bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular and Genetic Basis for Strain-Dependent NK1.1 Alloreactivity of Mouse NK Cells
Authors: Carlyle James R. , Mesci Aruz , Ljutic Belma , Belanger Simon , Tai Lee-Hwa , Rousselle Etienne , Troke Angela D. , Proteau Marie-France , Makrigiannis Andrew P. 
Published: April 2014

AbstractNK1.1 alloantigen expression can be used to define NK cells in certain mouse strains, such as B6 (NKR-P1C) and SJL (NKR-P1B). However, BALB/c NK cells do not react with the anti-NK1.1 mAb, PK136. To investigate the NK1.1− phenotype of BALB/c NK cells, we have undertaken NK1.1 epitope mapping and genomic analysis of the BALB/c Nkrp1 region. Bacterial artificial chromosome library analysis reveals that, unlike the Ly49 region, the Nkrp1-Ocil/Clr region displays limited genetic divergence between B6 and BALB/c mice. In fact, significant divergence is confined to the Nkrp1b and Nkrp1c genes. Strikingly, the B6 Nkrp1d gene appears to represent a divergent allele of the Nkrp1b gene in BALB/c mice and other strains. Importantly, BALB/c NK cells express abundant and functional Nkrp1 transcripts, and the BALB/c NKR-P1B receptor functionally binds Ocil/Clr-b ligand. However, the BALB/c NKR-P1B/C sequences differ from those of the known NK1.1 alloantigens, and epitope mapping demonstrates that directed mutation of a single amino acid in the NKR-P1BBALB protein confers NK1.1 reactivity. Thus, PK136 mAb recognizes, in part, a distal C-terminal epitope present in NKR-P1BSw/SJL and NKR-P1CB6, but absent in NKR-P1A/D/FB6 and NKR-P1B/CBALB. Allelic divergence of the Nkrp1b/c gene products and limited divergence of the BALB/c Nkrp1-Ocil/Clr region explain a longstanding confusion regarding the strain-specific NK1.1 alloantigen reactivity of mouse NK cells.
Bacillus anthracisToxins Inhibit Human Neutrophil NADPH Oxidase Activity
Authors: Crawford Matthew A. , Aylott Caroline V. , Bourdeau Raymond W. , Bokoch Gary M. 
Published: April 2014

AbstractBacillus anthracis, the causative agent of anthrax, is a Gram-positive, spore-forming bacterium. B. anthracis virulence is ascribed mainly to a secreted tripartite AB-type toxin composed of three proteins designated protective Ag (PA), lethal factor, and edema factor. PA assembles with the enzymatic portions of the toxin, the metalloprotease lethal factor, and/or the adenylate cyclase edema factor, to generate lethal toxin (LTx) and edema toxin (ETx), respectively. These toxins enter cells through the interaction of PA with specific cell surface receptors. The anthrax toxins act to suppress innate immune responses and, given the importance of human neutrophils in innate immunity, they are likely relevant targets of the anthrax toxin. We have investigated in detail the effects of B. anthracis toxin on superoxide production by primary human neutrophils. Both LTx and ETx exhibit distinct inhibitory effects on fMLP (and C5a) receptor-mediated superoxide production, but have no effect on PMA nonreceptor-dependent superoxide production. These inhibitory effects cannot be accounted for by induction of neutrophil death, or by changes in stimulatory receptor levels. Analysis of NADPH oxidase regulation using whole cell and cell-free systems suggests that the toxins do not exert direct effects on NADPH oxidase components, but rather act via their respective effects, inhibition of MAPK signaling (LTx), and elevation of intracellular cAMP (ETx), to inhibit upstream signaling components mediating NADPH oxidase assembly and/or activation. Our results demonstrate that anthrax toxins effectively suppress human neutrophil-mediated innate immunity by inhibiting their ability to generate superoxide for bacterial killing.
A Novel Functional T Cell Hybridoma Recognizes Macrophage Cell Death Induced by Bacteria: A Possible Role for Innate Lymphocytes in Bacterial Infection
Authors: Kubota Koichi 
Published: April 2014

