bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional Human Antigen-Specific T Cells Produced In Vitro Using Retroviral T Cell Receptor Transfer into Hematopoietic Progenitors
Authors: van Lent Anja U. , Nagasawa Maho , van Loenen Marleen M. , Schotte Remko , Schumacher Ton N. M. , Heemskerk Mirjam H. M. , Spits Hergen , Legrand Nicolas 
Published: April 2014

Abstract
In vitro production of human T cells with known Ag specificity is of major clinical interest for immunotherapy against tumors and infections. We have performed TCRαβ gene transfer into human hemopoietic progenitors from postnatal thymus or umbilical cord blood, and subsequently cultured these precursors on OP9 stromal cells expressing the Notch human ligand Delta-like1. We report here that fully mature, functional T cells with controlled Ag specificity are obtained from such cultures. Using vectors encoding TCRαβ-chains directed against melanoma (MART-1), viral (CMV), and minor histocompatibility (HA-2) Ags, we show that the obtained Ag-specific T cells exert cytolytic activity against their cognate Ag and expand in vitro upon specific TCR stimulation. Therapeutic applications may arise from these results because they provide a way to produce large numbers of autologous mature Ag-specific T cells in vitro from undifferentiated hemopoietic progenitors.
Differential Requirements for OX40 Signals on Generation of Effector and Central Memory CD4+ T Cells
Authors: Soroosh Pejman , Ine Shouji , Sugamura Kazuo , Ishii Naoto 
Published: April 2014

Abstract
Memory T cells can be divided into effector memory (TEM) and central memory (TCM) subsets based on their effector function and homing characteristics. Although previous studies have demonstrated that TCR and cytokine signals mediate the generation of the two memory subsets of CD8+ T cells, the mechanisms for generation of the CD4+ TEM and TCM cell subsets are unknown. We found that OX40-deficient mice showed a marked reduction in the number of CD4+ TEM cells, whereas the number of CD4+ TCM cells was normal. Adoptive transfer experiments using Ag-specific CD4+ T cells revealed that OX40 signals during the priming phase were indispensable for the optimal generation of the CD4+ TEM, but not the CD4+ TCM population. In a different transfer experiment with in vitro established CD4+CD44highCD62Llow (TEM precursor) and CD4+CD44highCD62Lhigh (TCM precursor) subpopulations, OX40-KO TEM precursor cells could not survive in the recipient mice, whereas wild-type TEM precursor cells differentiated into both TEM and TCM cells. In contrast, TCM precursor cells mainly produced TCM cells regardless of OX40 signals, implying the dispensability of OX40 for generation of TCM cells. Nevertheless, survival of OX40-KO TEM cells was partially rescued in lymphopenic mice. During in vitro recall responses, the OX40-KO TEM cells that were generated in lymphopenic recipient mice showed impaired cytokine production, suggesting an essential role for OX40 not only on generation but also on effector function of CD4+ TEM cells. Collectively, the present results indicate differential requirements for OX40 signals on generation of CD4+ TEM and TCM cells.
The Importance of Myeloid-Derived Suppressor Cells in the Regulation of Autoimmune Effector Cells by a Chronic Contact Eczema
Authors: Marhaba Rachid , Vitacolonna Mario , Hildebrand Dagmar , Baniyash Michal , Freyschmidt-Paul Pia , Zöller Margot 
Published: April 2014

Abstract
Induction of a chronic eczema is a most efficient therapy for alopecia areata (AA). We had noted a reduction in regulatory T cells during AA induction and wondered whether regulatory T cells may become recruited or expanded during repeated skin sensitization or whether additional regulatory cells account for hair regrowth. AA could not be cured by the transfer of CD4+CD25high lymph node cells from mice repeatedly treated with a contact sensitizer. This obviously is a consequence of a dominance of freshly activated cells as compared with regulatory CD4+CD25+ T cells. Instead, a population of Gr-1+CD11b+ cells was significantly increased in skin and spleen of AA mice repeatedly treated with a contact sensitizer. Gr-1+CD11b+ spleen cells mostly expressed CD31. Expression of several proinflammatory cytokines as well as of the IFN-γ receptor and the TNF receptor I were increased. Particularly in the skin, Gr-1+ cells expressed several chemokines and CCR8 at high levels. Gr-1+CD11b+ cells most potently suppressed AA effector cell proliferation in vitro and promoted partial hair regrowth in vivo. When cocultured with CD4+ or CD8+ cells from AA mice, the Gr-1+CD11b+ cells secreted high levels of NO. However, possibly due to high level Bcl-2 protein expression in AA T cells, apoptosis induction remained unaltered. Instead, ζ-chain expression was strongly down-regulated, which was accompanied by a decrease in ZAP70 and ERK1/2 phosphorylation. Thus, a chronic eczema supports the expansion and activation of myeloid suppressor cells that, via ζ-chain down-regulation, contribute to autoreactive T cell silencing in vitro and in vivo.
CD8 T Cell Responses to Myelin Oligodendrocyte Glycoprotein-Derived Peptides in Humanized HLA-A*0201-Transgenic Mice
Authors: Mars Lennart T. , Bauer Jan , Gross David A. , Bucciarelli Florence , Firat Huseyin , Hudrisier Denis , Lemonnier François , Kosmatopoulos Kostas , Liblau Roland S. 
Published: April 2014

