bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of HIV-1 Infection on VH3 Gene Repertoire of Naive Human B Cells
Authors: Scamurra Ronald W. , Miller Darren J. , Dahl Linda , Abrahamsen Mitchell , Kapur Vivek , Wahl Sharon M. , Milner Eric C. B. , Janoff Edward N. 
Published: April 2014

AbstractB cells of the largest Ig variable heavy chain gene (VH) family, VH3, are reportedly decreased in patients with late stage HIV-1 disease. This deficit may contribute to their impaired responses to infections and vaccines. We confirmed that the VH3 family was underrepresented in serum IgM proteins, with a 45% decrease in patients with advanced HIV-1 disease. However, the proportion of VH3 within VH(1–6) IgM mRNA from peripheral B cells did not differ from that of control subjects (mean ± SD, 57.1 ± 9.7 vs 61.1 ± 8.7%). Similarly, within VH(1–6) IgD mRNA, which even more closely represents the unstimulated naive repertoire, the relative expression of VH3 mRNA was comparable in the two groups. Moreover, the frequency of individual genes within the VH3 family for IgD, particularly genes which encode putative HIV-1 gp120 binding sites, also was normal in HIV-1-infected patients. However, VH3 family expression for IgG mRNA was significantly decreased (17%) and VH4 IgG was increased (33%) relative to other VH families in advanced HIV-1-infected patients. Thus, the changes in VH family expression were more readily apparent in previously activated IgG “memory” B cell populations and, likely, in cells actively producing IgM rather than in resting naive cells. The presence of a relatively normal naive VH3 IgM and IgD mRNA repertoire in resting cells supports the prospect that with proper stimulation, particularly in conjunction with effective antiviral therapy, vigorous humoral immune responses to infections and vaccines may be elicited in this high-risk population.
Induction of an Antigen-Specific CTL Response by a Conformationally Biased Agonist of Human C5a Anaphylatoxin as a Molecular Adjuvant
Authors: Ulrich J. Terry , Cieplak Witold , Paczkowski Natalii J. , Taylor Stephen M. , Sanderson Sam D. 
Published: April 2014

AbstractA conformationally biased decapeptide agonist of human C5a anaphylatoxin (YSFKPMPLaR) was used as a molecular adjuvant in stimulating an Ag-specific CTL response against murine P815S target cells expressing an Ld-restricted CTL epitope of the hepatitis B surface Ag (HBsAg). Groups of BALB/c mice (H-2d) were immunized with aqueous solutions of the HBsAg CTL epitopes (IPQSLDSWWTSL and IPQSLDSWWTSLRR); the C5a agonist (YSFKPMPLaR); the C5a agonist and HBsAg CTL epitopes admixed (IPQSLDSWWTSL and IPQSLDSWWTSLRR + YSFKPMPLaR); the C5a-active, HBsAg CTL epitope-C5a agonist constructs (IPQSLDSWWTSLYSFKPMPLaR, IPQSLDSWWTSLRRYSFKPMPLaR, and IPQSLDSWWTSLRVRRYSFPMPLaR); a C5a-inactive, reverse-moiety construct (YSFKPMPLaRRRIPQSLDSWWTSL); and a C5a-attenuated, carboxyl-terminal-blocked construct (IPQSLDSWWTSLRRYSFKPMPLaRG). Ag-specific CD8+ CTL responses were observed after the secondary boost in the absence of any added adjuvant only in mice that were immunized with C5a-active contructs, IPQSLDSWWTSLRRYSFKPMPLaR and IPQSLDSWWTSLRVRRYSFKPMPLaR. These two C5a-active immunogens contained potential subtilisin-sensitive linker sequences between the HBsAg CTL epitope and the C5a agonist; i.e., a double-Arg (RR) and a furin protease sensitive sequence (RVRR). The introduction of these potentially cleavable sequences may be a method of increasing the likelihood of liberating the CTL epitope from the C5a agonist by intracellular proteases, thereby facilitating entry of the epitope into Ag-processing pathways via an exogenous route.
Human Dendritic Cells Transfected with RNA Encoding Prostate-Specific Antigen Stimulate Prostate-Specific CTL Responses In Vitro
Authors: Heiser Axel , Dahm Philipp , R. Yancey Donna , Maurice Margaret A. , Boczkowski David , Nair Smita K. , Gilboa Eli , Vieweg Johannes 
Published: April 2014