AbstractWe have established a novel TCRαβ (TCRVβ6)+CD4−CD8− T cell hybridoma designated B6HO3. When the B6HO3 cells were cocultured with bacterial-infected J774 macrophage-like cells, IFN-γ production by B6HO3 cells was triggered through direct cell-cell contact with dying J774 cells infected with Listeria monocytogenes (LM), Shigella flexneri, or Salmonella typhimurium that expressed the type III secretion system, but not with intact J774 cells infected with heat-killed LM, nonhemolytic lysteriolysin O-deficient (Hly−) LM, plasmid-cured Shigella, or stationary-phase Salmonella. However, the triggering of B6HO3 cells for IFN-γ production involved neither dying hepatoma cells infected with LM nor dying J774 cells caused by gliotoxin treatment or freeze thawing. Cycloheximide and Abs to H-2Kd, H-2Dd, Iad, CD1d, TCRVβ6, and IL-12 did not inhibit the contact-dependent IFN-γ response, indicating that this IFN-γ response did not require de novo protein synthesis in bacterial-infected J774 cells and was TCR and IL-12 independent. Thus, in an as yet undefined way, B6HO3 hybridoma recognizes a specialized form of macrophage cell death resulting from bacterial infection and consequently produces IFN-γ. Moreover, contact-dependent interaction of minor subsets of splenic αβ T cells, including NKT cells with dying LM-infected J774 and bone marrow-derived macrophage (BMM) cells, proved to provide an IFN-γ-productive stimulus for these minor T cell populations, to which the parental T cell of the B6HO3 hybridoma appeared to belong. Unexpectedly, subsets of γδ T and NK cells similarly responded to dying LM-infected macrophage cells. These results propose that innate lymphocytes may possess a recognition system sensing macrophage cell “danger” resulting from bacterial infection.
CXC Chemokine Ligand 13 Plays a Role in Experimental Autoimmune Encephalomyelitis
Authors: Bagaeva Ludmila V. , Rao Praveen , Powers James M. , Segal Benjamin M. 
Published: April 2014

AbstractExperimental autoimmune encephalomyelitis (EAE) is a Tcell-mediated autoimmune disease of the CNS that is widely used as an animal model of multiple sclerosis. In this study, we investigate the role of CXCL13, a chemokine involved in the development and organization of secondary lymphoid tissues, in the pathogenesis of EAE. We detected CXCL13 mRNA and protein in spinal cords of mice with EAE. CXCL13-deficient mice exhibited a mild, self-limited form of disease. CXCL13 appeared to be important for the establishment of chronic white matter lesions. Furthermore, adoptive transfer experiments with CXCL13-deficient hosts indicate that the chemokine plays a distinct role during the effector phase. Our findings raise the possibility that reagents that antagonize or inhibit CXCL13 might be useful for the treatment of neuroinflammatory diseases such as multiple sclerosis.
Antitumor Activity of IFN-λ in Murine Tumor Models
Authors: Sato Atsuko , Ohtsuki Mamitaro , Hata Megumi , Kobayashi Eiji , Murakami Takashi 
Published: April 2014

Abstract
IFN-λ 1, -λ 2 and -λ 3 have been discovered as the latest members of the class II cytokine family and shown to possess antiviral activity. Murine B16 melanoma and Colon26 cancer cells were transduced with mouse IFN-λ to determine whether IFN-λ possesses antitumor activity. Overexpression of IFN-λ induced cell surface MHC class I expression and Fas/CD95 Ag, induced significant caspase-3/7 activity, and increased p21Waf1/Cip1 and dephosphorylated Rb (Ser780) in B16 cells in vitro. IFN-λ expression in tumor cell lines markedly inhibited s.c. and metastatic tumor formation in vivo compared with mock transfections (p &lt; 0.05). Moreover, IFN-λ expression induced lymphocytic infiltrates, and an Ab-mediated immune cell depletion assay showed that NK cells were critical to IFN-λ-mediated tumor growth inhibition. Hydrodynamic injection of IFN-λ cDNA successfully targeted liver metastatic foci of Colon26 cells, and moderately decreased the mortality of mice with tumors. IFN-λ overexpression in the liver increased NK/NKT cells and enhanced their tumor-killing activity, and suggested the activation of innate immune responses. Thus, IFN-λ induced both tumor apoptosis and NK cell-mediated immunological tumor destruction through innate immune responses. These findings suggested that local delivery of IFN-λ might prove a useful adjunctive strategy in the clinical treatment of human malignancies.
NK Cells and γδ+ T Cells Are Phenotypically and Functionally Defective due to Preferential Apoptosis in Patients with Atopic Dermatitis
Authors: Katsuta Michie , Takigawa Yukio , Kimishima Momoko , Inaoka Miyuki , Takahashi Ryo , Shiohara Tetsuo 
Published: April 2014

