bluuebunny/crossref_metadata_2025_split huggingface dataset:
Selective Unresponsiveness to Conformational B Cell Epitopes of the Myelin Oligodendrocyte Glycoprotein in H-2b Mice
Authors: Bourquin Carole , Schubart Anna , Tobollik Stephanie , Mather Ian , Ogg Sherry , Liblau Roland , Linington Christopher 
Published: April 2014

Abstract
Autoantibodies directed against conformation-dependent epitopes of the extracellular domain of the myelin oligodendrocyte glycoprotein (MOGIgd) play a major role in the immunopathogenesis of demyelination in experimental autoimmune encephalomyelitis. We now demonstrate that one or more genes encoded within the MHC selectively censor the ability of H-2b mice to mount this conformation-dependent autoantibody response, while leaving T and B cell responses to linear MOGIgd epitopes intact. This novel form of selective B cell unresponsiveness discriminates between pathogenic and nonpathogenic Ab responses to MOG and determines whether or not Ab-dependent effector mechanisms play an important role in the pathogenesis of MOG-induced experimental autoimmune encephalomyelitis in the mouse.
Rat and Human Myelin Oligodendrocyte Glycoproteins Induce Experimental Autoimmune Encephalomyelitis by Different Mechanisms in C57BL/6 Mice
Authors: Oliver Alfred R. , Lyon Geoffrey M. , Ruddle Nancy H. 
Published: April 2014

Abstract
C57BL/6 mice immunized with the extracellular Ig-like domain of rat myelin oligodendrocyte glycoprotein (MOG) developed experimental autoimmune encephalomyelitis (EAE) resembling that induced by rodent MOG 35-55 in its B cell independence and predominantly mononuclear CNS infiltrate. In contrast, human MOG protein-induced EAE was B cell dependent with polymorphonuclear leukocytes. Human MOG differs from rat MOG at several residues, including a proline for serine substitution at position 42. Human MOG 35-55 was only weakly encephalitogenic, and a proline substitution in rat MOG at position 42 severely attenuated its encephalitogenicity. However, human MOG 35-55 was immunogenic, inducing proliferation and IFN-γ and IL-3 to human, but not rodent MOG 35-55. The B cell dependence of EAE induced by human MOG protein was not due to a requirement for Ag presentation by B cells, because spleen cells from B cell-deficient mice processed and presented human and rat MOG proteins to T cells. The different pathogenic mechanisms of human and rat MOG proteins might result from different Abs induced by these proteins. However, rat and human MOG proteins induced Abs to mouse MOG that were equivalent in titer and IgG subclass. These data demonstrate that EAE can be induced in C57BL/6 mice by two mechanisms, depending on the nature of the immunogen: an encephalitogenic T cell response to rat MOG or rodent MOG 35-55, or an encephalitogenic B cell response to epitopes on human MOG protein that most likely cross-react with mouse determinants.
More Stringent Conditions of Plasmid DNA Vaccination Are Required to Protect Grafted Versus Endogenous Islets in Nonobese Diabetic Mice
Authors: Seifarth Christian , Pop Shannon , Liu Bo , Wong Carmen P. , Tisch Roland 
Published: April 2014

