bluuebunny/crossref_metadata_2025_split huggingface dataset:
C/EBPα and Ets Protein Family Members Regulate the Human Myeloid IgA Fc Receptor (FcαR, CD89) Promoter
Authors: Shimokawa Toshibumi , Ra Chisei 
Published: April 2014

Abstract
FcαR (CD89), the FcR for IgA, is expressed exclusively in myeloid cells, including monocytes/macrophages, neutrophils, and eosinophils, and is thought to mediate IgA-triggered cellular functions in immunity. Here we demonstrate that the FcαR 5′-flanking region from −102 to −64 relative to the ATG translation initiation codon is essential for promoter activity and contains two functional binding motifs for C/EBP and Ets family members at −74 and −92, respectively. EMSAs and cotransfection experiments show that C/EBPα acts as a major activator of the FcαR promoter at least in immature myeloid cells. In addition, we found two additional functional targets of C/EBPα at −139 and −127. On the other hand, the FcαR Ets binding motif could bind Elf-1 and mediate the trans-activation by cotransfected Elf-1, but a major component of the complex forming on this site appears to be an unidentified Ets-like nuclear protein that is preferentially detected in cells of hemopoietic origin. Furthermore, separation of the C/EBP and Ets binding sites reduces FcαR promoter activity, suggesting some functional interaction between these factors. As the in vivo role of FcαR is still incompletely defined, these findings reveal the features controlling the FcαR promoter in myeloid lineage and provide a foundation for clarifying regulatory mechanisms of FcαR gene expression associated with its potential roles.
The T Cell Receptor β Locus of the Channel Catfish,Ictalurus punctatus, Reveals Unique Features
Authors: Zhou He , Bengtén Eva , Miller Norman W. , Clem L. William , Wilson Melanie 
Published: April 2014

AbstractPreviously, a series of clonal alloantigen-dependent T cell lines established from the channel catfish revealed distinctly different TCRβ rearrangements. Here, a follow-up study of the junctional diversity of these TCR gene rearrangements focuses on characterization of the genomic organization of the TCRB locus. Surprisingly, a total of 29 JB genes and two substantially different CB genes were identified downstream of a single DB gene. This is in contrast to the situation in mammals, where two clusters of a DB gene, six or seven JB genes, and a CB gene are found in tandem. The catfish CB genes are ∼36% identical at the amino acid level. All 29 catfish JB gene segments appear functional. Thirteen were used in the 19 cDNAs analyzed, of these eight were used by the 11 catfish clonal alloantigen-dependent T cell lines. As might be expected, CDR3 diversity is enhanced by N-nucleotide additions as well as nucleotide deletions at the V-D and D-J junctions. Taken together, compared with that in mammals, genomic sequencing of the catfish TCR DB-JB-CB region reveals a unique locus containing a greater number of JB genes and two distinct CB genes.
Up-Regulation of Proteinase-Activated Receptor 1 Expression in Astrocytes During HIV Encephalitis
Authors: Boven Leonie A. , Vergnolle Nathalie , Henry Scot D. , Silva Claudia , Imai Yoshinori , Holden Janet , Warren Kenneth , Hollenberg Morley D. , Power Christopher 
Published: April 2014

