bluuebunny/crossref_metadata_2025_split huggingface dataset:
IL-4 Up-Regulates the Expression of Tissue Inhibitor of Metalloproteinase-2 in Dermal Fibroblasts Via the p38 Mitogen-Activated Protein Kinase-Dependent Pathway
Authors: Ihn Hironobu , Yamane Kenichi , Asano Yoshihide , Kubo Masahide , Tamaki Kunihiko 
Published: April 2014

Abstract
Tissue inhibitor of metalloproteinase-2 (TIMP-2) is a potent inhibitor of activated matrix metalloproteinases such as gelatinase and collagenase, and thus helps to control extracellular matrix metabolism and deposition by connective tissue cells. We examined the responsiveness of the expression of TIMP-2 to various cytokines in dermal fibroblasts and studied the regulatory and signaling mechanisms of the response. TIMP-2 protein and mRNA expression was induced by IL-4 in a dose- and time-dependent manner, but not by TGF-β, oncostatin M, or IL-6. IL-4 induction of TIMP-2 expression was dependent upon transcription. The p38 mitogen-activated protein kinase (MAPK) inhibitors SB202190 and SB203580 suppressed IL-4-induced TIMP-2 expression, suggesting the involvement of p38 MAP kinase in the signaling of IL-4 leading to TIMP-2 expression. Immunoblotting analysis using a specific Ab against phosphorylated p38 MAP kinase (Thr180/Tyr182) showed that IL-4 induced phosphorylation of p38 MAP kinase in human dermal fibroblasts. Furthermore, the p38 MAP kinase assay showed that IL-4 induces p38 MAPK activation in human dermal fibroblasts. The expression of the dominant-negative mutant p38 MAPK represses the IL-4-induced TIMP-2 expression in human dermal fibroblasts. Thus, IL-4 can potentially alter the dermal matrix metabolism by regulating TIMP-2.
Functional IL-10 Deficiency in the Lung of Cystic Fibrosis (cftr−/−) and IL-10 Knockout Mice Causes Increased Expression and Function of B7 Costimulatory Molecules on Alveolar Macrophages
Authors: Soltys Jindrich , Bonfield Tracey , Chmiel James , Berger Melvin 
Published: April 2014

Abstract
Alveolar macrophages are poor APCs that only minimally express B7 costimulatory molecules. Because our previous data suggest that bronchial epithelial cells constitutively secrete IL-10, and IL-10 inhibits B7 expression in vitro, we hypothesized that this IL-10 is responsible for suppressing B7 expression on macrophages that enter the airways. Furthermore, because we have shown that cystic fibrosis (CF) lungs are deficient in IL-10, we hypothesized that bronchoalveolar macrophages (BALMs) from cystic fibrosis transmembrane conductance regulator (CFTR)−/− as well as IL-10−/− mice might express increased B7. Immunofluorescence for B7 was positive on BALMs from CF patients and CFTR−/− and IL-10−/− mice, but was negative on controls. FACS showed that 63.9% of BALMs from IL-10−/− mice were B7-1 positive, as were 67.4% of BALMs from CFTR−/− mice, whereas &lt;7% of BALMs from wild-type controls were positive. Using BALMs to costimulate splenic T cells with anti-CD3 as a mitogen showed 9202 ± 2107 cpm [3H]thymidine incorporation for BALMs from IL-10−/− mice and 4082 ± 1036 cpm for BALMs from CFTR−/− mice, but &lt;200 cpm with BALMs from either type of +/+ mouse. Treatment of CFTR−/− mice with recombinant mouse IL-10 reduced the B7 expression and costimulatory activity of the BALMs. These data suggest that the IL-10 secreted in the healthy lung may be responsible for the absence of B7 and poor costimulatory activity of BALMs and that reductions of pulmonary IL-10 in CF may enhance B7 expression and local immune responses.
Molecular Mechanisms Involved in Lymphocyte Recruitment in Inflamed Brain Microvessels: Critical Roles for P-Selectin Glycoprotein Ligand-1 and Heterotrimeric Gi-Linked Receptors
Authors: Piccio Laura , Rossi Barbara , Scarpini Elio , Laudanna Carlo , Giagulli Cinzia , Issekutz Andrew C. , Vestweber Dietmar , Butcher Eugene C. , Constantin Gabriela 
Published: April 2014

