bluuebunny/crossref_metadata_2025_split huggingface dataset:
In Vitro and In Vivo Induction of a Th Cell Response Toward Peptides of the Melanoma-Associated Glycoprotein 100 Protein Selected by the TEPITOPE Program
Authors: Cochlovius Björn , Stassar Marike , Christ Oliver , Raddrizzani Laura , Hammer Jürgen , Mytilineos Ioannis , Zöller Margot 
Published: April 2014

AbstractThe melanoma-associated Ag glycoprotein 100 was analyzed by the T cell epitope prediction software TEPITOPE. Seven HLA-DR promiscuous peptides predicted with a stringent threshold were used to load dendritic cells (DC), and induction of a proliferative response was monitored. PBMC of all nine donors including two patients with malignant melanoma responded to at least one of the peptides. The proliferative response was defined as a Th response by the selective expansion of CD4+ cells, up-regulation of CD25 and CD40L, and IL-2 and IFN-γ expression. Peptide-loaded DC also initiated a T helper response in vivo (i.e., tumor growth in the SCID mouse was significantly retarded by the transfer of PBMC together with peptide-loaded DC). Because the use of the TEPITOPE program allows for a prediction of T cell epitopes; because the predicted peptides can be rapidly confirmed by inducing a Th response in the individual patient; and because application of peptide-loaded DC suffices for the in vivo activation of helper cells, vaccination with MHC class II-binding peptides of tumor-associated Ags becomes a feasible and likely powerful tool in the immunotherapy of cancer.
Multiepitopic HLA-A*0201-Restricted Immune Response Against Hepatitis B Surface Antigen After DNA-Based Immunization
Authors: Loirat Delphine , Lemonnier François A. , Michel Marie-Louise 
Published: April 2014

AbstractCTL together with anti-envelope Abs represent major effectors for viral clearance during hepatitis B virus (HBV) infection. The induction of strong cytotoxic and Ab responses against the envelope proteins after DNA-based immunization has been proposed as a promising therapeutic approach to mediate viral clearance in chronically infected patients. Here, we studied the CTL responses against previously described hepatitis B surface Ag (HBsAg)-HLA-A*0201-restricted epitopes after DNA-based immunization in HLA-A*0201 transgenic mice. The animal model used was Human Human Db (HHD) mice, which are deficient for mouse MHC class I molecules (β2-microglobulin−/− Db−/−) and transgenic for a chimeric HLA-A*0201/Db molecule covalently bound to the human β2-microglobulin (HHD+/+). Immunization of these mice with a DNA vector encoding the small and the middle HBV envelope proteins carrying HBsAg induced CTL responses against several epitopes in each animal. This study performed on a large number of animals described dominant epitopes with specific CTL induced in all animals and others with a weaker frequency of recognition. These results confirmed the relevance of the HHD transgenic mouse model in the assessment of vaccine constructs for human use. Moreover, genetic immunization of HLA-A2 transgenic mice generates IFN-γ-secreting CD8+ T lymphocytes specific for endogenously processed peptides and with recognition specificities similar to those described during self-limited infection in humans. This suggests that responses induced by DNA immunization could have the same immune potential as those developing during natural HBV infection in human patients.
Cutting Edge: Resistance to Apoptosis and Continuous Proliferation of Dendritic Cells Deficient for TNF Receptor-1
Authors: Funk Jens Oliver , Walczak Henning , Voigtländer Constanze , Berchtold Susanne , Baumeister Thomas , Rauch Pia , Rössner Susanne , Steinkasserer Alexander , Schuler Gerold , Lutz Manfred B. 
Published: April 2014

