bluuebunny/crossref_metadata_2025_split huggingface dataset:
LPS-Stimulated SJL Macrophages Produce IL-12 and IL-18 That Inhibit IgE Production In Vitro by Induction of IFN-γ Production from CD3intIL-2Rβ+ T Cells
Authors: Yoshimoto Tomohiro , Nagai Nobuhiko , Ohkusu Kazunobu , Ueda Haruyasu , Okamura Haruki , Nakanishi Kenji 
Published: December 2022

AbstractSJL mice are known for their poor IgE production upon helminth infection. In this study, we have demonstrated that SJL standard B cells (85% IgM+ or B220+), prepared by complement-mediated T cell lysis, failed to proliferate and to produce IgE and IgG1 in response to LPS plus IL-4 in vitro. This diminished IgE production was restored by anti-IL-12 and enhanced by additional treatment with anti-IL-18, suggesting active suppression by the cells that produce IL-12 and IL-18. Indeed, SJL standard B cells were contaminated with Mac-1+ cells. Therefore, we removed macrophages by passing standard B cells through a Sephadex G-10 column (G10). Resultant cells (95% IgM+), designated as G10-B cells, responded to LPS and IL-4 by their proliferation and differentiation. G-10 treatment markedly diminished the proportion of B220− cells and Mac-1+ cells in SJL standard B cells. Furthermore, addition of SJL B220− cells dose dependently and MHC independently inhibited LPS plus IL-4-induced B cell growth and IgE production in SJL and BALB/c B cells. B220− cells in SJL standard B cells contained Mac-1+ cells (51%) and Fas ligand+ CD4−CD8− double-negative CD3intIL-2Rβ+ T cells (26%). Thus, IL-12 and IL-18 produced by LPS-stimulated Mac-1+ cells stimulate this unique subpopulation of T cells to produce IFN-γ, which in combination with Fas ligand, inhibits IgE production from the B cells. Our present results indicate that Mac-1+ cells and double-negative CD3intIL-2Rβ+ T cells, uniquely abundant in the spleens of SJL mice, inhibit IgE production, indicating their new role in IgE response.
Endothelial Myosin Light Chain Kinase Regulates Neutrophil Migration Across Human Umbilical Vein Endothelial Cell Monolayer
Authors: Saito Hajime , Minamiya Yoshihiro , Kitamura Michihiko , Saito Satoshi , Enomoto Katsuhiko , Terada Kunihiko , Ogawa Jun-ichi 
Published: December 2022

AbstractAlthough extravasation of neutrophils is a critical step in acute inflammation, the role of the endothelial cytoskeleton in neutrophil transmigration has not been fully investigated. We used an in vitro model of neutrophil transmigration across a monolayer of HUVEC cultured on amniotic membrane. Human neutrophils were allowed to migrate across the HUVEC monolayer in response to a gradient leukotriene B4 and then the number of migrated neutrophils were counted microscopically. We also followed endothelial F-actin and myosin filament formation using rhodamine-phalloidin and anti-myosin Ab staining. Myosin light chain (MLC) phosphorylation in endothelial cells was determined by immunoprecipitation of 32P-labeled HUVEC with anti-myosin polyclonal Ab. Normally, neutrophil migration induced F-actin formation, myosin filament formation, and MLC phosphorylation in HUVEC. When HUVEC was pretreated with the myosin light chain kinase (MLCK) inhibitor, ML-9, neutrophil migration was diminished and F-actin formation, myosin filament formation, and MLC phosphorylation were inhibited. Pretreatments of HUVEC with the intracellular calcium ion chelator, bis-(O-aminophenoxyl)ethane-N, N, N′, N′-tetraacetic acid acetoxymethyl ester (BAPTA/AM), and the calmodulin antagonist, trifluoperazine, had similar effects. These results indicate that a calcium/calmodulin-dependent MLCK in endothelial cells regulates neutrophil transendothelial migration.
Circulating Form of Human Vascular Adhesion Protein-1 (VAP-1): Increased Serum Levels in Inflammatory Liver Diseases
Authors: Kurkijärvi Riikka , Adams David H. , Leino Rauli , Möttönen Timo , Jalkanen Sirpa , Salmi Marko 
Published: December 2022

