bluuebunny/crossref_metadata_2025_split huggingface dataset:
Myelin-Associated Oligodendrocytic Basic Protein: Identification of an Encephalitogenic Epitope and Association with Multiple Sclerosis
Authors: Holz Andreas , Bielekova Bibiana , Martin Roland , Oldstone Michael B. A. 
Published: April 2014

Abstract
Myelin-associated oligodendrocytic basic protein (MOBP) is an abundant myelin constituent expressed exclusively by oligodendrocytes, the myelin-forming cells of the CNS. We report that MOBP causes experimental allergic encephalomyelitis and is associated with multiple sclerosis. First, we note that purified recombinant MOBP inoculated into SJL/J mice produces CNS disease. Tests of overlapping peptides spanning the murine MOBP molecule map the encephalitogenic site to amino acids 37–60. MOBP-induced experimental allergic encephalomyelitis shows a severe clinical course and is characterized by a prominent CD4+ T lymphocyte infiltration and a lesser presence of CD8+ T cells and microglia/macrophages around vessels and in the white matter of the CNS. Second, PBL obtained from patients with relapsing/remitting multiple sclerosis mount a proliferative response to human MOBP, especially at amino acids 21–39. This response equals or exceeds the response to myelin basic protein and an influenza virus hemagglutinin peptide, both serving as internal controls. Thus, a novel myelin Ag, MOBP aa 37–60, plays a role in rodent autoimmune CNS disease, and its human MOBP counterpart is associated with the human demyelinating disease multiple sclerosis.
Rheumatoid Arthritis Synovial Stromal Cells Inhibit Apoptosis and Up-Regulate Bcl-xL Expression by B Cells in a CD49/CD29-CD106-Dependent Mechanism
Authors: Hayashida Kenji , Shimaoka Yasunori , Ochi Takahiro , Lipsky Peter E 
Published: April 2014

AbstractInflammatory sites, such as rheumatoid arthritis (RA) synovial tissue, contain large numbers of activated B cells and plasma cells. However, the mechanisms maintaining B cell viability and promoting their differentiation are not known, but interactions with stromal cells may play a role. To examine this, purified human peripheral B cells were cultured with a stromal cell line (SCL) derived from RA synovial tissue, and the effects on apoptosis and expression of Bcl-2-related proteins were analyzed. As a control, B cells were also cultured with SCL from osteoarthritis synovium or skin fibroblasts. B cells cultured with medium alone underwent spontaneous apoptosis. However, B cells cultured with RA SCL cells exhibited less apoptosis and greater viability. Although SCL from osteoarthritis synovium and skin fibroblasts also rescued B cells from apoptosis, they were less effective than RA SCL. B cell expression of Bcl-xL was markedly increased by RA SCL in a contact-dependent manner, whereas B cell expression of Bcl-2 was unaffected. Protection of B cells from apoptosis and up-regulation of Bcl-xL by RA SCL were both blocked by mAbs to CD106 (VCAM-1), but not CD54 (ICAM-1). Furthermore, cross-linking of CD49d/CD29 (very late Ag-4) on the surface of B cells rescued them from apoptosis and up-regulated Bcl-xL expression. These results indicate that SCL derived from RA synovial tissue play a role in promoting B cell survival by inducing Bcl-xL expression and blocking B cell apoptosis in a CD49d/CD29-CD106-dependent manner.
Therapeutic Potential of Phosphodiesterase-4 and -3 Inhibitors in Th1-Mediated Autoimmune Diseases
Authors: Bielekova Bibiana , Lincoln Anne , McFarland Henry , Martin Roland 
Published: April 2014