Abstract
The individual roles of the two TNFRs on dendritic cells (DC) are poorly understood. Investigating bone marrow-derived DC from TNFR-deficient mice, we found that cultures from TNFR1−/− mice continue to form proliferating clusters for 6–9 mo. In contrast, DC derived from wild-type, TNFR2−/−, or TNFR1/2−/− mice survived for only 3–4 wk. DC obtained from these TNFR1−/− long term cultures (LTC) mice show an unusual mixed immature/mature phenotype. The continuous proliferation of the LTC is GM-CSF dependent and correlates with decreased protein levels of the cyclin-dependent kinase inhibitors p27KIP1 and p21CIP1. Prolonged survival of TNFR1−/− DC appears to be independent from NF-κB and Bcl-2 pathways and is rather enabled by the down-regulation of CD95, resulting in the resistance to CD95 ligand-induced apoptosis. These data point to proapoptotic signals mediated via TNFR1 and antiapoptotic signals mediated via TNFR2 in DC.
The Ability of B Cells and Dendritic Cells to Present Antigen Increases During Ontogeny
Authors: Muthukkumar Subramanian , Goldstein Julia , Stein Kathryn E. 
Published: April 2014

Abstract
The immune response to polysaccharide (PS) Ags in mice is delayed during ontogeny even when administered in a thymus-dependent (TD) form. In this study, Neisseria meningitidis group C PS-tetanus toxoid conjugate (MCPS-TT) vaccine was used to examine whether the delay in the development of Ab responses to TD PS conjugate vaccines in neonatal mice is due to defective Ag presentation. The results show that B cells and dendritic cells (DC) from 3- and 7-day-old mice were severely defective in presenting TT and MCPS-TT to Ag-specific T cell clones. The ability of these cells to present Ag reaches adult levels by 4 wk. The development of anti-MCPS and anti-TT Abs in neonatal mice parallels the functional ability of their APC to present Ag. DC from neonatal mice expressed very low levels of MHC class II, costimulatory molecules B7.1, B7.2, and CD11c but high levels of monocyte-specific markers F4/80 and CD11b and granulocyte marker, Ly6G. Significant changes in the expression of these markers were observed as the age of the mice increased. MHC class II, B7.1 and B7.2, and CD11c all increased with age, reaching adult levels between 3 and 4 wk, concurrent with the function of APC. These results demonstrate that one reason neonates fail to produce high titers of anti-PS Abs even when immunized in a TD form is that their B cells and DC are not fully functional.
Changing Patterns of Dominant TCR Usage with Maturation of an EBV-Specific Cytotoxic T Cell Response
Authors: Annels Nicola E. , Callan Margaret F. C. , Tan Linda , Rickinson Alan B. 
Published: April 2014

Abstract
Infection with EBV provides a unique opportunity to follow the human CD8+ T cell response to a persistent, genetically stable agent from the primary phase, as seen in infectious mononucleosis (IM) patients, into long-term memory. This study focuses on the response to an immunodominant HLA-A2.01-restricted epitope, GLCTLVAML, from the EBV-lytic cycle Ag BMLF1. TCR analysis of the highly amplified primary response to this epitope revealed markedly oligoclonal receptor usage among in vitro-derived clones, with similar clonotypes dominant in all three IM patients studied. Direct staining of IM T cell preparations with the A2.01/GLCTLVAML tetramer linked this oligoclonal epitope-specific response with appropriate Vβ subset expansions in the patients’ blood. These patients were studied again &gt;2 years later, at which time TCR analysis of in vitro-reactivated clones suggested that rare clonotypes within the primary response had now come to dominate memory. Five additional A2.01-positive IM patients were studied prospectively for Vβ subset representation within primary and memory epitope-specific populations as identified by tetramer staining. In each case, the primary response contained large Vβ2, Vβ16, or Vβ22 components, and in three of five cases the originally dominant Vβ was represented very poorly, if at all, in memory. We conclude 1) that an EBV epitope-specific primary response large enough to account for up to 10% CD8+ T cells in IM blood may nevertheless be dominated by just a few highly expanded clonotypes, and 2) that with persistent viral challenge such dominant T cell clonotypes may be lost and replaced by others in memory.
Defining the Requirements for Peptide Recognition in Gene Therapy-Induced T Cell Tolerance
Authors: Bagley Jessamyn , Wu Yin , Sachs David H. , Iacomini John 
Published: April 2014

