bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of Epitope Regions Recognized by Tumor Inhibitory and Stimulatory Anti-ErbB-2 Monoclonal Antibodies: Implications for Vaccine Design
Authors: Yip Yum L. , Smith Glenn , Koch Joachim , Dübel Stefan , Ward Robyn L. 
Published: April 2014

Abstract
The self-oncoprotein ErbB-2 is overexpressed in a number of malignancies. The presence of endogenous anti-ErbB-2 Ab and T cell immune responses to this protein in cancer patients has made ErbB-2 an attractive target for active immunization. However, the finding that murine anti-ErbB-2 Abs can have stimulatory, inhibitory, or no effects on cancer cell growth suggests that an inappropriately induced immune response may have an adverse effect. To ensure the induction of a beneficial Ab response, it is important to identify the epitopes recognized by these Abs. In this study we have used phage-displayed ErbB-2 gene fragment libraries and synthetic peptides to epitope-map a panel of anti-ErbB-2 mAbs. The epitopes of three mAbs, N12, N28, and L87, were successfully located to C531-A586, T216-C235, and C220-C235 of ErbB-2, respectively. It was found that while N12 inhibited tumor cell proliferation, N28 stimulated the proliferation of a subset of breast cancer cell lines overexpressing ErbB-2. The peptide region recognized by N12, (C531-A586; EP531), was used as an immunogen to selectively induce an inhibitory immune response in mice. Mice immunized with the GST fusion peptide (GST-EP531) recognized the peptide region EP531 as well as native ErbB-2. More importantly, Igs purified from mouse sera were able to inhibit up to 85% of tumor cell proliferation. In conclusion, our study provides direct evidence of the function-epitope relationship of anti-ErbB-2 Abs and also emphasizes the value of inducing a potent tumor inhibitory polyclonal Ab response by rationally selecting regions of ErbB-2 used for immunization.
Molecular Mimicry in Lyme Arthritis Demonstrated at the Single Cell Level: LFA-1αL Is a Partial Agonist for Outer Surface Protein A-Reactive T Cells
Authors: Trollmo Christina , Meyer Abbie L. , Steere Allen C. , Hafler David A. , Huber Brigitte T. 
Published: April 2014

AbstractAntibiotic treatment-resistant Lyme arthritis is a chronic inflammatory joint disease that follows infection with Borrelia burgdorferi (Bb). A marked Ab and T cell response to Bb outer surface protein A (OspA) often develops during prolonged episodes of arthritis. Furthermore, cross-reaction between the bacterial OspA and human LFA-1αL at the T cell level and the inability to detect Bb in the joint implicate an autoimmune mechanism. To analyze the nature of response to OspA and LFA-1αL, we used OspA-specific T cell hybrids from DR4 transgenic mice, as well as cloned human cells specific for OspA165–184, the immunodominant epitope, from five DRB1*0401+ patients, using OspA-MHC class II tetramers. Although OspA165–184 stimulated nearly all OspA-specific human T cell clones tested to proliferate and secrete IFN-γ and IL-13, LFA-1αL326–345 stimulated ∼10% of these clones to proliferate and a greater percentage to secrete IL-13. Assays with LFA- or OspA-DR4 monomers revealed that higher concentrations of LFA-DR4 were needed to stimulate dual-reactive T cell hybrids. Our analysis at the clonal level demonstrates that human LFA-1αL326–345 behaves as a partial agonist, perhaps playing a role in perpetuating symptoms of arthritis.
Oral Exposure to Alloantigen Generates Intragraft CD8+ Regulatory Cells
Authors: Zhou Juan , Carr Ronald I. , Liwski Robert S. , Stadnyk Andrew W. , G. Lee Timothy D. 
Published: April 2014