Abstract
Phosphodiesterase-4 (PDE4) inhibitors have the potential to modulate immune responses from the Th1 toward the Th2 phenotype and are considered candidate therapies for Th1-mediated autoimmune disorders. However, depending on the model and cell types employed, studies of atopic individuals have come to the opposite conclusion, i.e., that PDE inhibitors may be beneficial in asthma. Using in vitro immunopharmacologic techniques we analyzed the effects of PDE4 and PDE3 inhibitors on human immune cells to address these discrepancies and broaden our understanding of their mechanism of action. Our results indicate that PDE inhibitors have complex inhibitory effects within in vivo achievable concentration ranges on Th1-mediated immunity, whereas Th2-mediated responses are mostly unaffected or enhanced. The Th2 skewing of the developing immune response is explained by the effects of PDE inhibitors on several factors contributing to T cell priming: the cytokine milieu; the type of costimulatory signal, i.e., up-regulation of CD86 and down-regulation of CD80; and the Ag avidity. The combination of PDE4 and PDE3 inhibitors expresses synergistic effects and may broaden the therapeutic window. Finally, we observed a differential sensitivity to PDE inhibition in autoreactive vs foreign Ag-specific T cells and cells derived from multiple sclerosis patients vs those derived from healthy donors. This suggests that PDE inhibition weakens the strength of the T cell stimulus and corrects the underlying disease-associated cytokine skew in T cell-mediated autoimmune disorders. These new findings broaden the understanding of the immunomodulatory actions of PDE inhibitors and underscore their promising drug profile for the treatment of autoimmune disorders.
Induction of Potent Antitumor CTL Responses by Recombinant Vaccinia Encoding a Melan-A Peptide Analogue
Authors: Valmori Danila , Lévy Frederic , Miconnet Isabelle , Zajac Paul , Spagnoli Giulio C. , Rimoldi Donata , Liénard Danielle , Cerundolo Vincenzo , Cerottini Jean-Charles , Romero Pedro 
Published: April 2014

AbstractThere is considerable interest in the development of vaccination strategies that would elicit strong tumor-specific CTL responses in cancer patients. One strategy consists of using recombinant viruses encoding amino acid sequences corresponding to natural CTL-defined peptide from tumor Ags as immunogens. However, studies with synthetic tumor antigenic peptides have demonstrated that introduction of single amino acid substitutions may dramatically increase their immunogenicity. In this study we have used a well-defined human melanoma tumor Ag system to test the possibility of translating the immunological potency of synthetic tumor antigenic peptide analogues into recombinant vaccinia viruses carrying constructs with the appropriate nucleotide substitutions. Our results indicate that the use of a mutated minigene construct directing the expression of a modified melanoma tumor Ag leads to improved Ag recognition and, more importantly, to enhanced immunogenicity. Thus, recombinant vaccinia viruses containing mutated minigene sequences may lead to new strategies for the induction of strong tumor-specific CTL responses in cancer patients.
Cutting Edge: Cationic Antimicrobial Peptides Block the Binding of Lipopolysaccharide (LPS) to LPS Binding Protein
Authors: Scott Monisha G. , Vreugdenhil Anita C. E. , Buurman Wim A. , Hancock Robert E. W. , Gold Michael R. 
Published: April 2014

Abstract
We investigated the mechanism by which cationic antimicrobial peptides block the activation of macrophages by LPS. The initial step in LPS signaling is the transfer of LPS to CD14 by LPS binding protein (LBP). Because many cationic antimicrobial peptides bind LPS, we asked whether these peptides block the binding of LPS to LBP. Using an assay that measures the binding of LPS to immobilized LBP, we show for the first time that a variety of structurally diverse cationic antimicrobial peptides block the interaction of LPS with LBP. The relative ability of different cationic peptides to block the binding of LPS to LBP correlated with their ability to block LPS-induced TNF-α production by the RAW 264.7 macrophage cell line.
Cutting Edge: Preferentially the R-Stereoisomer of the Mycoplasmal Lipopeptide Macrophage-Activating Lipopeptide-2 Activates Immune Cells Through a Toll-Like Receptor 2- and MyD88-Dependent Signaling Pathway
Authors: Takeuchi Osamu , Kaufmann Andreas , Grote Karsten , Kawai Taro , Hoshino Katsuaki , Morr Michael , Mühlradt Peter F. , Akira Shizuo 
Published: April 2014

