bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative Genetic Variation in CD19 Expression Correlates with Autoimmunity
Authors: Sato Shinichi , Hasegawa Minoru , Fujimoto Manabu , Tedder Thomas F. , Takehara Kazuhiko 
Published: April 2014

AbstractSignaling thresholds influence the balance between humoral immunity and autoimmunity. Cell surface CD19 regulates intrinsic and Ag receptor-induced B lymphocyte signaling thresholds, and transgenic mice that overexpress CD19 by 3-fold generate spontaneous autoantibodies in a genetic background not associated with autoimmunity. To quantify the extent that genetically determined differences in expression of a single cell surface molecule can influence autoantibody production, we have assessed autoimmunity in a C57BL/6-transgenic mouse line with subtle 15–29% increases in CD19 cell surface expression (CD19 transgenic). Antinuclear Abs, especially anti-spindle pole Abs, rheumatoid factor, and autoantibodies for ssDNA, dsDNA, and histone were produced in these transgenic mice, but not littermate controls. This demonstrates that small changes in CD19 expression can induce autoantibody production. Remarkably, similar changes in CD19 expression were found on B cells from patients with systemic sclerosis, a multisystem disorder of connective tissue with autoantibody production. CD19 density on blood B cells from systemic sclerosis patients was significantly (∼20%) higher compared with normal individuals, whereas CD20, CD22, and CD40 expression were normal. These results suggest that modest changes in the expression or function of regulatory molecules such as CD19 may shift the balance between tolerance and immunity to autoimmunity. Thereby autoimmune disease may result from a collection of subtle multigenic alterations that could include incremental density changes in cell surface signaling molecules.
T Cell Epitope-Containing Hypoallergenic Recombinant Fragments of the Major Birch Pollen Allergen, Bet v 1, Induce Blocking Antibodies
Authors: Vrtala Susanne , Akdis Cezmi A. , Budak Ferah , Akdis Mübeccel , Blaser Kurt , Kraft Dietrich , Valenta Rudolf 
Published: April 2014

AbstractAllergen-specific immunotherapy represents one of the few curative approaches toward type I allergy. Up to 25% of allergic patients are sensitized against the major birch pollen allergen, Bet v 1. By genetic engineering we produced two recombinant (r) Bet v 1 fragments comprising aa 1–74 and aa 75–160 of Bet v 1, which, due to a loss of their native-like fold, failed to bind IgE Abs and had reduced allergenic activity. Here we show that both fragments covering the full Bet v 1 sequence induced human lymphoproliferative responses similar to rBet v 1 wild type. The C-terminal rBet v 1 fragment induced higher lymphoproliferative responses than the N-terminal fragment and represented a Th1-stimulating segment with high IFN-γ production, whereas the N-terminal fragment induced higher IL-4, IL-5, and IL-13 secretion. Immunization of mice and rabbits with rBet v 1 fragments induced IgG Abs, which cross-reacted with complete Bet v 1 and Bet v 1-related plant allergens and strongly inhibited the IgE binding of allergic patients to these allergens. Thus, our results demonstrate that hypoallergenic T cell epitope-containing rBet v 1 fragments, despite lacking IgE epitopes, can induce Abs in vivo that prevent the IgE binding of allergic patients to the wild-type allergen. The overall demonstration of the immunogenic features of the hypoallergenic rBet v 1 fragments will now enable clinical studies for safer and more efficient specific immunotherapy.
Role of Oxidants in NF-κB Activation and TNF-α Gene Transcription Induced by Hypoxia and Endotoxin
Authors: Chandel Navdeep S. , Trzyna Wendy C. , McClintock David S. , Schumacker Paul T. 
Published: April 2014