AbstractLymphocyte recruitment into the brain is a critical event in the pathogenesis of multiple sclerosis and experimental autoimmune encephalomyelitis. We developed a novel intravital microscopy model to directly analyze through the skull the interactions between lymphocytes and the endothelium in cerebral venules of mice. No adhesive interactions were observed between lymphocytes and the nonactivated endothelium in the cerebral microcirculation. When brain venules were activated by pretreating mice with TNF-α or LPS, proteolipid protein 139–151 autoreactive T lymphocytes rolled and arrested; notably, only a few peripheral lymph node cells rolled and firmly adhered. Abs anti-P-selectin glycoprotein ligand-1 and anti-E- and P-selectin blocked tethering and rolling of autoreactive lymphocytes, suggesting that P-selectin glycoprotein ligand-1/endothelial selectins are critical in the recruitment of lymphocytes in inflamed brain venules. E- and P-selectin were expressed on cerebral vessels upon in vivo activation and had a patchy distribution during the preclinical phase of active and passive experimental autoimmune encephalomyelitis. LFA-1/ICAM-1 and α4 integrins/VCAM-1 supported rolling, but were not relevant to rolling velocity. Firm arrest was mainly mediated by LFA-1 and ICAM-1. Pretreatment of autoreactive lymphocytes with pertussis toxin blocked integrin-dependent arrest, implicating a requirement for Gi protein-dependent signaling in vessels from nonlymphoid districts. In conclusion, our data unveils the molecular mechanisms controlling the recruitment of autoreactive lymphocytes in inflamed cerebral vessels and suggest new insights into the pathogenesis of autoimmune inflammatory diseases of the CNS.
Long-Term Survival of Corneal Allografts Is Dependent on Intact CD1d-Reactive NKT Cells
Authors: Sonoda Koh-Hei , Taniguchi Masaru , Stein-Streilein Joan 
Published: April 2014

AbstractBALB/c mice that tolerate the allogeneic grafts develop allogeneic-specific anterior chamber-associated immune deviation. Because CD1d-reactive NKT cells are essential for anterior chamber-associated immune deviation, we postulated that the survival of C57BL/6 (B6) cornea graft in BALB/c mice was also dependent on CD1d-reactive NKT cells. The B6 corneal graft rejection rate in BALB/c vs Jα281 knockout (KO) mice, which lack NKT cells, was measured. While there were no difference in the early phase of rejection, the survival rates at 12 wk after grafting for BALB/c and Jα281 KO mice were 50 and 0%, respectively. Because anti-CD1d mAb abrogated the corneal graft survival in the wild-type mice we concluded that CD1d-reactive NKT cells were essential for graft survival. Moreover, allospecific T regulatory (Tr) cells correlated with acceptance of B6 grafts in BALB/c mice, and the adoptive transfer of these allospecific Tr cells to Jα281 KO mice allowed a 50% survival rate of B6 cornea grafts. In conclusion, CD1d-reactive NKT cells are required for induction of allospecific Tr cells and are essential for survival of corneal allografts. Mechanisms that contribute to cornea graft acceptance may lead to new therapies for improvement in graft survival in high-risk corneas and other transplanted tissues and grafts.
Cross-Linking Surface Ig Delays CD40 Ligand- and IL-4-Induced B Cell Ig Class Switching and Reveals Evidence for Independent Regulation of B Cell Proliferation and Differentiation
Authors: Rush James S. , Hasbold Jhagvaral , Hodgkin Philip D. 
Published: April 2014