Abstract
Multiple sclerosis (MS) is a demyelinating inflammatory disease of the CNS. Though originally believed to be CD4-mediated, additional immune effector mechanisms, including myelin-specific CD8+ T cells, are now proposed to participate in the pathophysiology of MS. To study the immunologic and encephalitogenic behavior of HLA-A*0201-binding myelin-derived epitopes in vivo, we used a humanized HLA-A*0201-transgenic mouse model. Eight HLA-A*0201-binding peptides derived from myelin oligodendrocyte glycoprotein (MOG), an immunodominant myelin self-Ag, were identified in silico. After establishing their relative affinity for HLA-A*0201 and their capacity to form stable complexes with HLA-A*0201 in vitro, their immunological characteristics were studied in HLA-A*0201-transgenic mice. Five MOG peptides, which bound stably to HLA-A*0201 exhibited strong immunogenicity by inducing a sizeable MOG-specific HLA-A*0201-restricted CD8+ T cell response in vivo. Of these five candidate epitopes, four were processed by MOG-transfected RMA target cells and two peptides proved immunodominant in vivo in response to a plasmid-encoding native full-length MOG. One of the immunodominant MOG peptides (MOG181) generated a cytotoxic CD8+ T cell response able to aggravate CD4+-mediated EAE. Therefore, this detailed in vivo characterization provides a hierarchy of candidate epitopes for MOG-specific CD8+ T cell responses in HLA-A*0201 MS patients identifying the encephalitogenic MOG181 epitope as a primary candidate.
CD11b+Ly-6Chi Suppressive Monocytes in Experimental Autoimmune Encephalomyelitis
Authors: Zhu Bing , Bando Yoshio , Xiao Sheng , Yang Kaiyong , Anderson Ana C. , Kuchroo Vijay K. , Khoury Samia J. 
Published: April 2014

Abstract
Innate immune cells may regulate adaptive immunity by balancing different lineages of T cells and providing negative costimulation. In addition, CD11b+Gr-1+ myeloid-derived suppressor cells have been described in tumor, parasite infection, and severe trauma models. In this study, we observe that splenic CD11b+ cells markedly increase after experimental autoimmune encephalomyelitis (EAE) immunization, and they suppress T cell proliferation in vitro. Although &gt;80% of CD11b+ cells express varying levels of Gr-1, only a small population of CD11b+Ly-6Chigh inflammatory monocytes (IMC) can efficiently suppress T cell proliferation and induce T cell apoptosis through the production of NO. IFN-γ produced by activated T cells is essential to induce IMC suppressive function. EAE immunization increases the frequencies of IMC in the bone marrow, spleen, and blood, but not in the lymph nodes. At the peak of EAE, IMC represent ∼30% of inflammatory cells in the CNS. IMC express F4/80 and CD93 but not CD31, suggesting that they are immature monocytes. Furthermore, IMC have the plasticity to up-regulate NO synthase 2 or arginase 1 expression upon different cytokine treatments. These findings indicate that CD11b+Ly-6Chigh IMC induced during EAE priming are powerful suppressors of activated T cells. Further understanding of suppressive monocytes in autoimmune disease models may have important clinical implications for human autoimmune diseases.
Protein Kinase C Regulates Expression and Function of Inhibitory Killer Cell Ig-Like Receptors in NK Cells
Authors: Alvarez-Arias Diana A. , Campbell Kerry S. 
Published: April 2014