Abstract
Although immunological tolerance to self Ags represents an important mechanism to prevent normal tissue injury, there is growing evidence that tolerance to tumor Ags, which often represent normal peripherally expressed proteins, is not absolute and can be effectively reverted. Prostate-specific Ag (PSA) is a self Ag expressed by both normal and malignant prostatic epithelium, and therefore offers a unique opportunity to examine the ability of self Ags to serve as specific CTL targets. In this study, we investigated the efficacy of autologous dendritic cells (DC) transfected with mRNA encoding PSA to stimulate CTL against PSA Ags in vitro. Ag in form of RNA carries the advantage to encode multiple epitopes for many HLA alleles, thus permitting induction of CTL responses among many cancer patients independent of their HLA repertoire. In this study, we show that PSA mRNA-transfected DC were capable of stimulating primary CTL responses against PSA Ags in vitro. The PSA-specific CTL did not cross-react with kallikrein Ags, a protein, which shares significant homology with PSA, suggesting that harmful autoimmune toxicity may not represent a significant problem with this approach. PSA RNA-transfected DC generated from male or female healthy volunteers or from cancer patients were equally effective in stimulating PSA-specific CTL in vitro, implying that neither natural tolerance to PSA Ags nor tumor-mediated T cell anergy may represent major barriers for CTL generation against the self Ag PSA. This study provides a preclinical rationale for using PSA RNA-transfected DC in active or adoptive immunization protocols.
Cutting Edge: B Cells Promote CD8+ T Cell Activation in MRL-FaslprMice Independently of MHC Class I Antigen Presentation
Authors: Chan Owen T. M. , Shlomchik Mark J. 
Published: April 2014

AbstractSpontaneous CD8+ T cell activation in MRL-Faslpr mice is B cell dependent. It is unclear whether this B-dependent activation is mediated by direct Ag presentation via MHC class I proteins (i.e., cross-presentation) or whether activation occurs by an indirect mechanism, e.g., via effects on CD4+ cells. To determine how CD8+ T cell activation is promoted by B cells, we created mixed bone marrow chimeras where direct MHC class I Ag presentation by B cells was abrogated while other leukocyte compartments could express MHC class I. Surprisingly, despite the absence of B cell class I-restricted Ag presentation, CD8+ T cell activation was intact in the chimeric mice. Therefore, the spontaneous B cell-dependent CD8+ T cell activation that occurs in systemic autoimmunity is not due to direct presentation by B cells to CD8+ T cells.
Cutting Edge: Lipoxins Rapidly Stimulate Nonphlogistic Phagocytosis of Apoptotic Neutrophils by Monocyte-Derived Macrophages
Authors: Godson Catherine , Mitchell Siobhan , Harvey Killeen , Petasis Nicos A. , Hogg Nancy , Brady Hugh R. 
Published: April 2014