Abstract
Recurrent autoimmune destruction of the insulin-producing β cells is a key factor limiting successful islet graft transplantation in type I diabetic patients. In this study, we investigated the feasibility of using an Ag-specific plasmid DNA (pDNA)-based strategy to protect pro-islets that had developed from a neonatal pancreas implanted under the kidney capsule of nonobese diabetic (NOD) mice. NOD recipient mice immunized with pDNA encoding a glutamic acid decarboxylase 65 (GAD65)-IgFc fusion protein (JwGAD65), IL-4 (JwIL4), and IL-10 (pIL10) exhibited an increased number of intact pro-islets expressing high levels of insulin 15 wk posttransplant, relative to NOD recipient mice immunized with pDNA encoding a hen egg lysozyme (HEL)-IgFc fusion protein (JwHEL)+JwIL4 and pIL10 or left untreated. Notably, the majority of grafted pro-islets detected in JwGAD65+JwIL4- plus pIL10-treated recipients was free of insulitis. In addition, administration of JwGAD65+JwIL4+pIL10 provided optimal protection for engrafted islets compared with recipient NOD mice treated with JwGAD65+JwIL4 or JwGAD65+pIL10, despite effective protection of endogenous islets mediated by the respective pDNA treatments. Efficient protection of pro-islet grafts correlated with a marked reduction in GAD65-specific IFN-γ reactivity and an increase in IL-10-secreting T cells. These results demonstrate that pDNA vaccination can be an effective strategy to mediate long-term protection of pro-islet grafts in an Ag-specific manner and that conditions are more stringent to suppress autoimmune destruction of grafted vs endogenous islets.
Relationships Among Murine CD11chigh Dendritic Cell Subsets as Revealed by Baseline Gene Expression Patterns
Authors: Edwards Alexander D. , Chaussabel Damien , Tomlinson Simon , Schulz Oliver , Sher Alan , Reis e Sousa Caetano 
Published: April 2014

AbstractThe functional relationships and properties of different subtypes of dendritic cells (DC) remain largely undefined. To better characterize these cells, we used global gene analysis to determine gene expression patterns among murine CD11chigh DC subsets. CD4+, CD8α+, and CD8α− CD4− (double negative (DN)) DC were purified from spleens of normal C57/BL6 mice and analyzed using Affymetrix microarrays. The CD4+ and CD8α+ DC subsets showed distinct basal expression profiles differing by &gt;200 individual genes. These included known DC subset markers as well as previously unrecognized, differentially expressed CD Ags such as CD1d, CD5, CD22, and CD72. Flow cytometric analysis confirmed differential expression in nine of nine cases, thereby validating the microarray analysis. Interestingly, the microarray expression profiles for DN cells strongly resembled those of CD4+ DC, differing from them by &lt;25 genes. This suggests that CD4+ and DN DC are closely related phylogenetically, whereas CD8α+ DC represent a more distant lineage, supporting the historical distinction between CD8α+ and CD8α− DC. However, staining patterns revealed that in contrast to CD4+ DC, the DN subset is heterogeneous and comprises at least two subpopulations. Gene Ontology and literature mining analyses of genes expressed differentially among DC subsets indicated strong associations with immune response parameters as well as cell differentiation and signaling. Such associations offer clues to possible unique functions of the CD11chigh DC subsets that to date have been difficult to define as rigid distinctions.
Longitudinal Assessment of Changes in HIV-Specific Effector Activity in HIV-Infected Patients Starting Highly Active Antiretroviral Therapy in Primary Infection
Authors: Alter Galit , Hatzakis George , Tsoukas Christos Micheal , Pelley Karen , Rouleau Danielle , LeBlanc Roger , Baril Jean-Guy , Dion Harold , Lefebvre Eric , Thomas Réjean , Côté Pierre , Lapointe Normand , Routy Jean-Pierre , Sékaly Rafik-Pierre , Conway Brian , Bernard Nicole Flore 
Published: April 2014