AbstractInnate immune cells mediate a first line of defense against pathogens and determine the nature of subsequent acquired immune responses, mainly by producing profound amounts of cytokines. Given these diverse tasks, it is predictable that defective NK and γδ+ T cell responses could be the underlying mechanism for the immunological alterations observed in atopic dermatitis (AD). Indeed, the frequencies of circulating NK cells and γδ+ T cells were profoundly reduced in AD patients. They also displayed a defective ability to sustain TNF-α and IFN-γ, but not IL-4, production after in vitro stimulation, and the defect was restricted to innate immune cells. Surprisingly, on the depletion of CD14+ monocytes, this selective impairment of TNF-α and IFN-γ production was restored to levels comparable to that observed in controls. Release of IL-10 from monocytes was not a major mechanism of the NK and γδ+ T cell dysfunction. Apoptosis as revealed by annexin V binding, was preferentially observed in NK and γδ+ T cells from AD patients when stimulated in the presence of monocytes, and depletion of monocytes significantly protected these cells from apoptotic cell death. Preferential apoptosis of NK cells by activated monocytes in AD patients was cell-contact-dependent. These results indicate that, once NK and γδ+ T cells in AD patients are in immediate contact with activated monocytes, these cells are specifically targeted for apoptosis, leading to the reduced type 1 cytokine production, thereby directing subsequent acquired immune responses toward a type-2 pattern and increasing susceptibility to infection.
Bone Marrow Mesenchymal Stem Cells Suppress Lymphocyte Proliferation In Vitro but Fail to Prevent Graft-versus-Host Disease in Mice
Authors: Sudres Muriel , Norol Françoise , Trenado Aurélie , Grégoire Sylvie , Charlotte Frédéric , Levacher Béatrice , Lataillade Jean-Jacques , Bourin Philippe , Holy Xavier , Vernant Jean-Paul , Klatzmann David , Cohen José L. 
Published: April 2014

Abstract
Several reports have suggested that mesenchymal stem cells (MSCs) could exert a potent immunosuppressive effect in vitro, and thus may have a therapeutic potential for T cell-dependent pathologies. We aimed to establish whether MSCs could be used to control graft-vs-host disease (GVHD), a major cause of morbidity and mortality after allogeneic hemopoietic stem cell transplantation. From C57BL/6 and BALB/c mouse bone marrow cells, we purified and expanded MSCs characterized by the lack of expression of CD45 and CD11b molecules, their typical spindle-shaped morphology, together with their ability to differentiate into osteogenic, chondrogenic, and adipogenic cells. These MSCs suppressed alloantigen-induced T cell proliferation in vitro in a dose-dependent manner, independently of their MHC haplotype. However, when MSCs were added to a bone marrow transplant at a MSCs:T cells ratio that provided a strong inhibition of the allogeneic responses in vitro, they yielded no clinical benefit on the incidence or severity of GVHD. The absence of clinical effect was not due to MSC rejection because they still could be detected in grafted animals, but rather to an absence of suppressive effect on donor T cell division in vivo. Thus, in these murine models, experimental data do not support a significant immunosuppressive effect of MSCs in vivo for the treatment of GVHD.
Differential Effects of IL-15 and IL-21 in Myeloid (CD11b+) and Lymphoid (CD11b−) Bone Marrow Cells
Authors: Pelletier Martin , Girard Denis 
Published: April 2014

