bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Novel Mechanism for TNF-α Regulation by p38 MAPK: Involvement of NF-κB with Implications for Therapy in Rheumatoid Arthritis
Authors: Campbell Jamie , Ciesielski Cathleen J. , Hunt Abigail E. , Horwood Nicole J. , Beech Jonathan T. , Hayes Louise A. , Denys Agnes , Feldmann Marc , Brennan Fionula M. , Foxwell Brian M. J. 
Published: April 2014

AbstractTNF-α is a key factor in a variety of inflammatory diseases. This study examines the role of p38 MAPK in the regulation of TNF-α in primary human cells relevant to inflammation, e.g., macrophages and rheumatoid synovial cells. Using a dominant negative variant (D168A) of p38 MAPK and a kinase inhibitor, SB203580, we confirm in primary human macrophages that p38 MAPK regulates TNF-α production using a posttranscriptional mechanism requiring the 3′ untranslated region of the gene. However, in LPS-activated primary human macrophages we also detect a second previously unidentified mechanism, the p38 MAPK modulation of TNF-α transcription. This is mediated through p38 MAPK regulation of NF-κB. Interestingly this mechanism was not observed in rheumatoid synovial cells. Importantly however, the dominant negative mutant of p38 MAPK, but not SB203580 was effective at inhibiting spontaneous TNF-α production in these ex vivo rheumatoid synovial cell cultures. These data indicate there are potential major differences in the role of p38 MAPK in inflammatory signaling that have a bearing on the use of this kinase as a target for therapy. These results indicate despite disappointing results with p38 MAPK inhibitors in the clinic, this kinase is a valid target in rheumatoid disease.
Interaction of Soluble Form of Recombinant Extracellular TLR4 Domain with MD-2 Enables Lipopolysaccharide Binding and Attenuates TLR4-Mediated Signaling
Authors: Hyakushima Naoki , Mitsuzawa Hiroaki , Nishitani Chiaki , Sano Hitomi , Kuronuma Koji , Konishi Masanori , Himi Tetsuo , Miyake Kensuke , Kuroki Yoshio 
Published: April 2014

AbstractTLRs have been implicated in recognition of pathogen-associated molecular patterns. TLR4 is a signaling receptor for LPS, but requires MD-2 to respond efficiently to LPS. The purposes of this study were to examine the interactions of the extracellular TLR4 domain with MD-2 and LPS. We generated soluble forms of rTLR4 (sTLR4) and TLR2 (sTLR2) lacking the putative intracellular and transmembrane domains. sTLR4 consisted of Glu24-Lys631. MD-2 bound to sTLR4, but not to sTLR2 or soluble CD14. BIAcore analysis demonstrated the direct binding of sTLR4 to MD-2 with a dissociation constant of KD = 6.29 × 10−8 M. LPS-conjugated beads precipitated MD-2, but not sTLR4. However, LPS beads coprecipitated sTLR4 and MD-2 when both proteins were coincubated. The addition of sTLR4 to the medium containing the MD-2 protein significantly attenuated LPS-induced NF-κB activation and IL-8 secretion in wild-type TLR4-expressing cells. These results indicate that the extracellular TLR4 domain-MD-2 complex is capable of binding LPS, and that the extracellular TLR4 domain consisting of Glu24-Lys631 enables MD-2 binding and LPS recognition to TLR4. In addition, the use of sTLR4 may lead to a new therapeutic strategy for dampening endotoxin-induced inflammation.
RhoA/Rho-Associated Kinase Pathway Selectively Regulates Thrombin-Induced Intercellular Adhesion Molecule-1 Expression in Endothelial Cells via Activation of IκB Kinase β and Phosphorylation of RelA/p65
Authors: Anwar Khandaker N. , Fazal Fabeha , Malik Asrar B. , Rahman Arshad 
Published: April 2014

