bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of Cross-Talk between IFN-α-Induced Monocyte-Derived Dendritic Cells and NK Cells in Priming CD8+ T Cell Responses against Human Tumor Antigens
Authors: Tosi Diego , Valenti Roberta , Cova Agata , Sovena Gloria , Huber Veronica , Pilla Lorenzo , Arienti Flavio , Belardelli Filippo , Parmiani Giorgio , Rivoltini Licia 
Published: April 2014

Abstract
In the present study we evaluated the role of IFN-α in the generation of dendritic cells (IFN-DCs) with priming activity on CD8+ T lymphocytes directed against human tumor Ags. A 3-day treatment of monocytes, obtained as adherent PBMCs from HLA-A*0201+ healthy donors, with IFN-α and GM-CSF led to the differentiation of DCs displaying a semimature phenotype, but promptly inducing CD8+ T cell responses after one in vitro sensitization with peptides derived from melanoma (gp100209–217 and MART-1/Melan-A27–35) and adenocarcinoma (CEA605–613) Ags. However, these features were lost when IFN-DCs were generated from immunosorted CD14+ monocytes. The ability of adherent PBMCs to differentiate into IFN-DCs expressing higher levels of costimulatory molecules and exerting efficient T cell priming capacity was associated with the presence of contaminating NK cells, which underwent phenotypic and functional activation upon IFN-α treatment. NK cell boost appeared to be mediated by both direct and indirect (i.e., mediated by IFN-DCs) mechanisms. Experiments performed to prove the role of contaminating NK cells in DC differentiation showed that IFN-DCs generated in the absence of NK were phenotypically less mature and could not efficiently prime antitumor CD8+ lymphocytes. Reciprocally, IFN-DCs raised from immunosorted CD14+ monocytes regained their T cell priming activity when NK cells were added to the culture before IFN-α and GM-CSF treatment. Together, our data suggest that the ability of IFN-DCs to efficiently prime anti-tumor CD8+ T lymphocytes relied mostly on the positive cross-talk occurring between DCs and NK cells upon stimulation with IFN-α.
Human T Cell Activation by Costimulatory Signal-Deficient Allogeneic Cells Induces Inducible Costimulator-Expressing Anergic T Cells with Regulatory Cell Activity
Authors: Vermeiren Jan , Ceuppens Jan L. , Van Ghelue Marijke , Witters Peter , Bullens Dominique , Mages Hans Werner , Kroczek Richard A. , Van Gool Stefaan W. 
Published: April 2014

Abstract
Although immunoregulation by several types of regulatory T cells is now clearly established in mice, the demonstration of such regulatory T cells in humans has been proven more difficult. In this study we demonstrate the induction of anergic regulatory T cells during an MLR performed in the presence of blocking mAb to the costimulatory molecules CD40, CD80, and CD86. Despite this costimulation blockade, which totally blocks T cell proliferation and cytokine production, a nonproliferating T cell subpopulation was activated to express inducible costimulator (ICOS). These ICOS+ cells were anergic when restimulated with unmanipulated allogeneic stimulator cells at the level of proliferation and Th1 and Th2 cytokine production, but they did produce IL-10. These ICOS-expressing cells also blocked the capacity of reciprocal ICOS-negative cells to proliferate and to produce cytokines. ICOS+ anergic cells could suppress allogenic responses of either primed or naive T cells through inhibition of IL-2 gene transcription. Suppression was not mediated by IL-10 and did not require ICOS-ICOS ligand interaction, but depended on cell-cell contact. Thus, a subtype of regulatory T cells in human blood can be activated in the absence of costimulatory signals from CD40, CD80, and CD86, and they can be identified by expression of ICOS after activation.
Dendritic Cells Exposed to Herpes Simplex Virus In Vivo Do Not Produce IFN-α after Rechallenge with Virus In Vitro and Exhibit Decreased T Cell Alloreactivity
Authors: Björck Pia 
Published: April 2014