AbstractLipoxins (LX) are lipoxygenase-derived eicosanoids generated during inflammation. LX inhibit polymorphonuclear neutrophil (PMN) chemotaxis and adhesion and are putative braking signals for PMN-mediated tissue injury. In this study, we report that LXA4 promotes another important step in the resolution phase of inflammation, namely, phagocytosis of apoptotic PMN by monocyte-derived macrophages (Mφ). LXA4 triggered rapid, concentration-dependent uptake of apoptotic PMN. This bioactivity was shared by stable synthetic LXA4 analogues (picomolar concentrations) but not by other eicosanoids tested. LXA4-triggered phagocytosis did not provoke IL-8 or monocyte chemoattractant protein-1 release. LXA4-induced phagocytosis was attenuated by anti-CD36, αvβ3, and CD18 mAbs. LXA4-triggered PMN uptake was inhibited by pertussis toxin and by 8-bromo-cAMP and was mimicked by Rp-cAMP, a protein kinase A inhibitor. LXA4 attenuated PGE2-stimulated protein kinase A activation in Mφ. These results suggest that LXA4 is an endogenous stimulus for PMN clearance during inflammation and provide a novel rationale for using stable synthetic analogues as anti-inflammatory compounds in vivo.
Adenoviral-Mediated Overexpression of Monocyte Chemoattractant Protein-1 Differentially Alters the Development of Th1 and Th2 Type Responses In Vivo
Authors: Matsukawa Akihiro , Lukacs Nicholas W. , Standiford Theodore J. , Chensue Stephen W. , Kunkel Steven L. 
Published: April 2014

AbstractThe expression of chemokines during an immune response may participate in determining the intensity and type of the developing immune response. In the present study, we have examined the effect of overexpressing monocyte chemoattractant protein (MCP)-1 at the site of immunization during different stages of Th1- and Th2-type granulomatous responses. The overexpression of MCP-1 by MCP-1 adenovirus during the sensitization phase of the purified protein derivative Th1-type model significantly reduced the elicitation of the granulomatous response. In contrast, the overexpression of MCP-1 during the sensitization phase of the schistosome egg Ag Th2 response led to an enhanced granulomatous reaction. When cytokines were examined upon restimulation of splenocytes ex vivo, an altered cytokine profile was observed, as compared with control mice. IFN-γ and IL-12 were significantly reduced in the purified protein derivative Th1-type response, whereas IL-10 and IL-13 were up-regulated in the schistosome egg Ag Th2-type response. The regulation of the immune response was further examined by using the MCP-1 adenovirus at later time points during the elicitation phase. When MCP-1 was overexpressed during the elicitation phase of the responses, neither the Th1-type nor the Th2-type granuloma was altered. Likewise, the cytokine profiles after restimulation of splenocytes ex vivo were unchanged. Thus, the function of MCP-1 may depend on the stage and type of immune response.
Functional Maturation of Adult Mouse Resting Microglia into an APC Is Promoted by Granulocyte-Macrophage Colony-Stimulating Factor and Interaction with Th1 Cells
Authors: Aloisi Francesca , De Simone Roberta , Columba-Cabezas Sandra , Penna Giuseppe , Adorini Luciano 
Published: April 2014

AbstractA precise knowledge of the early events inducing maturation of resting microglia into a competent APC may help to understand the involvement of this cell type in the development of CNS immunopathology. To elucidate whether signals from preactivated T cells are sufficient to induce APC features in resting microglia, microglia from the adult BALB/c mouse CNS were cocultured with Th1 and Th2 lines from DO11.10 TCR transgenic mice to examine modulation of APC-related molecules and Ag-presenting capacity. Upon Ag-specific interaction with Th1, but not Th2, cells, microglia strongly up-regulated the surface expression of MHC class II, CD40, and CD54 molecules. Induction of CD86 on mouse microglia did not require T cell-derived signals. Acutely isolated adult microglia stimulated Th1 cells to secrete IFN-γ and, to a lesser extent, IL-2, but were inefficient stimulators of IL-4 secretion by Th2 cells. Microglia exposed in vitro to IFN-γ showed enhanced expression of MHC class II, CD40, and CD54 molecules and became able to restimulate Th2 cells. In addition to IFN-γ, GM-CSF increased the ability of microglia to activate Th1, but not Th2, cells without up-regulating MHC class II, CD40, or CD54 molecules. These results suggest that interaction with Th1 cells and/or Th1-secreted soluble factors induces the functional maturation of adult mouse microglia into an APC able to sustain CD4+ T cell activation. Moreover, GM-CSF, a cytokine secreted by T cells as well as reactive astrocytes, could prime microglia for Th1-stimulating capacity, possibly by enhancing their responsiveness to Th1-derived signals.
Clonal Characterization of a Bipotent T Cell and NK Cell Progenitor in the Mouse Fetal Thymus
Authors: Michie Alison M. , Carlyle James R. , Schmitt Thomas M. , Ljutic Belma , Cho Sarah K. , Fong Quyen , Zúñiga-Pflücker Juan Carlos 
Published: April 2014