Abstract
The inhibitory killer cell Ig-like receptors (KIR) negatively regulate NK cell cytotoxicity by activating the Src homology 2 domain-containing protein tyrosine phosphatases 1 and 2 following ligation with MHC class I molecules expressed on normal cells. This requires tyrosine phosphorylation of KIR on ITIMs in the cytoplasmic domain. Surprisingly, we have found that KIR3DL1 is strongly and constitutively phosphorylated on serine and weakly on threonine residues. In this study, we have mapped constitutive phosphorylation sites for casein kinases, protein kinase C, and an unidentified kinase on the KIR cytoplasmic domain. Three of these phosphorylation sites are highly conserved in human inhibitory KIR. Functional studies of the wild-type receptor and serine/threonine mutants indicated that phosphorylation of Ser394 by protein kinase C slightly suppresses KIR3DL1 inhibitory function, and reduces receptor internalization and turnover. Our results provide evidence that serine/threonine phosphorylation is an important regulatory mechanism of KIR function.
A Fas-Associated Death Domain Protein/Caspase-8-Signaling Axis Promotes S-Phase Entry and Maintains S6 Kinase Activity in T Cells Responding to IL-2
Authors: Arechiga Adrian F. , Bell Bryan D. , Leverrier Sabrina , Weist Brian M. , Porter Melissa , Wu Zhengqi , Kanno Yuka , Ramos Stephanie J. , Ong S. Tiong , Siegel Richard , Walsh Craig M. 
Published: April 2014

Abstract
Fas-associated death domain protein (FADD) constitutes an essential component of TNFR-induced apoptotic signaling. Paradoxically, FADD has also been shown to be crucial for lymphocyte development and activation. In this study, we report that FADD is necessary for long-term maintenance of S6 kinase (S6K) activity. S6 phosphorylation at serines 240 and 244 was only observed after long-term stimulation of wild-type cells, roughly corresponding to the time before S-phase entry, and was poorly induced in T cells expressing a dominantly interfering form of FADD (FADDdd), viral FLIP, or possessing a deficiency in caspase-8. Defects in S6K1 phosphorylation were also observed. However, defective S6K1 phosphorylation was not a consequence of a wholesale defect in mammalian target of rapamycin function, because 4E-BP1 phosphorylation following T cell activation was unaffected by FADDdd expression. Although cyclin D3 up-regulation and retinoblastoma hypophosphorylation occurred normally in FADDdd T cells, cyclin E expression and cyclin-dependent kinase 2 activation were markedly impaired in FADDdd T cells. These results demonstrate that a FADD/caspase-8-signaling axis promotes T cell cycle progression and sustained S6K activity.
STAT5 Is Essential for Akt/p70S6 Kinase Activity during IL-2-Induced Lymphocyte Proliferation
Authors: Lockyer Heather M. , Tran Eric , Nelson Brad H. 
Published: April 2014

Abstract
IL-2R activates two distinct signaling pathways mediated by the adaptor protein Shc and the transcription factor STAT5. Prior mutagenesis studies of the IL-2R have indicated that the Shc and STAT5 pathways are redundant in the ability to induce lymphocyte proliferation. Yet paradoxically, T cells from STAT5-deficient mice fail to proliferate in response to IL-2, suggesting that the Shc pathway is unable to promote mitogenesis in the genetic absence of STAT5. Here we show in the murine lymphocyte cell line Ba/F3 that low levels of STAT5 activity are essential for Shc signaling. In the absence of STAT5 activity, Shc was unable to sustain activation of the Akt/p70S6 kinase pathway or promote lymphocyte proliferation and viability. Restoring STAT5 activity via a heterologous receptor rescued Shc-induced Akt/p70S6 kinase activity and cell proliferation with kinetics consistent with a transcriptional mechanism. Thus, STAT5 appears to regulate the expression of one or more unidentified components of the Akt pathway. Our results not only explain the severe proliferative defect in STAT5-deficient T cells but also provide mechanistic insight into the oncogenic properties of STAT5 in various leukemias and lymphomas.
Analysis of Epitope-Specific Immune Responses Induced by Vaccination with Structurally Folded and Unfolded Recombinant Bet v 1 Allergen Derivatives in Man
Authors: Pree Ines , Reisinger Jürgen , Focke Margit , Vrtala Susanne , Pauli Gabrielle , van Hage Marianne , Cromwell Oliver , Gadermaier Elisabeth , Egger Cornelia , Reider Norbert , Horak Friedrich , Valenta Rudolf , Niederberger Verena 
Published: April 2014

