bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nonclassical IL-1β Secretion Stimulated by P2X7 Receptors Is Dependent on Inflammasome Activation and Correlated with Exosome Release in Murine Macrophages
Authors: Qu Yan , Franchi Luigi , Nunez Gabriel , Dubyak George R. 
Published: April 2014

Abstract
Several mechanistically distinct models of nonclassical secretion, including exocytosis of secretory lysosomes, shedding of plasma membrane microvesicles, and direct efflux through plasma membrane transporters, have been proposed to explain the rapid export of caspase-1-processed IL-1β from monocytes/macrophages in response to activation of P2X7 receptors (P2X7R) by extracellular ATP. We compared the contribution of these mechanisms to P2X7R-stimulated IL-1β secretion in primary bone marrow-derived macrophages isolated from wild-type, P2X7R knockout, or apoptosis-associated speck-like protein containing a C-terminal CARD knockout mice. Our experiments revealed the following: 1) a novel correlation between IL-1β secretion and the release of the MHC-II membrane protein, which is a marker of plasma membranes, recycling endosomes, multivesicular bodies, and released exosomes; 2) a common and absolute requirement for inflammasome assembly and active caspase-1 in triggering the cotemporal export of IL-1β and MHC-II; and 3) mechanistic dissociation of IL-1β export from either secretory lysosome exocytosis or plasma membrane microvesicle shedding on the basis of different requirements for extracellular Ca2+ and differential sensitivity to pharmacological agents that block activation of caspase-1 inflammasomes. Thus, neither secretory lysosome exocytosis nor microvesicle shedding models constitute the major pathways for nonclassical IL-1β secretion from ATP-stimulated murine macrophages. Our findings suggest an alternative model of IL-1β release that may involve the P2X7R-induced formation of multivesicular bodies that contain exosomes with entrapped IL-1β, caspase-1, and other inflammasome components.
IFN-γ-Mediated Survival Enables Human Neutrophils to Produce MCP-1/CCL2 in Response to Activation by TLR Ligands
Authors: Yoshimura Teizo , Takahashi Munehisa 
Published: April 2014

Abstract
TLRs are key elements of the pathogen recognition mechanism used by the host immune system. Neutrophils express almost all TLRs, and activation of TLRs, such as TLR2 and TLR4, has been shown to induce the production of proinflammatory cytokines and chemokines, potentially linking innate and adaptive immunity. In the present study, we investigated whether activation of TLRs induces neutrophil production of MCP-1/CCL2, a key mediator involved in the development of adaptive immunity. Activation of neutrophils with LPS, lipoteichoic acid, or N-palmitoyl-S-[2,3-bis(palmitoyloxy)-(2RS)-propyl]-[R]-Cys-[S]-Ser-[S]-Lys did not induce significant MCP-1 production and release; however, the Th1 cytokine IFN-γ dramatically up-regulated MCP-1 production in cells activated with each TLR ligand. The majority of MCP-1 was released between 24 and 48 h of culture, indicating that this is a late event. The effect of IFN-γ appeared to be due to its antiapoptotic effect, but not priming effect, revealing a biological consequence of IFN-γ-induced neutrophil survival. Although IFN-γ failed to protect neutrophils from cell death at a higher dose of LPS, the p38 MAPK inhibitor SB203580 dramatically increased MCP-1 release and neutrophil survival at this LPS concentration. Thus, p38 MAPK plays a previously uncharacterized role in neutrophil function. Taken together, our results indicate that human neutrophils produce MCP-1 in a Th1 microenvironment and this neutrophil-derived MCP-1 potentially amplifies the development of Th1 adaptive responses.
CCR4-Expressing T Cell Tumors Can Be Specifically Controlled via Delivery of Toxins to Chemokine Receptors
Authors: Baatar Dolgor , Olkhanud Purevdorj , Newton Dianne , Sumitomo Kenya , Biragyn Arya 
Published: April 2014