AbstractProteinase-activated receptor 1 (PAR-1) is a G protein-coupled receptor that is activated by thrombin and is implicated in the pathogenesis of inflammation. Although PAR-1 is expressed on immunocompetent cells within the brain such as astrocytes, little is known about its role in the pathogenesis of inflammatory brain diseases. Herein, we investigated PAR-1 regulation of brain inflammation by stimulating human astrocytic cells with thrombin or the selective PAR-1-activating peptide. Activated cells expressed significantly increased levels of IL-1β, inducible NO synthase, and PAR-1 mRNA. Moreover, supernatants of these same cells were neurotoxic, which was inhibited by an N-methyl-d-aspartate receptor antagonist. Striatal implantation of the PAR-1-activating peptide significantly induced brain inflammation and neurobehavioral deficits in mice compared with mice implanted with the control peptide or saline. Since HIV-related neurological disease is predicated on brain inflammation and neuronal injury, the expression of PAR-1 in HIV encephalitis (HIVE) was investigated. Immunohistochemical analysis revealed that PAR-1 and (pro)-thrombin protein expression was low in control brains, but intense immunoreactivity was observed on astrocytes in HIVE brains. Similarly, PAR-1 and thrombin mRNA levels were significantly increased in HIVE brains compared with control and multiple sclerosis brains. These data indicated that activation and up-regulation of PAR-1 probably contribute to brain inflammation and neuronal damage during HIV-1 infection, thus providing new therapeutic targets for the treatment of HIV-related neurodegeneration.
Paralytic Autoimmune Myositis Develops in Nonobese Diabetic Mice Made Th1 Cytokine-Deficient by Expression of an IFN-γ Receptor β-Chain Transgene
Authors: Serreze David V. , Pierce Melissa A. , Post Cristina M. , Chapman Harold D. , Savage Holly , Bronson Roderick T. , Rothman Paul B. , Cox Gregory A. 
Published: April 2014

Abstract
Nonobese diabetic (NOD) mice and some human type 1 diabetes (T1D) patients manifest low to high levels of other autoimmune pathologies. Skewing their cytokine production from a Th1 (primarily IFN-γ) to a Th2 (primarily IL-4 and IL-10) pattern is a widely proposed approach to dampen the pathogenicity of autoreactive diabetogenic T cells. However, it is important that altered cytokine balances not enhance any other autoimmune proclivities to dangerous levels. Murine CD4 T cells are characterized by a reciprocal relationship between the production of IFN-γ and expression of the β-chain component of its receptor (IFN-γRB). Thus, NOD mice constitutively expressing a CD2 promoter-driven IFN-γRB transgene in all T cells are Th1-deficient. Unexpectedly, NOD.IFN-γRB Tg mice were found to develop a lethal early paralytic syndrome induced by a CD8 T cell-dependent autoimmune-mediated myositis. Furthermore, pancreatic insulitis levels were not diminished in 9-wk-old NOD.IFN-γRB Tg females, and overt T1D developed in the few that survived to an older age. Autoimmune-mediated myositis is only occasionally detected in standard NOD mice. Hence, some manipulations diminishing Th1 responses can bring to the forefront what are normally secondary autoimmune pathologies in NOD mice, while also failing to dependably abrogate pancreatic β cell destruction. This should raise a cautionary note when considering the use of protocols that induce alterations in cytokine balances as a means of blocking progression to overt T1D in at-risk humans.
Endogenous Dendritic Cells Are Required for Amplification of T Cell Responses Induced by Dendritic Cell Vaccines In Vivo
Authors: Kleindienst Petra , Brocker Thomas 
Published: April 2014

Abstract
Dendritic cells (DCs) loaded in vitro with Ag are used as cellular vaccines to induce Ag-specific immunity. These cells are thought to be responsible for direct stimulation of Ag-specific T cells, which may subsequently mediate immunity. In this study, in transgenic mouse models with targeted MHC class II expression specifically on DCs, we show that the DC vaccine is responsible only for partial CD4+ T cell activation, but to obtain optimal expansion of T cells in vivo, participation of endogenous (resident) DCs, but not endogenous B cells, is crucial. Transfer of Ag to endogenous DCs seems not to be mediated by simple peptide diffusion, but rather by DC-DC interaction in lymph nodes as demonstrated by histological analysis. In contrast, injection of apoptotic or necrotic DC vaccines does not induce T cell responses, but rather represents an immunological null event, which argues that viability of DC vaccines can be crucial for initial triggering of T cells. We propose that viable DCs from the DC vaccine must migrate to the draining lymph nodes and initiate a T cell response, which thereafter requires endogenous DCs that present transferred Ag in order induce optimal T cell expansion. These results are of specific importance with regard to the applicability of DC vaccinations in tumor patients, where the function of endogenous DCs is suppressed by either tumors or chemotherapy.
Conditional Expression of Murine Flt3 Ligand Leads to Expansion of Multiple Dendritic Cell Subsets in Peripheral Blood and Tissues of Transgenic Mice
Authors: Manfra Denise J. , Chen Shu-Cheng , Jensen Kristian K. , Fine Jay S. , Wiekowski Maria T. , Lira Sergio A. 
Published: April 2014

