bluuebunny/crossref_metadata_2025_split huggingface dataset:
KIR2DL4 Is an IL-2-Regulated NK Cell Receptor That Exhibits Limited Expression in Humans but Triggers Strong IFN-γ Production
Authors: Kikuchi-Maki Akiko , Yusa Sei-ichi , Catina Tracey L. , Campbell Kerry S. 
Published: April 2014

AbstractKiller cell Ig-like receptor (KIR)2DL4 (2DL4, CD158d) was previously described as the only KIR expressed by every human NK cell. It is also structurally atypical among KIRs because it possesses a basic transmembrane residue, which is characteristic of many activating receptors, but also contains a cytoplasmic immunoreceptor tyrosine-based inhibitory motif (ITIM). We expressed epitope-tagged 2DL4 in an NK-like cell line to study receptor function. Three distinct 2DL4 cDNA clones were analyzed: one encoding the “conventional” 2DL4 with the cytoplasmic ITIM (2DL4.1) and two encoding different cytoplasmic truncated forms lacking the ITIM (2DL4.2 and 2DL4∗). Surprisingly, one truncated receptor (2DL4.2), which is the product of a prevalent human 2DL4 allele, was not expressed on the cell surface, indicating that some individuals may lack functional 2DL4 protein expression. Conversely, both 2DL4.1 and 2DL4∗ were expressed on the cell surface and up-regulated by IL-2. Analysis of primary NK cells with anti-2DL4 mAb confirmed the lack of surface expression in a donor with the 2DL4.2 genotype. Donors with the 2DL4.1 genotype occasionally expressed receptor only on CD56high NK cells, although their expression was up-regulated by IL-2. Interestingly, Ab engagement of epitope-tagged 2DL4 triggered rapid and robust IFN-γ production, but weak redirected cytotoxicity in an NK-like cell line, which was the opposite pattern to that observed upon engagement of another NK cell activating receptor, NKp44. Importantly, both 2DL4.1 and 2DL4∗ exhibited similar activation potential, indicating that the ITIM does not influence 2DL4.1 activating function. The unique activation properties of 2DL4 suggest linkage to a distinct signaling pathway.
Essential Role for STAT5 Signaling in CD25+CD4+ Regulatory T Cell Homeostasis and the Maintenance of Self-Tolerance
Authors: Antov Andrey , Yang Lili , Vig Monika , Baltimore David , Van Parijs Luk 
Published: April 2014

Abstract
A population of CD25+CD4+ regulatory T cells (T regs) functions to maintain immunological self tolerance by inhibiting autoreactive T cell responses. CD25+CD4+ T regs are present in low, but steady, numbers in the peripheral lymphoid tissues of healthy mice. Recent studies have shown that IL-2 is an essential growth factor for these cells. How this cytokine functions to regulate CD25+CD4+ T reg homeostasis and prevent autoimmune disease remains unknown. In conventional CD4+ T cells, IL-2 triggers signaling pathways that promote proliferation and survival by activating the STAT5 transcription factor and by increasing the expression of the antiapoptotic protein, Bcl-2. We show here that bcl-2 deficiency does not affect CD25+CD4+ T reg homeostasis, and that ectopic expression of this molecule fails to rescue CD25+CD4+ T reg numbers or to prevent the development of autoimmunity in IL-2-deficient mice. Furthermore, transient activation of STAT5 is sufficient to increase CD25+CD4+ T reg numbers in IL-2-deficient mice. Our study uncovers an essential role for STAT5 in maintaining CD25+CD4+ T reg homeostasis and self-tolerance.
CD4+CD25+ and CD4+CD25− T Cells Act Respectively as Inducer and Effector T Suppressor Cells in Superantigen-Induced Tolerance
Authors: Feunou Pascal , Poulin Lionel , Habran Claude , Le Moine Alain , Goldman Michel , Braun Michel Y. 
Published: April 2014