Abstract
IL-15 has been found to activate NF-κB in various types of cells. However, the role of this transcription factor in IL-15- and IL-21-stimulated murine bone marrow (BM) cells is unclear. In this study, we demonstrated that both IL-15 and IL-21 are capable of delaying BM cell factor deprivation-induced apoptosis, but only IL-15 induced their proliferation. Following separation of BM cells into myeloid (CD11b+) and lymphoid (CD11b−) cell populations, we found that IL-15, but not IL-21, significantly induced proliferation in both cell populations. Both cytokines significantly delayed apoptosis, but only in CD11b− BM cells. IL-15Rα, CD122 (IL-2/15Rβ), and common γ-chains (CD132) were expressed in both populations, whereas IL-21Rα was expressed only in CD11b− BM cells. In addition, we demonstrated that IL-15-induced BM cell proliferation was significantly inhibited in NF-κBp50−/− mice when compared with littermate controls. The ability of IL-15 and IL-21 to delay BM cell apoptosis was slightly inhibited in NF-κBp50−/− mice, whereas the antiapoptotic effect of LPS was markedly reversed. We conclude that IL-15, but not IL-21, induces BM cell proliferation and that both cytokines delay BM cell apoptosis. These biological activities were preferentially observed in CD11b− BM cells. Using NF-κBp50−/− mice, we demonstrated for the first time that NF-κB plays a greater role in IL-15-induced cell proliferation than in IL-15- and IL-21-induced suppression of apoptosis.
The Basic Helix-Loop-Helix Transcription Factor HEBAlt Is Expressed in Pro-T Cells and Enhances the Generation of T Cell Precursors
Authors: Wang Duncheng , Claus Carol L. , Vaccarelli Giovanna , Braunstein Marsela , Schmitt Thomas M. , Zúñiga-Pflücker Juan Carlos , Rothenberg Ellen V. , Anderson Michele K. 
Published: April 2014

AbstractThe basic helix-loop-helix (bHLH) transcription factors HEB and E2A are critical mediators of gene regulation during lymphocyte development. We have cloned a new transcription factor, called HEBAlt, from a pro-T cell cDNA library. HEBAlt is generated by alternative transcriptional initiation and splicing from the HEB gene locus, which also encodes the previously characterized E box protein HEBCan. HEBAlt contains a unique N-terminal coding exon (the Alt domain) that replaces the first transactivation domain of HEBCan. Downstream of the Alt domain, HEBAlt is identical to HEBCan, including the DNA binding domain. HEBAlt is induced in early thymocyte precursors and down-regulated permanently at the double negative to double positive (DP) transition, whereas HEBCan mRNA expression peaks at the DP stage of thymocyte development. HEBAlt mRNA is up-regulated synergistically by a combination of HEBCan activity and Delta-Notch signaling. Retroviral transduction of HEBAlt or HEBCan into hemopoietic stem cells followed by OP9-DL1 coculture revealed that HEBAlt-transduced precursors generated more early T lineage precursors and more DP pre-T cells than control transduced cells. By contrast, HEBCan-transduced cells that maintained high level expression of the HEBCan transgene were inhibited in expansion and progression through T cell development. HEB−/− fetal liver precursors transduced with HEBAlt were rescued from delayed T cell specification, but HEBCan-transduced HEB−/− precursors were not. Therefore, HEBAlt and HEBCan are functionally distinct transcription factors, and HEBAlt is specifically required for the efficient generation of early T cell precursors.
G Protein-Coupled Receptor 83 Overexpression in Naive CD4+CD25− T Cells Leads to the Induction of Foxp3+ Regulatory T Cells In Vivo
Authors: Hansen Wiebke , Loser Karin , Westendorf Astrid M. , Bruder Dunja , Pfoertner Susanne , Siewert Christiane , Huehn Jochen , Beissert Stefan , Buer Jan 
Published: April 2014