AbstractThe transcription factor NF-κB stimulates the transcription of proinflammatory cytokines including TNF-α. LPS (endotoxin) and hypoxia both induce NF-κB activation and TNF-α gene transcription. Furthermore, hypoxia augments LPS induction of TNF-α mRNA. Previous reports have indicated that antioxidants abolish NF-κB activation in response to LPS or hypoxia, which suggests that reactive oxygen species (ROS) are involved in NF-κB activation. This study tested whether mitochondrial ROS are required for both NF-κB activation and the increase in TNF-α mRNA levels during hypoxia and LPS. Our results indicate that hypoxia (1.5% O2) stimulates NF-κB and TNF-α gene transcription and increases ROS generation as measured by the oxidant sensitive dye 2′,7′-dichlorofluorescein diacetate in murine macrophage J774.1 cells. The antioxidants N-acetylcysteine and pyrrolidinedithiocarbamic acid abolished the hypoxic activation of NF-κB, TNF-α gene transcription, and increases in ROS levels. Rotenone, an inhibitor of mitochondrial complex I, abolished the increase in ROS signal, the activation of NF-κB, and TNF-α gene transcription during hypoxia. LPS stimulated NF-κB and TNF-α gene transcription but not ROS generation in J774.1 cells. Rotenone, pyrrolidinedithiocarbamic acid, and N-acetylcysteine had no effect on the LPS stimulation of NF-κB and TNF-α gene transcription, indicating that LPS activates NF-κB and TNF-α gene transcription through a ROS-independent mechanism. These results indicate that mitochondrial ROS are required for the hypoxic activation of NF-κB and TNF-α gene transcription, but not for the LPS activation of NF-κB.
Helicobacter pylori-Induced Mucosal Inflammation Is Th1 Mediated and Exacerbated in IL-4, But Not IFN-γ, Gene-Deficient Mice
Authors: Smythies Lesley E. , Waites Ken B. , Lindsey J. Russell , Harris Paul R. , Ghiara Paolo , Smith Phillip D. 
Published: April 2014

AbstractTo elucidate the pathogenesis of Helicobacter pylori-associated gastritis, we studied immune responses of C57BL/6J wild-type (WT), SCID, and gene deficient (IFN-γ−/− and IL-4−/−) mice following infection with a pathogenic isolate of H. pylori (SPM326). During early infection in WT mice, mononuclear and polymorphonuclear cells accumulated in the gastric lamina propria, and the numbers of cells in the inflamed mucosa expressing IFN-γ, but not IL-4, mRNA rose significantly (p &lt; 0.005), consistent with a local Th1 response. Splenic T cells from the same infected WT mice produced high levels of IFN-γ, no detectable IL-4, and low amounts of IL-10 following in vitro H. pylori urease stimulation, reflecting a systemic Th1 response. Infected C57BL/6J SCID mice did not develop gastric inflammation despite colonization by many bacteria. Infected C57BL/10J and BALB/c mice also did not develop gastric inflammation and displayed a mixed Th1/Th2 splenic cytokine profile. These data imply a major role for the Th1 cytokine IFN-γ in H. pylori-associated gastric inflammation in C57BL/6J mice. Compared with WT animals, infected IL-4−/− animals had more severe gastritis and higher levels of IFN-γ production by urease-stimulated splenocytes (p &lt; 0.01), whereas IFN-γ−/− mice exhibited no gastric inflammation and higher levels of IL-4 production by stimulated splenocytes. These findings establish C57BL/6J mice as an important model for H. pylori infection and demonstrate that up-regulated production of IFN-γ, in the absence of the opposing effects of IL-4 (and possibly IL-10), plays a pivotal role in promoting H. pylori-induced mucosal inflammation.
Complement-Dependent Acute-Phase Expression of C-Reactive Protein and Serum Amyloid P-Component
Authors: Szalai Alexander J. , van Ginkel Frederik W. , Wang Yue , McGhee Jerry R. , Volanakis John E. 
Published: April 2014