Abstract
We have previously reported that oral administration of allogeneic rat spleen cells before kidney allotransplantation significantly prolongs graft survival. This prolongation was alloantigen specific and was associated with a decrease in graft-infiltrating cells (GIC) and an increase in transcription of IL-4 mRNA in the GIC. In this study increased splenic mixed lymphocyte responses from animals orally exposed to alloantigen before kidney transplantation suggested that the kidney allograft prolongation was not due to a masking of allorecognition, but to an immunomodulation of the immune response. We have assessed GIC T cell subsets on day 5 post-transplant and found decreased numbers of CD4+ T cells in fed animals compared with controls, but there was no change in CD8+ T cell numbers. The CD8+ GIC from fed animals transcribed substantial levels of perforin, granzyme, and Fas ligand mRNA, indicating the presence of active CTL. Direct CTL assays showed that the GIC from fed recipients exhibited higher allo-CTL activity than GIC from control unfed recipients. In addition, the CD8+ GIC exhibited high levels of IL-4 mRNA, suggesting Tc2-type regulatory cells. Prolonged graft survival in the face of active CTL and Tc2 cells suggests the presence of a CD8+ regulatory cell population in the allograft. To confirm this, cell transfer experiments were performed. Prolongation of graft survival was transferred from rats orally exposed to alloantigen to naive animals by transfer of CD8+ GIC. This is the first report that oral exposure to alloantigen prolongs kidney allograft survival by the generation of intragraft CD8+ regulatory cells.
Antibody-Induced Shedding of CD44 from Adherent Cells Is Linked to the Assembly of the Cytoskeleton
Authors: Shi Mei , Dennis Kathryn , Peschon Jacques J. , Chandrasekaran Raman , Mikecz Katalin 
Published: April 2014

Abstract
CD44 is a widely expressed integral membrane glycoprotein that serves as a specific adhesion receptor for the extracellular matrix glycosaminoglycan hyaluronan. CD44 participates in a variety of physiological and pathological processes through its role in cell adhesion. Under appropriate conditions, the ectodomain of CD44 is proteolytically removed from the cell surface. In this study we show that excessive CD44 shedding can be induced in mouse fibroblasts and monocytes upon exposure of these cells to a CD44-specific Ab immobilized on plastic, whereas treatment with phorbol ester induces significantly enhanced CD44 release from the monocytes only. CD44 shedding proceeds normally in fibroblasts and monocytes deficient in TNF-α converting enzyme (TACE), a sheddase involved in the processing of several substrates. Conversely, activation of the CD44 protease has no effect on the release of TNF-α from TACE-expressing cells, although the same metalloprotease inhibitor effectively blocks both TACE and the CD44 sheddase. Concomitant with anti-CD44 Ab- or phorbol ester-induced CD44 shedding, dramatic changes are observed in cell morphology and the structure of the actin cytoskeleton. Disruption of actin assembly with cytochalasin reduces CD44 shedding, but not the release of TNF-α. Moreover, pharmacological activation of Rho family GTPases Rac1 and Cdc42, which regulate actin filament assembly into distinct cytoskeletal structures, has a profound effect on CD44 release. We conclude that the CD44 sheddase and TACE are distinct enzymes, and that Ab- and phorbol ester-enhanced cleavage of CD44 is controlled in a cell type-dependent fashion by Rho GTPases through the cytoskeleton.
An Immunodominant MHC Class II-Restricted Tumor Antigen Is Conformation Dependent and Binds to the Endoplasmic Reticulum Chaperone, Calreticulin
Authors: Golgher Denise , Korangy Firouzeh , Gao Bin , Gorski Kevin , Jaffee Elizabeth , Edidin Michael , Pardoll Drew M. , Elliott Tim 
Published: April 2014