Abstract
The analysis of the development and function of distinct subsets of murine dendritic cells (DC) has been hampered by the limited number of these cells in vivo. To circumvent this limitation we have developed a conditional transgenic mouse model for producing large numbers of DC. We used the tetracycline-inducible system to conditionally express murine Flt3 ligand (FL), a potent hemopoietic growth factor that promotes the differentiation and mobilization of DC. Acute treatment (96 h) of the transgenic animals with the tetracycline analog doxycycline (DOX) promoted an ∼200-fold increase in serum levels of FL without affecting the number of circulating DC. However, within 1 wk of DOX treatment, the relative number of DC in peripheral blood increased from ∼8 to ∼40%. Interestingly, both the levels of FL and the number of DC remained elevated for at least 9 mo with continual DOX treatment. Chronic treatment of the mice with DOX led to dramatic increases in the number of DC in multiple tissues without any apparent pathological consequences. Most DC populations were expanded, including immature and mature DC, myeloid (CD11c+CD11b+CD8a−), lymphoid (CD11c+CD11b−CD8a+), and the recently defined plasmacytoid (pDC) subsets. Finally, transplantation of BM from green fluorescent protein-expressing mice into lethally irradiated transgenic mice followed by subsequent DOX treatment led to expansion of green fluorescent protein-labeled DC. The transgenic mice described here should thus provide a readily available source of multiple DC subsets and should facilitate the analysis of their role in homeostasis and disease.
Role of the Cytoplasmic Tails of CXCR1 and CXCR2 in Mediating Leukocyte Migration, Activation, and Regulation
Authors: Richardson Ricardo M. , Marjoram Robin J. , Barak Larry S. , Snyderman Ralph 
Published: April 2014

Abstract
IL-8 (or CXCL8) activates the receptors CXCR1 (IL-8RA) and CXCR2 (IL-8RB) to induce chemotaxis in leukocytes, but only CXCR1 mediates cytotoxic and cross-regulatory signals. This may be due to the rapid internalization of CXCR2. To investigate the roles of the intracellular domains in receptor regulation, wild-type, chimeric, phosphorylation-deficient, and cytoplasmic tail (C-tail) deletion mutants of both receptors were expressed in RBL-2H3 cells and studied for cellular activation, receptor phosphorylation, desensitization, and internalization. All but one chimeric receptor bound IL-8 and mediated signal transduction, chemotaxis, and exocytosis. Upon IL-8 activation, the chimeric receptors underwent receptor phosphorylation and desensitization. One was resistant to internalization, yet it mediated normal levels of β-arrestin 2 (βarr-2) translocation. The lack of internalization by this receptor may be due to its reduced association with βarr-2 and the adaptor protein-2β. The C-tail-deleted and phosphorylation-deficient receptors were resistant to receptor phosphorylation, desensitization, arrestin translocation, and internalization. They also mediated greater phosphoinositide hydrolysis and exocytosis and sustained Ca2+ mobilization, but diminished chemotaxis. These data indicate that phosphorylation of the C-tails of CXCR1 and CXCR2 are required for arrestin translocation and internalization, but are not sufficient to explain the rapid internalization of CXCR2 relative to CXCR1. The data also show that receptor internalization is not required for chemotaxis. The lack of receptor phosphorylation was correlated with greater signal transduction but diminished chemotaxis, indicating that second messenger production, not receptor internalization, negatively regulates chemotaxis.
Provision of 4-1BB Ligand Enhances Effector and Memory CTL Responses Generated by Immunization with Dendritic Cells Expressing a Human Tumor-Associated Antigen
Authors: Wiethe Carsten , Dittmar Kurt , Doan Tracy , Lindenmaier Werner , Tindle Robert 
Published: April 2014

