bluuebunny/crossref_metadata_2025_split huggingface dataset:
Generation of High-Affinity Antibody against T Cell-Dependent Antigen in the Ganp Gene-Transgenic Mouse
Authors: Sakaguchi Nobuo , Kimura Tetsuya , Matsushita Shuzo , Fujimura Satoru , Shibata Junji , Araki Masatake , Sakamoto Tamami , Minoda Chiemi , Kuwahara Kazuhiko 
Published: April 2014

Abstract
Generation of high-affinity Ab is impaired in mice lacking germinal center-associated DNA primase (GANP) in B cells. In this study, we examined the effect of its overexpression in ganp transgenic C57BL/6 mice (GanpTg). GanpTg displayed normal phenotype in B cell development, serum Ig levels, and responses against T cell-independent Ag; however, it generated the Ab with much higher affinity against nitrophenyl-chicken gammaglobulin in comparison with C57BL/6. To further examine the affinity increase, we established hybridomas producing high-affinity mAbs and compared their affinities using BIAcore. C57BL/6 generated high-affinity anti-nitrophenyl mAbs (KD ∼ 2.50 × 10−7 M) of IgG1/λ1 and contained the VH186.2 region with W33L mutation. GanpTg generated much higher affinity (KD &gt; 1.57 × 10−9 M) by usage of VH186.2 as well as noncanonical VH7183 regions. GanpTg also generated exceptionally high-affinity anti-HIV-1 (V3 peptide) mAbs (KD &gt; 9.90 × 10−11 M) with neutralizing activity. These results demonstrated that GANP is involved in V region alteration generating high-affinity Ab.
Regulation of Highly Cytokinergic IgE-Induced Mast Cell Adhesion by Src, Syk, Tec, and Protein Kinase C Family Kinases
Authors: Kitaura Jiro , Eto Koji , Kinoshita Tatsuya , Kawakami Yuko , Leitges Michael , Lowell Clifford A. , Kawakami Toshiaki 
Published: April 2014

AbstractMast cells play a critical role in IgE-dependent immediate hypersensitivity. Recent studies have shown that, contrary to the traditional view, binding of monomeric IgE to FcεRI results in a number of biological outcomes in mast cells, including survival. However, IgE molecules display heterogeneity in inducing cytokine production; highly cytokinergic (HC) IgEs cause extensive FcεRI aggregation, which leads to potent enhancement of survival and other activation events, whereas poorly cytokinergic (PC) IgEs can do so inefficiently. The present study demonstrates that HC, but not PC, IgEs can efficiently induce adhesion and spreading of mouse mast cells on fibronectin-coated plates in slow and sustained kinetics. HC IgE-induced adhesion through β1 and β7 integrins promotes survival, IL-6 production, and DNA synthesis. Importantly, we have identified Lyn and Syk as requisite tyrosine kinases and Hck, Btk, and protein kinase C θ as contributory kinases in HC IgE-induced adhesion and spreading, whereas protein kinase C ε plays a negative role. Consistent with these results, Lyn, Syk, and Btk are activated in HC IgE-stimulated cells in a slower but more sustained manner, compared with cells stimulated with IgE and Ag. Thus, binding of HC IgEs to FcεRI induces adhesion of mast cells to fibronectin by modulating cellular activation signals in a unique fashion.
Active Tolerance Induction and Prevention of Autoimmune Diabetes by Immunogene Therapy Using Recombinant Adenoassociated Virus Expressing Glutamic Acid Decarboxylase 65 Peptide GAD500–585
Authors: Han Gencheng , Li Yan , Wang Jianan , Wang Renxi , Chen Guojiang , Song Lun , Xu Ruonan , Yu Ming , Wu Xiaobing , Qian Jiahua , Shen Beifen 
Published: April 2014

