bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protective Antitumor Immunity Induced by a Costimulatory Thalidomide Analog in Conjunction with Whole Tumor Cell Vaccination Is Mediated by Increased Th1-Type Immunity
Authors: Dredge Keith , Marriott J. Blake , Todryk Stephen M. , Muller George W. , Chen Roger , Stirling David I. , Dalgleish Angus G. 
Published: April 2014

AbstractThalidomide and its novel T cell costimulatory analogs (immunomodulatory drugs) are currently being assessed in the treatment of patients with advanced cancer. However, neither tumor-specific T cell costimulation nor effective antitumor activity has been demonstrated in vivo. In this study, we assessed the ability of an immunomodulatory drug (CC-4047/ACTIMID) to prime a tumor-specific immune response following tumor cell vaccination. We found that the presence of CC-4047 during the priming phase strongly enhanced antitumor immunity in the vaccinated group, and this correlated with protection from subsequent live tumor challenge. Protection was associated with tumor-specific production of IFN-γ and was still observed following a second challenge with live tumor cells 60 days later. Furthermore, CD8+ and CD4+ splenocyte fractions from treated groups secreted increased IFN-γ and IL-2 in response to tumor cells in vitro. Coculture of naive splenocytes with anti-CD3 mAb in the presence of CC-4047 directly costimulated T cells and increased Th1-type cytokines. Our results are the first to demonstrate that a costimulatory thalidomide analog can prime protective, long-lasting, tumor-specific, Th1-type responses in vivo and further support their ongoing clinical development as novel anti-cancer agents.
Patterns of Chemokine Receptor Expression on Peripheral Blood γδ T Lymphocytes: Strong Expression of CCR5 Is a Selective Feature of Vδ2/Vγ9 γδ T Cells
Authors: Glatzel Andrea , Wesch Daniela , Schiemann Florian , Brandt Ernst , Janssen Ottmar , Kabelitz Dieter 
Published: April 2014

Abstract
γδ T lymphocytes play an important role in the immune defense against infection, based on the unique reactivity of human Vδ2Vγ9 γδ T cells toward bacterial phosphoantigens. Chemokines and their corresponding receptors orchestrate numerous cellular reactions, including leukocyte migration, activation, and degranulation. In this study we investigated the expression of various receptors for inflammatory and homeostatic chemokines on peripheral blood γδ T cells and compared their expression patterns with those on αβ T cells. Although several of the analyzed receptors (including CCR6, CCR7, CXCR4, and CXCR5) were not differentially expressed on γδ vs αβ T cells, γδ T cells expressed strongly increased levels of the RANTES/macrophage inflammatory protein-1α/-1β receptor CCR5 and also enhanced levels of CCR1–3 and CXCR1–3. CCR5 expression was restricted to Vδ2 γδ T cells, while the minor subset of Vδ1 γδ T cells preferentially expressed CXCR1. Stimulation with heat-killed extracts of Mycobacterium tuberculosis down-modulated cell surface expression of CCR5 on γδ T cells in a macrophage-dependent manner, while synthetic phosphoantigen isopentenyl pyrophosphate and CCR5 ligands directly triggered CCR5 down-modulation on γδ T cells. The functionality of chemokine receptors CCR5 and CXCR3 on γδ T cells was demonstrated by Ca2+ mobilization and chemotactic response to the respective chemokines. Our results identify high level expression of CCR5 as a characteristic and selective feature of circulating Vδ2 γδ T cells, which is in line with their suspected function as Th1 effector T cells.
Absence of Fer Protein-Tyrosine Kinase Exacerbates Leukocyte Recruitment in Response to Endotoxin
Authors: McCafferty Donna-Marie , Craig Andrew W. B. , Senis Yotis A. , Greer Peter A. 
Published: April 2014