Abstract
Plasmacytoid dendritic cells (DC) are known to produce large amounts of IFN-α when stimulated with virus in vivo and in vitro. Immunohistological staining of spleens from mice taken at different times after HSV infection revealed an early infiltration of plasmacytoid DC whereas both the myeloid DC and lymphoid-related DC had different kinetics. Upon rechallenge with virus in vitro, total splenic DCs from viral-infected mice were unable to produce IFN-α when compared with DC from mice that received an initial in vivo injection with PBS. Furthermore, DC from mice that were infected with increasing doses of HSV expressed high levels of accessory and activation molecules compared with control mice. However, when cultured in vitro together with allogeneic T cells, DC from mice that had been exposed to the highest viral titers in vivo induced the lowest levels of T cell proliferation. DC exposed to PBS in vivo promoted a Th1 response upon coculture with CD4+ T cells whereas T cells cultured with DC exposed to increasing viral titers in vivo resulted in a gradually decreased Th1 response. The data suggest HSV induces DC maturation and at higher titers, exhaustion, diminishing T cell proliferation, and IFN-γ secretion.
Nonmyeloablative Bone Marrow Transplantation of BXSB Lupus Mice Using Fully Matched Allogeneic Donor Cells from Green Fluorescent Protein Transgenic Mice
Authors: Jones Olcay Y. , Steele Ann , Jones Joe M. , Marikar Yasmin , Chang Yenhui , Feliz Alexander , Cahill Richard A. , Good Robert A. 
Published: April 2014

Abstract
Male BXSB mice, a mouse model of systemic lupus erythematosus, were given bone marrow transplants (BMT) at 20 wk of age using MHC-matched donor cells and nonmyeloablative conditioning (550 cGy irradiation). Transplanted mice and irradiation controls were followed for a period of 20 wk. Mice transgenic for green fluorescent protein were used as donors to allow tracking of donor cells and a determination of chimerism. Radiation controls had reduced renal pathology at 10 wk posttransplant, but not at 20 wk compared with untreated mice, while nonmyeloablative BMT mice had significantly reduced pathology at both time intervals. The monocytosis characteristic of older BXSB mice was also reduced by BMT, but the treatment did not prevent production of Ab to dsDNA. A stable chimerism of 24–40% donor CD45-positive cells was achieved in spleen and bone marrow, and there was no evidence of clinical graft vs host disease. Donor cells were detected in most recipient organs, notably the thymus and renal glomeruli. The results suggest that complete depletion of mature lymphocytes or of progenitor stem cells is not required to control lupus nephritis in BXSB mice.
Helper Requirements for Generation of Effector CTL to Islet β Cell Antigens
Authors: Behrens Georg M. N. , Li Ming , Davey Gayle M. , Allison Janette , Flavell Richard A. , Carbone Francis R. , Heath William R. 
Published: April 2014

Abstract
We have dissected the helper requirements for converting a tolerogenic CD8 T cell response into one capable of causing destruction of the pancreatic islets. Injection of naive OVA-specific CD8 T cells into transgenic mice expressing OVA in the pancreas only resulted in islet destruction when activated CD4 Th cells were coinjected. This requirement for activated CD4 T cell help for induction of primary CD8 T cell-mediated immunity to tissue Ags contrasts recent reports suggesting that help is only important for CTL memory. Our findings show that signaling of CD40 on the dendritic cell presenting to CD8 T cells is important, but not sufficient, for induction of diabetes. Furthermore, once helpers are activated, they need not recognize Ag on the dendritic cells they license. This provides insight into the helper requirements for adoptive transfer immunotherapy of tumors and suggests key points for inhibition of CTL-mediated autoimmunity.
A Proline-Rich Motif in the C Terminus of Akt Contributes to Its Localization in the Immunological Synapse
Authors: Kane Lawrence P. , Mollenauer Marianne N. , Weiss Arthur 
Published: April 2014

Abstract
The serine/threonine kinases of the Akt/protein kinase B family are regulated in part by recruitment to the plasma membrane, which is accomplished by the binding of an N-terminal PH domain to the phosphatidylinositol 3-kinase products phosphoinositol 3,4,5-trisphosphate and phosphoinositol 3,4-bisphosphate. We have examined Akt localization in a murine T cell clone (D10) before and after stimulation by APC/Ag, and we found that whereas the pleckstrin homology domain is required for plasma membrane recruitment of Akt upon T cell activation, the C terminus of the kinase restricts its cellular localization to the immunologic synapse formed at the site of T cell/APC contact. A recently described proline-rich motif in this region appears to be important for proper localization of full-length Akt. Moreover, a form of Akt in which this motif was mutated acts as a potent dominant negative construct to block T cell activation. Therefore, multiple mechanisms are involved in the proper targeting of Akt during the early events of T cell activation.
Lymphocyte Activation Gene-3 (CD223) Regulates the Size of the Expanding T Cell Population Following Antigen Activation In Vivo
Authors: Workman Creg J. , Cauley Linda S. , Kim In-Jeong , Blackman Marcia A. , Woodland David L. , Vignali Dario A. A. 
Published: April 2014