AbstractBoth the magnitude and breadth of HIV-specific immunity were evaluated longitudinally on samples collected from six subjects starting highly active antiretroviral therapy (HAART) preseroconversion (group 1), 11 recently infected subjects starting HAART postseroconversion (group 2), five subjects starting HAART in the second half of the first year of infection (group 3), and six persons starting treatment in the chronic phase of infection (group 4). HIV-specific immunity was measured by IFN-γ ELISPOT, detecting the frequency of cells responding to a panel of HLA-restricted HIV-1 peptides. Intracellular cytokine staining was used to detect the frequency of HIV-1 Gag p55-specific CD4+ and CD8+ T cells in a subset of participants. The magnitude and breadth of HIV-specific responses persisted in all group 1 subjects and in 5 of 11 (45%) group 2 subjects. Both of these parameters declined in 6 of 11 (55%) group 2 and in all group 3 and 4 individuals. All persons who maintained detectable numbers of HIV-1 Gag p55-specific CD4+ and CD8+ T cells after starting HAART preserved the intensity and breadth of their HIV-specific effector response. Our results show that HIV-specific immunity can be preserved even if HAART is initiated beyond the acute phase of infection.
Short Term Administration of Costimulatory Blockade and Cyclophosphamide Induces Remission of Systemic Lupus Erythematosus Nephritis in NZB/W F1 Mice by a Mechanism Downstream of Renal Immune Complex Deposition
Authors: Schiffer Lena , Sinha Jayashree , Wang Xiaobo , Huang Weiqing , von Gonsdorff Gero , Schiffer Mario , Madaio Michael P. , Davidson Anne 
Published: April 2014

AbstractNZB/W F1 mice with established nephritis were treated with a single dose of cyclophosphamide with or without a 2-wk course of murine CTLA4Ig, either alone or in combination with anti-CD154. Sixty to 80% of treated mice entered remission, and remission could be reinduced following relapse. A decrease in the frequency of anti-DNA-producing B cells and activated T cells was observed in treated mice, but this effect lasted only 3–6 wk, while remissions were sustained for up to 20 wk. Light microscopy of the kidneys of mice in remission revealed less glomerular inflammation, less tubular damage, and less infiltration of inflammatory cells. By immunofluorescence, however, IgG and C3 staining of glomeruli was no different in treated mice vs controls. Since chemokines and their receptors play an important role in inflammatory cell infiltration of affected organs in autoimmune diseases, we examined chemokine expression in the kidneys. Decreases in the expression of inflammatory cytokines and chemokines were evident in mice in the early stages of remission, but these differences were no longer present in late remission. Increased expression of CXCL13 was detected in the inflammatory infiltrates of the control NZB/NZW mice. Strikingly, we could not detect any CXCL13 in the kidneys of the treated group even in late remission. These findings suggest that costimulatory blockade together with cyclophosphamide influence the activation state of renal CD11c-positive cells and therefore lead to less B and T cell infiltration and nephritis.
Homeostasis of Naive and Memory CD4+ T Cells: IL-2 and IL-7 Differentially Regulate the Balance Between Proliferation and Fas-Mediated Apoptosis
Authors: Jaleco Sara , Swainson Louise , Dardalhon Valérie , Burjanadze Maryam , Kinet Sandrina , Taylor Naomi 
Published: April 2014

AbstractCytokines play a crucial role in the maintenance of polyclonal naive and memory T cell populations. It has previously been shown that ex vivo, the IL-7 cytokine induces the proliferation of naive recent thymic emigrants (RTE) isolated from umbilical cord blood but not mature adult-derived naive and memory human CD4+ T cells. We find that the combination of IL-2 and IL-7 strongly promotes the proliferation of RTE, whereas adult CD4+ T cells remain relatively unresponsive. Immunological activity is controlled by a balance between proliferation and apoptotic cell death. However, the relative contributions of IL-2 and IL-7 in regulating these processes in the absence of MHC/peptide signals are not known. Following exposure to either IL-2 or IL-7 alone, RTE, as well as mature naive and memory CD4+ T cells, are rendered only minimally sensitive to Fas-mediated cell death. However, in the presence of the two cytokines, Fas engagement results in a high level of caspase-dependent apoptosis in both RTE as well as naive adult CD4+ T cells. In contrast, equivalently treated memory CD4+ T cells are significantly less sensitive to Fas-induced cell death. The increased susceptibility of RTE and naive CD4+ T cells to Fas-induced apoptosis correlates with a significantly higher IL-2/IL-7-induced Fas expression on these T cell subsets than on memory CD4+ T cells. Thus, IL-2 and IL-7 regulate homeostasis by modulating the equilibrium between proliferation and apoptotic cell death in RTE and mature naive and memory T cell subsets.
Thy-1 Signaling in the Context of Costimulation Provided by Dendritic Cells Provides Signal 1 for T Cell Proliferation and Cytotoxic Effector Molecule Expression, but Fails to Trigger Delivery of the Lethal Hit
Authors: Haeryfar S. M. Mansour , Al-alwan Monther M. , Mader Jamie S. , Rowden Geoffry , West Kenneth A. , Hoskin David W. 
Published: April 2014