AbstractThere is accumulating evidence that CD4+ T cell responses are important in antitumor immunity. Accordingly, we generated CD4+ T cells against the murine CT26 colon cancer. Three of three independent CT26-specific CD4+ hybridomas were found to recognize the high m.w. precursor of the env gene product gp90. The CD4+ response was completely tumor specific in that the same glycoprotein expressed by other tumors was not recognized by the CT26-specific hybridomas. The recognition of gp90 by the hybridomas was strictly dependent on the conformation of gp90. Different procedures that disrupted the conformation of the glycoprotein, such as disulfide bond reduction and thermal denaturation, completely abrogated recognition of gp90 by all three hybridomas. In CT26 cells, but not in other tumor cells tested, a large proportion of gp90 was retained in the endoplasmic reticulum, mostly bound to the endoplasmic reticulum chaperone, calreticulin. Although calreticulin was not essential for the stimulation of the gp90-specific hybridomas, most of the antigenic form of gp90 was bound to it. The antigenicity of gp90 correlated well with calreticulin binding, reflecting the fact that specificity of binding of calreticulin to its substrate required posttranslational modifications that were also necessary for the generation of this tumor-specific CD4+ epitope.
Pertussis Toxin Inhibits Induction of Tissue-Specific Autoimmune Disease by Disrupting G Protein-Coupled Signals
Authors: Su Shao Bo , Silver Phyllis B. , Zhang Meifen , Chan Chi-Chao , Caspi Rachel R. 
Published: April 2014

AbstractPertussis toxin (PTX) has been used for many years as an adjuvant that promotes development of tissue-specific experimental autoimmune diseases such as experimental autoimmune encephalomyelitis, experimental autoimmune uveitis (EAU), and others. Enhancement of vascular permeability and of Th1 responses have been implicated in this effect. Here we report a surprising observation that, in a primed system, PTX can completely block the development of EAU. Disease was induced in B10.RIII mice by adoptive transfer of uveitogenic T cells, or by immunization with a uveitogenic peptide. A single injection of PTX concurrently with infusion of the uveitogenic T cells, or two injections 7 and 10 days after active immunization, completely blocked development of EAU. EAU also was prevented by a 1-h incubation in vitro of the uveitogenic T cells with PTX before infusing them into recipients. Uveitogenic T cells treated with PTX in vitro and lymphoid cells from mice treated with PTX in vivo failed to migrate to chemokines in a standard chemotaxis assay. Neither the isolated B-oligomer subunit of PTX that lacks ADP ribosyltransferase activity nor the related cholera toxin that ADP-ribosylates Gs (but not Gi) proteins blocked EAU induction or migration to chemokines. We conclude that PTX present at the time of cell migration to the target organ prevents EAU, and propose that it does so at least in part by disrupting signaling through Gi protein-coupled receptors. Thus, the net effect of PTX on autoimmune disease would represent an integration of enhancing and inhibitory effects.
Human Notch-1 Inhibits NF-κB Activity in the Nucleus Through a Direct Interaction Involving a Novel Domain
Authors: Wang Jinhai , Shelly Lesile , Miele Lucio , Boykins Robert , Norcross Michael A. , Guan Ennan 
Published: April 2014

Abstract
Notch participates in diverse cell fate decisions throughout embryonic development and postnatal life. Members of the NF-κB/Rel family of transcription factors are involved in the regulation of a variety of genes important for immune function. The biological activity of the NF-κB transcription factors is controlled by IκB proteins. Our previous work demonstrated that an intracellular, constitutively active form of human Notch-1/translocation-associated Notch homologue-1 (NotchIC) functions as an IκB molecule with specificity for the NF-κB p50 subunit and physically interacts with NF-κB in T cells. In the current study, we investigated the roles of different domains of NotchIC in the regulation of NF-κB-directed gene expression and NF-κB DNA binding activity. We found that NotchIC localizes to the nucleus and that a region in the N-terminal portion of NotchIC, not the six ankyrin repeats, is responsible for the inhibitory effects of Notch on NF-κB-directed gene expression and NF-κB DNA binding activity. The N-terminal portion of NotchIC inhibited p50 DNA binding and interacted specifically with p50 subunit, not p65 of NF-κB. The interaction between Notch and NF-κB indicates that in addition to its role in the development of the immune system, Notch-1 may also have critical functions in the immune response, inflammation, viral infection, and apoptosis through control of NF-κB-mediated gene expression.
Human Thymic Stromal Lymphopoietin Preferentially Stimulates Myeloid Cells
Authors: Reche Pedro A. , Soumelis Vassili , Gorman Daniel M. , Clifford Teresa , Liu Man-ru , Travis Marilyn , Zurawski Sandra M. , Johnston Jim , Liu Yong-Jun , Spits Hergen , de Waal Malefyt Rene , Kastelein Robert A. , Bazan J. Fernando 
Published: April 2014