AbstractVascular adhesion protein-1 (VAP-1) is a dimeric 170-kDa endothelial transmembrane molecule that under normal conditions is most strongly expressed on the high endothelial venules of peripheral lymph nodes and on hepatic endothelia. It is a glycoprotein that mediates tissue-selective lymphocyte adhesion in a sialic acid-dependent manner. In this study, we report the detection of a soluble form of VAP-1 in circulation. We developed a quantitative sandwich ELISA using novel anti-VAP-1 mAbs and used it to determine the levels of soluble VAP-1 (sVAP-1) in the serum of healthy individuals and in patients with inflammatory diseases. In healthy persons, circulating sVAP-1 concentrations were 49 to 138 ng/ml. Immunoblotting studies revealed that the apparent molecular mass of dimeric sVAP-1 is slightly (∼10 kDa) higher than that of transmembrane VAP-1 under nonreducing conditions. In contrast, the electrophoretic mobilities of monomeric sVAP-1 and transmembrane VAP-1 were similar after reduction and boiling. Adhesion assays showed that the circulating sVAP-1 modulates lymphocyte binding to endothelial cells. Inflammation can cause an elevation of serum sVAP-1 levels, because sVAP-1 concentrations in patients with certain liver diseases were two- to fourfold higher than those in normal individuals. In contrast, rheumatoid arthritis and inflammatory bowel diseases were not associated with elevated levels of sVAP-1. These findings indicate that there is a functionally active, soluble form of VAP-1 in circulation and suggest that the serum level of sVAP-1 might be a useful marker of disease activity in inflammatory liver diseases.
Involvement of the Fas/Fas Ligand Pathway in Activation-Induced Cell Death of Mycobacteria-Reactive Human γδ T Cells: A Mechanism for the Loss of γδ T Cells in Patients with Pulmonary Tuberculosis
Authors: Li Baiqing , Bassiri Hamid , Rossman Milton D. , Kramer Peter , Eyuboglu A. Fusun-Oner , Torres Martha , Sada Eduardo , Imir Turgut , Carding Simon R. 
Published: December 2022

AbstractAlthough the identity of T cells involved in the protection against Mycobacterium tuberculosis (Mtb) in humans remain unknown, patients with pulmonary tuberculosis (TB) have reduced numbers of Mtb-reactive, Vγ9+/Vδ2+ T cells in their blood and lungs. Here we have determined whether this γδ T loss is a consequence of Mtb Ag-mediated activation-induced cell death (AICD). Using a DNA polymerase-mediated dUTP nick translation labeling assay, 5% or less of freshly isolated CD4+ αβ or γδ T cells from normal healthy individuals and TB patients were apoptotic. However, during culture Mtb Ags induced apoptosis in a large proportion of Vγ9+/Vδ2+ peripheral blood T cells from healthy subjects (30–45%) and TB patients (55–68%); this was increased further in the presence of IL-2. By contrast, anti-CD3 did not induce any significant level of apoptosis in γδ T cells from healthy subjects or TB patients. Mtb Ag stimulation rapidly induced Fas and Fas ligand (FasL) expression by γδ T cells, and in the presence of metalloproteinase-inhibitors &gt;70% of γδ T cells were FasL+. Blockade of Fas-FasL interactions reduced the level of Mtb-mediated γδ T cell apoptosis by 75 to 80%. Collectively, these findings demonstrate that Mtb-reactive γδ T cells are more susceptible to AICD and that the Fas-FasL pathways of apoptosis is involved. AICD of γδ T cells, therefore, provides an explanation for the loss of Mtb-reactive T cells during mycobacterial infection.
Cutting Edge: Selective Deamidation by Tissue Transglutaminase Strongly Enhances Gliadin-Specific T Cell Reactivity
Authors: van de Wal Yvonne , Kooy Yvonne , van Veelen Peter , Peña Salvador , Mearin Luisa , Papadopoulos George , Koning Frits 
Published: December 2022