AbstractWe investigated the involvement of the RhoA/Rho-associated kinase (ROCK) pathway in regulating ICAM-1 expression in endothelial cells by the procoagulant, thrombin. Exposure of HUVECs to C3 exoenzyme, a selective inhibitor of Rho, markedly reduced thrombin-induced ICAM-1 expression. Inhibition of ROCK, the downstream effector of Rho, also prevented thrombin-induced ICAM-1 expression. Blockade of thrombin-induced ICAM-1 expression was secondary to inhibition of NF-κB activity, the key regulator of ICAM-1 expression in endothelial cells. In parallel studies we observed that inhibition of the RhoA/ROCK pathway by the same pharmacological and genetic approaches failed to inhibit TNF-α-induced NF-κB activation and ICAM-1 expression. The effect of RhoA/ROCK inhibition on thrombin-induced NF-κB activation was secondary to inhibition of IκB kinase activation and subsequent IκBα degradation and nuclear uptake and the DNA binding of NF-κB. Inhibition of the RhoA/ROCK pathway also prevented phosphorylation of Ser536 within the transactivation domain 1 of NF-κB p65/RelA, a critical event conferring transcriptional competency to the bound NF-κB. Thus, the RhoA/ROCK pathway signals thrombin-induced ICAM-1 expression through the activation of IκB kinase, which promotes NF-κB binding to ICAM-1 promoter and phosphorylation of RelA/p65, thus mediating the transcriptional activation of bound NF-κB.
Lipopolysaccharide Induces Matrix Metalloproteinase-9 Expression via a Mitochondrial Reactive Oxygen Species-p38 Kinase-Activator Protein-1 Pathway in Raw 264.7 Cells
Authors: Woo Chang-Hoon , Lim Jae-Hyang , Kim Jae-Hong 
Published: April 2014

AbstractWe have identified a novel signaling pathway that leads to expression of matrix metalloproteinase-9 (MMP-9) in murine macrophages in response to the bacterial endotoxin, LPS. We showed that p38 kinase was essential for this induction and observed that LPS-induced MMP-9 expression was sensitive to rottlerin, a putative protein kinase Cδ (PKCδ) inhibitor. However neither infection with a retrovirus expressing a dominant negative mutant of PKCδ nor down-regulation of PKCδ by prolonged PMA treatment affected MMP-9 expression, thus excluding involvement of PKCδ. Interestingly, LPS-induced MMP-9 expression and p38 kinase phosphorylation were shown to be suppressed by the antioxidant N-acetylcysteine and the flavoenzyme inhibitor diphenyleneiodonium chloride, but not by pyrrolidine dithiocarbamate, an NF-κB inhibitor. In addition, LPS was found to induce the production of mitochondrial reactive oxygen species (ROS) and this effect was rottlerin-sensitive, suggesting an inhibitory effect of rottlerin on mitochondrial ROS. LPS-induced MMP-9 expression and p38 kinase phosphorylation were also inhibited by rotenone, a specific inhibitor of mitochondrial complex I, supporting the role of mitochondrial ROS in LPS signaling to MMP-9. Finally, we showed that the ROS-p38 kinase cascade targets the transcription factor AP-1. Taken together, our findings identify a ROS-p38 kinase-AP-1 cascade as a novel pathway mediating LPS signaling to MMP-9 expression in macrophages.
Inhibition of Fractalkine Ameliorates Murine Collagen-Induced Arthritis
Authors: Nanki Toshihiro , Urasaki Yasuyo , Imai Toshio , Nishimura Miyuki , Muramoto Kenzo , Kubota Tetsuo , Miyasaka Nobuyuki 
Published: April 2014

