in Lung-Challenged Aged Mice
Authors: Chiu Bo-Chin , Stolberg Valerie R. , Chensue Stephen W. 
Published: April 2014

Abstract
Previously, we reported that IL-10-producing mononuclear phagocytes increase in lungs of aged mice, causing impaired innate cytokine expression. Since dendritic cells (DCs) contribute to innate NK cell and adaptive T cell immunity, we tested the hypothesis that age-related IL-10 might influence DC function with effects on NK and T cell activation. The results showed that DC recruitment to sites of lung inflammation was normal in aged mice (&gt;20 mo). However, IFN-γ-producing NK cells in LPS-challenged lungs were decreased in aged as compared with young mice, which was associated with increased IL-10+CD11b+Gr-1lowCD11c− cells consistent with mononuclear phagocytes. In vivo or in vitro blockade of IL-10 signaling restored IFN-γ-producing NK cells. This restoration was reversed by IL-12 neutralization, indicating that IL-10 suppressed sources of IL-12 in aged mice. To probe DC function in adaptive immunity, we transferred young naive OVA-specific TCR transgenic T cells to old mice. Following challenge with OVA plus LPS, Ag presentation in the context of MHC-I and MHC-II occurred with similar kinetics and intensity in draining lymph nodes of young and old recipients as measured by proliferation. Despite this, aged hosts displayed impaired induction of IFN-γ+CD4+, but not IFN-γ+CD8+, effector T cells. Blockade of IL-10 signaling reversed age-associated defects. These studies indicate that the innate IL-12/IFN-γ axis is not intrinsically defective in lungs of aged mice, but is rather suppressed by enhanced production of mononuclear phagocyte-derived IL-10. Our data identify a novel mechanism of age-associated immune deficiency.
KLRE/I1 and KLRE/I2: A Novel Pair of Heterodimeric Receptors That Inversely Regulate NK Cell Cytotoxicity
Authors: Saether Per C. , Westgaard Ingunn H. , Hoelsbrekken Sigurd E. , Benjamin Jonathan , Lanier Lewis L. , Fossum Sigbjørn , Dissen Erik 
Published: April 2014

Abstract
NK cells identify infected, neoplastic, or MHC-disparate target cells via several different receptors. The NK cell receptor KLRE1 lacks known signaling motifs but has nevertheless been shown to regulate NK cell-mediated cytotoxicity. Here we demonstrate that KLRE1 forms functional heterodimers with either KLRI1 or KLRI2. Cotransfection with KLRE1 was necessary for surface expression of the NK cell receptor chains KLRI1 and KLRI2 in 293T cells. Moreover, KLRE1 can be coimmunoprecipitated with KLRI1 or KLRI2 from transfected NK cell lines. By flow cytometry, KLRE1 and KLRI1 showed colinear expression on NK cells, suggesting surface expression as heterodimers. Unlike other killer cell lectin-like receptors, KLRE1/KLRI1 and KLRE1/KLRI2 heterodimers predominantly migrated as single chains in SDS-PAGE, indicating noncovalent association. KLRI1 was coimmunoprecipitated with the tyrosine phosphatase Src homology region 2 domain-containing phosphatase 1. In accordance with an inhibitory function, anti-HA Ab induced reduced killing of FcR-bearing targets by KLRI1-HA-transfected NK cell lines in a redirected cytotoxicity assay. Reciprocally, KLRI2-HA transfectants displayed increased killing in this assay. Finally, Ab to KLRE1 induced inhibition in KLRI1-transfected cells but increased cytotoxicity in KLRI2 transfectants, demonstrating that KLRE/I1 is a functional inhibitory heterodimer in NK cells, whereas KLRE/I2 is an activating heterodimeric receptor.
Myelin-Reactive Type B T Cells and T Cells Specific for Low-Affinity MHC-Binding Myelin Peptides Escape Tolerance in HLA-DR Transgenic Mice
Authors: Kawamura Kazuyuki , McLaughlin Katherine A. , Weissert Robert , Forsthuber Thomas G. 
Published: April 2014