Abstract
Mycoplasmas and their membranes are potent activators of macrophages, the active principle being lipoproteins and lipopeptides. Two stereoisomers of the mycoplasmal lipopeptide macrophage-activating lipopeptide-2 (MALP-2) differing in the configuration of the lipid moiety were synthesized and compared in their macrophage-activating potential, the R-MALP being &gt;100 times more active than the S-MALP in stimulating the release of cytokines, chemokines, and NO. To assess the role of the Toll-like receptor (TLR) family in mycoplasmal lipopeptide signaling, the MALP-2-mediated responses were analyzed using macrophages from wild-type, TLR2-, TLR4-, and MyD88-deficient mice. TLR2- and MyD88-deficient cells showed severely impaired cytokine productions in response to R- and S-MALP. The MALP-induced activation of intracellular signaling molecules was fully dependent on both TLR2 and MyD88. There was a strong preference for the R-MALP in the recognition by its functional receptor, TLR2.
Cutting Edge: Heat Shock Protein 60 Is a Putative Endogenous Ligand of the Toll-Like Receptor-4 Complex
Authors: Ohashi Koji , Burkart Volker , Flohé Stefanie , Kolb Hubert 
Published: April 2014

Abstract
Human heat shock protein 60 (hsp60) elicits a potent proinflammatory response in cells of the innate immune system and therefore has been proposed as a danger signal of stressed or damaged cells. We report here that macrophages of C3H/HeJ mice, carrying a mutant Toll-like-receptor (Tlr) 4 are nonresponsive to hsp60. Both the induction of TNF-α and NO formation were found dependent on a functional Tlr4 whereas stimulation of macrophages by CpG DNA was Tlr4 independent. We conclude that Tlr4 mediates hsp60 signaling. This is the first report of a putative endogenous ligand of the Tlr4 complex.
Cutting Edge: CD4+ T Cell Control of CD8+ T Cell Reactivity to a Model Tumor Antigen
Authors: Surman Deborah R. , Dudley Mark E. , Overwijk Willem W. , Restifo Nicholas P. 
Published: April 2014

Abstract
Neoantigens resulting from the inherent genomic instability of tumor cells generally do not trigger immune recognition. Similarly, transfection of tumors with model Ags often fails to elicit CD8+ T cell responses or alter a tumor’s growth rate or lethality. We report here that the adoptive transfer of activated Th1-type CD4+ T cells specific for a model tumor Ag results in the de novo generation of CD8+ T cells with specificity to that Ag and concomitant tumor destruction. The anti-tumor effects of the CD4+ T cells required the presence of both MHC class I and class II on host cells, as evidenced by experiments in knockout mice, suggesting that CD4+ T cells enhanced the ability of host APC to activate endogenous CD8+ T cells. These results indicate that the apparent inability of tumor cells expressing highly immunogenic epitopes to activate tumor-specific CD8+ T cells can be altered by activated CD4+ T cells.
IFN-α-Expressing Tumor Cells Enhance Generation and Promote Survival of Tumor-Specific CTLs
Authors: Hiroishi Kazumasa , Tüting Thomas , Lotze Michael T. 
Published: April 2014