Abstract
Rheumatoid arthritis (RA) is a chronic inflammatory disease associated with massive infiltration of inflammatory cells in the synovium of multiple joints. We and others have shown that fractalkine (FKN/CX3CL1), a chemokine expressed on fibroblast-like synoviocytes and endothelial cells in RA synovium, may contribute to the accumulation of T cells, macrophages, and dendritic cells, which express CX3CR1, the receptor for FKN. This interaction might be involved in adhesion of the inflammatory cells to endothelial cells, migration into the synovium, and cytokine production. In this study, we examined the effect of FKN inhibition on murine collagen-induced arthritis. Anti-FKN mAb significantly lowered clinical arthritis score compared with control Ab, and reduced infiltration of inflammatory cells and bone erosion in the synovium. However, anti-FKN mAb did not affect the production of either serum anti-collagen type II (CII) IgG or IFN-γ by CII-stimulated splenic T cells. Furthermore, treatment with anti-FKN mAb inhibited migration of adoptively transferred splenic macrophages into the inflamed synovium. Our results suggest that anti-FKN mAb ameliorates arthritis by inhibiting infiltration of inflammatory cells into the synovium. Thus, FKN can be a new target molecule for the treatment of RA.
A Novel HLA-A*3303-Restricted Minor Histocompatibility Antigen Encoded by an Unconventional Open Reading Frame of Human TMSB4Y Gene
Authors: Torikai Hiroki , Akatsuka Yoshiki , Miyazaki Mikinori , Warren Edus H. , Oba Taku , Tsujimura Kunio , Motoyoshi Kazuo , Morishima Yasuo , Kodera Yoshihisa , Kuzushima Kiyotaka , Takahashi Toshitada 
Published: April 2014

AbstractFemale-to-male hemopoietic stem cell transplantation (HSCT) elicits T cell responses against male-specific minor histocompatibility (H-Y) Ags encoded by the Y chromosome. All previously identified H-Y Ags are encoded by conventional open reading frames, but we report in this study the identification of a novel H-Y Ag encoded in the 5′-untranslated region of the TMSB4Y gene. An HLA-A*3303-restricted CD8+ CTL clone was isolated from a male patient after an HSCT from his HLA-identical sister. Using a panel of cell lines carrying Y chromosome terminal deletions, a narrow region controlling the susceptibility of these target cells to CTL recognition was localized. Minigene transfection and epitope reconstitution assays identified an 11-mer peptide, EVLLRPGLHFR, designated TMSB4Y/A33, whose first amino acid was located 405 bp upstream of the TMSB4Y initiation codon. Analysis of the precursor frequency of CTL specific for recipient minor histocompatibility Ags in post-HSCT peripheral blood T cells revealed that a significant fraction of the total donor CTL response in this patient was directed against the TMSB4Y epitope. Tetramer analysis continued to detect TMSB4Y/A33-specific CD8+ T cells at least up to 700 days post-HSCT. This finding underscores the in vivo immunological relevance of minor histocompatibility Ags derived from unconventional open reading frame products.
Anti-Phospholipid Antibodies Restore Mesenteric Ischemia/Reperfusion-Induced Injury in Complement Receptor 2/Complement Receptor 1-Deficient Mice
Authors: Fleming Sherry D. , Egan Ryan P. , Chai Chunyan , Girardi Guillermina , Holers V. Michael , Salmon Jane , Monestier Marc , Tsokos George C. 
Published: April 2014

AbstractComplement receptor 2-deficient (Cr2−/−) mice are resistant to mesenteric ischemia/reperfusion (I/R) injury because they lack a component of the natural Ab repertoire. Neither the nature of the Abs that are involved in I/R injury nor the composition of the target Ag, to which recognition is lacking in Cr2−/− mice, is known. Because anti-phospholipid Abs have been shown to mediate fetal growth retardation and loss when injected into pregnant mice, we performed experiments to determine whether anti-phospholipid Abs can also reconstitute I/R injury and, therefore, represent members of the injury-inducing repertoire that is missing in Cr2−/− mice. We demonstrate that both murine and human monoclonal and polyclonal Abs against negatively charged phospholipids can reconstitute mesenteric I/R-induced intestinal and lung tissue damage in Cr2−/− mice. In addition, Abs against β2 glycoprotein I restore local and remote tissue damage in the Cr2−/− mice. Unlike Cr2−/− mice, reconstitution of I/R tissue damage in the injury-resistant Rag-1−/− mouse required the infusion of both anti-β2-glycoprotein I and anti-phospholipid Ab. We conclude that anti-phospholipid Abs can bind to tissues subjected to I/R insult and mediate tissue damage.
Self-Reactive T Cell Receptor-Reactive CD8+ T Cells Inhibit T Cell Lymphoma Growth In Vivo
Authors: Gonthier Marie , Llobera Régine , Arnaud Jacques , Rubin Bent 
Published: April 2014