Abstract
Expression of a retrovirally transduced MHC class I Ag, H-2Kb (Kb), in bone marrow-derived cells leads to specific prolongation of Kb disparate skin grafts. To examine the extent to which peptides derived from Kb contribute to the induction of tolerance, retroviruses carrying mutant Kb genes designed to enter separate pathways of Ag presentation were constructed. Thymectomized and CD8 T cell-depleted mice that had been irradiated and reconstituted with bone marrow cells expressing a secreted form of Kb showed prolongation of Kb disparate skin graft survival. Skin graft prolongation was not observed when similar experiments were performed using mice that were not CD8 T cell depleted. This suggests that hyporesponsiveness can be induced in CD4 T cells, but not CD8 T cells by Ags presented via the exogenous pathway of Ag processing. Modest prolongation of skin allografts was observed in mice reconstituted with bone marrow cells transduced with retroviruses carrying a gene encoding a mutant Kb molecule expressed only in the cytoplasm. Prolongation was also observed in similar experiments in mice that were thymectomized and CD4 T cell depleted following complete reconstitution, but not in mice that were reconstituted and then thymectomized and CD8 T cell depleted. Thus, hyporesponsiveness can be induced in a subset of CD8 T cells by recognition of peptides derived from Kb through both the direct and indirect pathways of Ag recognition, while CD4 T cell hyporesponsiveness to MHC class I disparate grafts occurs only through the indirect pathway of Ag recognition.
The Down-Regulation of HLA-DM Gene Expression in Rheumatoid Arthritis Is Not Related to Their Promoter Polymorphism
Authors: Louis-Plence Pascale , Kerlan-Candon Sophie , Morel Jacques , Combe Bernard , Clot Jacques , Pinet Valérie , Eliaou Jean-François 
Published: April 2014

AbstractHLA-DM molecule, a class II-like heterodimer, is a critical factor of HLA class II-dependent Ag presentation. It acts as a molecular chaperone and also functions as a peptide editor favoring the presentation of high-stability peptides. Thus, it appears to skew the peptide repertoire presented to T cells. Variation in HLA-DM expression has considerable effect on Ag presentation and regulation of these genes is likely to be a prerequisite to prevent autoimmunity. In this study, rheumatoid arthritis (RA) was chosen as a model of human autoimmune disease since its genetic susceptibility is known to be associated with the HLA-DR and -DM components. We described a limited nucleotide polymorphism in the HLA-DM promoters with functional impact on basal transcriptional activity and IFN-γ induction as assessed in vitro. However, no difference of allele frequencies was found between controls and RA patients. Despite of this lack of association, expression of HLA-DM molecules was also investigated. Interestingly, an underexpression of HLA-DM transcripts and protein was shown in peripheral blood B cells from RA patients compared with controls or inflammatory arthritis patients. This underexpression does not affect HLA-DR genes and is responsible for a decrease of the DM:DR ratio in RA patients. This specific HLA-DM down-regulation is likely to have important consequences on Ag presentation and could participate in the autoimmune process in RA.
Graded Deletion and Virus-Induced Activation of Autoreactive CD4+ T Cells
Authors: Riley Michael P. , Cerasoli Douglas M. , Jordan Martha S. , Petrone Andria L. , Shih Fei F. , Caton Andrew J. 
Published: April 2014