Abstract
Expression of chemokine receptors by tumors, specifically CCR4 on cutaneous T cell lymphomas, is often associated with a poor disease outcome. To test the hypothesis that chemokine receptor-expressing tumors can be successfully controlled by delivering toxins through their chemokine receptors, we have generated fusion proteins designated chemotoxins: chemokines fused with toxic moieties that are nontoxic unless delivered into the cell cytosol. We demonstrate that chemokines fused with human RNase eosinophil-derived neurotoxin or with a truncated fragment of Pseudomonas exotoxin 38 are able to specifically kill tumors in vitro upon internalization through their respective chemokine receptors. Moreover, treatment with the thymus and activation-regulated chemokine (CCL17)-expressing chemotoxin efficiently eradicated CCR4-expressing cutaneous T cell lymphoma/leukemia established in NOD-SCID mice. Taken together, this work represents a novel concept that may allow control of growth and dissemination of tumors that use chemokine receptors to metastasize and circumvent immunosurveillance.
Molecular Analysis of Alloreactive CTL Post-Hemopoietic Stem Cell Transplantation
Authors: O’Keefe Christine L. , Gondek Lukasz , Davis Randall , Kuczkowski Elizabeth , Sobecks Ronald M. , Rodriguez Alexander , Narvaez Yadira , McIver Zachariah , Tuthill Ralph , Laughlin Mary , Bolwell Brian , Maciejewski Jaroslaw P. 
Published: April 2014

Abstract
The development of laboratory tests for the diagnosis and monitoring of graft-vs-host disease (GVHD) is hampered by a lack of knowledge of minor histocompatibility Ags triggering alloresponses. We hypothesized that the unique molecular structure of the TCR could be used as a marker for the unidentified Ags and exploited for molecular monitoring of GVHD posttransplant. To identify alloreactive T cell clones, we performed in vitro allostimulation cultures for a cohort of patients undergoing hemopoietic stem cell transplantation and determined the sequence of the CDR3 of immunodominant alloreactive clones; 10 corresponding clonotypes restricted to activated T cells were identified. As an alternative method for the identification of alloreactive clones, molecular TCR analysis was applied to biopsies of GVHD-affected tissues. Culture- and biopsy-derived clonotypes were used to design sequence-specific quantitative PCR assays to monitor the levels of putative allospecific clonotypes in posttransplant blood samples and subsequent biopsies. Because of the rational design of the methods used to identify immunodominant clonotypes, we were able to follow the behavior of potentially GVHD-specific T cells during the transplant course. Based on our results, we conclude that molecular T cell diagnostics can be a powerful tool for monitoring immune responses posttransplantation.
Structure and Function: Heat Shock Proteins and Adaptive Immunity
Authors: Javid Babak , MacAry Paul A. , Lehner Paul J. 
Published: April 2014

Abstract
Heat shock proteins (HSPs) have been implicated in the stimulation and generation of both innate and adaptive immunity. The ability of HSPs to bind antigenic peptides and deliver them to APCs is the basis of the generation of peptide-specific T lymphocyte responses both in vitro and in vivo. The different HSP families are genetically and biochemically unrelated, and the structural basis of peptide binding and the dynamic models of ligand interaction are known only for some of the HSPs. We examine the contribution of HSP structure to its immunological functions and the potential “immunological repertoire” of HSPs as well as the use of biophysical techniques to quantify HSP-peptide interactions and optimize vaccine design. Although biochemical evidence for HSP-mediated endogenous processing of Ag has now emerged, the issue of whether HSP-peptide complexes act as physiological sources of Ag in cross-presentation is controversial. We assess the contribution of biochemical studies in this field.
Cutting Edge: Trans-Signaling via the Soluble IL-6R Abrogates the Induction of FoxP3 in Naive CD4+CD25− T Cells
Authors: Dominitzki Sabine , Fantini Massimo C. , Neufert Clemens , Nikolaev Alexei , Galle Peter R. , Scheller Jürgen , Monteleone Giovanni , Rose-John Stefan , Neurath Markus F. , Becker Christoph 
Published: April 2014

Abstract
Chronic inflammatory diseases may develop when regulatory T cells (Tregs) fail to control the balance between tolerance and immunity. Alternatively, activated immune cells might prevent the induction or activation of Tregs in such diseases. In this study, we demonstrate that trans-signaling into T cells via the soluble IL-6 receptor completely abrogates the de novo induction of adaptive Tregs. Mechanistically, IL-6 trans-signaling augmented the expression of the TGF-β signaling inhibitor SMAD7. Consequently, SMAD7 overexpression in T cells using newly created transgenic mice rendered CD4+CD25− T cells resistant to the induction of FoxP3. Finally, IL-6 trans-signaling inhibited Treg-mediated suppression in a murine model of colitis. In summary, IL-6 trans-signaling into T cells emerges as a key pathway for blockade of the development of adaptive Tregs and thus may play a pivotal role in shifting the balance between effector and regulatory T cell numbers in chronic inflammatory and autoimmune diseases.
Cutting Edge: A Hypomorphic Mutation in Igβ (CD79b) in a Patient with Immunodeficiency and a Leaky Defect in B Cell Development
Authors: Dobbs A. Kerry , Yang Tianyu , Farmer Dana , Kager Leo , Parolini Ornella , Conley Mary Ellen 
Published: April 2014