Abstract
IFN-α gene therapy has been successfully applied in several tumor models. Our studies involving the murine colorectal adenocarcinoma cell line MC38 confirm that IFN-α transduction of a poorly immunogenic tumor cell reduces tumorigenicity and leads to long-lasting tumor immunity. To investigate the effect of IFN-α transduction on the development of antitumor immune responses, we restimulated splenocytes from MC38-immune mice in vitro. Detection of MC38-specific cytotoxicity was markedly enhanced when murine IFN-α2-transduced MC38 (MC38-IFNα) or CD80-transduced MC38 (MC38-CD80) was used for restimulation compared with wild type (MC38-WT) or neomycin resistance gene-transduced MC38 (MC38-Neo) cells. MC38-specific CD8+ CTL line and clone were established from splenocytes of mouse immunized with MC38-IFNα. Stimulation with MC38-IFNα as well as MC38-CD80 enhanced the proliferation of MC38-specific CTLs in vitro much more effectively than stimulation with WT or MC38-Neo (p &lt; 0.05). Coincubation of MC38-specific CTLs with MC38-IFNα or MC38-CD80 resulted in significantly less DNA fragmentation (8.0% and 12.8%, respectively) compared with coincubation of the CTLs with MC38-WT (43.5%; p &lt; 0.001) or MC38-Neo cells (38.1%; p &lt; 0.003). These results suggest that prevention of apoptotic cell death in tumor-specific CTLs may be one mechanism by which IFN-α-expressing tumor cells can promote the generation of antitumor immunity. The effect of IFN-α on CTLs appears to be similar to that of CD80, which also prevents apoptotic cell death after stimulation of T lymphocytes.
Presentation of IFN-γ to Nitric Oxide-Producing Cells: A Novel Function for Mast Cells
Authors: Brooks Bernadette , Briggs David M. , Eastmond Nigel C. , Fernig David G. , Coleman John W. 
Published: April 2014

AbstractWe report that mast cells can bind and present IFN-γ in a functionally active form to macrophages. Flow-cytometric analysis revealed that biotinylated IFN-γ bound equally well to purified peritoneal mast cells from both IFN-γR knockout and wild-type mice, indicating a non-IFN-γR binding site. Purified peritoneal mast cells, loaded with IFN-γ for 30 min and washed, were able to induce NO synthesis by peritoneal macrophages. This response required cell contact and expression of IFN-γR on the responding macrophages, but not the mast cells. Human HMC-1 mast cells were also able to present IFN-γ to mouse macrophages. Enzyme treatment of mouse mast cells revealed that binding of IFN-γ was predominantly to chondroitin sulfate B (dermatan sulfate). Binding of IFN-γ to dermatan sulfate was confirmed by inhibition ELISA. This study demonstrates for the first time that mast cells can present IFN-γ to other cells via glycosaminoglycans. Mast cells may act as a reservoir of surface-stored functionally active cytokines.
Modulation of Th2 Responses by Peptide Analogues in a Murine Model of Allergic Asthma: Amelioration or Deterioration of the Disease Process Depends on the Th1 or Th2 Skewing Characteristics of the Therapeutic Peptide
Authors: Janssen Edith M. , van Oosterhout Antoon J. M. , van Rensen Annemiek J. M. L. , van Eden Willem , Nijkamp Frans P. , Wauben Marca H. M. 
Published: April 2014

Abstract
Allergen-specific CD4+ Th2 cells play an important role in the immunological processes of allergic asthma. Previously we have shown that, by using the immunodominant epitope OVA323–339, peptide immunotherapy in a murine model of OVA induced allergic asthma, stimulated OVA-specific Th2 cells, and deteriorated airway hyperresponsiveness and eosinophilia. In the present study, we defined four modulatory peptide analogues of OVA323–339 with comparable MHC class II binding affinity. These peptide analogues were used for immunotherapy by s.c. injection in OVA-sensitized mice before OVA challenge. Compared with vehicle-treated mice, treatment with the Th2-skewing wild-type peptide and a Th2-skewing partial agonistic peptide (335N-A) dramatically increased airway eosinophilia upon OVA challenge. In contrast, treatment with a Th1-skewing peptide analogue (336E-A) resulted in a significant decrease in airway eosinophilia and OVA-specific IL-4 and IL-5 production. Our data show for the first time that a Th1-skewing peptide analogue of a dominant allergen epitope can modulate allergen-specific Th2 effector cells in an allergic response in vivo. Furthermore, these data suggest that the use of Th1-skewing peptides instead of wild-type peptide may improve peptide immunotherapy and may contribute to the development of a successful and safe immunotherapy for allergic patients.
HIV-1 gp120 Induces IL-4 and IL-13 Release from Human FcεRI+ Cells Through Interaction with the VH3 Region of IgE
Authors: Patella Vincenzo , Florio Giovanni , Petraroli Angelica , Marone Gianni 
Published: April 2014