AbstractTolerance induction of autoreactive T cells against pancreatic β cell-specific autoantigens such as glutamic acid decarboxylase 65 (GAD65) and insulin has been attempted as a method to prevent autoimmune diabetes. In this study, we investigate whether adenoassociated virus (AAV) gene delivery of multiple immunodominant epitopes expressing GAD500–585 could induce potent immune tolerance and persistently suppress autoimmune diabetes in NOD mice. A single muscle injection of 7-wk-old female NOD mice with rAAV/GAD500–585 (3 × 1011 IU/mouse) quantitatively reduced pancreatic insulitis and efficiently prevented the development of overt type I diabetes. This prevention was marked by the inactivation of GAD500–585-responsive T lymphocytes, the enhanced GAD500–585-specific Th2 response (characterized by increased IL-4, IL-10 production, and decreased IFN-γ production; especially elevated anti-GAD500–585 IgG1 titer; and relatively unchanged anti-GAD500–585 IgG2b titer), the increased secretion of TGF-β, and the production of protective regulatory cells. Our studies also revealed that peptides 509–528, 570–585, and 554–546 in the region of GAD500–585 played important roles in rAAV/GAD500–585 immunization-induced immune tolerance. These data indicate that using AAV, a vector with advantage for therapeutic gene delivery, to transfer autoantigen peptide GAD500–585, can induce immunological tolerance through active suppression of effector T cells and prevent type I diabetes in NOD mice.
A Sexual Dimorphism in Intrathymic Sialylation Survey Is Revealed by thetrans-Sialidase fromTrypanosoma cruzi
Authors: Mucci Juan , Mocetti Esteban , Leguizamón María Susana , Campetella Oscar 
Published: April 2014

AbstractSialylation is emerging as an important issue in developing thymocytes and is considered among the most significant cell surface modifications, although its physiologic relevance is far from being completely understood. It is regulated by the concerted expression of sialyl transferases along thymocyte development. After in vivo administration of trans-sialidase, a virulence factor from the American trypanosomatid Trypanosoma cruzi that directly transfers the sialyl residue among macromolecules, we found that the alteration of the sialylation pattern induces thymocyte apoptosis inside the “nurse cell complex.” This suggests a glycosylation survey in the development of the T cell compartment. In this study, we report that this thymocyte apoptosis mechanism requires the presence of androgens. No increment in apoptosis was recorded after trans-sialidase administration in females or in antiandrogen-treated, gonadectomized, or androgen receptor mutant male mice. The androgen receptor presence was required only in the thymic epithelial cells as determined by bone marrow chimeric mouse approaches. The presence of the CD43 surface mucin, a molecule with a still undefined function in thymocytes, was another absolute requirement. The trans-sialidase-induced apoptosis proceeds through the TNF-α receptor 1 deathly signaling leading to the activation of the caspase 3. Accordingly, the production of the cytokine was increased in thymocytes. The ability of males to delete thymocytes altered in their sialylation pattern reveals a sexual dimorphism in the glycosylation survey during the development of the T cell compartment that might be related to the known differences in the immune response among sexes.
Signals from CD28 Induce Stable Epigenetic Modification of the IL-2 Promoter
Authors: Thomas Rajan M. , Gao Ling , Wells Andrew D. 
Published: April 2014