Abstract
Although null mutations in Igα have been identified in patients with defects in B cell development, no mutations in Igβ have been reported. We recently identified a patient with a homozygous amino acid substitution in Igβ, a glycine to serine at codon 137, adjacent to the cysteine required for the disulfide bond between Igα and Igβ. This patient has a small percentage of surface IgMdim B cells in the peripheral circulation (0.08% compared with 5–20% in healthy controls). Using expression vectors in 293T cells or Jurkat T cells, we show that the mutant Igβ can form disulfide-linked complexes and bring the μ H chain to the cell surface as part of the BCR but is inefficient at both tasks. The results show that minor changes in the ability of the Igα/Igβ complex to bring the BCR to the cell surface have profound effects on B cell development.
The Adaptor Molecule CIN85 Regulates Syk Tyrosine Kinase Level by Activating the Ubiquitin-Proteasome Degradation Pathway
Authors: Peruzzi Giovanna , Molfetta Rosa , Gasparrini Francesca , Vian Laura , Morrone Stefania , Piccoli Mario , Frati Luigi , Santoni Angela , Paolini Rossella 
Published: April 2014

AbstractTriggering of mast cells and basophils by IgE and Ag initiates a cascade of biochemical events that lead to cell degranulation and the release of allergic mediators. Receptor aggregation also induces a series of biochemical events capable of limiting FcεRI-triggered signals and functional responses. Relevant to this, we have recently demonstrated that Cbl-interacting 85-kDa protein (CIN85), a multiadaptor protein mainly involved in the process of endocytosis and vesicle trafficking, regulates the Ag-dependent endocytosis of the IgE receptor, with consequent impairment of FcεRI-mediated cell degranulation. The purpose of this study was to further investigate whether CIN85 could alter the FcεRI-mediated signaling by affecting the activity and/or expression of molecules directly implicated in signal propagation. We found that CIN85 overexpression inhibits the FcεRI-induced tyrosine phosphorylation of phospholipase Cγ, thus altering calcium mobilization. This functional defect is associated with a substantial decrease of Syk protein levels, which are restored by the use of selective proteasome inhibitors, and it is mainly due to the action of the ubiquitin ligase c-Cbl. Furthermore, coimmunoprecipitation experiments demonstrate that CIN85 overexpression limits the ability of Cbl to bind suppressor of TCR signaling 1 (Sts1), a negative regulator of Cbl functions, while CIN85 knockdown favors the formation of Cbl/Sts1 complexes. Altogether, our findings support a new role for CIN85 in regulating Syk protein levels in RBL-2H3 cells through the activation of the ubiquitin-proteasome pathway and provide a mechanism for this regulation involving c-Cbl ligase activity.
Enhancement of Human Melanoma Antigen Expression by IFN-β
Authors: Dunn Ian S. , Haggerty Timothy J. , Kono Michihiro , Durda Paul J. , Butera David , Macdonald David B. , Benson Elizabeth M. , Rose Lenora B. , Kurnick James T. 
Published: April 2014

Abstract
Although many immunotherapeutic investigations have focused on improving the effector limb of the antitumor response, few studies have addressed preventing the loss of tumor-associated Ag (TAA) expression, associated with immune escape by tumors. We found that TAA loss from human melanomas usually results from reversible gene down-regulation, rather than gene deletion or mutation. Previously, we showed that inhibitors of MAPK-signaling pathways up-regulate TAA expression in melanoma cell lines. We have now identified IFN-β as an additional stimulus to TAA expression, including Melan-A/MART-1, gp100, and MAGE-A1. IFN-β (but neither IFN-α nor IFN-γ) augmented both protein and mRNA expression of melanocytic TAA in 15 melanoma lines (irrespective of initial Ag-expression levels). Treatment of low Ag melanoma lines with IFN-β increased expression of melanocyte-lineage Ags, inducing susceptibility to lysis by specific CTLs. Treatment with IFN-β also enhances expression of class I HLA molecules, thereby inducing both nominal TAA and the presenting HLA molecule. Data from fluorescent cellular reporter systems demonstrated that IFN-β triggers promoter activation, resulting in augmentation of Ag expression. In addition to enhancing TAA expression in melanomas, IFN-β also stimulated expression of the melanocytic Ag gp100 in cells of other neural crest-derived tumor lines (gliomas) and certain unrelated tumors. Because IFN-β is already approved for human clinical use in other contexts, it may prove useful as a cotreatment for augmenting tumor Ag expression during immunotherapy.
Chronic Immunodeficiency in Mice Lacking RasGRP1 Results in CD4 T Cell Immune Activation and Exhaustion
Authors: Priatel John J. , Chen Xiaoxi , Zenewicz Lauren A. , Shen Hao , Harder Kenneth W. , Horwitz Marc S. , Teh Hung-Sia 
Published: April 2014