Abstract
Up-regulation of receptor-ligand pairs during interaction of an MHC-presented epitope on dendritic cells (DCs) with cognate TCR may amplify, sustain, and drive diversity in the ensuing T cell immune response. Members of the TNF ligand superfamily and the TNFR superfamily contribute to this costimulatory molecule signaling. In this study, we used replication deficient adenoviruses to introduce a model tumor-associated Ag (the E7 oncoprotein of human papillomavirus 16) and the T cell costimulatory molecule 4-1BBL into murine DCs, and monitored the ability of these recombinant DCs to elicit E7-directed T cell responses following immunization. Splenocytes from mice immunized with DCs expressing E7 alone elicited E7-directed effector and memory CTL responses. Coexpression of 4-1BBL in these E7-expressing DCs increased effector and memory CTL responses when they were used for immunization. 4-1BBL expression up-regulated CD80 and CD86 second signaling molecules in DCs. We also report an additive effect of 4-1BBL and receptor activator of NF-κB/receptor activator of NF-κB ligand coexpression in E7-transduced DC immunogens on E7-directed effector and memory CTL responses and on MHC class II and CD80/86 expression in DCs. Additionally, expression of 4-1BBL in E7-transduced DCs reduced nonspecific T cell activation characteristic of adenovirus vector-associated immunization. The results have generic implications for improved or tumor Ag-expressing DC vaccines by incorporation of exogenous 4-1BBL. There are also specific implications for an improved DC-based vaccine for human papillomavirus 16-associated cervical carcinoma.
Protein Kinase A Regulates GATA-3-Dependent Activation of IL-5 Gene Expression in Th2 Cells
Authors: Klein-Hessling Stefan , Jha Mithilesh Kumar , Santner-Nanan Brigitte , Berberich-Siebelt Friederike , Baumruker Thomas , Schimpl Anneliese , Serfling Edgar 
Published: April 2014

Abstract
Treatment of Th cells with compounds that elevate cAMP levels augments Th2-type lymphokine expression, in particular the synthesis of IL-5. Using primary murine CD4+ T lymphocytes, we show in this study that inhibition of protein kinase A (PKA) activity in Th2 effector cells impairs IL-5 synthesis, whereas the expression of PKA catalytic subunit α enhances IL-5 synthesis in Th0 cells. In addition, we observed by coexpression of PKA catalytic subunit and GATA-3 in Th1 cells that the stimulatory effect of PKA is dependent on GATA-3 activity. These data demonstrate that activation of PKA in Th effector cells induces the IL-5 gene expression in a GATA-3-dependent manner.
Role of NFATx (NFAT4/NFATc3) in Expression of Immunoregulatory Genes in Murine Peripheral CD4+ T Cells
Authors: Chen Jingtao , Amasaki Yoshiharu , Kamogawa Yumiko , Nagoya Miho , Arai Naoko , Arai Ken-ichi , Miyatake Shoichiro 
Published: April 2014

Abstract
Ca2+-regulated NFAT family members are transcription factors crucial for the expression of various cytokine genes and other immunoregulatory genes. Analyses of mice defective in one or two NFAT family members have revealed functions specific to each NFAT gene. However, the redundant functions of several family members limit the usefulness of gene disruption analysis. For example, CD4+ T cells isolated from NFATx-disrupted mice do not show any modulation in cytokine gene expression, perhaps because other family members compensate for its absence. To analyze the role of NFATx in the regulation of immunoregulatory genes in T cells, we made a gain-of-function mutant by creating transgenic mice expressing a constitutively nuclear form of NFATx in T cell lineages. In naive CD4+ T cells, NFATx up-regulated the expression of several cytokine genes and activation markers and suppressed the expression of CD154. In Th1 cells, NFATx enhanced the expression of the Th1 cytokine genes, IFN-γ and TNF-α. In contrast, NFATx suppressed Th2 cytokine genes such as IL-4 and IL-5 in Th2 cells. It has been reported that both NFAT1 and NFATx are required to maintain the homeostasis of the immune system. Our results suggest that NFATx exerts this function by inhibiting the expression of some critical immunoregulatory genes.
Human NKT Cells Express Granulysin and Exhibit Antimycobacterial Activity
Authors: Gansert Jennifer L. , Kieβler Viviane , Engele Matthias , Wittke Frederick , Röllinghoff Martin , Krensky Alan M. , Porcelli Steven A. , Modlin Robert L. , Stenger Steffen 
Published: April 2014