Abstract
The group IV cytoplasmic protein-tyrosine kinase Fer has been linked to cellular signaling responses to many different stimuli, including growth factors and cytokines. However, the biological relevance of Fer activation in vivo has not been demonstrated to date. Recently, we generated a transgenic mouse line in which Fer protein is expressed but lacks catalytic activity. Homozygous mutant mice were viable and fertile, and showed no overt defects. In this study, we used intravital microscopy to examine the role of Fer kinase in leukocyte recruitment (rolling adhesion and emigration) in response to LPS challenge in skeletal muscle microcirculation. In addition, we measured vascular permeability changes (FITC-albumin leakage, venular-to-interstitial space) in response to Ag to examine general endothelial cell function. Local administration of LPS induced decreased leukocyte rolling velocity and increased leukocyte adhesion and emigration in wild-type mice. LPS-induced changes in leukocyte rolling velocity and rolling flux were not significantly different in Fer mutants. However, LPS-induced leukocyte adhesion (23 ± 3 vs 11 ± 3 cells/100 μm) and emigration (100 ± 5 vs 28 ± 7 cells/field) were significantly elevated in Fer-mutant mice relative to wild-type mice, respectively, suggesting an essential role for the Fer kinase in regulating inflammation-induced leukocyte emigration. Vascular permeability increases in response to Ag were similar between the two groups, indicating that the ability of endothelial cells to retract is intact in the absence of Fer kinase. These data provide the first evidence for a biological role for Fer in regulation of leukocyte recruitment during the innate immune response.
Sustained NFAT Signaling Promotes a Th1-Like Pattern of Gene Expression in Primary Murine CD4+ T Cells
Authors: Porter Cynthia M. , Clipstone Neil A. 
Published: April 2014

Abstract
T cell activation is known to be critically regulated by the extent and duration of TCR-induced signaling pathways. The NFAT family of transcription factors is believed to play an important role in coupling these quantitative differences in TCR-induced signaling events into changes in gene expression. In this study we have specifically investigated the effects of sustained NFAT signaling on T cell activation by introducing a constitutively active mutant version of NFATc1 (caNFATc1) into primary murine CD4+ T cells and examining its effects on gene expression. We now report that ectopic expression of caNFATc1 partially mimics TCR signaling, resulting in enhanced expression of CD25 and CD40 ligand and down-regulation of CD62L. More importantly, we find that expression of caNFATc1 in T cells maintained under either nonpolarizing or Th1-skewing conditions leads to a marked selective increase in the number of cells expressing the prototypical Th1 cytokine, IFN-γ. Furthermore, when expressed in Th2-skewed cells, caNFATc1 appears to attenuate Th2 differentiation by decreasing production of IL-4 and promoting the expression of IFN-γ. Finally, we find that caNFATc1 enhances expression of functional P-selectin glycoprotein ligand-1, up-regulates Fas ligand expression, and increases susceptibility to activation-induced cell death, cellular traits that are preferentially associated with Th1 effector cells. Taken together, these results suggest that sustained NFAT signaling, mediated by ectopic expression of caNFATc1, acts to promote a Th1-like pattern of gene expression and thereby serves to highlight the important relationship between the degree of NFAT signaling and the qualitative pattern of gene expression induced during T cell activation.
A Role for CD147 in Thymic Development
Authors: Renno Toufic , Wilson Anne , Dunkel Caroline , Coste Isabelle , Maisnier-Patin Karine , Benoit de Coignac Amélie , Aubry Jean-Pierre , Lees Rosemary K. , Bonnefoy Jean-Yves , MacDonald H. Robson , Gauchat Jean-François 
Published: April 2014

Abstract
We have previously identified a mAb that binds to a molecule expressed preferentially on the surface of cycling thymocytes. In this study the molecule recognized by this mAb has been identified in the mouse as CD147 (basigin) by expression cloning. We show that CD147 expression correlates with cycling of immature thymocytes even in the absence of TCRβ selection and that ligation of this molecule on immature fetal thymocytes inhibits their further development into mature T cells.
Priming Th1 Immunity to Viral Core Particles Is Facilitated by Trace Amounts of RNA Bound to Its Arginine-Rich Domain
Authors: Riedl Petra , Stober Detlef , Oehninger Claude , Melber Karl , Reimann Jörg , Schirmbeck Reinhold 
Published: April 2014