Abstract
The Ras-guanyl nucleotide exchange factor RasGRP1 is an important link between TCR-mediated signaling and the activation of Ras and its downstream effectors. RasGRP1 is especially critical for the survival and differentiation of developing thymocytes whereas negative selection of thymocytes bearing an autoreactive TCR appears to be RasGRP1 independent. Despite apparently normal central tolerance, RasGRP1−/− mice spontaneously acquire an acutely activated and proliferating CD4 T cell population that exhibits characteristics of T cell exhaustion, including strong expression of programmed cell death-1. To elucidate the basis for RasGRP1−/− CD4 T cell immune activation, we initiated a series of adoptive transfer experiments. Remarkably, the copious amounts of cytokines and self-Ags present in hosts made lymphopenic through irradiation failed to induce the majority of RasGRP1−/− CD4 T cells to enter cell cycle. However, their infusion into either congenitally T cell- or T/B cell-deficient recipients resulted in robust proliferation and L-selectin down-regulation. These findings imply that the activation and proliferation of RasGRP1−/− CD4 T cells may be dependent on their residence in a chronically immunocompromised environment. Accordingly, bacterial and viral challenge experiments revealed that RasGRP1−/− mice possess a weakened immune system, exhibiting a T cell-autonomous defect in generating pathogen-specific T cells and delayed pathogen clearance. Collectively, our study suggests that chronic T cell immunodeficiency in RasGRP1−/− mice may be responsible for CD4 T cell activation, proliferation, and exhaustion.
Age-Dependent TCR Revision Mediated by Interaction between αβ TCR and Self-Antigens
Authors: Takase Mitsuyo , Kanagawa Edith M. , Kanagawa Osami 
Published: April 2014

Abstract
Interactions between TCR and self-peptide/MHC complex play an important role in homeostasis and Ag reactivity of mature peripheral T cells. In this report, we demonstrate that the interactions between mature peripheral T cells and endogenous Ags have a negative impact on the maintenance of foreign Ag-specific T cells in an age-dependent manner. This is mediated by RAG-dependent secondary rearrangement of the TCR α-chain (receptor revision). The TCR revision in mature T cells is readily observed in mouse expressing transgenic TCR α-chain inserted into the physiological locus (knockin mouse) but not in conventional transgenic mouse with an identical TCR α-chain. Thus, our results suggest that under physiological conditions in which all TCR α-chains are susceptible to deletion by secondary rearrangement, TCR revision in mature peripheral T cells is an ongoing process in adult animals and contributes to age-dependent changes in T cell function and repertoire.
OX40 Costimulation Promotes Persistence of Cytomegalovirus-Specific CD8 T Cells: A CD4-Dependent Mechanism
Authors: Humphreys Ian R. , Loewendorf Andrea , de Trez Carl , Schneider Kirsten , Benedict Chris A. , Munks Michael W. , Ware Carl F. , Croft Michael 
Published: April 2014

AbstractThe mechanisms that regulate CMV-specific T cell responses in vivo are poorly understood. During murine CMV infection of B6 mice, primary responses in the spleen are dominated by CD8 T cells reactive with antigenic epitopes in M45, M57, and m139 murine CMV gene products. However, during the later persistent phase of infection, CD8 T cell responses to epitopes in m139 and M38 viral gene products predominate. The basis for this shift in CD8 T populations is unknown. In this study, we demonstrate that OX40, a TNFR superfamily member, specifically regulates the accumulation of CD8 T cells reactive with the persistent-phase epitopes. Defective CD8 T cell responses in OX40−/− mice were replicated in MHC class II−/− mice implying that CD4 T cells in part controlled the differentiation of the CD8 T cell clones responsive to these epitopes during persistent infection. Furthermore, treatment of infected mice with an agonist OX40 Ab induced expansion of protective primary virus-specific CD8 T cells independent of CD4 T cell help, but CD4 T cells were crucial for anti-OX40 to promote CD8 T cells reactive to the persistent dominant epitopes. Collectively, these results indicate manipulation of OX40 may be useful in improving cellular immunotherapy regimes for treatment of persistent virus infections.
NKT Cell-Derived Urokinase-Type Plasminogen Activator Promotes Peripheral Tolerance Associated with Eye
Authors: Sonoda Koh-Hei , Nakamura Takahiko , Young Howard A. , Hart David , Carmeliet Peter , Stein-Streilein Joan 
Published: April 2014