Abstract
Cross-linking of the GPI-anchored protein Thy-1 results in T cell proliferation and IL-2 synthesis. However, the exact function of Thy-1 in the process of T cell activation remains unknown, as does the effect of costimulation on Thy-1-driven T cell responses. In this study, we have investigated the ability of Thy-1 to substitute for traditional signal 1 in the context of costimulation provided by dendritic cells. Dendritic cells dramatically enhanced T cell proliferation and IL-2 synthesis in response to Thy-1 triggering by anti-Thy-1 mAb. This effect was not dependent on dendritic cell Fcγ receptors, but was a result of B7-mediated costimulation (signal 2). T cells were also activated when microbeads coated with a combination of anti-Thy-1 and anti-CD28 mAbs were used to supply signals 1 and 2, respectively. Thy-1-stimulated T cells adhere to target cells and express perforin, granzyme B, and Fas ligand, but fail to kill target cells due to an inability to reorganize their secretion machinery. Moreover, in contrast to TCR signaling, Thy-1 triggering failed to induce cytotoxicity in redirected lysis assays. We conclude that Thy-1 triggering can partially substitute for signal 1, which, in combination with a strong signal 2, leads to robust T cell proliferation, IL-2 synthesis, and cytotoxic effector molecule expression, but does not induce cytolytic function. The block at the level of cytotoxic effector function that results when T cells are activated in the absence of a classical, Ag-specific signal 1 may constitute a mechanism to ensure the specificity of CTL responses and prevent potentially harmful promiscuous cytotoxicity.
T Cell Glycolipid-Enriched Membrane Domains Are Constitutively Assembled as Membrane Patches That Translocate to Immune Synapses
Authors: Jordan Stephen , Rodgers William 
Published: April 2014

Abstract
In T cells, glycolipid-enriched membrane (GEM) domains, or lipid rafts, are assembled into immune synapses in response to Ag presentation. However, the properties of T cell GEM domains in the absence of stimulatory signals, such as their size and distribution in the plasma membrane, are less clear. To address this question, we used confocal microscopy to measure GEM domains in unstimulated T cells expressing a GEM-targeted green fluorescent protein molecule. Our experiments showed that the GEM domains were assembled into membrane patches that were micrometers in size, as evidenced by a specific enrichment of GEM-associated molecules and resistance of the patches to extraction by Triton X-100. However, treatment of cells with latrunculin B disrupted the patching of the GEM domains and their resistance to Triton X-100. Similarly, the patches were coenriched with F-actin, and actin occurred in the detergent-resistant GEM fraction of T cells. Live-cell imaging showed that the patches were mobile and underwent translocation in the plasma membrane to immune synapses in stimulated T cells. Targeting of GEM domains to immune synapses was found to be actin-dependent, and required phosphatidylinositol 3-kinase activity and myosin motor proteins. We conclude from our results that T cell GEM domains are constitutively assembled by the actin cytoskeleton into micrometer-sized membrane patches, and that GEM domains and the GEM-enriched patches can function as a vehicle for targeting molecules to immune synapses.
Inhibition of Constitutive NF-κB Activation in Mantle Cell Lymphoma B Cells Leads to Induction of Cell Cycle Arrest and Apoptosis
Authors: Pham Lan V. , Tamayo Archito T. , Yoshimura Linda C. , Lo Piao , Ford Richard J. 
Published: April 2014