Abstract
HIV-1 glycoprotein (gp) 120 from different clades is a potent stimulus for IL-4 and IL-13 release from basophils purified from healthy individuals seronegative for Abs to HIV-1 and HIV-2. IL-4 mRNA, constitutively present in basophils, was increased after stimulation by gp120 and was inhibited cyclosporin A and tacrolimus. IL-4 and IL-13 secretion from basophils activated by gp120 was not correlated. There was a correlation between the maximum gp120- and anti-IgE-induced IL-4 release from basophils. The average t1/2 gp120-induced IL-4 release was lower than for IL-13 release. Basophils from which IgE had been dissociated by brief exposure to lactic acid no longer released IL-4 in response to gp120 or to anti-IgE. The response to a mAb cross-linking the α-chain of high-affinity receptor for IgE (FcεRI) was unaffected by this treatment. Three human VH3+ monoclonal IgM inhibited gp120-induced secretion of IL-4 from basophils. In contrast, VH6+ monoclonal IgM did not inhibit the release of IL-4 induced by gp120. Synthetic peptides distant from the NH2 and COOH termini of gp120MN inhibited the activating property of gp120MN. These results indicate that gp120, which acts as a viral superantigen, interacts with the VH3 region of IgE to induce the release of IL-4 and IL-13 from human FcεRI+ cells.
The Use of HLA A2.1/p53 Peptide Tetramers to Visualize the Impact of Self Tolerance on the TCR Repertoire
Authors: Hernández Javier , Lee Peter P. , Davis Mark M. , Sherman Linda A. 
Published: April 2014

Abstractp53 is an attractive target for cancer immunotherapy since it is overexpressed in half of all tumors. However, it is also expressed in normal lymphoid tissue, and self tolerance leaves a p53-specific repertoire purged of high avidity CTL. To better understand the mechanism of tolerance and the basis for such low avidity interaction, p53-specific CTL from p53 deficient (p53−) and sufficient (p53+) A2.1/Kb transgenic mice were compared with respect to their ability to bind HLA-A2.1 tetramers containing cognate murine p53 peptide Ag, p53 261–269. Since the murine CD8 molecule cannot interact with human HLA-A2.1, this tests the ability of the TCR to bind the A2.1/peptide complex tetramer. CTL from p53− mice demonstrated strong binding of such A2.1/p53 261–269 tetramers; however, the CTL from tolerant p53+ mice were devoid of tetramer-binding CD8+ T cells. Examination of TCR expression at the clonal level revealed that CTL from p53+ and p53− mice each expressed comparable levels of the p53-specific TCR. These results indicate that normal expression of p53 promotes elimination of T cells expressing TCRs with sufficient affinity to achieve stable binding of the A2.1/p53 261–269 tetramers.
Interaction of Ly-49D+ NK Cells with H-2Dd Target Cells Leads to Dap-12 Phosphorylation and IFN-γ Secretion
Authors: Mason Llewellyn H. , Willette-Brown Jamie , Mason Anna T. , McVicar Daniel , Ortaldo John R. 
Published: April 2014

AbstractMurine Ly-49D augments NK cell function upon recognition of target cells expressing H-2Dd. Ly-49D activation is mediated by the immunoreceptor tyrosine-based activation motif-containing signaling moiety Dap-12. In this report we demonstrate that Ly-49D receptor ligation can lead to the rapid and potent secretion of IFN-γ. Cytokine secretion can be induced from Ly-49D+ NK cells after receptor ligation with Ab or after interaction with target cells expressing their H-2Dd ligand. Consistent with the dominant inhibitory function of Ly-49G, NK cells coexpressing Ly-49D and Ly-49G show a profound reduction in IFN-γ secretion after interaction with targets expressing their common ligand, H-2Dd. Importantly, we are able to demonstrate for the first time that effector/target cell interactions using Ly-49D+ NK cells and H-2Dd targets result in the rapid phosphorylation of Dap-12. However, Dap-12 is not phosphorylated when Ly-49D+ NK cells coexpress the inhibitory receptor, Ly-49G. These studies are novel in describing Ly-49 activation vs inhibition, where two Ly-49 receptors recognize the same class I ligand, with the dominant inhibitory receptor down-regulating phosphorylation of Dap-12, cytokine secretion, and cytotoxicity in NK cells.
Analysis of the Requirements for the Induction of CD4+ T Cell Alloantigen Hyporesponsiveness by Ex Vivo Anti-CD40 Ligand Antibody
Authors: Taylor Patricia A. , Panoskaltsis-Mortari Angela , Noelle Randolph J. , Blazar Bruce R. 
Published: April 2014