Abstract
We recently described a population of fetal thymocytes with a CD117+NK1.1+CD90lowCD25− phenotype, which were shown to contain committed T cell and NK cell progenitors. However, the characterization of a single cell with a restricted T and NK cell precursor potential was lacking. Here, using an in vitro model for T and NK cell differentiation, we provide conclusive evidence demonstrating the existence of a clonal lineage-restricted T and NK cell progenitor. These results establish that fetal thymocytes with a CD117+NK1.1+CD90lowCD25− phenotype represent bipotent T and NK cell progenitors.
CD27-Mediated Activation of Murine NK Cells
Authors: Takeda Kazuyoshi , Oshima Hideo , Hayakawa Yoshihiro , Akiba Hisaya , Atsuta Machiko , Kobata Tetsuji , Kobayashi Kimio , Ito Mamoru , Yagita Hideo , Okumura Ko 
Published: April 2014

Abstract
CD27, a member of the TNF receptor superfamily, has been implicated in T cell activation, T cell development, and T cell-dependent Ab production by B cells. In the present study we examined the expression and function of CD27 on murine NK cells. Murine NK cells constitutively expressed CD27 on their surface. Stimulation with immobilized anti-CD27 mAb or murine CD27 ligand (CD70) transfectans solely could induce proliferation and IFN-γ production of freshly isolated NK cells and enhanced the proliferation and IFN-γ production of anti-NK1.1-sutimulated NK cells. Although NK cell cytotoxicity was not triggered by anti-CD27 mAb or against CD70 transfectants, prestimulation via CD27 enhanced the cytotoxic activity of NK cells in an IFN-γ-dependent manner. These results suggest that CD27-mediated activation may be involved in the NK cell-mediated innate immunity against virus-infected or transformed cells expressing CD70.
Measles Virus Induces Abnormal Differentiation of CD40 Ligand-Activated Human Dendritic Cells
Authors: Servet-Delprat Christine , Vidalain Pierre-Olivier , Bausinger Huguette , Manié Serge , Le Deist Françoise , Azocar Olga , Hanau Daniel , Fischer Alain , Rabourdin-Combe Chantal 
Published: April 2014

Abstract
Measles virus (MV) infection induces a profound immunosuppression responsible for a high rate of mortality in malnourished children. MV can encounter human dendritic cells (DCs) in the respiratory mucosa or in the secondary lymphoid organs. The purpose of this study was to investigate the consequences of DC infection by MV, particularly concerning their maturation and their ability to generate CD8+ T cell proliferation. We first show that MV-infected Langerhans cells or monocyte-derived DCs undergo a maturation process similarly to the one induced by TNF-α or LPS, respectively. CD40 ligand (CD40L) expressed on activated T cells is shown to induce terminal differentiation of DCs into mature effector DCs. In contrast, the CD40L-dependent maturation of DCs is inhibited by MV infection, as demonstrated by CD25, CD69, CD71, CD40, CD80, CD86, and CD83 expression down-regulation. Moreover, the CD40L-induced cytokine pattern in DCs is modified by MV infection with inhibition of IL-12 and IL-1α/β and induction of IL-10 mRNAs synthesis. Using peripheral blood lymphocytes from CD40L-deficient patients, we demonstrate that MV infection of DCs prevents the CD40L-dependent CD8+ T cell proliferation. In such DC-PBL cocultures, inhibition of CD80 and CD86 expression on DCs was shown to require both MV replication and CD40 triggering. Finally, for the first time, MV was shown to inhibit tyrosine-phosphorylation level induced by CD40 activation in DCs. Our data demonstrate that MV replication modifies CD40 signaling in DCs, thus leading to impaired maturation. This phenomenon could play a pivotal role in MV-induced immunosuppression.
Processing and Reactivity of T Cell Epitopes Containing Two Cysteine Residues from Hen Egg-White Lysozyme (HEL74–90)
Authors: Kang Hee-Kap , Mikszta John A. , Deng Hongkui , Sercarz Eli E. , Jensen Peter E. , Kim Byung S. 
Published: April 2014