AbstractLymphocyte activation gene-3 (LAG-3) is a CD4-related, activation-induced cell surface molecule that binds to MHC class II with high affinity. In this study, we used four experimental systems to reevaluate previous suggestions that LAG-3−/− mice had no T cell defect. First, LAG-3−/− T cells exhibited a delay in cell cycle arrest following in vivo stimulation with the superantigen staphylococcal enterotoxin B resulting in increased T cell expansion and splenomegaly. Second, increased T cell expansion was also observed in adoptive recipients of LAG-3−/− OT-II TCR transgenic T cells following in vivo Ag stimulation. Third, infection of LAG-3−/− mice with Sendai virus resulted in increased numbers of memory CD4+ and CD8+ T cells. Fourth, CD4+ T cells exhibited a delayed expansion in LAG-3−/− mice infected with murine gammaherpesvirus. In summary, these data suggest that LAG-3 negatively regulates T cell expansion and controls the size of the memory T cell pool.
IL-4 Protects Tumor Cells from Anti-CD95 and Chemotherapeutic Agents via Up-Regulation of Antiapoptotic Proteins
Authors: Conticello Concetta , Pedini Francesca , Zeuner Ann , Patti Mariella , Zerilli Monica , Stassi Giorgio , Messina Angelo , Peschle Cesare , De Maria Ruggero 
Published: April 2014

Abstract
We recently proposed that Th1 and Th2 cytokines exert opposite effects on the pathogenesis and clinical outcome of organ-specific autoimmunity by altering the expression of genes involved in target cell survival. Because a Th2 response against tumors is associated with poor prognosis, we investigated the ability of IL-4 to protect tumor cells from death receptor- and chemotherapy-induced apoptosis. We found that IL-4 treatment significantly reduced CD95 (Fas/APO-1)- and chemotherapeutic drug-induced apoptosis in prostate, breast, and bladder tumor cell lines. Analysis of antiapoptotic protein expression revealed that IL-4 stimulation resulted in up-regulation of cellular (c) FLIP/FLAME-1 and Bcl-xL. Exogenous expression of cFLIP/FLAME-1 inhibited apoptosis induced by CD95 and to a lesser extent by chemotherapy, while tumor cells transduced with Bcl-xL were substantially protected both from CD95 and chemotherapeutic drug stimulation. Moreover, consistent IL-4 production and high expression of both cFLIP/FLAME-1 and Bcl-xL were observed in primary prostate, breast, and bladder cancer in vivo. Finally, primary breast cancer cells acquired sensitivity to apoptosis in vitro only in the absence of IL-4. Thus, IL-4 protects tumor cells from CD95- and chemotherapy-induced apoptosis through the up-regulation of antiapoptotic proteins such as cFLIP/FLAME-1 and Bcl-xL. These findings may provide useful information for the development of therapeutic strategies aimed at restoring the functionality of apoptotic pathways in tumor cells.
Mutational Analysis of Terminal Deoxynucleotidyltransferase- Mediated N-Nucleotide Addition in V(D)J Recombination
Authors: Repasky Jamie A. E. , Corbett Elizabeth , Boboila Cristian , Schatz David G. 
Published: April 2014

Abstract
The addition of nontemplated (N) nucleotides to coding ends in V(D)J recombination is the result of the action of a unique DNA polymerase, TdT. Although N-nucleotide addition by TdT plays a critical role in the generation of a diverse repertoire of Ag receptor genes, the mechanism by which TdT acts remains unclear. We conducted a structure-function analysis of the murine TdT protein to determine the roles of individual structural motifs that have been implicated in protein-protein and protein-DNA interactions important for TdT function in vivo. This analysis demonstrates that the N-terminal portion of TdT, including the BRCA-1 C-terminal (BRCT) domain, is not required for TdT activity, although the BRCT domain clearly contributes quantitatively to N-nucleotide addition activity. The second helix-hairpin-helix domain of TdT, but not the first, is required for activity. Deletional analysis also suggested that the entire C-terminal region of TdT is necessary for N-nucleotide addition in vivo. The long isoform of TdT was found to reduce N-nucleotide addition by the short form of TdT, but did not increase nucleotide deletion from coding ends in either human or rodent nonlymphoid cells. We consider these results in light of the recently reported structure of the catalytic region of TdT.
V Region Carbohydrate and Antibody Expression
Authors: Gala Françoise A. , Morrison Sherie L. 
Published: April 2014