AbstractSyngenic C57BL/6 mice (H-2b) vaccinated with mitomycin C-treated L12R4 T lymphoma cells develop protective immunity toward the MHC class II-negative tumor cells. In the present study, we characterize the nature, mode of function, and specificity of the effector cells in this immunity. These cells are TCR-specific CD8+ T lymphocytes with effector function in vitro as well as in vivo upon transfer to naive mice. They produce high levels of IFN-γ and TNF-α, but little or no IL-4. By means of TCRβ-negative variant L12R4 cells, P3.3, and TCR-Vβ2 cDNA-transfected and TCR-Vβ2-expressing P3.3 lymphoma cells, we found that a significant part of the effector T cells are specific for the Vβ12 region. The growth inhibition of L12R4 cells in vitro was inhibited by anti-H-2, anti-Kb, and anti-Db mAb. Furthermore, vaccination with Vβ12 peptide p67–78, which binds to both Kb and Db MHC class I molecules, induces partial protection against L12R4 T lymphoma cells. Thus, self-reactive TCR-Vβ-specific, Kb-, or Db-restricted CD8+ T cells mediate inhibition of T cell lymphoma growth in vitro and in vivo.
TLR4 Contributes to Disease-Inducing Mechanisms Resulting in Central Nervous System Autoimmune Disease
Authors: Kerfoot Steven M. , Long Elizabeth M. , Hickey Michael J. , Andonegui Graciela , Lapointe Benoit M. , Zanardo Renata C. O. , Bonder Claudine , James Will G. , Robbins Stephen M. , Kubes Paul 
Published: April 2014

AbstractEnvironmental factors strongly influence the development of autoimmune diseases, including multiple sclerosis. Despite this clear association, the mechanisms through which environment mediates its effects on disease are poorly understood. Pertussis toxin (PTX) functions as a surrogate for environmental factors to induce animal models of autoimmunity, such as experimental autoimmune encephalomyelitis. Although very little is known about the molecular mechanisms behind its function in disease development, PTX has been hypothesized to facilitate immune cell entry to the CNS by increasing permeability across the blood-brain barrier. Using intravital microscopy of the murine cerebromicrovasculature, we demonstrate that PTX alone induces the recruitment of leukocytes and of active T cells to the CNS. P-selectin expression was induced by PTX, and leukocyte/endothelial interactions could be blocked with a P-selectin-blocking Ab. P-selectin blockade also prevented PTX-induced increase in permeability across the blood-brain barrier. Therefore, permeability is a secondary result of recruitment, rather than the primary mechanism by which PTX induces disease. Most importantly, we show that PTX induces intracellular signals through TLR4, a receptor intimately associated with innate immune mechanisms. We demonstrate that PTX-induced leukocyte recruitment is dependent on TLR4 and give evidence that the disease-inducing mechanisms initiated by PTX are also at least partly dependent on TLR4. We propose that this innate immune pathway is a novel mechanism through which environment can initiate autoimmune disease of the CNS.
Intranasal HIV-1-gp160-DNA/gp41 Peptide Prime-Boost Immunization Regimen in Mice Results in Long-Term HIV-1 Neutralizing Humoral Mucosal and Systemic Immunity
Authors: Devito Claudia , Zuber Bartek , Schröder Ulf , Benthin Reinhold , Okuda Kenji , Broliden Kristina , Wahren Britta , Hinkula Jorma 
Published: April 2014