Abstract
The repeated injection of low doses of bacterial superantigens (SAg) is known to induce specific T cell unresponsiveness. We show in this study that the spleen of BALB/c mice receiving chronically, staphylococcal enterotoxin B (SEB) contains SEB-specific CD4+ TCRBV8+ T cells exerting an immune regulatory function on SEB-specific primary T cell responses. Suppression affects IL-2 and IFN-γ secretion as well as proliferation of T cells. However, the suppressor cells differ from the natural CD4+ T regulatory cells, described recently in human and mouse, because they do not express cell surface CD25. They are CD152 (CTLA-4)-negative and their regulatory activity is not associated with expression of the NF Foxp3. By contrast, after repeated SEB injection, CD4+CD25+ splenocytes were heterogenous and contained both effector as well as regulatory cells. In vivo, CD4+CD25− T regulatory cells prevented SEB-induced death independently of CD4+CD25+ T cells. Nevertheless, SEB-induced tolerance could not be achieved in thymectomized CD25+ cell-depleted mice because repeated injection of SEB did not avert lethal toxic shock in these animals. Collectively, these data demonstrate that, whereas CD4+CD25+ T regulatory cells are required for the induction of SAg-induced tolerance, CD4+CD25− T cells exert their regulatory activity at the maintenance stage of SAg-specific unresponsiveness.
Critical Role of Preconceptional Immunization for Protective and Nonpathological Specific Immunity in Murine Neonates
Authors: Uthoff Heiko , Spenner Achim , Reckelkamm Werner , Ahrens Birgit , Wölk Guido , Hackler Rolf , Hardung Frank , Schaefer Jürgen , Scheffold A. , Renz Harald , Herz Udo 
Published: April 2014

Abstract
Expression of Th2 immunity against environmental Ags is the hallmark of the allergic phenotype and contrasts with the Th1-like pattern, which is stably expressed in healthy adults throughout life. Epidemiological studies indicate that the prenatal environment plays an important and decisive role in the development of allergy later in life. Since the underlying mechanisms were unclear, an animal model was developed to study the impact of maternal allergy on the development of an allergic immune response in early life. An allergic Th2 response was induced in pregnant mice by sensitization and aerosol allergen exposure. Both, IgG1 and IgG2a, but not IgE, Abs cross the placental barrier. Free allergen also crosses the placental area and was detected in serum and amniotic fluids of neonatal F1 mice. These F1 mice demonstrated a suppressed Th1 response, as reflected by lowered frequencies and reduced levels of IFN-γ production. Development of an IgE response against the same allergen was completely prevented early in life. This effect was mediated by diaplacental transfer of allergen-specific IgG1 Abs. In contrast, allergic sensitization against a different allergen early in life was accelerated in these mice. This effect was mediated by maternal CD4 and OVA-specific Th2 cells induced by allergic sensitization during pregnancy. These data indicate a critical role for maternal T and B cell response in shaping pre- and postnatal maturation of specific immunity to allergens.
Genetic Control of Tolerance to Type II Collagen and Development of Arthritis in an Autologous Collagen-Induced Arthritis Model
Authors: Bäcklund Johan , Nandakumar Kutty Selva , Bockermann Robert , Mori Lucia , Holmdahl Rikard 
Published: April 2014

AbstractT cell recognition of the type II collagen (CII) 260–270 peptide is a bottleneck for the development of collagen-induced arthritis (CIA), an animal model of rheumatoid arthritis. We have earlier made C3H.Q mice expressing CII with glutamic acid instead of aspartic acid at position 266 (the MMC-C3H.Q mouse), similar to the rat and human CII epitope, which increases binding to MHC class II and leads to effective presentation of the peptide in vivo. These mice show T cell tolerance to CII, but also develop severe arthritis. The present investigation shows that non-MHC genes play a decisive role in determining tolerance and arthritis susceptibility. We bred MMC into B10.Q mice, which display similar susceptibility to CIA induced with rat CII as the C3H.Q mice. In contrast to MMC-C3H.Q mice, MMC-B10.Q mice were completely resistant to arthritis. Nontransgenic (B10.Q × C3H.Q)F1 mice were more susceptible to CIA than either of the parental strains, but introduction of the MMC transgene leads to CIA resistance, showing that the protection is dominantly inherited from B10.Q. In an attempt to break the B10-mediated CIA protection in MMC-transgenic mice, we introduced a transgenic, CII-specific, TCR β-chain specific for the CII260–270 glycopeptide, in the highly CIA-susceptible (B10.Q × DBA/1)F1 mice. The magnification of the autoreactive CII-specific T cell repertoire led to increased CIA susceptibility, but the disease was less severe than in mice lacking the MMC transgene. This finding is important for understanding CIA and perhaps also rheumatoid arthritis, as in both diseases MHC class II-restricted T cell recognition of the glycosylated CII peptide occurs.
Transduction of Multiple Effects of Sphingosine 1-Phosphate (S1P) on T Cell Functions by the S1P1 G Protein-Coupled Receptor
Authors: Dorsam Glenn , Graeler Markus H. , Seroogy Christine , Kong Yvonne , Voice Julia K. , Goetzl Edward J. 
Published: April 2014