Abstract
The Ag processing and structural requirements involved in the generation of a major T cell epitope from the hen egg-white lysozyme protein (HEL74–88), containing two cysteine residues at positions 76 and 80, were investigated. Several T cell hybridomas derived from both low responder (I-Ab) and high responder (I-Ak) mice recognize this region. These hybridomas are strongly responsive to native HEL, but unresponsive to the reduced and carboxymethylated protein. Air-oxidized HEL74–88 peptide was unable to bind I-Ak molecules and failed to stimulate T cells in the absence of intracellular Ag processing. Further functional competition assays showed that alkylation of cysteine residues with bulky methyl groups interferes with the contacts for the MHC class II molecules (I-Ak) of high responder mice and the I-Ab-restricted TCR of low responder mice. Serine substitutions of the cysteine residues of HEL74–88 either enhanced or abrogated T cell stimulation by the peptides without significant alterations in the class II binding. These results suggest that the cysteine residues of peptides must be free from disulfide bonding for efficient stimulation of T cells and yet frequently used modifications of cysteine residues may not be suitable for peptide-based vaccine development.
Analysis of the Virus-Specific and Nonspecific B Cell Response to a Persistent B-Lymphotropic Gammaherpesvirus
Authors: Sangster Mark Y. , Topham David J. , D’Costa Sybil , Cardin Rhonda D. , Marion Tony N. , Myers Linda K. , Doherty Peter C. 
Published: April 2014

Abstract
Respiratory challenge of mice with murine gammaherpesvirus 68 (γHV68) results in acute replication in respiratory epithelial cells and persistent, latent infection of B cells and macrophages. γHV68 elicits virus-specific Ab, and also nonspecifically activates B cells to Ab production through a CD4+ T cell-dependent process. The current analysis characterizes virus-specific and nonspecific Ab production at the single cell level and investigates the requirements and nature of the nonspecific response. Virus-specific Ab-forming cell (AFC) numbers were dwarfed by the increase in total AFC in all sites examined, indicating substantial nonspecific Ab production. Clear increases and decreases in specific and total AFC numbers occurred in the lymph nodes draining the respiratory tract and the spleen, but AFC numbers in the bone marrow (BM) increased to a plateau and remained constant. The longevity of the BM response was reflected in a sustained increase in virus-specific and total serum Ab levels. Generally, the IgG2a and IgG2b isotypes predominated. Analysis of cytokine-deficient mice, CD40 ligand-deficient mice, and radiation BM chimeras lacking MHC class II expression specifically on B cells indicated that nonspecific Ab production is independent of IL-6 or IFN-γ, and dependent on cognate CD4+ T cell help. Several observations were consistent with polyclonal B cell activation by γHV68, including the induction of durable serum levels of IgG reactive with mammalian dsDNA and murine type II collagen. Our findings indicate new directions for studies of this valuable model of γ-herpesvirus pathogenesis.
Human Interdigitating Dendritic Cells Induce Isotype Switching and IL-13-Dependent IgM Production in CD40-Activated Naive B Cells
Authors: Johansson Bengt , Ingvarsson Sigurdur , Björck Pia , Borrebaeck Carl A. K. 
Published: April 2014