AbstractT cells stimulate B cells to divide and differentiate by providing activating signals in the form of inducible membrane-bound molecules and secreted cytokines. Provision of these signals in vitro reproduces many of the consequences of T-B collaboration in the absence of any form of Ag stimulation. Although clearly not obligatory, Ag signals appear to play an important regulatory role in numerous aspects of the B cell response. To examine directly the effect of an Ag signal, naive B cells were stimulated in the presence of rCD40 ligand, with or without IL-4 in the presence or absence of different anti-Ig mAbs. Anti-Ig mAbs exerted variable effects on the B cell division rate, from enhancement to no effect to inhibition. In contrast, all anti-Ig mAbs tested inhibited division-linked isotype switching to IgG1 and IgE. Thus, B cell Ag receptor ligands could modify the rates of B cell expansion and class switching independently. The ability of anti-Ig reagents to modify class switching suggests the B cell Ag receptor may play an important role in the selection of Ig isotypes during T cell-dependent humoral immune responses to Ags of different physical structure.
IL-4 and T Cells Are Required for the Generation of IgG1 Isotype Antibodies Against Cardiolipin
Authors: Fischer Karsten , Collins Helen , Taniguchi Masaru , Kaufmann Stefan H. E. , Schaible Ulrich E. 
Published: April 2014

Abstract
Infection with Mycobacterium tuberculosis induces Abs against a vast array of mycobacterial lipids and glycolipids. One of the most prominent lipid Ags recognized is cardiolipin (CL). The kinetics of the generation of anti-CL Abs during infection reveals that IgM titers to CL increase over time. Interestingly, at day 30 postinfection CL-specific IgG1 appears, an isotype usually dependent on T cell help. Using an immunization schedule with CL/anti-CL Ab complexes, which induces antiphospholipid syndrome in mice, we show that the generation of IgG1 to CL requires IL-4 and that optimal production is T cell dependent. IgG1 production to CL was impaired in nude (nu/nu) mice devoid in conventional T cells, but was not affected in mice deficient for either αβ TCR+, γδ TCR+, CD4+, CD8+, or NK1.1+ T cells. We conclude that IgG1 production to CL depends on T cell help and IL-4, which can be provided by different T cell populations. This is the first report that IL-4 is indispensable for the induction of IgG1 Abs to lipid Ags.
Impaired Precursor B Cell Differentiation in Bruton’s Tyrosine Kinase-Deficient Mice
Authors: Middendorp Sabine , Dingjan Gemma M. , Hendriks Rudolf W. 
Published: April 2014

AbstractBruton’s tyrosine kinase (Btk) is a cytoplasmic signaling molecule that is crucial for precursor (pre-B) cell differentiation in humans. In this study, we show that during the transition of large cycling to small resting pre-B cells in the mouse, Btk-deficient cells failed to efficiently modulate the expression of CD43, surrogate L chain, CD2, and CD25. In an analysis of the kinetics of pre-B cell differentiation in vivo, Btk-deficient cells manifested a specific developmental delay within the small pre-B cell compartment of ∼3 h, when compared with wild-type cells. Likewise, in in vitro bone marrow cultures, Btk-deficient large cycling pre-B cells showed increased IL-7 mediated expansion and reduced developmental progression into noncycling CD2+CD25+ surrogate L chain-negative small pre-B cells and subsequently into Ig-positive B cells. Furthermore, the absence of Btk resulted in increased proliferative responses to IL-7 in recombination-activating gene-1-deficient pro-B cells. These findings identify a novel role for Btk in the regulation of the differentiation stage-specific modulation of IL-7 responsiveness in pro-B and pre-B cells. Moreover, our results show that Btk is critical for an efficient transit through the small pre-B cell compartment, thereby regulating cell surface phenotype changes during the developmental progression of cytoplasmic μ H chain expressing pre-B cells into immature IgM+ B cells.
Characterization of the Fas Ligand/Fas-Dependent Apoptosis of Antiretroviral, Class I MHC Tetramer-Defined, CD8+ CTL by In Vivo Retrovirus-Infected Cells
Authors: Rich Robert F. , Green William R. 
Published: April 2014