AbstractCD28 costimulation controls multiple aspects of T cell function, including the expression of proinflammatory cytokine genes. One of these genes encodes IL-2, a growth factor that influences T cell proliferation, survival, and differentiation. Antigenic signaling in the absence of CD28 costimulation leads to anergy, a mechanism of tolerance that renders CD4+ T cells unable to produce IL-2. The molecular mechanisms by which CD28 costimulatory signals induce gene expression are not fully understood. In eukaryotic cells, the expression of many genes is influenced by their physical structure at the level of DNA methylation and local chromatin remodeling. To address whether these epigenetic mechanisms are operative during CD28-dependent gene expression in CD4+ T cells, we compared cytosine methylation and chromatin structure at the IL-2 locus in fully activated CD4+ effector T cells and CD4+ T cells rendered anergic by TCR ligation in the absence of CD28 costimulation. Costimulation through CD28 led to marked, stable histone acetylation and loss of cytosine methylation at the IL-2 promoter/enhancer. This was accompanied by extensive remodeling of the chromatin in this region to a structure highly accessible to DNA binding proteins. Conversely, TCR activation in the absence of CD28 costimulation was not sufficient to promote histone acetylation or cytosine demethylation, and the IL-2 promoter/enhancer in anergic cells remained completely inaccessible. These data suggest that CD28 may function through epigenetic mechanisms to promote CD4+ T cell responses.
T Cell-Mediated Delay of Spontaneous Mammary Tumor Onset: Increased Efficacy with In Vivo versus In Vitro Activation
Authors: O’Mara Leigh A. , Norian Lyse A. , Kreamalmeyer Darren , White J. Michael , Allen Paul M. 
Published: April 2014

AbstractPeripheral tolerance to shared Ags expressed on both tumors and normal self-tissues presents a major barrier to T cell-based immunotherapy as a treatment for cancer. To assess the activity of tumor-specific T cells against spontaneously arising carcinomas in the context of shared Ag expression, we developed a model system whereby an identified tumor Ag, tumor ERK (tERK), is expressed transgenically on both normal mammary tissue and spontaneous mammary carcinomas. Transfer of in vitro-activated, tERK-specific DUC18 T cells delayed spontaneous tumor development in tERK-expressing mice when T cells were given before the development of palpable carcinomas. However, antitumor activity mediated by in vitro-activated DUC18 T cells, as measured by responsiveness against a transplanted tERK-expressing fibrosarcoma challenge, was lost within days of transfer. This loss was due to expression of tERK as a self-Ag on normal tissues and was independent of the presence of mammary tumors. In contrast, transferred naive DUC18 T cells maintained a long-term protective function in tERK-expressing mice. Ten-fold fewer naive T cells activated in vivo were able to replicate the delay in spontaneous tumor development achieved by in vitro-activated T cells. These results are in contrast to our earlier studies using transplanted tumors alone, in which in vitro-activated DUC18 T cells were more efficacious than naive DUC18 T cells and highlight the need to perform tumor studies in the presence of tumor Ag expression on normal self-tissue.
γδ T Cells Regulate the Extent and Duration of Inflammation in the Central Nervous System by a Fas Ligand-Dependent Mechanism
Authors: Ponomarev Eugene D. , Dittel Bonnie N. 
Published: April 2014

Abstractγδ T cells have been shown to regulate immune responses associated with inflammation, but the mechanism of this regulation is largely unknown. Using the experimental autoimmune encephalomyelitis (EAE) model of the human CNS autoimmune disease multiple sclerosis, we demonstrate that γδ T cells are important regulators of CNS inflammation. This was shown using γδ T cell-deficient mice that were unable to recover from EAE. The chronic disease was accompanied by a prolonged presence of both macrophages and lymphocytes in the CNS. This extended inflammatory response was due to alterations in both cell proliferation and death. In mice lacking γδ T cells, proliferation of encephalitogenic T cells was 3-fold higher, and caspase activity, indicating apoptosis, was 2-fold lower compared with those in control mice recovering from EAE. γδ T cell-deficient mice reconstituted with wild-type γδ T cells recovered from EAE and resolved inflammation in the CNS, whereas mice reconstituted with Fas ligand-dysfunctional γδ T cells did not. Thus, γδ T cells regulate both inflammation in the CNS and disease recovery via Fas/Fas ligand-induced apoptosis of encephalitogenic T cells, and a quick resolution of inflammation in the CNS is essential to prevent permanent damage to the CNS resulting in chronic disease.
IL-12-Independent LIGHT Signaling Enhances MHC Class II Disparate CD4+ T Cell Alloproliferation, IFN-γ Responses, and Intestinal Graft-versus-Host Disease
Authors: Brown Geri R. , Lee Edward L. , El-Hayek Jihad , Kintner Katherine , Luck Cheryl 
Published: April 2014