AbstractThe sequence of a novel hemopoietic cytokine was discovered in a computational screen of genomic databases, and its homology to mouse thymic stromal lymphopoietin (TSLP) suggests that it is the human orthologue. Human TSLP is proposed to signal through a heterodimeric receptor complex that consists of a new member of the hemopoietin family termed human TSLP receptor and the IL-7R α-chain. Cells transfected with both receptor subunits proliferated in response to purified, recombinant human TSLP, with induced phosphorylation of Stat3 and Stat5. Human TSLPR and IL-7Rα are principally coexpressed on monocytes and dendritic cell populations and to a much lesser extent on various lymphoid cells. In accord, we find that human TSLP functions mainly on myeloid cells; it induces the release of T cell-attracting chemokines from monocytes and, in particular, enhances the maturation of CD11c+ dendritic cells, as evidenced by the strong induction of the costimulatory molecules CD40 and CD80 and the enhanced capacity to elicit proliferation of naive T cells.
Enhanced Protection Against Fatal Mycobacterial Infection in SCID Beige Mice by Reshaping Innate Immunity with IFN-γ Transgene
Authors: Xing Zhou , Zganiacz Anna , Wang Jun , Sharma Sudhir K. 
Published: April 2014

Abstract
Humans with immune-compromised conditions such as SCID are unable to control infection caused by normally nonpathogenic intracellular pathogens such as Mycobacterium bovis bacillus Calmette-Guérin. We found that SCID beige mice lacking both lymphocytes and NK cells had functionally normal lung macrophages and yet a selectively impaired response of type 1 cytokines IFN-γ and IL-12, but not TNF-α, during M. bovis bacillus Calmette-Guérin infection. These mice succumbed to such infection. A repeated lung gene transfer strategy was designed to reconstitute IFN-γ in the lung, which allowed investigation of whether adequate activation of innate macrophages could enhance host defense in the complete absence of lymphocytes. IFN-γ transgene-based treatment was initiated 10 days after the establishment of mycobacterial infection and led to increased levels of both IFN-γ and IL-12, but not TNF-α, in the lung. Lung macrophages were activated to express increased MHC molecules, type 1 cytokines and NO, and increased phagocytic and mycobactericidal activities. Activation of innate immunity markedly inhibited otherwise uncontrollable growth of mycobacteria and prolonged the survival of infected SCID hosts. Thus, our study proposes a cytokine transgene-based therapeutic modality to enhance host defense in immune-compromised hosts against intracellular bacterial infection, and suggests a central effector activity played by IFN-γ-activated macrophages in antimycobacterial cell-mediated immunity.
Serum Proteins Modified by Neutrophil-Derived Oxidants as Mediators of Neutrophil Stimulation
Authors: Körmöczi Günther F. , Wölfel Ulrike M. , Rosenkranz Alexander R. , Hörl Walter H. , Oberbauer Rainer , Zlabinger Gerhard J. 
Published: April 2014