AbstractC57BL/6 (B6; H-2b) mice mount strong AKR/Gross murine leukemia virus (MuLV)-specific CD8+ CTL responses to the immunodominant Kb-restricted epitope, KSPWFTTL, of endogenous AKR/Gross MuLV. In sharp contrast, spontaneous virus-expressing AKR.H-2b congenic mice are low/nonresponders for the generation of AKR/Gross MuLV-specific CTL. Furthermore, when viable AKR.H-2b spleen cells are cocultured with primed responder B6 antiviral precursor CTL, the AKR.H-2b cells function as “veto” cells that actively mediate the inhibition of antiviral CTL generation. AKR.H-2b veto cell inhibition is virus specific, MHC restricted, contact dependent, and mediated through veto cell Fas ligand/responder T cell Fas interactions. In this study, following specific priming and secondary in vitro restimulation, antiretroviral CD8+ CTL were identified by a labeled Kb/KSPWFTTL tetramer and flow cytometry, enabling direct visualization of AKR.H-2b veto cell-mediated depletion of these CTL. A 65–93% reduction in the number of B6 Kb/KSPWFTTL tetramer+ CTL correlated with a similar reduction in antiviral CTL cytotoxicity. Addition on sequential days to the antiviral CTL restimulation cultures of either 1) AKR.H-2b veto cells or 2) a blocking Fas-Ig fusion protein (to cultures also containing AKR.H-2b veto cells) to block inhibition demonstrated that AKR.H-2b veto cells begin to inhibit B6 precursor CTL/CTL expansion during days 2 and 3 of the 6-day culture. Shortly thereafter, a high percentage of B6 tetramer+ CTL cocultured with AKR.H-2b veto cells was annexin V positive and Fashigh, indicating apoptosis as the mechanism of veto cell inhibition. Experiments using the irreversible inhibitor emetine demonstrated that AKR.H-2b cells had to be metabolically active and capable of protein synthesis to function as veto cells. Of the tetramer-positive CTL that survived veto cell-mediated apoptosis, there was no marked skewing from the preferential usage of Vβ4, 8.1/8.2, and 11 TCR normally observed. These findings provide further insight into the complexity of host/virus interactions and suggest a fail-safe escape mechanism by virus-infected cells for epitopes residing in critical areas of viral proteins that cannot accommodate variations of amino acid sequence.
Complement Receptor Type 1 (CD35) Mediates Inhibitory Signals in Human B Lymphocytes
Authors: Józsi Mihály , Prechl József , Bajtay Zsuzsa , Erdei Anna 
Published: April 2014

AbstractThe complement system—particularly component C3—has been demonstrated to be a key link between innate and adaptive immunity. The trimolecular complex of complement receptor type 2 (CR2), CD19, and CD81 is known to promote B cell activation when coligated with the B cell Ag receptor. In the present study, we aimed to elucidate the role of human complement receptor type 1 (CR1), the other C3-receptor on B cells. As ligand, aggregated C3 and aggregated C3(H2O), i.e., multimeric “C3b-like C3”, are used, which bind to CR1, but not to CR2. In experiments studying the functional consequences of CR1-clustering, the multimeric ligand is shown to inhibit the proliferation of tonsil B cells activated with a suboptimal dose of anti-IgM F(ab′)2. Importantly, this inhibitory activity also occurs in the presence of the costimulatory cytokines IL-2 and IL-15. The anti-IgM-induced transient increase in the concentration of intracellular free Ca2+ and phosphorylation of several cytoplasmic proteins are strongly reduced in the presence of the CR1 ligand. Data presented indicate that CR1 has a negative regulatory role in the B cell Ag receptor mediated activation of human B lymphocytes.
Two New Isotype-Specific Switching Activities Detected for Ig Class Switching
Authors: Ma Limei , Wortis Henry H. , Kenter Amy L. 
Published: April 2014