AbstractParticulate hepatitis B core Ag (C protein) (HBcAg) and soluble hepatitis B precore Ag (E protein) (HBeAg) of the hepatitis B virus share &gt;70% of their amino acid sequence and most T and B cell-defined epitopes. When injected at low doses into mice, HBcAg particles prime Th1 immunity while HBeAg protein primes Th2 immunity. HBcAg contains 5–20 ng RNA/μg protein while nucleotide binding to HBeAg is not detectable. Deletion of the C-terminal arginine-rich domain of HBcAg generates HBcAg-144 or HBcAg-149 particles (in which &gt;98% of RNA binding is lost) that prime Th2-biased immunity. HBcAg particles, but not truncated HBcAg-144 or -149 particles stimulate IL-12 p70 release by dendritic cells and IFN-γ release by nonimmune spleen cells. The injection of HBeAg protein or HBcAg-149 particles into mice primes Th1 immunity only when high doses of RNA (i.e., 20–100 μg/mouse) are codelivered with the Ag. Particle-incorporated RNA has thus a 1000-fold higher potency as a Th1-inducing adjuvant than free RNA mixed to a protein Ag. Disrupting the particulate structure of HBcAg releases RNA and abolishes its Th1 immunity inducing potency. Using DNA vaccines delivered intradermally with the gene gun, inoculation of 1 μg HBcAg-encoding pCI/C plasmid DNA primes Th1 immunity while inoculation of 1 μg HBeAg-encoding pCI/E plasmid DNA or HBcAg-149-encoding pCI/C-149 plasmid DNA primes Th2 immunity. Expression data show eukaryotic RNA associated with HBcAg, but not HBeAg, expressed by the DNA vaccine. Hence, codelivery of an efficient, intrinsic adjuvant (i.e., nanogram amounts of prokaryotic or eukaryotic RNA bound to arginine-rich sequences) by HBcAg nucleocapsids facilitates priming of anti-viral Th1 immunity.
Fas-Dependent Elimination of Nonselected CD8 Cells andlprDisease
Authors: Trimble Linda A. , Prince Kenya A. , Pestano Gary A. , Daley John , Cantor Harvey 
Published: April 2014

AbstractMHC/self peptide interactions with cognate coreceptor/TCR complexes are central to homeostasis of the T cell repertoire. Recent reports have also underlined the critical role of IL-15/IL-2 cytokines in regulating this homeostatic process. In this study, we investigate mechanisms that regulate potentially autoreactive CD8 cells that have escaped intrathymic selection. These cells, upon exit from the thymus, express high levels of CD44, B220, and the IL-15R/IL-2R, and undergo fas-dependent apoptosis. Defects in fas signaling allow increased IL-15/IL-2-dependent survival of these CD44/B220+ CD8+ as well as the double-negative T cells characteristic of lpr disease.
Reevaluation of T Cell Receptor Excision Circles as a Measure of Human Recent Thymic Emigrants
Authors: Ye Ping , Kirschner Denise E. 
Published: April 2014

Abstract
The human thymus exports newly generated T cells to the periphery. As no markers have been identified for these recent thymic emigrants (RTE), it is presently impossible to measure human thymic output. T cell receptor excision circles (TREC) have been recently used to assess thymic output during both health and disease. Using a mathematical model, we quantify age-dependent changes both in the number of RTE generated per day and in TREC concentration during an 80-year lifespan. Through analyses, we demonstrate that RTE and peripheral T cell division have the same potential to affect TREC concentration at any age in healthy people. T cell death also influences TREC concentration, but to a lesser extent. During aging, our results indicate that thymic involution primarily induces an age-dependent decline in TREC concentrations within both CD4+ and CD8+ T cell populations. We further apply this model for studying TREC concentration during HIV-1 infection. Our analyses reveal that a decrease in thymic output is the major contributor to the decline in TREC concentration within CD4+ T cells, whereas both increased peripheral T cell division and decreased thymic output induce the decline in TREC concentration within CD8+ T cells. Therefore, we suggest that T cell turnover should be examined together with TREC concentration as a measure of RTE. If peripheral T cell division remains relatively unchanged, then TREC concentration indeed reflects thymic output.
Orderly and Nonstochastic Acquisition of CD94/NKG2 Receptors by Developing NK Cells Derived from Embryonic Stem Cells In Vitro
Authors: Lian Rebecca H. , Maeda Motoi , Lohwasser Stefan , Delcommenne Marc , Nakano Toru , Vance Russell E. , Raulet David H. , Takei Fumio 
Published: April 2014