AbstractInhibition of LIGHT (a cellular ligand for herpes virus entry mediator and lymphotoxin receptor)/herpes simplex virus entry mediator (HVEM) and LIGHT/lymphotoxin β receptor (LTβR) interactions decreases mortality in MHC class I and II disparate graft-vs-host disease (GVHD). The present studies assessed the effects of these interactions on the generation of CD4+ T cell alloresponses in MHC class II-disparate MLC and GVHD. An inhibitor protein of LIGHT and LTαβ2 (LTβR-Ig) and an inhibitor protein of LIGHT (HVEM-Ig) caused similar decreases in alloresponses of control B6 or B6.129S1-IL12rb2tm1Jm (B6.IL12R−/−) spleen cells (SpC) in a MHC class II-disparate MLC. GVHD-induced wasting disease in MHC class II-disparate recipients of B6 CD4+ SpC who received either the LTβR-Ig-encoding adenovirus (LTβR-Ig Adv; 13.1 ± 10.9%; n = 10; p = 0.0004) or the HVEM-Ig-encoding adenovirus (HVEM-Ig Adv; 16.4 ± 9.9%; n = 13; p = 0.0008) was significantly reduced compared with that in recipients of a control adenovirus (30.4 ± 8.8%; n = 13). Furthermore, gut GVHD histologic scores of recipients of B6 CD4+ SpC who received the LTβR-Ig Adv (0.8 ± 0.8; n = 5; p = 0.0007) or the HVEM-Ig Adv (1.4 ± 0.5; n = 5; p = 0.008) were reduced compared with scores of recipients of a control adenovirus (2.5 ± 0.75; n = 11). In the intestine, both LTβR-Ig Adv and HVEM-Ig Adv decreased CD4+ T cells (0.35 ± 0.4 × 106 (n = 6) vs 0.36 ± 0.02 × 106 (n = 9); p = 0.03 and p = 0.007) compared with control adenovirus (0.86 ± 0.42 × 106; n = 9). LIGHT is critical for optimal CD4+ T cell alloresponses in MHC class II-disparate MLC and GVHD.
Macrophage Colony-Stimulating Factor Drives Cord Blood Monocyte Differentiation into IL-10highIL-12absent Dendritic Cells with Tolerogenic Potential
Authors: Li Geling , Kim Young-June , Broxmeyer Hal E. 
Published: April 2014

AbstractImmature dendritic cells (DCs) induce tolerance and mature DCs induce inflammatory immune responses. However, the likelihood of maturation of immature DCs in vivo limits its potential application for suppression of unwanted immune reactions in vivo. The aim of this study was to generate DCs with anti-inflammatory properties in both the immature and mature states. GM-CSF combined with IL-4 drives monocyte differentiation into DCs. As M-CSF is a critical cytokine in development of the monocytic lineage and its level is dramatically elevated in immunosuppressive conditions, we investigated whether M-CSF could replace GM-CSF and generate DCs with distinct functions from umbilical cord blood monocytes. Highly purified umbilical cord blood monocytes cultured with M-CSF and IL-4, in a GM-CSF-independent fashion, differentiated into IL-10highIL-12absent cells with a DC phenotype (termed M-DC). Single time stimulation with immature DCs (both M-DCs and DCs) derived from cord blood induced hyporesponsive and regulatory CD4+ T cells. In contrast to mature DCs, mature M-DCs induced decreased Th1 differentiation and proliferation of naive CD4+ T cells in both primary and secondary allogeneic MLR and showed tolerogenic potential. These results demonstrate an unrecognized role for M-CSF in alternative differentiation of monocytes into anti-inflammatory M-DCs and suggest that M-CSF-induced DCs may be of use for suppressing unwanted immune responses.
Pattern of Kvβ Subunit Expression in Macrophages Depends upon Proliferation and the Mode of Activation
Authors: Vicente Rubén , Escalada Artur , Soler Concepció , Grande Maribel , Celada Antonio , Tamkun Michael M. , Solsona Carles , Felipe Antonio 
Published: April 2014