Abstract
Reactive oxygen intermediates (ROI) released during inflammation may act as important mediators of neutrophil effector functions. The objective of this investigation was to evaluate the influence of ROI generation on neutrophil adhesion molecule regulation and degranulation. Induction of the neutrophil oxidative burst via Fcγ receptor cross-linking was accompanied by up-regulation of neutrophil surface CD11b, CD35, and CD66b only in the presence of selected serum proteins, such as purified human C4, C5, or human serum albumin (HSA). Scavenging of ROI attenuated protein-dependent receptor regulations. Moreover, exogenous hydrogen peroxide was effective to increase neutrophil CD11b expression in a protein-dependent way. HSA exposed to neutrophil-derived ROI displayed signs of oxidative modification in terms of carbonyl formation. Such modified HSA transferred to resting neutrophils bound readily to the cell surface and effected receptor modulation as well as cellular spreading. In contrast, neither native HSA nor HSA protected against oxidation by the tocopherol analog Trolox exhibited agonistic properties. In conclusion, we demonstrate that neutrophil-derived ROI modify selected serum proteins, which, in turn, act as proinflammatory mediators of neutrophil stimulation.
Microsomal Prostaglandin E Synthase Is Regulated by Proinflammatory Cytokines and Glucocorticoids in Primary Rheumatoid Synovial Cells
Authors: Stichtenoth Dirk O. , Thorén Staffan , Bian Huimin , Peters-Golden Marc , Jakobsson Per-Johan , Crofford Leslie J. 
Published: April 2014

Abstract
The selective induction of PGE2 synthesis in inflammation suggests that a PGE synthase may be linked to an inducible pathway for PG synthesis. We examined the expression of the recently cloned inducible microsomal PGE synthase (mPGES) in synoviocytes from patients with rheumatoid arthritis, its modulation by cytokines and dexamethasone, and its linkage to the inducible cyclooxygenase-2. Northern blot analysis showed that IL-1β or TNF-α treatment induces mPGES mRNA from very low levels at baseline to maximum levels at 24 h. IL-1β-induced mPGES mRNA was inhibited by dexamethasone in a dose-dependent fashion. Western blot analysis demonstrated that mPGES protein was induced by IL-1β, and maximum expression was sustained for up to 72 h. There was a coordinated up-regulation of cyclooxygenase-2 protein, although peak expression was earlier. Differential Western blot analysis of the microsomal and the cytosolic fractions revealed that the induced expression of mPGES protein was limited to the microsomal fraction. The detected mPGES protein was catalytically functional as indicated by a 3-fold increase of PGES activity in synoviocytes following treatment with IL-1β; this increased synthase activity was limited to the microsomal fraction. In summary, these data demonstrate an induction of mPGES in rheumatoid synoviocytes by proinflammatory cytokines. This novel pathway may be a target for therapeutic intervention for patients with arthritis.
Gi-Mediated Activation of the Syk Kinase by the Receptor Mimetic Basic Secretagogues of Mast Cells: Role in Mediating Arachidonic Acid/Metabolites Release
Authors: Shefler Irit , Sagi-Eisenberg Ronit 
Published: April 2014

Abstract
Syk kinase is essential for FcεRI-mediated signaling and release of inflammatory mediators from mast cells. We now show that activation of rat peritoneal mast cells by the nonimmunological, Gi-mediated pathway also results in the activation of Syk. We show that compound 48/80 (c48/80), a receptor analogue that activates directly G proteins, activates Syk in a pertussis toxin-sensitive fashion. We further show that Syk activation by c48/80 is blocked by the protein kinase C inhibitor GF109203X, by the phosphatidylinositol 3-kinase inhibitors, wortmannin and LY294002, by EGTA, and by the selective src-like kinase inhibitor PP1. These results suggest that in the nonimmunological, Gi-mediated pathway, Syk is located downstream from phospholipase C and phosphatidylinositol 3-kinase. However, in common with the FcεRI-mediated pathway, activation of Syk by c48/80 is dependent on a src-like protein tyrosine kinase. Finally, we show that in the nonimmunological pathway, Syk plays a central role in the release of arachidonic acid/eicosanoid metabolites, but not in the release of prestored mediators such as histamine.
Dissection of the Intracellular Pathways in Hepatocytes Suggests a Role for Jun Kinase and IFN Regulatory Factor-1 in Con A-Induced Liver Failure
Authors: Streetz Konrad , Fregien Bastian , Plümpe Jörg , Körber Kerstin , Kubicka Stefan , Sass G. , Bischoff Stephan C. , Manns Michael P. , Tiegs Gisa , Trautwein Christian 
Published: April 2014