Abstract
A major goal of the transplant field is to selectively tolerize only those donor T cells recognizing host alloantigen and mediating graft-vs-host disease (GVHD). Recently, we described an ex vivo approach in which the blockade of the CD40 ligand (CD40L):CD40 costimulatory pathway in bulk MLR cultures induces donor CD4+ T cells to become specifically tolerant to MHC class II-disparate alloantigenic-bearing stimulators, resulting in a profound reduction in GVHD generation in vivo. In studies presented in this work, we investigated the ex vivo requirements for tolerance induction. We found that CD4+ T cells become profoundly more hyporesponsive to alloantigen restimulation with prolonged culture duration such that 7 to 10 but not 4 days is needed to achieve maximum alloantigen hyporesponsiveness as assessed in secondary MLR cultures and GVHD generation. By day 7, both primed and tolerized cells had substantially increased blastogenesis and CD25 expression. Primed but not tolerized cells substantially down-regulated L-selectin expression, indicating that the tolerized cells do not become fully Ag experienced. Both Th1 and Th2 cytokine production is severely impaired by CD40L:CD40 blockade. Analysis of culture supernatants and results from IL-4 and IL-10 knockout mice indicated that GVHD prevention was not mediated by a skewing toward a Th2 phenotype. The addition of IL-4 to the cultures as a survival factor precluded the induction of tolerance in the anti-CD40L-cultured cells. These data provide further impetus for the ex vivo use of anti-CD40L mAb to block GVHD generation.
Characterization of the Roles of TNF Receptor-Associated Factor 6 in CD40-Mediated B Lymphocyte Effector Functions
Authors: Jalukar Sangita V. , Hostager Bruce S. , Bishop Gail A. 
Published: April 2014

Abstract
Signaling through CD40 in B cells leads to B cell proliferation, Ig and IL-6 secretion, isotype switching, and up-regulation of surface molecules. TNF receptor-associated factor (TRAF) proteins associate with the cytoplasmic tail of CD40 and act as adapter molecules. Of the six TRAFs identified to date, TRAFs 2, 3, 5, and 6 are reported to associate directly with the cytoplasmic tail of CD40, but previous studies have principally examined transient overexpression of TRAF6 in cells that do not normally express CD40. Thus, we examined the role of TRAF6 in CD40-mediated B lymphocyte effector functions using two approaches. We produced and stably expressed in mouse B cell lines a human CD40 molecule with two cytoplasmic domain point mutations (hCD40EEAA); this mutant fails to bind TRAF6, while showing normal association with TRAFs 2 and 3. We also inducibly expressed in B cells a transfected “dominant-negative” TRAF6 molecule which contains only the C-terminal TRAF-binding domain of TRAF6. Using both molecules, we found that TRAF6 association with CD40 is important for CD40-induced IL-6 and Ig secretion, and that TRAF6 mediates its effects on CD40-stimulated Ig secretion principally through its effects on IL-6 production by the B cell. TRAF6 association with CD40 was also found to be important for B7-1 up-regulation, but not for up-regulation of other surface molecules. Interestingly, however, although we could show TRAF6-dependent CD40-mediated activation of NF-κB in 293 kidney epithelial cells, no such effect was seen in B cells, suggesting that TRAF6 has cell-type-specific functions.