Abstract
Voltage-dependent potassium channels (Kv) in leukocytes are involved in the immune response. In bone marrow-derived macrophages (BMDM), proliferation and activation induce delayed rectifier K+ currents, generated by Kv1.3, via transcriptional, translational, and posttranslational controls. Furthermore, modulatory Kvβ subunits coassociate with Kvα subunits, increasing channel diversity and function. In this study we have identified Kvβ subunits in mouse BMDM, studied their regulation during proliferation and activation, and analyzed K+ current parameters influenced by these proteins. BMDM express all isoforms of Kvβ1 (Kvβ1.1, Kvβ1.2, and Kvβ1.3) and Kvβ2 (Kvβ2.1), but not Kvβ4, the alternatively spliced murine Kvβ3 variant. M-CSF-dependent proliferation induced all Kvβ isoforms. However, LPS- and TNF-α-induced activation differentially regulated these subunits. Although LPS increased Kvβ1.3, reduced Kvβ1.2, and maintained Kvβ1.1 mRNA levels constant, TNF-α up-regulated Kvβ1.1, down-regulated Kvβ1.2, and left Kvβ1.3 expression unchanged. Moreover, in contrast to TNF-α, M-CSF- and LPS- up-regulated Kvβ2.1. K+ currents from M-CSF- and LPS-stimulated BMDM exhibited faster inactivation, whereas TNF-α increased τ values. Although in M-CSF-stimulated cells the half-inactivation voltage shifted to more positive potentials, the incubation with LPS and TNF-α resulted in a hyperpolarizing displacement similar to that in resting BMDM. Furthermore, activation time constants of K+ currents and the kinetics of the tail currents were different depending upon the mode of activation. Our results indicate that differential Kvβ expression modifies the electrical properties of Kv in BMDM, dependent upon proliferation and the mode of activation. This could determine physiologically appropriate surface channel complexes, allowing for greater flexibility in the precise regulation of the immune response.
A Role for SATB1, a Nuclear Matrix Association Region-Binding Protein, in the Development of CD8SP Thymocytes and Peripheral T Lymphocytes
Authors: Nie Hui , Maika Shanna D. , Tucker Philip W. , Gottlieb Paul D. 
Published: April 2014

AbstractStudies have suggested that binding of the SATB1 protein to L2a, a matrix association region located 4.5 kb 5′ to the mouse CD8α gene, positively affects CD8 expression in T cells. Therefore, experiments were performed to determine the effect on T cell development of reduced expression of SATB1. Because homozygous SATB1-null mice do not survive to adulthood due to nonthymus autonomous defects, mice were produced that were homozygous for a T cell-specific SATB1-antisense transgene and heterozygous for a SATB1-null allele. Thymic SATB1 protein was reduced significantly in these mice, and the major cellular phenotype observed was a significant reduction in the percentage of CD8SP T cells in thymus, spleen, and lymph nodes. Mice were smaller than wild type but generally healthy, and besides a general reduction in cellularity and a slight increase in surface CD3 expression on CD8SP thymocytes, the composition of the thymus was similar to wild type. The reduction in thymic SATB1 does not lead to the variegated expression of CD8-negative single positive thymocytes seen upon deletion of several regulatory elements and suggested by others to reflect failure to activate the CD8 locus. Thus, the present results point to an essential role for SATB1 late in the development and maturation of CD8SP T cells.
Dysfunction of Simian Immunodeficiency Virus/Simian Human Immunodeficiency Virus-Induced IL-2 Expression by Central Memory CD4+ T Lymphocytes
Authors: Sun Yue , Schmitz Jörn E. , Acierno Paula M. , Santra Sampa , Subbramanian Ramu A. , Barouch Dan H. , Gorgone Darci A. , Lifton Michelle A. , Beaudry Kristin R. , Manson Kelledy , Philippon Valerie , Xu Ling , Maecker Holden T. , Mascola John R. , Panicali Dennis , Nabel Gary J. , Letvin Norman L. 
Published: April 2014