Abstract
Constitutive activation of the NF-κB has been documented to be involved in the pathogenesis of many human malignancies, including hemopoietic neoplasms. In this study, we examined the status of NF-κB in two non-Hodgkin’s lymphoma cell lines derived from mantle cell lymphoma (MCL) samples and in patient MCL biopsy specimens by EMSA and confocal microscopic analysis. We observed that NF-κB is constitutively activated in both the MCL cell lines and in the MCL patient biopsy cells. Since NF-κB has been shown to play an important role in a variety of cellular processes, including cell cycle regulation and apoptosis, targeting the NF-κB pathways for therapy may represent a rational approach in this malignancy. In the MCL cell lines, inhibition of constitutive NF-κB by the proteasome inhibitor PS-341 or a specific pIκBα inhibitor, BAY 11-7082, led to cell cycle arrest in G1 and rapid induction of apoptosis. Apoptosis was associated with the down-regulation of bcl-2 family members bcl-xL and bfl/A1, and the activation of caspase 3, that mediates bcl-2 cleavage, resulting in the release of cytochrome c from the mitochondria. PS-341or BAY 11-induced G1 cell cycle arrest was associated with the inhibition of cyclin D1 expression, a molecular genetic marker of MCL. These studies suggest that constitutive NF-κB expression plays a key role in the growth and survival of MCL cells, and that PS-341 and BAY 11 may be useful therapeutic agents for MCL, a lymphoma that is refractory to most current chemotherapy regimens.
Rho Kinase Promotes Alloimmune Responses by Regulating the Proliferation and Structure of T Cells
Authors: Tharaux Pierre-Louis , Bukoski Richard C. , Rocha Paulo N. , Crowley Steven D. , Ruiz Phillip , Nataraj Chandra , Howell David N. , Kaibuchi Kozo , Spurney Robert F. , Coffman Thomas M. 
Published: April 2014

AbstractCoordinated rearrangements of the actin-myosin cytoskeleton facilitate early and late events in T cell activation and signal transduction. As many important features of cell shape rearrangement involve small GTP-binding proteins, we examined the contribution of Rho kinase to the functions of mature T cells. Inhibitors of the Rho kinase pathway all had similar actions to inhibit the proliferation of primary lymphocyte cultures. Likewise, transfection of the human Jurkat T cell line with a dominant negative, kinase-defective mutant of Rho kinase diminished Jurkat cell proliferation. Furthermore, inhibition of Rho kinase substantially attenuated the program of cytokine gene expression that characterizes T cell activation, blocked actomyosin polymerization, and prevented aggregation of the TCR/CD3 complex colocalized with lipid rafts. These actions are relevant to immune responses in vivo, as treatment with a Rho kinase inhibitor considerably prolonged the survival of fully allogeneic heart transplants in mice and diminished intragraft expression of cytokine mRNAs. Thus, Rho GTPases acting through Rho kinase play a unique role in T cell activation during cellular immune responses by promoting structural rearrangements that are critical for T cell signaling.
Cutting Edge: IL-16/CD4 Preferentially Induces Th1 Cell Migration: Requirement of CCR5
Authors: Lynch Elizabeth A. , Heijens Claudia A. W. , Horst Noah F. , Center David M. , Cruikshank William W. 
Published: April 2014