AbstractIn mice there are two families of MHC class I-specific receptors, namely the Ly49 and CD94/NKG2 receptors. The latter receptors recognize the nonclassical MHC class I Qa-1b and are thought to be responsible for the recognition of missing-self and the maintenance of self-tolerance of fetal and neonatal NK cells that do not express Ly49. Currently, how NK cells acquire individual CD94/NKG2 receptors during their development is not known. In this study, we have established a multistep culture method to induce differentiation of embryonic stem (ES) cells into the NK cell lineage and examined the acquisition of CD94/NKG2 by NK cells as they differentiate from ES cells in vitro. ES-derived NK (ES-NK) cells express NK cell-associated proteins and they kill certain tumor cell lines as well as MHC class I-deficient lymphoblasts. They express CD94/NKG2 heterodimers, but not Ly49 molecules, and their cytotoxicity is inhibited by Qa-1b on target cells. Using RT-PCR analysis, we also report that the acquisition of these individual receptor gene expressions during different stages of differentiation from ES cells to NK cells follows a predetermined order, with their order of acquisition being first CD94; subsequently NKG2D, NKG2A, and NKG2E; and finally, NKG2C. Single-cell RT-PCR showed coexpression of CD94 and NKG2 genes in most ES-NK cells, and flow cytometric analysis also detected CD94/NKG2 on most ES-NK cells, suggesting that the acquisition of these receptors by ES-NK cells in vitro is nonstochastic, orderly, and cumulative.
Postgestational Lymphotoxin/Lymphotoxin β Receptor Interactions Are Essential for the Presence of Intestinal B Lymphocytes
Authors: Newberry Rodney D. , McDonough Jacquelyn S. , McDonald Keely G. , Lorenz Robin G. 
Published: April 2014

Abstract
Lymphotoxin (LT), a cytokine belonging to the TNF family, has established roles in the formation of secondary lymphoid structures and in the compartmentalization of T and B lymphocyte areas of the spleen. In this study, we examine the role of LT in directing the composition of intestinal lymphocytes. We report that mice deficient in LT have a normal composition of intestinal lamina propria (LP) T lymphocytes, and an absence of intestinal LP B lymphocytes. We further refine this observation to demonstrate that the interaction of LT with the LTβR is essential for the presence LP B lymphocytes. The LT/LTβR-dependent events relevant for the presence of LP B lymphocytes occur after birth, do not require the presence of Peyer’s patches, lymph nodes, or the spleen; and therefore, are distinct and independent from the previously identified roles of LT/LTβR. The LT-dependent signal relevant for the presence of LP B lymphocytes is optimally supplied by a LT-sufficient B lymphocyte, and requires a LTβR-sufficient radio-resistant, non-bone marrow-derived cell. Based upon the severity of the deficit of LP B lymphocytes we observed, these novel LT/LTβR-dependent events are of primary importance in directing the entry and residence of LP B lymphocytes.
Optimizing the Efficacy of Epitope-Directed DNA Vaccination
Authors: Wolkers Monika C. , Toebes Mireille , Okabe Masaru , Haanen John B. A. G. , Schumacher Ton N. M. 
Published: April 2014

Abstract
An increasing number of clinical trials has been initiated to test the potential of prophylactic or curative vaccination with tumor Ag-encoding DNA vaccines. However, in the past years it has become apparent that for many Ags and in particular for tumor Ags the intracellular processing and presentation are suboptimal. To improve epitope-directed DNA vaccines we have developed a murine model system in which epitope-specific, DNA vaccine-induced T cell immunity can be followed by MHC tetramer technology directly ex vivo. We have used this well-defined model to dissect the parameters that are crucial for the induction of strong cytotoxic T cell immunity using two independent model Ags. These experiments have led to a set of five guidelines for the design of epitope-directed DNA vaccines, indicating that carboxyl-terminal fusion of the epitope to a carrier protein of foreign origin is the most favorable strategy. DNA vaccines that are based on these guidelines induce high-magnitude CD8+ T cell responses in &gt;95% of vaccinated animals. Moreover, T cell immunity induced by this type of optimized DNA vaccine provides long-term protection against otherwise lethal tumor challenges.
Rat Peripheral CD4+CD8+ T Lymphocytes Are Partially Immunocompetent Thymus-Derived Cells That Undergo Post-Thymic Maturation to Become Functionally Mature CD4+ T Lymphocytes
Authors: Jiménez Eva , Sacedón Rosa , Vicente Angeles , Hernández-López Carmen , Zapata Agustín G. , Varas Alberto 
Published: April 2014