Abstract
We have examined factors governing the negative selection of autoreactive CD4+ T cells in transgenic mice expressing low (HA12 mice) vs high (HA104 mice) amounts of the influenza virus hemagglutinin (HA). When mated with TS1 mice that express a transgenic TCR specific for the I-Ed-restricted determinant site 1 (S1) of HA, thymocytes expressing high levels of the clonotypic TCR were deleted in both HA-transgenic lineages. However, through allelic inclusion, thymocytes with lower levels of the clonotypic TCR evaded deletion in TS1 × HA12 and TS1 × HA104 mice to graded degrees. Moreover, in both lineages, peripheral CD4+ T cells could be activated by the S1 peptide in vitro, and by influenza virus in vivo. These findings indicate that allelic inclusion can allow autoreactive CD4+ thymocytes to evade thymic deletion to varying extents reflecting variation in the expression of the self peptide, and can provide a basis for the activation of autoreactive peripheral T cells by viruses bearing homologues of self peptides (“molecular mimicry”).
Direct NK Cell-Mediated Lysis of Syngenic Dorsal Root Ganglia Neurons In Vitro
Authors: Backström Eva , Chambers Benedict J. , Kristensson Krister , Ljunggren Hans-Gustaf 
Published: April 2014

AbstractIn contrast to extensive studies on the role of T and B lymphocytes in the pathogenesis of autoimmune diseases of the nervous system, little is known about NK cells and their potential role in the destruction of neural tissue. NK cells have been implicated in the selective death of sympathetic neurons resident in the superior cervical ganglia of rats after exposure to the drug guanethidine. This observation suggests that NK cells may function as principle effectors in immunological diseases of the nervous system. However, the direct mechanism of action of NK cells in this model is not known. In particular, it is not known whether NK cells can kill autologous neurons directly. The aim of the present study was to examine whether NK cells can kill directly dorsal root ganglia neurons cultured in vitro. We demonstrate that C57BL/6 (B6)-derived dorsal root ganglia neurons can be killed directly by syngenic IL-2-activated NK cells, and that this nerve cell lysis is dependent on the expression of perforin in the NK cells. NK cells were less effective in destroying neurons grown in the presence of glial cells. These observations indicate a potential role for NK cells in nerve cell degeneration in inflammatory diseases of the nervous system.
Anatomical Origin of Dendritic Cells Determines Their Life Span in Peripheral Lymph Nodes
Authors: Ruedl Christiane , Koebel Pascale , Bachmann Martin , Hess Michael , Karjalainen Klaus 
Published: April 2014

AbstractDendritic cells (DCs) exhibit considerable heterogeneity in their anatomical location, surface phenotype, and functional properties. In this study, we demonstrate that peripheral lymph nodes contain at least four major, functionally separable, and independently derived, DC subsets, which can be clearly demarcated by their CD11c, CD40, and CD8 expression pattern. Surprisingly, all DCs derived directly from the bone marrow, the myeloid- and the lymphoid-related subsets, turned over fast with t1/2 of a couple of days. In contrast, DCs exported from the skin, both dermal and epidermal, accumulated 3- to 4-fold slower, turnover that is dramatically increased by cutaneous inflammation.
A Subset of NKT Cells That Lacks the NK1.1 Marker, Expresses CD1d Molecules, and Autopresents the α-Galactosylceramide Antigen
Authors: Hameg Agathe , Apostolou Irina , Leite-de-Moraes Maria , Gombert Jean-Marc , Garcia Corinne , Koezuka Yasuhiko , Bach Jean-François , Herbelin André 
Published: April 2014