AbstractIL-16 binds to CD4 and induces a migratory response in CD4+ T cells. Although it has been assumed that CD4 is the sole receptor and that IL-16 induces a comparable migratory response in all CD4+ T cells, this has not been investigated. In this study, we determined that IL-16 preferentially induces a migratory response in Th1 cells. Because chemokine receptor CCR5 is expressed predominantly in Th1 cells and is physically associated with CD4, we investigated whether IL-16/CD4 stimulation was enhanced in the presence of CCR5. Using T cells from CCR5null mice, we determined that IL-16-induced migration was significantly greater in the presence of CCR5. The presence of CCR5 significantly increased IL-16 binding vs CD4 alone; however, IL-16 could not bind to CCR5 alone. Because CD4+CCR5+ cells are prevalent at sites of inflammation, this intimate functional relationship likely plays a pivotal role for the recruitment and activation of Th1 cells.
Cutting Edge: Long-Term B Cell Memory in Humans after Smallpox Vaccination
Authors: Crotty Shane , Felgner Phil , Davies Huw , Glidewell John , Villarreal Luis , Ahmed Rafi 
Published: April 2014

Abstract
Memory B cells are a central component of humoral immunity, and yet little is known about their longevity in humans. Immune memory after smallpox vaccination (DryVax) is a valuable benchmark for understanding the longevity of B cell memory in the absence of re-exposure to Ag. In this study, we demonstrate that smallpox vaccine-specific memory B cells last for &gt;50 years in immunized individuals. Virus-specific memory B cells initially declined postimmunization, but then reached a plateau ∼10-fold lower than peak and were stably maintained for &gt;50 years after vaccination at a frequency of ∼0.1% of total circulating IgG+ B cells. These persisting memory B cells were functional and able to mount a robust anamnestic Ab response upon revaccination. Additionally, virus-specific CD4+ T cells were detected decades after vaccination. These data show that immunological memory to DryVax vaccine is long-lived and may contribute to protection against smallpox.
Cutting Edge: Predetermined Avidity of Human CD8 T Cells Expanded on Calibrated MHC/Anti-CD28-Coated Microspheres
Authors: Walter Steffen , Herrgen Leah , Schoor Oliver , Jung Gundram , Wernet Dorothee , Bühring Hans-Jörg , Rammensee Hans-Georg , Stevanović Stefan 
Published: April 2014

AbstractCytotoxic CD8 T cells are key effectors in the immunotherapy of malignant and viral diseases. However, the lack of efficient methods for their in vitro priming and expansion has become a bottleneck to the development of vaccines and adoptive transfer strategies. Synthetic artificial APCs (aAPCs) are now emerging as an attractive tool for eliciting and expanding CTL responses. We show that, by controlling the MHC density on aAPCs, high- or low-avidity tumor-directed human CTL lines can be raised effectively in vitro if costimulation via CD28 and IL-12 is provided. Compared with low-avidity CTL lines, high-avidity CTLs need 100- to 1000-fold less peptide for activation, bind more MHC tetramers, and, as expected, are superior in recognizing tumor cell lines expressing Ag. We believe that the possibility to raise Ag-specific T cells with predetermined avidity will be crucial for the future use of aAPCs in immunotherapeutical settings.
Cutting Edge: γδ T Cells Provide Help to B Cells with Altered Clonotypes and Are Capable of Inducing Ig Gene Hypermutation
Authors: Zheng Biao , Marinova Ekaterina , Han Jin , Tan Tse-Hua , Han Shuhua 
Published: April 2014

AbstractIt has not been resolved whether γδ T cells can collaborate with germinal center B cells and support Ig hypermutation during an Ab response to a truly defined T-dependent Ag. In this study, we show that in the absence of αβ T cells, immunization with the well-defined T-dependent Ag, (4-hydroxy-3-nitrophenyl) acetyl (NP) conjugate, was able to induce Ig hypermutation. However, the clonotypes of B cells responding to NP were dramatically altered in TCR β−/− mice. Unlike B cells in wild-type mice that use canonical VDJ rearrangements, most NP-responding B cells in mutant mice use analog genes of the J558 gene family. In addition, the majority of anti-NP Abs produced in mutant mice use κL chain instead of λ1L chain, which dominates in mice of Ighb background. Thus, the B cell population that collaborates with γδ T cells is distinct from B cells interacting with conventional αβ Th cells.