Abstract
Genes of the MHC show the strongest genetic association with multiple sclerosis (MS), but the underlying mechanisms have remained unresolved. In this study, we asked whether the MS-associated MHC class II molecules, HLA-DRB1*1501, HLA-DRB5*0101, and HLA-DRB1*0401, contribute to autoimmune CNS demyelination by promoting pathogenic T cell responses to human myelin basic protein (hMBP), using three transgenic (Tg) mouse lines expressing these MHC molecules. Unexpectedly, profound T cell tolerance to the high-affinity MHC-binding hMBP82-100 epitope was observed in all Tg mouse lines. T cell tolerance to hMBP82-100 was abolished upon back-crossing the HLA-DR Tg mice to MBP-deficient mice. In contrast, T cell tolerance was incomplete for low-affinity MHC-binding hMBP epitopes. Furthermore, hMBP82-100-specific type B T cells escaped tolerance in HLA-DRB5*0101 Tg mice. Importantly, T cells specific for low-affinity MHC-binding hMBP epitopes and hMBP82-100-specific type B T cells were highly encephalitogenic. Collectively, the results show that MS-associated MHC class II molecules are highly efficient at inducing T cell tolerance to high-affinity MHC-binding epitope, whereas autoreactive T cells specific for the low-affinity MHC-binding epitopes and type B T cells can escape the induction of T cell tolerance and may promote MS.
The Relative Efficiency of Acquisition of MHC:Peptide Complexes and Cross-Presentation Depends on Dendritic Cell Type
Authors: Smyth Lesley Ann , Harker Nicola , Turnbull Wayne , El-Doueik Haytham , Klavinskis Linda , Kioussis Dimitris , Lombardi Giovanna , Lechler Robert 
Published: April 2014

Abstract
Intercellular exchange of MHC molecules has been reported between many cells, including professional and nonprofessional APCs. This phenomenon may contribute to T cell immunity to pathogens. In this study, we addressed whether the transfer of MHC class I:peptide complexes between cells plays a role in T cell responses and compare this to conventional cross-presentation. We observed that dsRNA-matured bone marrow-derived dendritic cells (BMDCs) acquired peptide:MHC complexes from other BMDCs either pulsed with OVA257–264 peptide, soluble OVA, or infected with a recombinant adenovirus expressing OVA. In addition, BMDCs were capable of acquiring MHC:peptide complexes from epithelial cells. Spleen-derived CD8α+ and CD8α− dendritic cells (DCs) also acquired MHC:peptide complexes from BMDCs pulsed with OVA257–264 peptide. However, the efficiency of acquisition by these ex vivo derived DCs is much lower than acquisition by BMDC. In all cases, the acquired MHC:peptide complexes were functional in that they induced Ag-specific CD8+ T cell proliferation. The efficiency of MHC transfer was compared with cross-presentation for splenic CD8α+ and CD8α− as well as BMDCs. CD8α+ DCs were more efficient at inducing T cell proliferation when they acquired Ag via cross-presentation, the opposite was observed for BMDCs and splenic CD8α− DCs. We conclude from these observations that the relative efficiency of MHC transfer vs cross-presentation differs markedly between different DC subsets.
Anergy in Memory CD4+ T Cells Is Induced by B Cells
Authors: Dalai Sarat K. , Mirshahidi Saied , Morrot Alexandre , Zavala Fidel , Sadegh-Nasseri Scheherazade 
Published: April 2014

Abstract
Induction of tolerance in memory T cells has profound implications in the treatment of autoimmune diseases and transplant rejection. Previously, we reported that the presentation of low densities of agonist peptide/MHC class II complexes induced anergy in memory CD4+ T cells. In the present study, we address the specific interaction of different types of APCs with memory CD4+ T cells. A novel ex vivo anergy assay first suggested that B cells induce anergy in memory T cells, and an in vivo cell transfer assay further confirmed those observations. We demonstrated that B cells pulsed with defined doses of Ag anergize memory CD4 cells in vivo. We established that CD11c+ dendritic cells do not contribute to anergy induction to CD4 memory T cells, because diphtheria toxin receptor-transgenic mice that were conditionally depleted of dendritic cells optimally induced anergy in memory CD4+ T cells. Moreover, B cell-deficient muMT mice did not induce anergy in memory T cells. We showed that B2 follicular B cells are the specific subpopulation of B cells that render memory T cells anergic. Furthermore, we present data showing that anergy in this system is mediated by CTLA-4 up-regulation on T cells. This is the first study to demonstrate formally that B cells are the APCs that induce anergy in memory CD4+ T cells.