AbstractAn intranasal DNA vaccine prime followed by a gp41 peptide booster immunization was compared with gp41 peptide and control immunizations. Serum HIV-1-specific IgG and IgA as well as IgA in feces and vaginal and lung secretions were detected after immunizations. Long-term humoral immunity was studied for up to 12 mo after the booster immunization by testing the presence of HIV-1 gp41- and CCR5-specific Abs and IgG/IgA-secreting B lymphocytes in spleen and regional lymph nodes in immunized mice. A long-term IgA-specific response in the intestines, vagina, and lungs was obtained in addition to a systemic immune response. Mice immunized only with gp41 peptides and L3 adjuvant developed a long-term gp41-specific serum IgG response systemically, although over a shorter period (1–9 mo), and long-term mucosal gp41-specific IgA immunity. HIV-1-neutralizing serum Abs were induced that were still present 12 mo after booster immunization. HIV-1 SF2-neutralizing fecal and lung IgA was detectable only in the DNA-primed mouse groups. Intranasal DNA prime followed by one peptide/L3 adjuvant booster immunization, but not a peptide prime followed by a DNA booster, was able to induce B cell memory and HIV-1-neutralizing Abs for at least half of a mouse’s life span.
Regulatory Cells and Infectious Agents: Détentes Cordiale and Contraire
Authors: Rouse Barry T. , Suvas Susmit 
Published: April 2014

Abstract
This brief review describes the types of interactions that occur between CD4+CD25+ regulatory T cells (Treg) and microbial pathogens. These interactions range from one of mutual benefit (détente cordiale) such as occurs in Leishmania major infection of resistant mouse strains, to instances where the Treg response appears to mainly favor the pathogen and be detrimental to the host (détente contraire). Examples of the latter include chronic persistent infections with retroviruses, perhaps including HIV, and hepatitis C virus. The Treg response also hampers the effectiveness of immunity against some acute virus infections such as HSV. Evidence is also discussed showing that Treg can play a benevolent role to limit the severity of bystander tissue damage in circumstances where the immune response to pathogens is immunopathological. Finally, emerging approaches are discussed that either blunt or activate Treg and that could be used practically to manage host-pathogen interaction.
Cutting Edge: LFA-1 Integrin-Dependent T Cell Adhesion Is Regulated by Both Ag Specificity and Sensitivity
Authors: Mueller Kristen L. , Daniels Mark A. , Felthauser Alicia , Kao Charlly , Jameson Stephen C. , Shimizu Yoji 
Published: April 2014

Abstract
Ab stimulation of the TCR rapidly enhances the functional activity of the LFA-1 integrin. Although TCR-mediated changes in LFA-1 activity are thought to promote T cell-APC interactions, the Ag specificity and sensitivity of TCR-mediated triggering of LFA-1 is not clear. We demonstrate that peptide/MHC (pMHC) tetramers rapidly enhance LFA-1-dependent adhesion of OT-I TCR transgenic CD8+ T cells to purified ICAM-1. Inhibition of src family tyrosine kinase or PI3K activity blocked pMHC tetramer- and anti-CD3-stimulated adhesion. These effects are highly specific because partial agonist and antagonist pMHC tetramers are unable to stimulate OT-I T cell adhesion to ICAM-1. The Ag thresholds required for T cell adhesion to ICAM-1 resemble those of early T cell activation events, because optimal LFA-1 activation occurs at tetramer concentrations that fail to induce maximal T cell proliferation. Thus, TCR signaling to LFA-1 is highly Ag specific and sensitive to low concentrations of Ag.
Cutting Edge: Differential Roles for Phosphoinositide 3-Kinases, p110γ and p110δ, in Lymphocyte Chemotaxis and Homing
Authors: Reif Karin , Okkenhaug Klaus , Sasaki Takehiko , Penninger Joseph M. , Vanhaesebroeck Bart , Cyster Jason G. 
Published: April 2014