Abstract
In the present report, we characterize a novel T cell subset that shares with the NKT cell lineage both CD1d-restriction and high reactivity in vivo and in vitro to the α-galactosylceramide (α-GalCer) glycolipid. These cells preferentially use the canonical Vα14-Jα281 TCR-α-chain and Vβ8 TCR-β segments, and are stimulated by α-GalCer in a CD1d-dependent fashion. However, in contrast to classical NKT cells, they lack the NK1.1 marker and express high surface levels of CD1d molecules. In addition, this NK1.1− CD1dhigh T subset, further referred to as CD1dhigh NKT cells, can be distinguished by its unique functional features. Although NK1.1+ NKT cells require exogenous CD1d-presenting cells to make them responsive to α-GalCer, CD1dhigh NKT cells can engage their own surface CD1d in an autocrine and/or paracrine manner. Furthermore, in response to α-GalCer, CD1dhigh NKT cells produce high amounts of IL-4 and moderate amounts of IFN-γ, a cytokine profile more consistent with a Th2-like phenotype rather than the Th0-like phenotype typical of NK1.1+ NKT cells. Our work reveals a far greater level of complexity within the NKT cell population than previously recognized and provides the first evidence for T cells that can be activated upon TCR ligation by CD1d-restricted recognition of their ligand in the absence of conventional APCs.
Potent Costimulation of Effector T Lymphocytes by Human Collagen Type I
Authors: Rao Wei Hong , Hales Jonathan M. , Camp Richard D. R. 
Published: April 2014

Abstract
Purified, resting peripheral blood T lymphocytes were previously reported to undergo β1 integrin-dependent activation when cultured with anti-CD3 mAb coimmobilized with fibronectin, but not type I collagen. However, the extravascular T cells that encounter immobilized extracellular matrix proteins and are involved in disease pathogenesis have different properties from resting peripheral blood cells. In this study, we confirm that resting CD4+ and CD8+ T cells from peripheral blood are costimulated by immobilized fibronectin, but not type I collagen. In contrast, Ag- or mitogen-stimulated CD4+ and CD8+ T cell lines, used as models of the effector cells involved in disease, are more potently costimulated by type I collagen than fibronectin. The collagen-induced effects are similar in assays with serum-free medium and in more physiological assays in which anti-CD3 mAb is replaced by a threshold concentration of Ag and irradiated autologous PBMC as APC. The responses are β1 integrin dependent and mediated largely by very late Ag (VLA) 1 and 2, as shown by their up-regulation on the T cell lines as compared with freshly purified resting PBL, and by the effects of blocking mAb. Reversed phase HPLC located the major costimulatory sequence(s) in the α1 chain of type I collagen, the structure of which was confirmed by amino acid sequencing. The results demonstrate the potential importance of type I collagen, an abundant extracellular matrix protein, in enhancing the activation of extravascular effector T cells in inflammatory disease, and point to a new immunotherapeutic target.
Regulation of β1 Integrin-Mediated Adhesion by T Cell Receptor Signaling Involves ZAP-70 but Differs from Signaling Events That Regulate Transcriptional Activity
Authors: Epler Jennifer A. , Liu Rugao , Chung Heekyoung , Ottoson Nadine C. , Shimizu Yoji 
Published: April 2014

AbstractStimulation of the CD3/TCR results within minutes in an increase in T cell adhesion mediated by β1 integrins. The biochemical pathways that control CD3-mediated increases in β1 integrin-mediated adhesion remain poorly characterized. In this study, the role of the tyrosine kinase ZAP-70 in the regulation of β1 integrin activity by the CD3/TCR was investigated. CD3 stimulation did not increase β1 integrin-mediated adhesion of the ZAP-70-deficient Jurkat T cell line, P116, to the β1 integrin ligand fibronectin. Reintroduction of wild-type ZAP-70, but not a kinase-inactive variant, K369R, corrected the adhesive defect observed in P116 T cells. In addition, the kinase-inactive ZAP-70 mutant inhibited CD3-induced adhesion of primary human T cell blasts. Interestingly, a ZAP-70 mutant with a tyrosine to phenylalanine substitution at position 319 (Y319F) restored the adhesive defect in P116 T cells, even though Y319F ZAP-70 failed to fully reconstitute CD3-initiated NF-AT-dependent transcription and tyrosine phosphorylation of the LAT adapter protein. Finally, expression of mutants of LAT and the SLP-76 adapter protein that modulate CD3-mediated activation of an NF-AT reporter gene failed to block CD3-induced increases in β1 integrin-mediated adhesion. These observations support a model in which the tyrosine kinase activity of ZAP-70 kinase is critical for regulation of β1 integrin activity by CD3/TCR. However, the signaling events downstream of ZAP-70 that regulate CD3/TCR-mediated activation of β1 integrin function exhibit key differences when compared with the signaling pathways that regulate transcriptional events initiated by CD3/TCR stimulation.
TGF-β1 and IFN-γ Direct Macrophage Activation by TNF-α to Osteoclastic or Cytocidal Phenotype
Authors: Fox Simon W. , Fuller Karen , Bayley Kathryn E. , Lean Jenny M. , Chambers Timothy J. 
Published: April 2014