AbstractIg class switch recombination (CSR) occurs by an intrachromosomal deletional process between switch (S) regions in B cells. To facilitate the study of CSR, we derived a new B cell line, 1.B4.B6, which is uniquely capable of μ→γ3, μ→ε, and μ→α, but not μ→γ1 CSR at its endogenous loci. The 1.B4.B6 cell line was used in combination with plasmid-based isotype-specific S substrates in transient transfection assays to test for the presence of trans-acting switching activities. The 1.B4.B6 cell line supports μ→γ3, but not μ→γ1 recombination, on S substrates. In contrast, normal splenic B cells activated with LPS and IL-4 are capable of plasmid-based μ→γ1 CSR and demonstrate that this S plasmid is active. Activation-induced deaminase (AID) was used as a marker to identify existing B cell lines as possible candidates for supporting CSR. The M12 and A20 cell lines were identified as AID positive and, following activation with CD40L and other activators, were found to differentially support μ→ε and μ→α plasmid-based CSR. These studies provide evidence for two new switching activities for μ→γ1 and μ→ε CSR, which are distinct from μ→γ3 and μ→α switching activities previously described. AID is expressed in all the B cell lines capable of CSR, but cannot account for the isotype specificity defined by the S plasmid assay. These results are consistent with a model in which isotype-specific switching factors are either isotype-specific recombinases or DNA binding proteins with sequence specificity for S DNA.
Phosphorylation and O-Linked Glycosylation of Elf-1 Leads to Its Translocation to the Nucleus and Binding to the Promoter of the TCR ζ-Chain
Authors: Juang Yuang-Taung , Solomou Elena E. , Rellahan Barbara , Tsokos George C. 
Published: April 2014

Abstract
Elf-1, a member of the E 26-specific transcription factor family with a predicted molecular mass of 68 kDa, is involved in the transcriptional regulation of several hematopoietic cell genes. We demonstrate that Elf-1 exists primarily as a 98-kDa form in the nucleus and as an 80-kDa form in the cytoplasm. Phosphorylation and O-linked glycosylation contribute to the increased posttranslational molecular mass of Elf-1. The 98-kDa Elf-1 is released from the cytoplasm tethering retinoblastoma protein and moves to the nucleus, where it binds to the promoter of the TCR ζ-chain gene. Finally, the cytoplasmic 98-kDa form enters the proteasome pathway and undergoes degradation. In conclusion, different forms of Elf-1 are the products of posttranslational modifications that determine its subcellular localization, activity, and metabolic degradation.
Optimal T Cell Responses to Cryptococcus neoformans Mannoprotein Are Dependent on Recognition of Conjugated Carbohydrates by Mannose Receptors
Authors: Mansour Michael K. , Schlesinger Larry S. , Levitz Stuart M. 
Published: April 2014