Abstract
Con A administration results in dose-dependent immune-mediated liver injury. Cytokines are important to determine the outcome of liver failure in this model, and especially TNF-α and IFN-γ directly contribute to hepatocyte damage. The intracellular pathways of these two cytokines, which eventually result in tissue destruction, are not well defined. Here we used anti-IFN-γ Abs and adenoviral vectors that express molecules inhibiting distinct TNF-α-dependent pathways in hepatocytes to better understand the relevance of specific intracellular signaling cascades for Con A-induced liver failure. We show that activation of TNF-α- and IFN-γ-dependent intracellular pathways occurs prior to the influx of immune-activated cells into the liver and that anti-TNF-α and anti-IFN-γ neutralizing Abs cannot block infiltration of these cells. Blocking experiments with Abs and adenoviral vectors showed that NF-κB activation and the Fas-associated death domain protein/caspase 8 cascade in hepatocytes during Con A-induced liver failure have no impact on tissue injury. Additionally, STAT1 activation alone after Con A injection in liver cells does not result in liver damage. In contrast, IFN-γ-dependent expression of IFN regulatory factor-1 and TNF-α-dependent activation of c-Jun N-terminal kinase in liver cells correlates with liver cell damage after Con A injection. Therefore, our experiments indicate that IFN regulatory factor-1 and the c-Jun N-terminal kinase pathway are involved in determining hepatocyte damage during Con A-induced liver failure and thus may provide new targets for therapeutic intervention.
Stem Cell Factor-Induced Leukotriene B4 Production Cooperates with Eotaxin to Mediate the Recruitment of Eosinophils During Allergic Pleurisy in Mice
Authors: Klein André , Talvani André , Silva Patrícia M. R. , Martins Marco A. , Wells Tim N. C. , Proudfoot Amanda , Luckacs Nick W. , Teixeira Mauro M. 
Published: April 2014

Abstract
The understanding of the mechanisms underlying eosinophil recruitment in vivo may aid in the development of novel strategies for the treatment of allergic disorders. In this study, we investigated the role of chemokines in the cascade of events leading to eosinophil recruitment in a stem cell factor (SCF)- and leukotriene B4 (LTB4)-dependent allergic pleurisy model in mice. The intrapleural administration of the eosinophil-active chemokines eotaxin, RANTES, and macrophage-inflammatory protein 1α (MIP-1α) induced a time- and dose-dependent eosinophil recruitment. Pretreatment with anti-eotaxin, but not anti-RANTES or anti-MIP-1α, blocked the recruitment of eosinophils following Ag challenge of sensitized animals, and significant eotaxin immunoreactivity was detected in the pleural cavity of these animals. Similarly, only the anti-eotaxin inhibited the eosinophil recruitment induced by injection of SCF in naive animals. However, blockade of SCF did not inhibit the release of eotaxin after Ag challenge of sensitized mice. Akin to its effects on SCF and in the allergic reaction, eotaxin-induced eosinophil recruitment was blocked by the LTB4 receptor antagonist CP105696. Nevertheless, SCF, but not eotaxin, appeared to regulate the endogenous release of LTB4 after Ag challenge. Finally, we show that low doses of eotaxin synergized with LTB4 to induce eosinophil recruitment in the pleural cavity. Overall, the present results show that eotaxin and SCF-induced LTB4 cooperate to induce eosinophil recruitment into sites of allergic inflammation. Cooperation between inflammatory mediators must be an important phenomenon in vivo, explaining both the ability of lower concentrations of mediators to induce a full-blown functional response and the effectiveness of different strategies at inhibiting these responses.