Abstract
Foxp3 functions as a lineage specification factor for the development of naturally occurring thymus-derived CD4+CD25+ regulatory T (Treg) cells. Recent evidence suggests that naive Foxp3−CD4+CD25− T cells can be converted in the periphery into Foxp3+ Treg cells. In this study, we have identified the G protein-coupled receptor (GPR)83 to be selectively up-regulated by CD4+CD25+ Treg cells of both murine and human origin in contrast to naive CD4+CD25− or recently activated T cells. Furthermore, GPR83 was induced upon overexpression of Foxp3 in naive CD4+CD25− T cells. Transduction of naive CD4+CD25− T cells with GPR83-encoding retroviruses did not confer in vitro suppressive activity. Nevertheless, GPR83-transduced T cells were able to inhibit the effector phase of a severe contact hypersensitivity reaction of the skin, indicating that GPR83 itself or GPR83-mediated signals conferred suppressive activity to conventional CD4+ T cells in vivo. Most strikingly, this in vivo acquisition of suppressive activity was associated with the induction of Foxp3 expression in GPR83-transduced CD4+ T cells under inflammatory conditions. Our results suggest that GPR83 might be critically involved in the peripheral generation of Foxp3+ Treg cells in vivo.
Follicular Dendritic Cells Are Related to Bone Marrow Stromal Cell Progenitors and to Myofibroblasts
Authors: Muñoz-Fernández Raquel , Blanco Francisco Javier , Frecha Cecilia , Martín Francisco , Kimatrai Maria , Abadía-Molina Ana Clara , García-Pacheco José Marcos , Olivares Enrique G. 
Published: April 2014

AbstractFollicular dendritic cells (FDC) are involved in the presentation of native Ags to B cells during the secondary immune response. Some authors consider FDC to be hemopoietic cells, whereas others believe them to be mesenchymal cells. The low proportion of FDC in the lymphoid follicle, together with technical difficulties in their isolation, make these cells difficult to study. We show that Fibroblast Medium can be used successfully to isolate and maintain FDC lines. In this culture medium, we obtained 18 FDC lines from human tonsils, which proliferated for as long as 18 wk and showed a stable Ag phenotype as detected by flow cytometry and RT-PCR. FDC lines were CD45-negative and expressed Ags associated to FDC (CD21, CD23, CD35, CD40, CD73, BAFF, ICAM-1, and VCAM-1) and Ags specific for FDC (DRC-1, CNA.42, and HJ2). These cell lines were also able to bind B cells and secrete CXCL13, functional activities characteristic of FDC. Nevertheless, the additional expression of STRO-1, together with CD10, CD13, CD29, CD34, CD63, CD73, CD90, ICAM-1, VCAM-1, HLA-DR, alkaline phosphatase, and α-smooth muscle actin (α-SM actin) indicated that FDC are closely related to bone marrow stromal cell progenitors. The expression of α-SM actin also relates FDC with myofibroblasts. Like myofibroblasts, FDC lines expressed stress fibers containing α-SM actin and were able to contract collagen gels under the effect of TGFβ1 and platelet-derived growth factor. These findings suggest that FDC are a specialized form of myofibroblast and derive from bone marrow stromal cell progenitors.
TLR Activation of Langerhans Cell-Like Dendritic Cells Triggers an Antiviral Immune Response
Authors: Renn Claudia N. , Sanchez David Jesse , Ochoa Maria Teresa , Legaspi Annaliza J. , Oh Chang-Keun , Liu Philip T. , Krutzik Stephan R. , Sieling Peter A. , Cheng Genhong , Modlin Robert L. 
Published: April 2014

Abstract
Langerhans cells (LC) are a unique subset of dendritic cells (DC), present in the epidermis and serving as the first line of defense against pathogens invading the skin. To investigate the role of human LCs in innate immune responses, we examined TLR expression and function of LC-like DCs derived from CD34+ progenitor cells and compared them to DCs derived from peripheral blood monocytes (monocyte-derived DC; Mo-DC). LC-like DCs and Mo-DCs expressed TLR1–10 mRNAs at comparable levels. Although many of the TLR-induced cytokine patterns were similar between the two cell types, stimulation with the TLR3 agonist poly(I:C) triggered significantly higher amounts of the IFN-inducible chemokines CXCL9 (monokine induced by IFN-γ) and CXCL11 (IFN-γ-inducible T cell α chemoattractant) in LC-like DCs as compared with Mo-DCs. Supernatants from TLR3-activated LC-like DCs reduced intracellular replication of vesicular stomatitis virus in a type I IFN-dependent manner. Finally, CXCL9 colocalized with LCs in skin biopsy specimens from viral infections. Together, our data suggest that LCs exhibit a direct antiviral activity that is dependent on type I IFN as part of the innate immune system.
IL-2 In Vivo Activities and Antitumor Efficacy Enhanced by an Anti-IL-2 mAb
Authors: Kamimura Daisuke , Sawa Yukihisa , Sato Masae , Agung Eviryanti , Hirano Toshio , Murakami Masaaki 
Published: April 2014