AbstractDespite the established role for PI3Ks in cell migration, the PI3Ks involved in lymphocyte chemotaxis are poorly defined. In this study, we report that p110γ-deficient T cells, but not B cells, show reduced chemotactic responses to the lymphoid chemokines, CCL19, CCL21, and CXCL12. As B cell and T cell chemotactic responses were both sensitive to the general PI3K inhibitors, wortmannin (WMN) and LY294002, we explored whether B cell responses were affected in mice lacking p110δ, a major PI3K isoform in lymphocytes. B cells deficient in p110δ showed diminished chemotactic responses, especially to CXCL13. Adoptive transfer experiments with WMN-treated wild-type B cells and with p110δ-deficient B cells revealed diminished homing to Peyer’s patches and splenic white pulp cords. WMN selectively inhibited CXCR5-dependent B cell homing to Peyer’s patches. These observations establish that p110γ and p110δ function in lymphocyte chemotaxis, and show differential roles for PI3K family members in B and T cell migration.
Cutting Edge: Prolonged Antigen Presentation after Herpes Simplex Virus-1 Skin Infection
Authors: Stock Angus T. , Mueller Scott N. , van Lint Allison L. , Heath William R. , Carbone Francis R. 
Published: April 2014

Abstract
It has been reported that MHC class I-restricted Ag presentation persists for only a short period following infection with certain pathogens, declining in parallel with the emergence of specific CTL activity. We have examined this issue in the case of murine infection with HSV-1. We found that the period of Ag presentation capable of priming naive CD8+ T cells is comparatively prolonged, persisting for at least 7 days after infection, and continuing despite the appearance of localized CTL activity. Ag presentation was abbreviated to 3 or 4 days postinfection by surgical excision of the inoculation site early after infection. This intervention attenuated the size of the primary CTL response, implying that prolonged presentation is necessary to drive maximal CTL expansion. Combined, these data show that, in some types of infection, CTL priming can extend well beyond the first 24–48 h after primary inoculation.
TNF Family Member B Cell-Activating Factor (BAFF) Receptor-Dependent and -Independent Roles for BAFF in B Cell Physiology
Authors: Sasaki Yoshiteru , Casola Stefano , Kutok Jeffery L. , Rajewsky Klaus , Schmidt-Supprian Marc 
Published: April 2014

Abstract
The cytokine TNF family member B cell-activating factor (BAFF; also termed BLyS) is essential for B cell generation and maintenance. Three receptors have been identified that bind to BAFF: transmembrane activator, calcium modulator, and cyclophilin ligand interactor (TACI); B cell maturation Ag (BCMA); and BAFF-R. Recently, it was shown that A/WySnJ mice, which contain a dramatically reduced peripheral B cell compartment due to decreased B cell life span, express a mutant BAFF-R. This finding, together with normal or enhanced B cell generation in mice deficient for BCMA or TACI, respectively, suggested that the interaction of BAFF with BAFF-R triggers signals essential for the generation and maintenance of mature B cells. However, B cells in mice deficient for BAFF differ phenotypically and functionally from A/WySnJ B cells. Residual signaling through the mutant BAFF-R could account for these differences. Alternatively, dominant-negative interference by the mutant receptor could lead to an overestimation of the importance of BAFF-R. To resolve this issue, we generated BAFF-R-null mice. Baff-r−/− mice display strongly reduced late transitional and follicular B cell numbers and are essentially devoid of marginal zone B cells. Overexpression of Bcl-2 rescues mature B cell development in Baff-r−/− mice, suggesting that BAFF-R mediates a survival signal. CD21 and CD23 surface expression are reduced on mature Baff-r−/− B cells, but not to the same extent as on mature B cells in BAFF-deficient mice. In addition, we found that Baff-r−/− mice mount significant, but reduced, Ag-specific Ab responses and are able to form spontaneous germinal centers in mesenteric lymph nodes. The reduction in Ab titers correlates with the reduced B cell numbers in the mutant mice.