Abstract
CD4+CD8+ double-positive (DP) T cells represent a minor subpopulation of T lymphocytes found in the periphery of adult rats. In this study, we show that peripheral DP T cells appear among the first T cells that colonize the peripheral lymphoid organs during fetal life, and represent ∼40% of peripheral T cells during the perinatal period. Later their proportion decreases to reach the low values seen in adulthood. Most DP T cells are small size lymphocytes that do not exhibit an activated phenotype, and their proliferative rate is similar to that of the other peripheral T cell subpopulations. Only 30–40% of DP T cells expresses CD8β chain, the remaining cells expressing CD8αα homodimers. However, both DP T cell subsets have an intrathymic origin since they appear in the recent thymic emigrant population after injection of FITC intrathymically. Functionally, although DP T cells are resistant to undergo apoptosis in response to glucocorticoids, they show poor proliferative responses upon CD3/TCR stimulation due to their inability to produce IL-2. A fraction of DP T cells are not actively synthesizing the CD8 coreceptor, and they gradually differentiate to the CD4 cell lineage in reaggregation cultures. Transfer of DP T lymphocytes into thymectomized SCID mice demonstrates that these cells undergo post-thymic maturation in the peripheral lymphoid organs and that their CD4 cell progeny is fully immunocompetent, as judged by its ability to survive and expand in peripheral lymphoid organs, to proliferate in response to CD3 ligation, and to produce IL-2 upon stimulation.
Aging-Dependent Exclusion of Antigen-Inexperienced Cells from the Peripheral B Cell Repertoire
Authors: Johnson Sara A. , Rozzo Stephen J. , Cambier John C. 
Published: April 2014

AbstractAging is accompanied by greatly reduced B cell production in the bone marrow, yet peripheral B cell numbers do not decline. We hypothesize that this may reflect filling of the peripheral pool with B cells that are long-lived as a consequence of specificity for, and chronic stimulation by, environmental Ags. To begin to explore this possibility, we analyzed the effects of aging on B cell population dynamics in the anti-H2k/b 3-83μδ Ig-transgenic mouse. We predicted that, because they presumably do not bind environmental Ags, B cells bearing the transgenic receptor may be lost in aged animals. As seen in nontransgenic animals, total splenic B cell numbers remained constant with age in the Ig-transgenic animals despite reduced B cell production. Importantly, although the few newly produced B cells in the bone marrow of aged mice are 3-83 positive, the peripheral compartment of these mice is dominated by B cells that express endogenous Ig genes rather than the transgenes. This population includes large numbers of marginal zone-like and CD21low/−CD23low/−IgMlow B cells, as well as elevated numbers of CD5+ B cells. Many of these cells express only non-B220 CD45 isoforms, suggesting that they may be memory cells. A significant proportion of aged transgenic animals produce autoantibodies that are reactive with ssDNA, dsDNA, or histones. Results support the hypothesis that, in the face of severely reduced production with age, B cells are selected based on reactivity to environmental Ags, accumulate, and display activated phenotypes. Cells bearing 3-83-transgenic receptors are excluded from this population due to their specificity. Beyond their importance in aging, these findings define a novel form of receptor revision in which B cells are selected rather than deleted based on Ag reactivity.
The Forkhead Transcription Factor FoxO Regulates Transcription of p27Kip1 and Bim in Response to IL-2
Authors: Stahl Marie , Dijkers Pascale F. , Kops Geert J. P. L. , Lens Susanne M. A. , Coffer Paul J. , Burgering Boudewijn M. T. , Medema René H. 
Published: April 2014

Abstract
The cytokine IL-2 plays a very important role in the proliferation and survival of activated T cells. These effects of IL-2 are dependent on signaling through the phosphatidylinositol 3-kinase (PI3K) pathway. We and others have shown that PI3K, through activation of protein kinase B/Akt, inhibits transcriptional activation by a number of forkhead transcription factors (FoxO1, FoxO3, and FoxO4). In this study we have investigated the role of these forkhead transcription factors in the IL-2-induced T cell proliferation and survival. We show that IL-2 regulates phosphorylation of FoxO3 in a PI3K-dependent fashion. Phosphorylation and inactivation of FoxO3 appears to play an important role in IL-2-mediated T cell survival, because mere activation of FoxO3 is sufficient to trigger apoptosis in T cells. Indeed, active FoxO3 can induce expression of IL-2-regulated genes, such as the cdk inhibitor p27Kip1 and the proapoptotic Bcl-2 family member Bim. Furthermore, we show that IL-2 triggers a rapid, PI3K-dependent, phosphorylation of FoxO1a in primary T cells. Thus, we propose that inactivation of FoxO transcription factors by IL-2 plays a critical role in T cell proliferation and survival.