AbstractIn a model of peripheral tolerance called anterior chamber-associated immune deviation (ACAID), the differentiation of the T regulatory cells depends on NKT cells and occurs in the spleen. In this study, we show that NKT cells that express the invariant (i) TCR and are the CD1d-reactive NKT cells (required for development of peripheral tolerance) actually produced urokinase-type plasminogen activator (uPA) during tolerance induction. The RT-PCR and in vitro plasmin assay showed that splenic iNKT cells derived uPA-converted plasminogen to plasmin. Moreover, uPA was required for tolerance induction because uPA knockout (KO) mice did not develop peripheral tolerance or develop CD8+ T regulatory cells after Ag inoculation into the anterior chamber. In contrast, other aspects of ACAID-induced tolerance, including recruitment of iNKT cells to the spleen and production of IL-10 by iNKT cells, were unchanged in uPA-deficient mice. The adoptive transfer of splenic NKT cells from wild-type mice restored ACAID in Jα18 KO mice (iNKT cell deficient), but NKT cells from uPA KO mice did not. We postulate that the mechanism of action of uPA is through its binding to the uPAR receptor, and enzymatic cleavage of plasminogen to plasmin, which in turn activates latent TGFβ. In conclusion, uPA derived from iNKT cells is required to induce peripheral tolerance via the eye.
TCR Affinity Promotes CD8+ T Cell Expansion by Regulating Survival
Authors: Hommel Mirja , Hodgkin Philip D. 
Published: April 2014

AbstractLigation with high affinity ligands are known to induce T lymphocytes to become fully activated effector cells while ligation with low affinity ligands (or partial agonists) may result in a delayed or incomplete response. We have examined the quantitative features of CD8+ T cell proliferation induced by peptides of different TCR affinities at a range of concentrations in the mouse OT-I model. Both the frequency of cells responding and the average time taken for cells to reach their first division are affected by peptide concentration and affinity. Consecutive division times, however, remained largely unaffected by these variables. Importantly, we identified affinity to be the sole regulator of cell death in subsequent division. These results suggest a mechanism whereby TCR affinity detection can modulate the subsequent rate of T cell growth and ensure the dominance of higher affinity clones over time.
Despite Increased CD4+Foxp3+ Cells within the Infection Site, BALB/c IL-4 Receptor-Deficient Mice Reveal CD4+Foxp3-Negative T Cells as a Source of IL-10 inLeishmania majorSusceptibility
Authors: Nagase Hisashi , Jones Kathryn M. , Anderson Charles F. , Noben-Trauth Nancy 
Published: April 2014

AbstractBALB/c IL-4Rα−/− mice, despite the absence of IL-4/IL-13 signaling and potent Th2 responses, remain highly susceptible to Leishmania major substain LV39 due exclusively to residual levels of IL-10. To address the contribution of CD4+CD25+ T regulatory (Treg) cells to IL-10-mediated susceptibility, we depleted CD4+CD25+ cells in vivo and reconstituted IL-4Rα × RAG2 recipients with purified CD4+CD25− T cells. Although anti-CD25 mAb treatment significantly decreased parasite numbers in IL-4Rα−/− mice, treatment with anti-IL-10R mAb virtually eliminated L. major parasites in both footpad and dermal infection sites. In addition, IL-4Rα × RAG2 mice reconstituted with CD4+ cells depleted of CD25+ Treg cells remained highly susceptible to infection. Analysis of L. major-infected BALB/c and IL-4Rα−/− inflammatory sites revealed that the majority of IL-10 was secreted by the CD4+Foxp3− population, with a fraction of IL-10 coming from CD4+Foxp3+ Treg cells. All T cell IFN-γ production was also derived from the CD4+Foxp3− population. Nevertheless, the IL-4Rα−/−-infected ear dermis, but not draining lymph nodes, consistently displayed 1.5- to 2-fold greater percentages of CD4+CD25+ and CD4+Foxp3+ Treg cells compared with the BALB/c-infected dermis. Thus, CD4+Foxp3− T cells are a major source of IL-10 that disrupts IFN-γ activity in L. major-susceptible BALB/c mice. However, the increase in CD4+Foxp3+ T cells within the IL-4Rα−/− dermis implies a possible IL-10-independent role for Treg cells within the infection site, and may indicate a novel immune escape mechanism used by L. major parasites in the absence of IL-4/IL-13 signaling.