Abstract
Sphingosine 1-phosphate (S1P) in blood, lymph, and immune tissues stimulates and regulates T cell migration through their S1P1 (endothelial differentiation gene encoded receptor-1) G protein-coupled receptors. We show now that S1P1Rs also mediate suppression of T cell proliferation and cytokine production. Uptake of [3H]thymidine by mouse CD4 T cells stimulated with anti-CD3 mAbs plus either anti-CD28 or IL-7 was inhibited up to 50% by 10−9–10−6 M S1P. Suppression by S1P required Ca2+ signaling and was reduced by intracellular cAMP. S1P decreased CD4 T cell generation of IFN-γ and IL-4, without affecting IL-2. A Th1 line from D011.10 TCR transgenic mice without detectable S1P1 was refractory to S1P until introduction of S1P1 by retroviral transduction. S1P then evoked chemotaxis, inhibited chemotaxis to CCL-5 and CCL-21, and suppressed Ag-stimulated proliferation and IFN-γ production. Thus, S1P1 signals multiple immune functions of T cells as well as migration and tissue distribution.
Activation of Discoidin Domain Receptor 1 Facilitates the Maturation of Human Monocyte-Derived Dendritic Cells Through the TNF Receptor Associated Factor 6/TGF-β-Activated Protein Kinase 1 Binding Protein 1β/p38α Mitogen-Activated Protein Kinase Signaling Cascade
Authors: Matsuyama Wataru , Faure Michel , Yoshimura Teizo 
Published: April 2014

Abstract
Maturation of dendritic cells (DCs) is critical for their ability to stimulate resting naive T cells in primary immune responses. Previous studies demonstrated that collagen, such as type I collagen, could facilitate DC maturation; however, the basis of collagen-mediated DC maturation remains unclear. Discoidin domain receptor 1 (DDR1) is a nonintegrin collagen receptor constitutively expressed in a variety of epithelial cells, including tumor cells, and is inducible in leukocytes. In this study, we evaluated the role of DDR1 in DC maturation using human monocyte-derived DCs. Two DDR1 isoforms, DDR1a and DDR1b, were expressed in both immature and mature DCs. Activation of DDR1 on immature DCs resulted in their partial maturation; however, DDR1 activation markedly amplified TNF-α- and LPS-induced phenotypic and functional maturation of DCs through activation of p38 mitogen-activated protein kinase (MAPK), suggesting the involvement of DDR1b in this process. Activation of DDR1b on differentiated DDR1b-overexpressing THP-1 cells or DDR1 on mature DCs induced the formation of TNFR associated factor 6 (TRAF6)/TGF-β-activated kinase 1 binding protein 1β/p38α MAPK complex and p38α autophosphorylation. Transfection of differentiated DDR1b-overexpressing THP-1 cells with dominant negative TRAF6 completely abrogated DDR1b-mediated p38 MAPK phosphorylation, indicating a critical role of TRAF6 in DDR1b-mediated p38 MAPK activation. Taken together, our data suggest that DDR1b-collagen interaction augments the maturation of DCs in a tissue microenvironment through a unique TRAF6/TGF-β-activated kinase 1 binding protein 1β/p38α MAPK signaling cascade and contributes to the development of adaptive immune responses.
Morpholino Antisense Oligonucleotide-Mediated Gene Knockdown During Thymocyte Development Reveals Role for Runx3 Transcription Factor in CD4 Silencing During Development of CD4−/CD8+ Thymocytes
Authors: Ehlers Marc , Laule-Kilian Kirsten , Petter Michaela , Aldrian Christine J. , Grueter Baerbel , Würch Andreas , Yoshida Naomi , Watanabe Toshio , Satake Masanobu , Steimle Viktor 
Published: April 2014

Abstract
During thymic T cell development, immature CD4+/CD8+ thymocytes develop into either CD4+/CD8− helper or CD4−/CD8+ CTLs. The molecular mechanisms governing the complex selection and differentiation steps during thymic T cell development are not well understood. Here we developed a novel approach to investigate gene function during thymocyte development. We transfected ex vivo isolated immature thymocytes with gene-specific morpholino antisense oligonucleotides and induced differentiation in cell or organ cultures. A morpholino oligonucleotide specific for CD8α strongly reduces CD8 expression. To our knowledge, this is the first demonstrated gene knockdown by morpholino oligonucleotides in primary lymphocytes. Using this approach, we show here that the transcription factor Runx3 is involved in silencing of CD4 expression during CD8 T cell differentiation. Runx3 protein expression appears late in thymocyte differentiation and is confined to mature CD8 single-positive thymocytes, whereas Runx3 mRNA is transcribed in mature CD4 and CD8 thymocytes. Therefore, Runx3 protein expression is regulated at a post-transcriptional level. The knockdown of Runx3 protein expression through morpholino oligonucleotides inhibited the development of CD4−/CD8+ T cells. Instead, mature cells with a CD4+/CD8+ phenotype accumulated. Potential Runx binding sites were identified in the CD4 gene silencer element, which are bound by Runx protein in EMSAs. Mutagenesis of potential Runx binding sites in the CD4 gene silencer abolished silencing activity in a reporter gene assay, indicating that Runx3 is involved in CD4 gene silencing. The experimental approach developed here should be valuable for the functional analysis of other candidate genes in T cell differentiation.
Global Gene Expression Profiles During Acute Pathogen-Induced Pulmonary Inflammation Reveal Divergent Roles for Th1 and Th2 Responses in Tissue Repair
Authors: Sandler Netanya G. , Mentink-Kane Margaret M. , Cheever Allen W. , Wynn Thomas A. 
Published: April 2014