Abstract
Human NKT cells are a unique subset of T cells that express an invariant Vα24 TCR that recognizes the nonclassical Ag-presenting molecule CD1d. Activation of NKT cells is greatly augmented by the marine sponge-derived glycolipid α-galactosylceramide (αGalCer). Because human monocyte-derived cells express CD1d and can harbor the intracellular pathogen Mycobacterium tuberculosis, we asked whether the addition of αGalCer could be used to induce effector functions of NKT cells against infected monocytes, macrophages, and monocyte-derived dendritic cells. NKT cells secreted IFN-γ, proliferated, and exerted lytic activity in response to αGalCer-pulsed monocyte-derived cells. Importantly, αGalCer-activated NKT cells restricted the growth of intracellular M. tuberculosis in a CD1d-dependent manner. NKT cells that exhibited antimycobacterial activity also expressed granulysin, an antimicrobial peptide shown to mediate an antimycobacterial activity through perturbation of the mycobacterial surface. Degranulation of NKT cells resulted in depletion of granulysin and abrogation of antimycobacterial activity. The detection of CD1d in granulomas of tuberculosis patients supports the potential interaction of NKT cells with CD1d-expressing cells at the site of disease activity. These studies provide evidence that αGalCer-activated CD1d-restricted T cells can participate in human host defense against M. tuberculosis infection.
Immunogene Therapy of Tumors with Vaccine Based on Xenogeneic Epidermal Growth Factor Receptor
Authors: Lu You , Wei Yu-quan , Tian Ling , Zhao Xia , Yang Li , Hu Bin , Kan Bin , Wen Yan-jun , Liu Feng , Deng Hong-xin , Li Jiong , Mao Yong-qiu , Lei Song , Huang Mei-juan , Peng Feng , Jiang Yu , Zhou Hao , Zhou Li-qun , Luo Feng 
Published: April 2014

Abstract
The breaking of immune tolerance against self epidermal growth factor receptor (EGFr) should be a useful approach for the treatment of receptor-positive tumors with active immunization. To test this concept, we constructed a plasmid DNA encoding extracellular domain of xenogeneic (human) EGFr (hEe-p) or corresponding control mouse EGFr (mEe-p) and empty vector (c-p). Mice immunized with hEe-p showed both protective and therapeutic antitumor activity against EGFr-positive tumor. Sera isolated from the hEe-p-immunized mice exhibited positive staining for EGFr-positive tumor cells in flow cytometric analysis and recognized a single 170-kDa band in Western blot analysis. Ig subclasses responded to rEGFr proteins were elevated in IgG1, Ig2a, and Ig2b. There was the deposition of IgG on the tumor cells. Adoptive transfer of the purified Igs showed the antitumor activity. The increased killing activity of CTL against EGFr-positive tumor cells could be blocked by anti-CD8 or anti-MHC class I mAb. In vivo depletion of CD4+ T lymphocytes could completely abrogate the antitumor activity, whereas the depletion of CD8+ cells showed partial abrogation. The adoptive transfer of CD4-depleted (CD8+) or CD8-depleted (CD4+) T lymphocytes isolated from mice immunized with hEe-p vaccine showed the antitumor activity. In addition, the increase in level of both IFN-γ and IL-4 was found. Taken together, these findings may provide a new vaccine strategy for the treatment of EGFr-positive tumors through the induction of the autoimmune response against EGFr in a cross-reaction between the xenogeneic homologous and self EGFr.
Reduced Macrophage Recruitment, Proliferation, and Activation in Colony-Stimulating Factor-1-Deficient Mice Results in Decreased Tubular Apoptosis During Renal Inflammation
Authors: Lenda Deborah M. , Kikawada Eriya , Stanley E. Richard , Kelley Vicki R. 
Published: April 2014