Abstract
IL-2 is a potent immunostimulant and has been tested for clinical use, including in immunotherapy for cancers and HIV infection. Here we show that a widely used neutralizing anti-murine IL-2 mAb (S4B6) exhibits unexpected activities that enhance the treatment effects of IL-2 in vivo. Coinjection of the anti-IL-2 mAb with a plasmid carrying murine IL-2 cDNA significantly increased the serum IL-2 levels and induced a substantial increase in the division of CD8+ T and NK1.1high cells in vivo. Injection of the mAb premixed with recombinant murine IL-2 showed the same enhanced effect. A 5-day treatment with the anti-IL-2 mAb alone gradually increased the CD44highCD8+ population, and the increased population was maintained for &gt;300 days, suggesting that the mAb can gradually maintain and potentially enhance the bioactivity of endogenous IL-2 for extended periods. Furthermore, combined treatment with the anti-IL-2 mAb plus the IL-2 plasmid markedly enhanced Ag-specific CTL activity in vivo and partially protected mice from tumor metastasis to the lungs, compared with the anti-IL-2 mAb or IL-2 plasmid alone. These results demonstrated IL-2-enhancing effects of the anti-IL-2 mAb in vivo and suggest that combining a neutralizing anti-IL-2 Ab with IL-2 gene delivery might be used effectively to enhance IL-2 functions in clinical applications.
Analysis of TLR4 Polymorphic Variants: New Insights into TLR4/MD-2/CD14 Stoichiometry, Structure, and Signaling
Authors: Rallabhandi Prasad , Bell Jessica , Boukhvalova Marina S. , Medvedev Andrei , Lorenz Eva , Arditi Moshe , Hemming Val G. , Blanco Jorge C. G. , Segal David M. , Vogel Stefanie N. 
Published: April 2014

Abstract
TLR4 is the signal-transducing receptor for structurally diverse microbial molecules such as bacterial LPS, respiratory syncytial virus fusion (F) protein, and chlamydial heat shock protein 60. Previous studies associated two polymorphic mutations in the extracellular domain of TLR4 (Asp299Gly and Thr399Ile) with decreased LPS responsiveness. To analyze the molecular basis for diminished responsiveness, site-specific mutations (singly or coexpressed) were introduced into untagged and epitope (Flag)-tagged wild-type (WT) TLR4 expression vectors to permit a direct comparison of WT and mutant signal transduction. Coexpression of WT TLR4, CD14, and MD-2 expression vectors in HEK293T cells was first optimized to achieve optimal LPS-induced NF-κB reporter gene expression. Surprisingly, transfection of cells with MD-2 at high input levels often used in the literature suppressed LPS-induced signaling, whereas supraoptimal CD14 levels did not. Under conditions where WT and polymorphic variants were comparably expressed, significant differences in NF-κB activation were observed in response to LPS and two structurally unrelated TLR4 agonists, chlamydial heat shock protein 60 and RSV F protein, with the double, cosegregating mutant TLR4 exhibiting the greatest deficiency. Overexpression of Flag-tagged WT and mutant vectors at input levels resulting in agonist-independent signaling led to equivalent NF-κB signaling, suggesting that these mutations in TLR4 affect appropriate interaction with agonist or coreceptor. These data provide new insights into the importance of stoichiometry among the components of the TLR4/MD-2/CD14 complex. A structural model that accounts for the diminished responsiveness of mutant TLR4 polymorphisms to structurally unrelated TLR4 agonists is proposed.