AbstractCeliac disease (CD) is caused by gluten ingestion in susceptible individuals. Tissue transglutaminase (tTG)-specific Abs are characteristic of CD, and increased tTG activity has been observed in the jejunal biopsies of patients. Here we demonstrate that tTG selectively deamidates gluten peptides, which results in strongly enhanced T cell-stimulatory activity. To our knowledge, this is the first example of an enzymatic modification of a food protein that affects T cell recognition. Moreover, these modifications may lead to the amplification of gluten-specific T cell responses in the gut and consequently may be important for the development of CD.
Human T Lymphocyte Proliferative Response to Resting Porcine Endothelial Cells Results from an HLA-Restricted, IL-10-Sensitive, Indirect Presentation Pathway But Also Depends on Endothelial-Specific Costimulatory Factors
Authors: Vallée Isabelle , Guillaumin Jean-Maurice , Thibault Gilles , Gruel Yves , Lebranchu Yvon , Bardos Pierre , Watier Hervé 
Published: December 2022

AbstractTo investigate the mechanisms of cellular rejection in pig-to-human xenotransplantation, the proliferation of different human purified lymphocyte subpopulations in response to swine leukocyte Ag class II-negative porcine aortic endothelial cells (PAEC) was measured in the presence or absence of human autologous adherent cells (huAPC). CD8+ lymphocytes proliferated moderately in the absence of huAPC, and the immune response was slightly increased when huAPC were added. CD56+ lymphocytes failed to proliferate in response to PAEC whether huAPC were present or not. CD4+ lymphocytes alone did not proliferate in response to PAEC, but a strong proliferative response was observed in the presence of metabolically active huAPC. This response was totally abolished by mAbs directed against HLA class II molecules or by pretreatment of huAPC by human IL-10. Even in the presence of huAPC, CD4+ lymphocytes failed to respond to fixed PAEC or to PAEC-lysates, suggesting that PAEC must be viable to support lymphocyte proliferation. Finally, none of the nonendothelial porcine adherent cells tested was able to induce human lymphocyte proliferation, despite the fact that they also provided a large set of xenogeneic peptides. Our results show that the indirect presentation pathway of xenoantigens by huAPC to CD4+ lymphocytes is crucial in the response to porcine endothelial cells, and that IL-10 could be of therapeutic interest to prevent human lymphocyte activation by this pathway. Furthermore, we demonstrated that stimulatory signals specifically provided by endothelial cells are also necessary for this huAPC-restricted proliferative response.
Protein Kinase C Is Involved in the Regulation of Both Signaling and Adhesion Mediated by DNAX Accessory Molecule-1 Receptor
Authors: Shibuya Akira , Lanier Lewis L. , Phillips Joseph H. 
Published: December 2022

Abstract
DNAX accessory molecule-1 (DNAM-1) is a signal-transducing adhesion molecule involved in the cytolytic function mediated by CTL and NK cells. In the present study, we have investigated various perimeters of DNAM-1-mediated signaling and adhesion. Although adhesion of DNAM-1 to its ligand does not require divalent cations, protein synthesis, or RNA transcription, activation of protein kinase C (PKC) is required for DNAM-1 functioning. Furthermore, mutation of the putative PKC-binding site in the cytoplasmic domain of DNAM-1 (Ser329 to Phe329) prevents both ligand binding and PMA-induced phosphorylation of the DNAM-1 receptor. These results indicate that PKC phosphorylates Ser329 of DNAM-1 and plays a critical role for both DNAM-1 adhesion and signaling.
Assembly of MHC Class I Molecules with Biosynthesized Endoplasmic Reticulum-Targeted Peptides Is Inefficient in Insect Cells and Can Be Enhanced by Protease Inhibitors
Authors: Deng Yuping , Gibbs James , Bačík Igor , Porgador Angel , Copeman James , Lehner Paul , Ortmann Bodo , Cresswell Peter , Bennink Jack R. , Yewdell Jonathan W. 
Published: December 2022