Abstract
N-Linked carbohydrates are frequently found in the V region of Ig H chains and can have a positive or negative effect on Ag binding affinity. We have studied a murine anti-α(1→6) dextran VH that contains a carbohydrate in complementarity-determining region 2 (CDR2). This carbohydrate remains high mannose rather than being processed to a complex form, as would be expected for glycans on exposed protein loops. We have shown that the glycan remained high mannose when murine-human chimeric Abs were produced in a variety of cell types. Also, when another carbohydrate was present in CDR1, CDR2, or CDR3 of the L chain, the VH CDR2 glycan remained high mannose. Importantly, we found that when the anti-dextran VH CDR2 replaced CDR2 of an anti-dansyl VH, the glycosylation site was used, but H chains were withheld in the endoplasmic reticulum and did not traffic to the Golgi apparatus. These results suggest that inappropriate V region glycosylation could contribute to ineffective Ab production from expressed Ig genes. In some cases, a carbohydrate addition sequence generated by either V region rearrangement or somatic hypermutation may result in an Ab that cannot be properly folded and secreted.
Cathepsin G, and Not the Asparagine-Specific Endoprotease, Controls the Processing of Myelin Basic Protein in Lysosomes from Human B Lymphocytes
Authors: Burster Timo , Beck Alexander , Tolosa Eva , Marin-Esteban Viviana , Rötzschke Olaf , Falk Kirsten , Lautwein Alfred , Reich Michael , Brandenburg Jens , Schwarz Gerold , Wiendl Heinz , Melms Arthur , Lehmann Rainer , Stevanovic Stefan , Kalbacher Hubert , Driessen Christoph 
Published: April 2014

Abstract
The asparagine-specific endoprotease (AEP) controls lysosomal processing of the potential autoantigen myelin basic protein (MBP) by human B lymphoblastoid cells, a feature implicated in the immunopathogenesis of multiple sclerosis. In this study, we demonstrate that freshly isolated human B lymphocytes lack significant AEP activity and that cleavage by AEP is dispensable for proteolytic processing of MBP in this type of cell. Instead, cathepsin (Cat) G, a serine protease that is not endogenously synthesized by B lymphocytes, is internalized from the plasma membrane and present in lysosomes from human B cells where it represents a major functional constituent of the proteolytic machinery. CatG initialized and dominated the destruction of intact MBP by B cell-derived lysosomal extracts, degrading the immunodominant MBP epitope and eliminating both its binding to MHC class II and a MBP-specific T cell response. Degradation of intact MBP by CatG was not restricted to a lysosomal environment, but was also performed by soluble CatG. Thus, the abundant protease CatG might participate in eliminating the immunodominant determinant of MBP. Internalization of exogenous CatG represents a novel mechanism of professional APC to acquire functionally dominant proteolytic activity that complements the panel of endogenous lysosomal enzymes.
Cathepsin E: A Novel Target for Regulation by Class II Transactivator
Authors: Yee Christina S. K. , Yao Yongxue , Li Ping , Klemsz Michael J. , Blum Janice S. , Chang Cheong-Hee 
Published: April 2014

Abstract
The aspartic proteinase cathepsin E (CatE) has been implicated in Ag processing. In this study we report that CatE expression is negatively regulated by the MHC class II transactivator (CIITA). CIITA-deficient murine and human B cells expressed greater CatE than wild-type B cells, whereas overexpression of CIITA in a human gastric carcinoma cell line, AGS, resulted in decreased CatE mRNA and protein. AGS cells expressing CIITA also exhibited decreased processing of OVA Ag. Inhibition of CatE expression is specific to the type III CIITA isoform and maps to the acidic and proline/serine/threonine-rich (PST) protein domains of CIITA. We found that CatE expression is inducible by PU.1 and p300, and that this induction can be reversed by CIITA. These findings demonstrate a novel phenomenon: regulation of CatE Ag processing by CIITA in an isoform-dependent manner.
Initial Stages of Mammary Tumor Virus Infection Are Superantigen Independent
Authors: Pobezinskaya Yelena , Chervonsky Alexander V. , Golovkina Tatyana V. 
Published: April 2014

Abstract
Exogenous mouse mammary tumor virus (MMTV) is transmitted via the milk from infected mothers to newborn pups. Efficient MMTV transmission is dependent on proliferation of T cells with particular TCR β-chains, which occurs upon recognition of virally encoded superantigen (SAg) bound to MHC class II molecules. It is assumed that infection of these dividing cells favors MMTV amplification. SAg is important for MMTV infection, as mice that lack SAg-cognate T cells due to expression of endogenous Mtv loci or mice that express inappropriate MHC haplotypes unable to present viral SAg efficiently were shown to be resistant to MMTV infection. However, this resistance was not absolute, as these mice developed late onset MMTV-induced mammary tumors. In this study, we show that the success of initial MMTV infection in neonates is independent of SAg function but depends on the developmentally regulated proliferation of target cells. However, SAg was absolutely required for virus spread following completion of this proliferative stage.
Immune-Deficient Drosophila melanogaster: A Model for the Innate Immune Response to Human Fungal Pathogens
Authors: Alarco Anne-Marie , Marcil Anne , Chen Jian , Suter Beat , Thomas David , Whiteway Malcolm 
Published: April 2014