AbstractThe acute-phase response (APR) is regulated by TNF-α, IL-1β, and IL-6 acting alone, in combination, or in concert with hormones. The anaphylotoxin C5a, generated during complement activation, induces in vitro the synthesis of these cytokines by leukocytes and of acute-phase proteins by HepG2 cells. However, there is no clear evidence for a role of C5a or any other complement activation product in regulation of the APR in vivo. In this study, using human C-reactive protein (CRP) transgenic mice deficient in C3 or C5, we investigated whether complement activation contributes to induction of the acute-phase proteins CRP and serum amyloid P-component (SAP). Absence of C3 or C5 resulted in decreased LPS-induced up-regulation of the CRP transgene and the mouse SAP gene. Also, LPS induced both the IL-1β and IL-6 genes in normocomplementemic mice, but in complement-deficient mice it significantly induced only IL-6. Like LPS injection, activation of complement by cobra venom factor led to significant elevation of serum CRP and SAP in normocomplementemic mice but not in complement-deficient mice. Injection of recombinant human C5a into human CRP transgenic mice induced the IL-1β gene and caused significant elevation of both serum CRP and SAP. However, in human CRP transgenic IL-6-deficient mice, recombinant human C5a did not induce the CRP nor the SAP gene. Based on these data, we conclude that during the APR, C5a generated as a consequence of complement activation acts in concert with IL-6 and/or IL-1β to promote up-regulation of the CRP and SAP genes.
Maintenance of Large Numbers of Virus-Specific CD8+ T Cells in HIV-Infected Progressors and Long-Term Nonprogressors
Authors: Gea-Banacloche Juan C. , Migueles Stephen A. , Martino Lisa , Shupert W. Lesley , McNeil Andrew C. , Sabbaghian M. Shirin , Ehler Linda , Prussin Calman , Stevens Randy , Lambert Laurie , Altman John , Hallahan Claire W. , de Quiros Juan Carlos Lopez Bernaldo , Connors Mark 
Published: April 2014

Abstract
The virus-specific CD8+ T cell responses of 21 HIV-infected patients were studied including a unique cohort of long-term nonprogressors with low levels of plasma viral RNA and strong proliferative responses to HIV Ags. HIV-specific CD8+ T cell responses were studied by a combination of standard cytotoxic T cell (CTL) assays, MHC tetramers, and TCR repertoire analysis. The frequencies of CD8+ T cells specific to the majority of HIV gene products were measured by flow cytometric detection of intracellular IFN-γ in response to HIV-vaccinia recombinant-infected autologous B cells. Very high frequencies (0.8–18.0%) of circulating CD8+ T cells were found to be HIV specific. High frequencies of HIV-specific CD8+ T cells were not limited to long-tern nonprogressors with restriction of plasma virus. No correlation was found between the frequency of HIV-specific CD8+ T cells and levels of plasma viremia. In each case, the vast majority of cells (up to 17.2%) responded to gag-pol. Repertoire analysis showed these large numbers of Ag-specific cells were scattered throughout the repertoire and in the majority of cases not contained within large monoclonal expansions. These data demonstrate that high numbers of HIV-specific CD8+ T cells exist even in patients with high-level viremia and progressive disease. Further, they suggest that other qualitative parameters of the CD8+ T cell response may differentiate some patients with very low levels of plasma virus and nonprogressive disease.
Myelin/Oligodendrocyte Glycoprotein-Induced Autoimmune Encephalomyelitis in Common Marmosets: The Encephalitogenic T Cell Epitope pMOG24–36 Is Presented by a Monomorphic MHC Class II Molecule
Authors: Brok Herbert P.M. , Uccelli Antonio , Kerlero de Rosbo Nicole , Bontrop Ronald E. , Roccatagliata Luca , de Groot Natasja G. , Capello Elisabetta , Laman Jon D. , Nicolay Klaas , Mancardi Gian-Luigi , Ben-Nun Avraham , ‘t Hart Bert A. 
Published: April 2014