AbstractTo study the requirements for assembly of MHC class I molecules with antigenic peptides in the endoplasmic reticulum (ER), we studied Ag processing in insect cells. Insects lack a class I recognition system, and their cells therefore provide a “blank slate” for identifying the proteins that have evolved to facilitate assembly of class I molecules in vertebrate cells. H-2Kb heavy chain, mouse β2-microglobulin, and an ER-targeted version of a peptide corresponding to Ova257–264 were expressed in insect cells using recombinant vaccinia viruses. Cell surface expression of Kb-OVA257–264 complexes was quantitated using a recently described complex-specific mAb (25-D1.16). Relative to TAP-deficient human cells, insect cells expressed comparable levels of native, peptide-receptive cell surface Kb molecules, but generated cell surface Kb-OVA257–264 complexes at least 20-fold less efficiently from ER-targeted peptides. The inefficient assembly of Kb-OVA257–264 complexes in the ER of insect cells cannot be attributed solely to a requirement for human tapasin, since first, human cells lacking tapasin expressed endogenously synthesized Kb-OVA257–264 complexes at levels comparable to tapasin-expressing cells, and second, vaccinia virus-mediated expression of human tapasin in insect cells did not detectably enhance the expression of Kb-OVA257–264 complexes. The assembly of Kb-OVA257–264 complexes could be greatly enhanced in insect but not human cells by a nonproteasomal protease inhibitor. These findings indicate that insect cells lack one or more factors required for the efficient assembly of class I-peptide complexes in vertebrate cells and are consistent with the idea that the missing component acts to protect antigenic peptides or their immediate precursors from degradation.
Regulation of Tyrosine Phosphorylation in Isolated T Cell Membrane by Inhibition of Protein Tyrosine Phosphatases
Authors: Jin Yong-Jiu , Friedman Jeff , Burakoff Steven J. 
Published: December 2022

Abstract
Jurkat T cells activated by the phosphotyrosine phosphatase inhibitors H2O2 or vanadate were found to have a similar pattern of tyrosine phosphorylation when compared with T cells stimulated by anti-CD3 Ab cross-linking, suggesting that protein tyrosine phosphatase (PTP) inhibitors affect the early steps of TCR signaling. To study the role of PTPs in the most proximal membrane events of tyrosine phosphorylation, subcellular fractions of T cells were treated with the PTP inhibitors in the presence of ATP. In the membrane fraction, tyrosine phosphorylation of Lck, Fyn, and CD3ζ can be induced by PTP inhibitors, but not by anti-CD3. Detailed characterization of this cell-free system showed that the pattern and the order of induced tyrosine phosphorylation is similar to that induced in intact cells. Upon removal of the PTP inhibitor, the tyrosine-phosphorylated proteins, including Lck, Fyn, Syk, Zap70, and CD3ζ, are rapidly dephosphorylated. Preliminary characterizations indicate that a PTP distinct from CD45, SHP1, and SHP2 is present in T cell membranes and the inhibition of this yet unidentified PTP is most likely responsible for the Lck-dependent tyrosine phosphorylation triggered by PTP inhibitors.
Cyclosporin A-Resistant Transactivation of the IL-2 Promoter Requires Activity of Okadaic Acid-Sensitive Serine/Threonine Phosphatases
Authors: Nebl Gabriele , Meuer Stefan C. , Samstag Yvonne 
Published: December 2022

AbstractExpression of the IL-2 gene requires activation of T cells through stimulation of the TCR and costimulation through accessory receptors. We have found recently that okadaic acid-sensitive Ser/Thr phosphatases are involved in a cyclosporin A-insensitive pathway that selectively transmits costimulatory signals. In this study, we analyzed whether activities of these phosphatases are necessary for the expression of the IL-2 gene. In both activated peripheral blood T lymphocytes and activated tumorigenic T cell lines, IL-2 gene expression was blocked at the transcriptional level by okadaic acid. The transcription factors active at the IL-2 promoter were differentially influenced: upon down-modulation of okadaic acid-sensitive phosphatases, transactivation by octamer, NF-κB, and NF of activated T cells proteins was abrogated, while transactivation by AP-1 proteins was even enhanced.
Synergistic Activation of the Germline ε Promoter Mediated by Stat6 and C/EBPβ
Authors: Mikita Thomas , Kurama Masae , Schindler Ulrike 
Published: December 2022