Abstract
Previously, we have constructed recombinant derivatives of the major birch pollen allergen, Bet v 1, with a more than 100-fold reduced ability to induce IgE-mediated allergic reactions. These derivatives differed from each other because the two recombinant Bet v 1 fragments represented unfolded molecules whereas the recombinant trimer resembled most of the structural fold of the Bet v 1 allergen. In this study, we analyzed the Ab (IgE, IgG subclass, IgA, IgM) response to Bet v 1, recombinant and synthetic Bet v 1-derived peptides in birch pollen allergic patients who had been vaccinated with the derivatives or adjuvant alone. Furthermore, we studied the induction of IgE-mediated skin responses in these patients using Bet v 1 and Bet v 1 fragments. Both types of vaccines induced a comparable IgG1 and IgG4 response against new sequential epitopes which overlap with the conformational IgE epitopes of Bet v 1. This response was 4- to 5-fold higher than that induced by immunotherapy with birch pollen extract. Trimer more than fragments induced also IgE responses against new epitopes and a transient increase in skin sensitivity to the fragments at the beginning of therapy. However, skin reactions to Bet v 1 tended to decrease one year after treatment in both actively treated groups. We demonstrate that vaccination with folded and unfolded recombinant allergen derivatives induces IgG Abs against new epitopes. These data may be important for the development of therapeutic as well as prophylactic vaccines based on recombinant allergens.
A Population of CD19highCD45R−/lowCD21low B Lymphocytes Poised for Spontaneous Secretion of IgG and IgA Antibodies
Authors: de Andrés Belén , Cortegano Isabel , Serrano Natalia , del Rio Borja , Martín Paloma , Gonzalo Pilar , Marcos Miguel A. R. , Gaspar María Luisa 
Published: April 2014

Abstract
Ab responses to selected Ags are produced by discrete B cell populations whose presence and functional relevance vary along the ontogeny. The earliest B lineage-restricted precursors in gestational day 11 mouse embryos display the CD19+CD45R/B220− phenotype. Phenotypically identical cells persist throughout gestation and in postnatal life, in parallel to the later-arising, CD19+CD45R+ B cells. Very early after birth, the CD19+CD45R− B cell subset included high frequencies of spontaneously Ig-secreting cells. In the adult spleen, a small subset of CD19highCD45R−/lowIgM+/−IgD−CD21/Cr2−/low cells, which was detected in perifollicular areas, displayed genetic and phenotypical traits of highly differentiated B cells, and was enriched in IgG- and IgA-secreting plasma cells. In vitro differentiation and in vivo adoptive transfer experiments of multipotent hemopoietic progenitors revealed that these CD19highCD45R−/low B cells were preferentially regenerated by embryo-, but not by adult bone marrow-, derived progenitors, except when the latter were inoculated into newborn mice. Both the early ontogenical emergence and the natural production of serum Igs, are shared features of this CD19highCD45R−/low B cell population with innate-like B lymphocytes such as B1 and marginal zone B cells, and suggest that the new population might be related to that category.
The Acquired Immune Response to the Mucosal Adjuvant LTK63 Imprints the Mouse Lung with a Protective Signature
Authors: Tritto Elaine , Muzzi Alessandro , Pesce Isabella , Monaci Elisabetta , Nuti Sandra , Galli Grazia , Wack Andreas , Rappuoli Rino , Hussell Tracy , De Gregorio Ennio 
Published: April 2014

Abstract
LTK63, a nontoxic mutant of Escherichia coli heat labile enterotoxin (LT), is a potent and safe mucosal adjuvant that has also been shown to confer generic protection to several respiratory pathogens. To understand the mechanisms of action underlying the LTK63 protective effect, we analyzed the molecular and cellular events triggered by its administration in vivo. We show here that LTK63 intrapulmonary administration induced in the mouse lung a specific gene expression signature characterized by the up-regulation of cell cycle genes, several host defense genes, chemokines, chemokine receptors, and immune cell-associated genes. Such a transcriptional profile reflected the activation of alveolar macrophages and the recruitment to the lung of T and B cells and innate immune cells such as granulocytes, NK, and dendritic cells. All of these events were T cell dependent and specific for LTK63 because they were absent in SCID and nude mice. Additionally, we showed that LTK63 induces a potent adaptive immune response against itself directed to the lung. We propose that acquired response to LTK63 is the driving force for the local recruitment of both adaptive and innate immune cells. Our data suggest that LTK63 acts as an airway infection mimic that establishes a generic protective environment limiting respiratory infection by innate immune mechanisms and by improving adaptive responses to invading pathogens.
Bone Marrow of Persistently Hepatitis C Virus-Infected Individuals Accumulates Memory CD8+ T Cells Specific for Current and Historical Viral Antigens: A Study in Patients with Benign Hematological Disorders
Authors: Racanelli Vito , Frassanito Maria Antonia , Leone Patrizia , Brunetti Claudia , Ruggieri Simona , Dammacco Franco 
Published: April 2014