AbstractImmunization of common marmosets (Callithrix jacchus) with a single dose of human myelin in CFA, without administration of Bordetella pertussis, induces a form of autoimmune encephalomyelitis (EAE) resembling in its clinical and pathological expression multiple sclerosis in humans. The EAE incidence in our outbred marmoset colony is 100%. This study was undertaken to assess the genetic and immunological basis of the high EAE susceptibility. To this end, we determined the separate contributions of immune reactions to myelin/oligodendrocyte glycoprotein (MOG) and myelin basic protein to the EAE induction. Essentially all pathological features of myelin-induced EAE were also found in animals immunized with MOG in CFA, whereas in animals immunized with myelin basic protein in CFA clinical and pathological signs of EAE were lacking. The epitope recognition by anti-MOG Abs and T cells were assessed. Evidence is provided that the initiation of EAE is based on T and B cell activation by the encephalitogenic phMOG14–36 peptide in the context of monomorphic Caja-DRB*W1201 molecules.
Differential Expression of CC Chemokines and the CCR5 Receptor in the Pancreas Is Associated with Progression to Type I Diabetes
Authors: Cameron Mark J. , Arreaza Guillermo A. , Grattan Marsha , Meagher Craig , Sharif Shayan , Burdick Marie D. , Strieter Robert M. , Cook Donald N. , Delovitch Terry L. 
Published: April 2014

AbstractWe investigated the biological role of CC chemokines in the Th1-mediated pathogenesis of spontaneous type I diabetes in nonobese diabetic (NOD) mice. Whereas an elevated ratio of macrophage inflammatory protein-1α (MIP-1α):MIP-1β in the pancreas correlated with destructive insulitis and progression to diabetes in NOD mice, a decreased intrapancreatic MIP-1α:MIP-1β ratio was observed in nonobese diabetes-resistant (NOR) mice. IL-4 treatment, which prevents diabetes in NOD mice by polarizing intraislet Th2 responses, decreased CCR5 expression in islets and potentiated a high ratio of MIP-1β and monocyte chemotactic protein-1 (MCP-1): MIP-1α in the pancreas. Furthermore, NOD.MIP-1α−/− mice exhibited reduced destructive insulitis and were protected from diabetes. Neutralization of MIP-1α with specific Abs following transfer of diabetogenic T cells delayed the onset of diabetes in NOD.Scid recipients. These studies illustrate that the temporal expression of certain CC chemokines, particularly MIP-1α, and the CCR5 chemokine receptor in the pancreas is associated with the development of insulitis and spontaneous type I diabetes.
Determination of Carrier Status for the Wiskott-Aldrich Syndrome by Flow Cytometric Analysis of Wiskott-Aldrich Syndrome Protein Expression in Peripheral Blood Mononuclear Cells
Authors: Yamada Masafumi , Ariga Tadashi , Kawamura Nobuaki , Yamaguchi Koji , Ohtsu Makoto , Nelson David L. , Kondoh Tatsuro , Kobayashi Ichiro , Okano Motohiko , Kobayashi Kunihiko , Sakiyama Yukio 
Published: April 2014

Abstract
The Wiskott-Aldrich syndrome (WAS) is caused by defects in the WAS protein (WASP) gene on the X chromosome. Previous study disclosed that flow cytometric analysis of intracellular WASP expression (FCM-WASP analysis) in lymphocytes was useful for the diagnosis of WAS patients. Lymphocytes from all WAS patients showed WASPdim instead of WASPbright. Here we report that FCM-WASP analysis in monocytes could be a useful tool for the WAS carrier diagnosis. Monocytes from all nine WAS carriers showed varied population of WASPdim together with WASPbright. None of control individuals possessed the WASPdim population. In contrast, lymphocytes from all the carriers except two lacked the WASPdim population. The difference of the WASPdim population in monocytes and lymphocytes observed in WAS carriers suggests that WASP plays a more critical role in the development of lymphocytes than in that of monocytes. The present studies suggest that a skewed X-chromosomal inactivation pattern observed in WAS carrier peripheral blood cells is not fixed at the hemopoietic stem cell level but progresses after the lineage commitment.
Long Term Persistence of Herpes Simplex Virus-Specific CD8+ CTL in Persons with Frequently Recurring Genital Herpes
Authors: Posavad Christine M. , Huang Meei Li , Barcy Serge , Koelle David M. , Corey Lawrence 
Published: April 2014