Abstract
Production of IL-2 and IFN-γ by CD4+ T lymphocytes is important for the maintenance of a functional immune system in infected individuals. In the present study, we assessed the cytokine production profiles of functionally distinct subsets of CD4+ T lymphocytes in rhesus monkeys infected with pathogenic or attenuated SIV/simian human immunodeficiency virus (SHIV) isolates, and these responses were compared with those in vaccinated monkeys that were protected from immunodeficiency following pathogenic SHIV challenge. We observed that preserved central memory CD4+ T lymphocyte production of SIV/SHIV-induced IL-2 was associated with disease protection following primate lentivirus infection. Persisting clinical protection in vaccinated and challenged monkeys is thus correlated with a preserved capacity of the peripheral blood central memory CD4+ T cells to express this important immunomodulatory cytokine.
IL-6 Increases Primed Cell Expansion and Survival
Authors: Rochman Irina , Paul William E. , Ben-Sasson S. Z. 
Published: April 2014

AbstractCytochrome c-specific CD4 T cells from transgenic donors transferred to syngeneic B10.A mice expand more vigorously upon immunization if exogenous IL-6 is provided during the initial phase of immunization. The resultant increase in the frequency and number of Ag-specific cells is observed in the blood, lymph nodes, spleen, liver, and lung and persists for at least 3 mo. Treatment of immunized recipients with anti-IL-6 or use of IL-6 knockout recipients reduced the frequency of Ag-specific CD4 T cells during a comparable period, indicating that IL-6 is physiologically involved in the expansion of memory and/or effector cells and thus in the persistence of memory. IL-6 did not alter the duration of Ag-presenting activity. Both CFSE dilution studies and labeling with BrdU indicated that IL-6 does not effect proliferative rates of responding CD4 T cells. By contrast, annexin V staining was diminished in responding cells from the IL-6-treated animals, particularly among those cells that had undergone five or more divisions. These results indicate that IL-6 reduces the level of apoptosis among Ag-stimulated cells; thus, it plays a central role in determining numbers of memory and/or effector CD4 T cells in response to immunization over extended periods.
B Cell Hyperresponsiveness and Expansion of Mature Follicular B Cells but Not of Marginal Zone B Cells in NFATc2/c3 Double-Deficient Mice
Authors: Samanta Devapriya Nandini , Palmetshofer Alois , Marinkovic Dragan , Wirth Thomas , Serfling Edgar , Nitschke Lars 
Published: April 2014

AbstractMarginal zone (MZ) B cells and peritoneal B-1 cells provide a first defense system of thymus-independent Ab responses against foreign pathogens and therefore share a number of functional properties. Recently, development of B-1a cells was shown to be controlled by the transcription factor NFATc1. We show here that mice deficient for NFATc2 and c3 display a distinct lower representation of MZ B cells, which is correlated with a reduced capturing of trinitrophenyl-Ficoll. In contrast, mature follicular B cells from NFATc2/c3−/− mice are strongly increased in number. NFATc2/c3−/− B cells exhibit a marked increase in BCR-induced intracellular Ca2+ mobilization and proliferation. However, trinitrophenyl-Ficoll-specific IgM and IgG3 responses of NFATc2/c3-deficient mice are intact, and chimeric mice reconstituted with NFATc2/3-deficient B cells show a normal number of MZ B cells and normal BCR responses. These observations suggest that the strongly elevated Th2 cytokine milieu in NFATc2/c3-deficient mice leads to a hyperactivation of mature, follicular B cells, whereas MZ B cells are less responsive to these signals.