Abstract
TNF-related activation-induced cytokine (TRANCE; also called receptor activator of NF-κB ligand (RANKL), osteoclast differentiation factor (ODF), osteoprotegerin ligand (OPGL), and TNFSF11) induces the differentiation of progenitors of the mononuclear phagocyte lineage into osteoclasts in the presence of M-CSF. Surprisingly, in view of its potent ability to induce inflammation and activate macrophage cytocidal function, TNF-α has also been found to induce osteoclast-like cells in vitro under similar conditions. This raises questions concerning both the nature of osteoclasts and the mechanism of lineage choice in mononuclear phagocytes. We found that, as with TRANCE, the macrophage deactivator TGF-β1 strongly promoted TNF-α-induced osteoclast-like cell formation from immature bone marrow macrophages. This was abolished by IFN-γ. However, TRANCE did not share the ability of TNF-α to activate NO production or heighten respiratory burst potential by macrophages, or induce inflammation on s.c. injection into mice. This suggests that TGF-β1 promotes osteoclast formation not only by inhibiting cytocidal behavior, but also by actively directing TNF-α activation of precursors toward osteoclasts. The osteoclast appears to be an equivalent, alternative destiny for precursors to that of cytocidal macrophage, and may represent an activated variant of scavenger macrophage.
Stimulatory Function of gp49A, a Murine Ig-Like Receptor, in Rat Basophilic Leukemia Cells
Authors: Lee Kwang Ho , Ono Masao , Inui Masanori , Yuasa Takae , Takai Toshiyuki 
Published: April 2014

Abstract
Murine gp49, a 49-kDa type I transmembrane glycoprotein, is a member of the Ig-like receptors expressed on the surface of cells involved in natural immunity such as mast cells, NK cells, and macrophages. The two major subtypes, gp49A and gp49B, are encoded by two different genes adjacent to each other. gp49B contains an immunoreceptor tyrosine-based inhibitory motif in its cytoplasmic region and is known to function as an inhibitory molecule. In contrast, gp49A does not harbor any specific motif for signal transduction, nor has its physiological role been determined. Here we report on the stimulatory nature of gp49A by analyzing biochemical characteristics of chimeric molecules consisting of an ectodomain of Fc receptor and a C-terminal half of gp49A, namely the pretransmembrane, transmembrane, and cytoplasmic portions, expressed on the rat basophilic leukemia mast cell line. Cross-linking of the chimeric receptors evoked cytoplasmic calcium mobilization, PGD2 release, and transcription of IL-3 and IL-4 genes, but did not elicit degranulation of the cells. The chimeric molecule could be expressed as a singlet and a homodimeric form on the cell surface. A pretransmembrane cysteine residue of gp49A was necessary for dimer formation. Dimerization was be necessary for their incorporation into glycolipid-enriched membrane fraction (GEM) upon cross-linking stimuli. The calcium mobilization response was inhibited by treatment of cells with methyl-β-cyclodextrin, an inhibitor of GEM formation. Together with these results, it was strongly suggested that gp49A could be expressed as a homodimer and elicit activation signals that lead to calcium mobilization, eicosanoid production, and cytokine gene transcription through its incorporation into GEM.