AbstractHerpes simplex virus (HSV) establishes a lifelong infection in humans. Reactivation of latent virus occurs intermittently so that the immune system is frequently exposed to viral Ag, providing an opportunity to evaluate memory T cells to a persistent human pathogen. We studied the persistence of genital herpes lesion-derived HSV-specific CD8+ CTL from three immunocompetent individuals with frequently recurring genital HSV-2 infection. All CTL clones were HSV-2 type specific and only one to three unique clonotypes were identified from any single biopsy specimen. The TCRBV genes utilized by these clonotypes were sequenced, and clonotype-specific probes were used to longitudinally track these clonotypes in PBMC and genital lesions. CTL clonotypes were consistently detected in PBMC and lesions for at least 2 and up to 7 years, and identical clonotypes infiltrated herpes lesions spaced as long as 7.5 years apart. Moreover, these clones were functionally lytic in vivo over these time periods. Additionally, CTL clones killed target cells infected with autologous viral isolates obtained 6.5 years after CTL clones were established, suggesting that selective pressure by these CTL did not result in the mutation of CTL epitopes. Thus, HSV recurs in the face of persistent CD8+ CTL with no evidence of clonal exhaustion or mutation of CTL epitopes as mechanisms of viral persistence.
Cutting Edge: Repurification of Lipopolysaccharide Eliminates Signaling Through Both Human and Murine Toll-Like Receptor 2
Authors: Hirschfeld Matthew , Ma Ying , Weis John H. , Vogel Stefanie N. , Weis Janis J. 
Published: April 2014

AbstractToll-like receptor (TLR) 2 has recently been associated with cellular responses to numerous microbial products, including LPS and bacterial lipoproteins. However, many preparations of LPS contain low concentrations of highly bioactive contaminants described previously as “endotoxin protein,” suggesting that these contaminants could be responsible for the TLR2-mediated signaling observed upon LPS stimulation. To test this hypothesis, commercial preparations of LPS were subjected to a modified phenol re-extraction protocol to eliminate endotoxin protein. While it did not influence the ability to stimulate cells from wild-type mice, repurification eliminated the ability of LPS to activate cells from C3H/HeJ (Lpsd) mice. Additionally, only cell lines transfected with human TLR4, but not human or murine TLR2, acquired responsiveness to both re-extracted LPS and to a protein-free, synthetic preparation of lipid A. These results suggest that neither human nor murine TLR2 plays a role in LPS signaling in the absence of contaminating endotoxin protein.
Identification of a Minimal T Cell Epitope Recognized by Antinucleosome Th Cells in the C-Terminal Region of Histone H4
Authors: Decker Patrice , Le Moal Anne , Briand Jean-Paul , Muller Sylviane 
Published: April 2014

AbstractAutoreactive T cells responding to systemic autoantigens have been characterized in patients and mice with autoimmune diseases and in healthy individuals. Using peptides covering the whole sequence of histone H4, we characterized several epitopes recognized by lymph node Th cells from nonsystemic lupus erythematosus-prone mice immunized with the same peptides, the H4 protein, or nucleosomes. Multiple T epitopes were identified after immunizing H-2d BALB/c mice with H4 peptides. They spanned residues 28–42, 30–47, 66–83, 72–89, and 85–102. Within the region 85–102, a minimal CD4+ T epitope containing residues 88–99 was characterized. Although Abs to peptide 88–99 recognized H4, this peptide does not contain a dominant B cell epitope recognized by anti-H4 Abs raised in BALB/c mice or Abs from NZB/NZW H-2d/z lupus mice. Th cells primed in vivo with H4 responded to H4, but not to peptide 88–99. However, this peptide was able to stimulate the proliferation and IL-2 secretion of Th cells generated after immunization with nucleosomes. H488–99 thus represents a cryptic epitope with regard to H4 and a supradominant epitope presented by nucleosome, a supramolecular complex that plays a key role in lupus. This study shows that in the normal repertoire of naive BALB/c mice, autoreactive Th cells specific for histones are not deleted. The reactivity of these Th cells seems to be relatively restricted and resembles that of Th clones generated from SNF1 ((SWR × NZB)F1; I-Ad/q) lupus mice described earlier.
Direct Immunosuppressive Effects of EBV-Encoded Latent Membrane Protein 1
Authors: Dukers Danny F. , Meij Pauline , Vervoort Marcel B. H. J. , Vos Wim , Scheper Rik J. , Meijer Chris J. L. M. , Bloemena Elisabeth , Middeldorp Jaap M. 
Published: April 2014