AbstractTranscription of the Ig H chain germline transcripts is a prerequisite for class switching. Expression of the ε germline transcript is induced by IL-4 and requires the integrity of a composite IL-4 response element. The element is bound by the IL-4-inducible transcription factor Stat6 and one or more members of the CAAT/enhancer-binding protein (C/EBP) family, a constitutively expressed class of transcription factors. Here, we show that Stat6 and C/EBPβ cooperate to synergistically activate transcription from the ε element. The effect was most pronounced in lymphoid cells, and the activation domains of both proteins were required to achieve this synergy. Although other members of the C/EBP family are able to bind the element, very little cooperativity was seen with C/EBPα and none with C/EBPγ. In fact, C/EBPγ was able to inhibit IL-4-induced reporter activity. Stat6 and C/EBPβ bind the IL-4 response element simultaneously. The fast dissociation rate apparent when Stat6 binds this DNA element alone is slowed when C/EBPβ binds at the neighboring site. These data suggest a mechanism whereby C/EBPβ stabilizes Stat6 binding at this element, thereby increasing the likelihood that both of their activation domains will interact, possibly with other factors, to activate transcription in an IL-4-dependent manner.
Fc Receptors Are Not Required for Antibody-Mediated Protection Against Lethal Malaria Challenge in a Mouse Model
Authors: Rotman Harris L. , Daly Thomas M. , Clynes Raphael , Long Carole A. 
Published: December 2022

AbstractThe mechanisms by which Abs mediate protection during blood-stage malaria infections is controversial, with some evidence pointing to the direct effect of Abs on parasite invasion and growth, while other studies suggest that Abs act in cooperation with monocytes to achieve parasite inhibition. To determine whether the effector phase of protection in vivo to the rodent parasite Plasmodium yoelii yoelii requires Fc receptor bearing cells, we passively transferred immune sera into FcR γ-chain knockout mice. Inflammatory macrophages from these knockout mice were unable to mediate phagocytosis or Ab-dependent cell-mediated cytotoxicity (ADCC) through FcγRI, FcγRII, or FcγRIII. Passive transfer of either P. y. yoelii hyperimmune sera or anti-GST-PYC2 sera directed to the major merozoite surface protein (MSP-1) of this parasite enabled both BALB/cByJ mice and FcR γ-chain-deficient mice to resist lethal P. y. yoelii 17XL (Py17XL) challenge. mAb302, a protective IgG3 Ab, also passively protected both strains of mice. Most of these samples contain Ab isotypes that would not be able to protect mice if their protective effects required Ab-dependent cell-mediated cytotoxicity. These results establish that, in this infection, protection is directly mediated by Abs and does not require the participation of Fc receptors.
IFNs Are Critical Regulators of IL-1 Receptor Antagonist and IL-1 Expression in Human Microglia
Authors: Liu Judy S. H. , Amaral Terry D. , Brosnan Celia F. , Lee Sunhee C. 
Published: December 2022