Abstract
Kidney tubular epithelial cell (TEC) death may be dependent on the number and activation state of macrophages (Mφ) during inflammation. Our prior studies indicate that activated Mφ release soluble mediators that incite TEC death, and reducing intrarenal Mφ during kidney disease diminishes TEC apoptosis. CSF-1 is required for Mφ proliferation and survival. We hypothesized that in the absence of CSF-1, Mφ-mediated TEC apoptosis would be prevented during renal inflammation. To test this hypothesis, we evaluated renal inflammation during unilateral ureter obstruction in CSF-1-deficient (Csf1op/Csf1op) mice. We detected fewer Mφ and T cells and less apoptotic TEC in the obstructed kidneys of Csf1op/Csf1op mice compared with wild-type (WT) mice. The decrease in intrarenal Mφ resulted from diminished recruitment and proliferation, not enhanced apoptosis. CSF-1 enhanced Mφ activation. There were far fewer activated (CD69, CD23, Ia, surface expression) Mφ in obstructed CSF-1-deficient compared with WT obstructed kidneys. Similarly, bone marrow Mφ preincubated with anti-CSF-1 receptor Ab or anti-CSF-1 neutralizing Ab were resistant to LPS- and IFN-γ-induced activation. We detected fewer apoptotic-inducing molecules (reactive oxygen species, TNF-α, inducible NO synthase) in 1) Mφ propagated from obstructed Csf1op/Csf1op compared with WT kidneys, and 2) WT bone marrow Mφ blocked with anti-CSF-1 receptor or anti-CSF-1 Ab compared with the isotype control. Furthermore, blocking CSF-1 or the CSF-1 receptor induced less TEC apoptosis than the isotype control. We suggest that during renal inflammation, CSF-1 mediates Mφ recruitment, proliferation, activation, and, in turn, TEC apoptosis.
CXCR2 Regulates Respiratory Syncytial Virus-Induced Airway Hyperreactivity and Mucus Overproduction
Authors: Miller Allison L. , Strieter Robert M. , Gruber Achim D. , Ho Samuel B. , Lukacs Nicholas W. 
Published: April 2014

Abstract
Severe inflammation and mucus overproduction are partially responsible for respiratory syncytial virus (RSV)-induced disease in infants. Using a murine model, we characterized the virally induced chemokine receptors responsible for mediating the pathophysiological response to RSV infection, we found that CXCR2 mRNA was induced at 4 days after RSV infection. Immunohistochemical staining demonstrated that CXCR2 protein was expressed on alveolar macrophages. Immunoneutralization of CXCR2 resulted in decreased airway hyperreactivity relative to the RSV-infected controls. In addition, there was decreased mucus in the bronchoalveolar lavage fluid, decreased periodic-acid Schiff staining, and significantly less mucus-associated gob-5 mRNA and protein in anti-CXCR2-treated mice. The effects of anti-CXCR2 treatment were not a result of differences in viral clearance or neutrophil influx, as these parameters were comparable in both groups of animals. To confirm our immunoneutralization studies, we performed experiments in CXCR2−/− mice. Results in CXCR2−/− mice recapitulated results from our immunoneutralization studies. However, CXCR2−/− mice also showed a statistically significant decrease in muc5ac, relative to RSV-infected wild-type animals. Thus, CXCR2 may be a relevant target in the pathogenesis of RSV bronchiolitis, since it contributes to mucus production and airway hyperreactivity in our model of RSV infection.