Abstract
In neoplastic cells of EBV-positive lymphoid malignancies latent membrane protein (LMP1) is expressed. Because no adequate cellular immune response can be detected against LMP1, we investigated whether LMP1 had a direct effect on T lymphocyte activation. In this study we show that nanogram amounts of purified recombinant LMP1 (rLMP1) strongly suppresses activation of T cells. By sequence alignment two sequences (LALLFWL and LLLLAL) in the first transmembrane domain of LMP1 were identified showing strong homology to the immunosuppressive domain (LDLLFL) of the retrovirus-encoded transmembrane protein p15E. The effects of rLMP1 and LMP1-derived peptides were tested in T cell proliferation and NK cytotoxicity assays and an Ag-induced IFN-γ release enzyme-linked immunospot assay. LMP1 derived LALLFWL peptides showed strong inhibition of T cell proliferation and NK cytotoxicity, while acetylated LALLFWL peptides had an even stronger effect. In addition, Ag-specific IFN-γ release was severely inhibited. To exert immunosuppressive effects in vivo, LMP1 has to be excreted from the cells. Indeed, LMP1 was detected in supernatant of EBV-positive B cell lines (LCL), and differential centrifugation in combination with Western blot analysis of the pellets indicated that LMP1 is probably secreted by LCL in the form of exosomes. The amount of secreted LMP1 in B cell cultures is well below the immunosuppressive level observed with rLMP1. Our results demonstrate direct immunosuppressive properties of LMP1 (fragments) and suggest that EBV-positive tumor cells may actively secrete LMP1 and thus mediate immunosuppressive effects on tumor-infiltrating lymphocytes. Moreover, we demonstrate, for the first time, that transmembrane protein-mediated immunosuppression is not solely restricted to RNA tumor viruses, but can also be found in DNA tumor viruses.
Membrane Lymphotoxin Is Required for the Development of Different Subpopulations of NK T Cells
Authors: Elewaut Dirk , Brossay Laurent , Santee Sybil M. , Naidenko Olga V. , Burdin Nicolas , De Winter Hilde , Matsuda Jennifer , Ware Carl F. , Cheroutre Hilde , Kronenberg Mitchell 
Published: April 2014

AbstractThe development of lymphoid organs requires membrane-bound lymphotoxin (LT), a heterotrimer containing LTα and LTβ, but the effects of LT on T cell function have not been characterized extensively. Upon TCR cross-linking in vitro, splenocytes from both LTα−/− and LTβ−/− mice failed to produce IL-4 and IL-10 due to a reduction in NK T cells. Concordantly, LTα−/− and LTβ−/− mice did not respond to the lipoglycan α-galactosylceramide, which is presented by mouse CD1 to Vα14+ NK T cells. Interestingly, both populations of NK T cells, including those that are mouse CD1 dependent and α-galactosylceramide reactive and those that are not, were affected by disruption of the LTα and LTβ genes. NK T cells were not affected, however, in transgenic mice in which LT signaling is blocked, beginning on day 3 after birth, by expression of a soluble decoy LTβ receptor. This suggests that membrane-bound LT is critical for NK T cells early in ontogeny, but not for the homeostasis of mature cells.