AbstractBecause IL-1 is implicated in the pathogenesis of multiple sclerosis, and IFNs are known to alter disease course, we sought to determine whether IFNs can regulate the expression of IL-1 and IL-1R antagonist (IL-1Ra) in primary cultures of human microglia and astrocytes. We found that IL-1 and IL-1Ra are products of microglia but not astrocytes, and IFN-β and IFN-γ differentially modulate LPS- and cytokine-induced IL-1 and IL-1Ra. IFN-β induces IL-1Ra and augments LPS- and IL-4-induced IL-1Ra, but suppresses LPS- and IL-1-induced IL-1, shifting the balance toward the expression of the IL-1Ra. Like IFN-β, IFN-γ suppresses the expression of both LPS and IL-1-induced IL-1β. However, IFN-γ also suppresses the expression of IFN-β- and IL-4-induced IL-1Ra so that IFN-γ may enhance or suppress IL-1 activity depending on the other cytokines present. IL-4 has similar effects to IFN-β; however, other anti-inflammatory cytokines, did not regulate IL-1 or IL-1Ra in human microglia. Our data demonstrate a novel suppressive effect of IFN-β and IL-4 on IL-1 activity in human microglia, suggesting that IFN-β, a therapeutic agent used for multiple sclerosis, could have wider applications in the treatment of other central nervous system disorders in which IL-1 activity has been implicated in the pathogenesis.
Molecular Analysis of Polyreactive Monoclonal Antibodies from Rheumatic Carditis: Human Anti-N-Acetylglucosamine/Anti-Myosin Antibody V Region Genes
Authors: Adderson Elisabeth E. , Shikhman Alexander R. , Ward Kent E. , Cunningham Madeleine W. 
Published: December 2022

AbstractAnti-myosin Abs are associated with inflammatory heart diseases such as rheumatic carditis and myocarditis. In this study, human cross-reactive anti-streptococcal/anti-myosin mAbs 1.C8, 1.H9, 5.G3, and 3.B6, produced from peripheral blood lymphocytes of patients with rheumatic carditis, and mAb 10.2.5, produced from a tonsil, were characterized, and the nucleotide sequences of their VH and VL genes were analyzed. Human mAbs 1.C8, 1.H9, 10.2.5, and 3.B6 reacted with human cardiac myosin while mAb 5.G3 did not. The mAbs were strongly reactive with N-acetyl-β-d-glucosamine, the dominant epitope of the group A streptococcal carbohydrate. mAb 1.H9 was moderately cytotoxic to rat heart cells in vitro in the presence of complement. The anti-myosin mAbs from rheumatic carditis were found to react with specific peptides from the light meromyosin region of the human cardiac myosin molecule. Anti-streptococcal/anti-myosin mAbs from normal individuals reacted with distinctly different light meromyosin peptides. The mAbs were encoded by VH3 gene segments V3-8, V3-23, and V3-30 and by the VH4 gene segment V4-59. The variable region genes encoding the anti-streptococcal/anti-myosin repertoire were heterogeneous and exhibited little evidence of Ag-driven somatic mutation.
Induction of Species-Specific Host Accommodation in the Hamster-to-Rat Xenotransplantation Model
Authors: Yin Dengping , Ma Lian Li , Blinder Leonard , Shen JiKun , Sankary Howard , Williams James W. , Chong Anita S.-F. 
Published: December 2022

AbstractThe combination of two immunosuppressants, leflunomide and cyclosporin A (CsA), completely inhibits immune xenoreactions in the hamster-to-Lewis rat xenotransplantation model. In addition, the control of acute xenograft rejection with this combination of immunosuppressants subdues early T-independent xenoreactivity and uncovers a late immune response that can be controlled by CsA alone. We attribute this acquired responsiveness to CsA to a modification in the recipient’s humoral response to the xenograft, and refer to this change as host accommodation. Host accommodation can be induced in Lewis rats receiving hamster hearts by the combination of leflunomide and CsA. A 7-day treatment with leflunomide and CsA was able to convert xenoreactivity from one that was resistant to CsA treatment into one that was controlled by CsA. The presence of the hamster xenograft was critical for the induction of host accommodation since the immunosuppressive regimen, either alone or in combination with a transfusion with donor-specific spleen cells, was unable to modify the anti-hamster reactivity in Lewis rats. When accommodation was induced in the presence of hamster hearts, these accommodated rats were able to acutely reject third-party mouse hearts while under CsA therapy, thus indicating that the host accommodation is species specific. Finally, we demonstrate that host accommodation is associated with a loss in the ability to produce species-specific, T-independent xenoantibodies. These novel observations suggest that xenoreactive T-independent humoral responses can be deleted selectively without significant loss of other innate, Ag-specific T-independent humoral responses.