Abstract
We explored the host-pathogen interactions of the human opportunistic fungus Candida albicans using Drosophila melanogaster. We established that a Drosophila strain devoid of functional Toll receptor is highly susceptible to the human pathogen C. albicans. Using this sensitive strain, we have been able to show that a set of specific C. albicans mutants of different virulence in mammalian infection models are also impaired in virulence in Drosophila and remarkably display the same rank order of virulence. This immunodeficient insect model also revealed virulence properties undetected in an immunocompetent murine model of infection. The genetic systems available in both host and pathogen will enable the identification of host-specific components and C. albicans genes involved in the host-fungal interplay.
Specific Recognition of the Viral Protein UL18 by CD85j/LIR-1/ILT2 on CD8+ T Cells Mediates the Non-MHC-Restricted Lysis of Human Cytomegalovirus-Infected Cells
Authors: Saverino Daniele , Ghiotto Fabio , Merlo Andrea , Bruno Silvia , Battini Lorenzo , Occhino Marzia , Maffei Massimo , Tenca Claudya , Pileri Stefano , Baldi Lucia , Fabbi Marina , Bachi Angela , De Santanna Amleto , Grossi Carlo E. , Ciccone Ermanno 
Published: April 2014

Abstract
Immune evasion mechanisms of human CMV are known; however, the immune control of infection remains poorly elucidated. We show that interaction between the viral protein UL18 on infected cells and the invariant receptor CD85j/LIR-1/ILT2 expressed on CTL is relevant for the control of infection. Resting and activated CD8+ T cells lysed UL18 expressing cells, whereas cells infected with CMV defective for UL18 were not killed. Lysis was not dependent on CD8+ T cell Ag specificity, MHC-unrestricted and specifically blocked by anti-CD85j and anti-UL18 mAb. Moreover, soluble recombinant UL18Fc immunoprecipitated CD85j from T cells. Activation is mediated by CD85j and its pathway is unrelated to CD3/TCR engagement. UL18 is detected in immunocompromised patients with productive infection and the mechanism used in vivo by human CMV to ensure survival of the immunocompetent host may be mediated by activation signals delivered by infected cells to T lymphocytes via UL18/CD85j interactions.
Monosodium Urate Crystals Synergize with IFN-γ to Generate Macrophage Nitric Oxide: Involvement of Extracellular Signal-Regulated Kinase 1/2 and NF-κB
Authors: Jaramillo Maritza , Naccache Paul H. , Olivier Martin 
Published: April 2014

Abstract
Elevated NO production has been detected in patients suffering from various arthropathies; however, its role and regulation during gouty arthritis remain largely unexplored. Monosodium urate (MSU) crystals, the causative agent of gout, have been shown to induce NO generation in vivo and inducible NO synthase (iNOS) expression in human monocytes. The present study was designed to evaluate the ability of MSU crystals to modulate macrophage (Mφ) iNOS expression and NO synthesis and to investigate the molecular mechanisms underlying these cellular responses. We found that MSU crystals did not induce NO production in murine J774 Mφ. However, a synergistic effect on the level of iNOS expression and NO generation was observed in cells exposed to MSU crystals in combination with IFN-γ. Characterization of the second messengers involved revealed the requirement of IFN-γ-mediated Janus kinase 2/STAT1α activation even though MSU crystals did not modulate this signaling cascade by themselves. MSU crystals exerted their up-regulating effect by increasing extracellular signal-regulated kinase (ERK) 1/2 phosphorylation and NF-κB nuclear translocation in response to IFN-γ. The use of specific inhibitors against either NF-κB or the ERK1/2 pathway significantly reduced MSU + IFN-γ-inducible NF-κB activity, iNOS expression, and NO production. Altogether, these data indicate that MSU crystals exert a potent synergistic effect on the IFN-γ-inducible Mφ NO generation via ERK1/2- and NF-κB-dependent pathways. Understanding the molecular mechanisms through which MSU crystals amplify Mφ responses to proinflammatory cytokines such as IFN-γ will contribute to better define their role in NO regulation during gout, in particular, and inflammation, in general.