Abstract
Interdigitating dendritic cells (IDC) represent a mature progeny of dendritic cells (DC) in vivo and are exhibiting a strong lymphocyte stimulatory potential. Because of the restricted localization to secondary lymphoid organs where decisive cellular interactions take place in the initial events of immunity, IDC regulatory function was addressed in relation to naive B cells. In this study, we demonstrate that human tonsillar IDC induce a dual response from CD40-activated IgD+/CD38− naive B lymphocytes. IDC direct naive B cells toward either isotype switching or an IL-13-dependent IgM secretion. IDC-dependent proliferation, isotype switching, and Ig production are all strictly mediated by soluble factors, suggesting that such skewing in B cell activation is the result of differential cytokine expression. Moreover, IDC-expressed IL-13 represents a novel source of a cytokine with recently established effects in Th2 induction as well as in immunological disorders resulting in allergic reactions.
Cancer Immunotherapy Targeting Wilms’ Tumor Gene WT1 Product
Authors: Oka Yoshihiro , Udaka Keiko , Tsuboi Akihiro , Elisseeva Olga A. , Ogawa Hiroyasu , Aozasa Katsuyuki , Kishimoto Tadamitsu , Sugiyama Haruo 
Published: April 2014

AbstractThe Wilms’ tumor gene WT1 is expressed at high levels not only in acute myelocytic and lymphocytic leukemia and in chronic myelocytic leukemia but also in various types of solid tumors including lung cancers. To determine whether the WT1 protein can serve as a target Ag for tumor-specific immunity, three 9-mer WT1 peptides (Db126, Db221, and Db235), which contain H-2Db-binding anchor motifs and have a comparatively higher binding affinity for H-2Db molecules, were tested in mice (C57BL/6, H-2Db) for in vivo induction of CTLs directed against these WT1 peptides. Only one peptide, Db126, with the highest binding affinity for H-2Db molecules induced vigorous CTL responses. The CTLs specifically lysed not only Db126-pulsed target cells dependently upon Db126 concentrations but also WT1-expressing tumor cells in an H-2Db-restricted manner. The sensitizing activity to the Db126-specific CTLs was recovered from the cell extract of WT1-expressing tumor cells targeted by the CTLs in the same retention time as that needed for the synthetic Db126 peptide in RP-HPLC, indicating that the Db126-specific CTLs recognize the Db126 peptide to kill WT1-expressing target cells. Furthermore, mice immunized with the Db126 peptide rejected challenges by WT1-expressing tumor cells and survived for a long time with no signs of autoaggression by the CTLs. Thus, the WT1 protein was identified as a novel tumor Ag. Immunotherapy targeting the WT1 protein should find clinical application for various types of human cancers.
The Murine Liver-Specific Nonclassical MHC Class I Molecule Q10 Binds a Classical Peptide Repertoire
Authors: Zappacosta Francesca , Tabaczewski Piotr , Parker Kenneth C. , Coligan John E. , Stroynowski Iwona 
Published: April 2014

Abstract
The biological properties of the nonclassical class I MHC molecules secreted into blood and tissue fluids are not currently understood. To address this issue, we studied the murine Q10 molecule, one of the most abundant, soluble class Ib molecules. Mass spectrometry analyses of hybrid Q10 polypeptides revealed that α1α2 domains of Q10 associate with 8–9 long peptides similar to the classical class I MHC ligands. Several of the sequenced peptides matched intracellularly synthesized murine proteins. This finding and the observation that the Q10 hybrid assembly is TAP2-dependent supports the notion that Q10 groove is loaded by the classical class I Ag presentation pathway. Peptides eluted from Q10 displayed a binding motif typical of H-2K, D, and L ligands. They carried conserved residues at P2 (Gly), P6 (Leu), and Pω (Phe/Leu). The role of these residues as anchors/auxiliary anchors was confirmed by Ala substitution experiments. The Q10 peptide repertoire was heterogeneous, with 75% of the groove occupied by a multitude of diverse peptides; however, 25% of the molecules bound a single peptide identical to a region of a TCR V β-chain. Since this peptide did not display enhanced binding affinity for Q10 nor does its origin and sequence suggest that it is functionally significant, we propose that the nonclassical class I groove of Q10 resembles H-2K, D, and L grooves more than the highly specialized clefts of nonclassical class I Ags such as Qa-1, HLA-E, and M3.