AbstractT helper 1 responses are typically proinflammatory, while Th2 responses have been considered regulatory. Interestingly, Th2 responses characterize a number of pulmonary diseases, many of which terminate in tissue remodeling and fibrosis. We developed a mouse model using Schistosoma mansoni eggs and cytokine-deficient mice to induce highly polarized Th1- or Th2-type inflammation in the lung. In this study, we examined the pathology and cytokine profiles in Th1- and Th2-polarized environments and used oligonucleotide microarray analysis to decipher the genes responsible for these effects. We further elaborated on the results using IL-10- and IL-13-deficient mice because these cytokines are believed to be the central regulators of Th2-associated pathology. We found that the Th1-polarized mice developed small granulomas with less fibrosis while expressing genes characteristic of tissue damage. Th2-polarized mice, in contrast, formed large granulomas with massive collagen deposition and up-regulated genes associated with wound healing, specifically, arginase, collagens, matrix metalloproteinases (MMPs), and tissue inhibitors of MMP. In addition, several members of the chitinase-like family were up-regulated in the lung following egg challenge. We also developed a method of defining the net collagen deposition using the expression profiles of several collagen, MMP, and tissue inhibitors of MMP genes. We found that Th1-polarized mice did not elaborate collagens or MMPs and therefore did not have a significant capacity for repair in this model. Thus, Th1-mediated inflammation is characterized by tissue damage, while Th2 directs wound healing and fibrosis.
Involvement of Leucine Residues at Positions 107, 112, and 115 in a Leucine-Rich Repeat Motif of Human Toll-Like Receptor 2 in the Recognition of Diacylated Lipoproteins and Lipopeptides and Staphylococcus aureus Peptidoglycans
Authors: Fujita Mari , Into Takeshi , Yasuda Motoaki , Okusawa Tsugumi , Hamahira Sumiko , Kuroki Yoshio , Eto Akiko , Nisizawa Toshiki , Morita Manabu , Shibata Ken-ichiro 
Published: April 2014

Abstract
S-(2,3-bispalmitoyloxypropyl)Cys-Gly-Asp-Pro-Lys-His-Pro-Lys-Ser-Phe (FSL-1) derived from Mycoplasma salivarium stimulated NF-κB reporter activity in human embryonic kidney 293 (HEK293) cells transfected with Toll-like receptor 2 (TLR2) or cotransfected with TLR2 and TLR6, but not in HEK293 cells transfected with TLR6, in a dose-dependent manner. The activity was significantly higher in HEK293 cells transfected with both TLR2 and TLR6 than in HEK293 cells transfected with only TLR2. The deletion mutant TLR2ΔS40-I64 (a TLR2 mutant with a deletion of the region of Ser40 to Ile64) failed to activate NF-κB in response to FSL-1. The deletion mutant TLR2ΔC30-S39 induced NF-κB reporter activity, but the level of activity was significantly reduced compared with that induced by wild-type TLR2. A TLR2 point mutant with a substitution of Glu178 to Ala (TLR2E178A), TLR2E180A, TLR2E190A, and TLR2L132E induced NF-κB activation when stimulated with FSL-1, M. salivarium lipoproteins, and Staphylococcus aureus peptidoglycans, but TLR2L107E, TLR2L112E (a TLR2 point mutant with a substitution of Leu112 to Glu), and TLR2L115E failed to induce NF-κB activation, suggesting that these residues are essential for their signaling. Flow cytometric analysis demonstrated that TLR2L115E, TLR2L112E, and TLR2ΔS40-I64 were expressed on the cell surface of the transfectants as wild-type TLR2 and TLR2E190A were. In addition, these mutants, except for TLR2E180A, functioned as dominant negative form of TLR2. This study strongly suggested that the extracellular region of Ser40-Ile64 and leucine residues at positions 107, 112, and 115 in a leucine-rich repeat motif of TLR2 are involved in the recognition of mycoplasmal diacylated lipoproteins and lipopeptides and in the recognition of S. aureus peptidoglycans.
IFN-γ-Independent Effects of IL-12 During Intestinal Nematode Infection
Authors: Helmby Helena , Grencis Richard K. 
Published: April 2014