Abstract
The role of virus-specific T cells in hepatitis C virus (HCV) pathogenesis is not clear. Existing knowledge on the frequency, phenotype, and behavior of these cells comes from analyses of blood and liver, but other lymphoid compartments that may be important sites for functionally mature T cells have not yet been analyzed. We studied HCV-specific T cells from bone marrow, in comparison to those from peripheral blood and liver biopsy tissue, from 20 persistently HCV-infected patients with benign hematological disorders. Bone marrow contained a sizeable pool of CD8+ T cells specific for epitopes from structural and nonstructural HCV proteins. These cells displayed the same effector memory phenotype as liver-derived equivalents and the same proliferative potential as blood-derived equivalents but had greater antiviral effector functions such as Ag-specific cytotoxicity and IFN-γ production. These features were not shared by influenza virus-specific CD8+ T cells in the same bone marrow samples. Despite their highly differentiated phenotype and activated status, some bone marrow-resident HCV-specific CD8+ T cells were not directed against the infecting virus but, instead, against historical HCV Ags (i.e., viral species of a previous infection or minor viral species of the current infection). These findings provide a snapshot view of the distribution, differentiation, and functioning of virus-specific memory T cells in patients with persistent HCV infection.
The Proinflammatory Cytokine Macrophage Migration Inhibitory Factor Regulates Glucose Metabolism during Systemic Inflammation
Authors: Atsumi Toshiya , Cho You-Ree , Leng Lin , McDonald Courtney , Yu Tim , Danton Cheryl , Hong Eun-Gyoung , Mitchell Robert A. , Metz Christine , Niwa Hirokatsu , Takeuchi Jun , Onodera Shin , Umino Tomomi , Yoshioka Narihito , Koike Takao , Kim Jason K. , Bucala Richard 
Published: April 2014

Abstract
Inflammation provokes significant abnormalities in host metabolism that result from the systemic release of cytokines. An early response of the host is hyperglycemia and resistance to the action of insulin, which progresses over time to increased glucose uptake in peripheral tissue. Although the cytokine TNF-α has been shown to exert certain catabolic effects, recent studies suggest that the metabolic actions of TNF-α occur by the downstream regulation of additional mediators, such as macrophage migration inhibitory factor (MIF). We investigated the glycemic responses of endotoxemic mice genetically deficient in MIF (MIF−/−). In contrast to wild-type mice, MIF−/− mice exhibit normal blood glucose and lactate responses following the administration of endotoxin, or TNF-α. MIF−/− mice also show markedly increased glucose uptake into white adipose tissue in vivo in the endotoxemic state. Treatment of adipocytes with MIF, or anti-MIF mAb, modulates insulin-mediated glucose transport and insulin receptor signal transduction; these effects include the phosphorylation of insulin receptor substrate-1, its association with the p85 regulatory subunit of PI3K, and the downstream phosphorylation of Akt. Genetic MIF deficiency also promotes adipogenesis, which is in accord with a downstream role for MIF in the action of TNF-α. These studies support an important role for MIF in host glucose metabolism during sepsis.
CD8 T Cells Inhibit Respiratory Syncytial Virus (RSV) Vaccine-Enhanced Disease
Authors: Olson Matthew R. , Varga Steven M. 
Published: April 2014

Abstract
Vaccination of children with a formalin-inactivated (FI) respiratory syncytial virus (RSV) vaccine led to exacerbated disease including pulmonary eosinophilia following a natural RSV infection. Immunization of BALB/c mice with FI-RSV or a recombinant vaccinia virus (vv) expressing the RSV attachment (G) protein (vvG) results in a pulmonary Th2 response and eosinophilia after RSV challenge that closely mimics the RSV vaccine-enhanced disease observed in humans. The underlying causes of RSV vaccine-enhanced disease remain poorly understood. We demonstrate here that RSV M2-specific CD8 T cells reduce the Th2-mediated pathology induced by vvG-immunization and RSV challenge in an IFN-γ-independent manner. We also demonstrate that FI-RSV immunization does not induce a measurable RSV-specific CD8 T cell response and that priming FI-RSV-immunized mice for a potent memory RSV-specific CD8 T cell response abrogates pulmonary eosinophilia after subsequent RSV challenge. Our results suggest that the failure of the FI-RSV vaccine to induce a CD8 T cell response may have contributed to the development of pulmonary eosinophilia and augmented disease that occurred in vaccinated individuals.