Abstract
Cryptococcosis is a leading cause of death among individuals with compromised T cell function. Soluble Cryptococcus neoformans mannoproteins (MP) have emerged as promising vaccine candidates due to their capacity to elicit delayed-type hypersensitivity and Th type 1-like cytokines, both critical to the clearance of this pathogenic yeast. In this study, the mechanisms responsible for the potent immunostimulatory properties of MP were explored. Using Chinese hamster ovary cells expressing human macrophage mannose receptor (MMR), we determined that MP is a MMR ligand. Functionally, competitive blockade of multilectin mannose receptors (MR) on APCs diminished MP-dependent stimulation of primary T cells from immunized mice and the MP-reactive CD4+ T cell hybridoma, P1D6, by 72 and 99%, respectively. Removal of O-linked saccharides from MP by β-elimination inhibited MP-dependent stimulation of P1D6 and primary T cells by 89 and 90%, respectively. In addition, MP-dependent stimulation of P1D6 was abrogated after digestion with proteinase K, suggesting the protein core of MP contributed the antigenic moiety presented by APC. Stimulation of P1D6 by MP also was abolished using APC obtained from invariant chain-deficient mice, demonstrating Ag presentation was MHC class II restricted. Our data suggest that MP is a ligand for the MMR and that T cell stimulation is functionally inhibited either by competitive blockade of MR or by removal of carbohydrate residues critical for recognition. The demonstration that efficient T cell responses to MP require recognition of terminal mannose groups by MMR provides both a molecular basis for the immunogenicity of cryptococcal MP and support for vaccination strategies that target MR.
Toll-Like Receptor 4-MD-2 Complex Mediates the Signal Transduction Induced by Flavolipin, an Amino Acid-Containing Lipid Unique toFlavobacterium meningosepticum
Authors: Gomi Kazunori , Kawasaki Kiyoshi , Kawai Yohko , Shiozaki Masao , Nishijima Masahiro 
Published: April 2014

AbstractFlavolipin, an amino acid-containing lipid isolated from Flavobacterium meningosepticum, induces many immune responses. It has been shown that flavolipin does not induce an immune response of macrophages derived from C3H/HeJ mice, which possess a point mutation in Toll-like receptor 4 (TLR4). To determine whether TLR4 or the molecular complex of TLR4 and TLR4 association molecule MD-2 mediates the flavolipin signal, flavolipin responsiveness was examined by measuring NF-κB activation in Ba/F3 cells and Ba/F3 transfectants expressing TLR4 or both TLR4 and MD-2. Flavolipin-induced NF-κB activation was detected in the cells expressing both TLR4 and MD-2, but not in the other cells. Expression of CD14 in the transfectant expressing both TLR4 and MD-2 increased the sensitivity to flavolipin. Furthermore, flavolipin stereoisomers were chemically synthesized, and their abilities to induce NF-κB activation were examined. (R)-Flavolipin, in which the configuration of the lipid moiety is R, induced NF-κB activation via the TLR4-MD-2 complex, but (S)-flavolipin did not. In this study, we demonstrated the involvement of TLR4-MD-2 and CD14 in flavolipin signaling and the importance of the (R)-configuration of the flavolipin lipid moiety for the induction of an immune response via TLR4-MD-2.
The Role of IFN in Respiratory Syncytial Virus Pathogenesis
Authors: Durbin Joan E. , Johnson Teresa R. , Durbin Russell K. , Mertz Sara E. , Morotti Rafaella A. , Peebles R. Stokes , Graham Barney S. 
Published: April 2014

AbstractFormalin-inactivated respiratory syncytial virus (RSV) vaccine preparations have been shown to cause enhanced disease in naive hosts following natural infection. In this study we demonstrate a similar pattern of enhanced disease severity following primary RSV infection of IFN-nonresponsive STAT1−/− mice. STAT1−/− mice showed markedly increased illness compared with wild-type BALB/c animals following RSV inoculation despite similar lung virus titers and rates of virus clearance. Histologically, STAT1−/− animals had eosinophilic and neutrophilic pulmonary infiltrates not present in wild-type or IFN-γ−/−-infected mice. In cytokine analyses of infected lung tissue, IFN-γ was induced in both STAT1−/− and wild-type mice, with preferential IL-4, IL-5, and IL-13 induction only in the STAT1−/− animals. Eotaxin was detected in the lungs of both wild-type and STAT1−/− mice following infection, with a 1.7-fold increase over wild-type in the STAT1−/− mice. Using a peptide epitope newly identified in the RSV fusion protein, we were able to demonstrate that wild-type memory CD4+ T cells stimulated by this peptide produce primarily IFN-γ, while STAT1−/−CD4+ cells produce primarily IL-13. These findings suggest that STAT1 activation by both type I (αβ) and type II (γ) IFNs plays an important role in establishing a protective, Th1 Ag-specific immune response to RSV infection.