Abstract
Expulsion of the gastrointestinal nematode Trichinella spiralis is associated with a pronounced mastocytosis mediated by a Th2-type response involving IL-4, IL-10, and IL-13. When exogenous rIL-12 was administered to T. spiralis-infected NIH mice, this resulted in significant suppression of intestinal mast cell responses, delayed worm expulsion, increased muscle larvae burdens, and a transient, but significant decrease in early Th2 cytokine secretion. rIL-12 treatment also altered chemokine expression in the jejunal mucosa. The effects of exogenous IL-12 administration were largely independent of IFN-γ as shown by rIL-12 treatment of IFN-γ knockout mice. Hence, IL-12 may play a significant biological role as a direct negative regulator of intestinal Th2 responses and may act to promote the survival of intestinal parasites in vivo also in the absence of IFN-γ.
Strong Cytosine-Guanosine-Independent Immunostimulation in Humans and Other Primates by Synthetic Oligodeoxynucleotides with PyNTTTTGT Motifs
Authors: Elias Fernanda , Flo Juan , Lopez Ricardo A. , Zorzopulos Jorge , Montaner Alejandro , Rodriguez Juan M. 
Published: April 2014

Abstract
Synthetic oligodeoxynucleotides (ODNs) containing cytosine-guanosine (CpG) motifs stimulate B and plasmacytoid dendritic cells of the vertebrate immune system. We found that in primates strong stimulation of these cells could also be achieved using certain non-CpG ODNs. The immunostimulatory motif in this case is a sequence with the general formula PyNTTTTGT in which Py is C or T, and N is A, T, C, or G. Assays performed on purified cells indicated that the immunostimulatory activity is direct. The use of a nuclease-resistant phosphorothioate backbone is not a necessary condition, since phosphodiester PyNTTTTGT ODNs are active. It was also demonstrated that ODN 2006, a widely used immunostimulant of human B cells, possess two kinds of immunostimulatory motifs: one of them mainly composed of two successive TCG trinucleotides located at the 5′ end and another one (duplicated) of the PyNTTTTGT kind here described. Even though PyNTTTTGT ODNs are mainly active on primate cells, some of them, bearing the CATTTTGT motif, have a small effect on cells from other mammals. This suggests that the immunostimulatory mechanism activated by these ODNs was present before, but optimized during, evolution of primates. Significant differences in the frequency of PyNTTTTGT sequences between bacterial and human DNA were not found. Thus, the possibility that PyNTTTTGT ODNs represent a class of pathogen-associated molecular pattern is unlikely. They could, more reasonably, be included within the category of danger signals of cell injury.
The Role of Interleukin-10 in Susceptibility of BALB/c Mice to Infection with Leishmania mexicana and Leishmania amazonensis
Authors: Padigel Udaikumar M. , Alexander James , Farrell Jay P. 
Published: April 2014

Abstract
Recent studies have demonstrated the critical role of IL-10 in susceptibility to cutaneous and visceral leishmaniasis caused by Leishmania major and Leishmania donovani, respectively. To determine whether IL-10 also plays a similar role in the susceptibility and pathogenesis of cutaneous leishmaniasis caused by the New World species, L. mexicana and L. amazonensis, we analyzed their course of infection in IL-10-deficient BALB/c mice and their wild-type counterparts. Although IL-10-deficient mice infected with either L. mexicana or L. amazonensis failed to control the lesion progression, we did observe consistently lower levels of infection in IL-10−/− mice compared with wild-type BALB/c mice. We also observed increased IFN-γ and NO production and higher levels for IL-12p40 and IL-12Rβ2 mRNA in cells from IL-10−/− mice compared with cells from BALB/c mice. The mRNA levels for IL-4, which increased significantly in both IL-10−/− and BALB/c mice, were comparable. When treated with anti-IL-4 mAb, IL-10−/− mice resolved the infection more effectively and had significantly fewer parasites in their lesions compared with similarly treated BALB/c mice. These findings suggest that IL-10, although not the dominant mediator of susceptibility of BALB/c mice to infection with L. mexicana and L. amazonensis, does play a significant role in regulating the development of a protective Th1-type response. However, effective resolution of infection with these New World parasites requires neutralization of both IL-4 and IL-10.