bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distinct Roles for PECAM-1, ICAM-1, and VCAM-1 in Recruitment of Neutrophils and Eosinophils to the Cornea in Ocular Onchocerciasis (River Blindness)
Authors: Kaifi Jussuf T. , Diaconu Eugenia , Pearlman Eric 
Published: April 2014

AbstractInfiltration of granulocytes into the transparent mammalian cornea can result in loss of corneal clarity and severe visual impairment. Since the cornea is an avascular tissue, recruitment of granulocytes such as neutrophils and eosinophils into the corneal stroma is initiated from peripheral (limbal) vessels. To determine the role of vascular adhesion molecules in this process, expression of platelet endothelial cell adhesion molecule 1 (PECAM-1), ICAM-1, and VCAM-1 on limbal vessels was determined in a murine model of ocular onchocerciasis in which Ags from the parasitic worm Onchocerca volvulus are injected into the corneal stroma. Expression of each of these molecules was elevated after injection of parasite Ags; however, PECAM-1 and ICAM-1 expression remained elevated from 12 h after injection until 7 days, whereas VCAM-1 expression was more transient, with peak expression at 72 h. Subconjunctival injection of Ab to PECAM-1 significantly inhibited neutrophil recruitment to the cornea compared with eyes injected with control Ab (p = 0.012). Consistent with this finding, corneal opacification was significantly diminished (p &lt; 0.0001). There was no significant reduction in eosinophils. Conversely, subconjunctival injection of Ab to ICAM-1 did not impair neutrophil recruitment, but significantly inhibited eosinophil recruitment (p = 0.0032). Injection of Ab to VCAM-1 did not significantly inhibit infiltration of either cell type to the cornea. Taken together, these results demonstrate important regulatory roles for PECAM-1 and ICAM-1 in recruitment of neutrophils and eosinophils, respectively, to the cornea, and may indicate a selective approach to immune intervention.
CD40 Activates NF-κB and c-Jun N-Terminal Kinase and Enhances Chemokine Secretion on Activated Human Hepatic Stellate Cells
Authors: Schwabe Robert F. , Schnabl Bernd , Kweon Young O. , Brenner David A. 
Published: April 2014

AbstractActivated hepatic stellate cells (HSCs) are the main producers of extracellular matrix in the fibrotic liver and contribute to hepatic inflammation through the secretion of chemokines and the recruitment of leukocytes. This study assesses the function of CD40 on human HSCs. Activated human HSCs express CD40 in culture and in fibrotic liver, as determined by flow cytometry, RT-PCR, and immunohistochemistry. CD40 expression is strongly enhanced by IFN-γ. Stimulation of CD40 with CD40 ligand (CD40L)-transfected baby hamster kidney cells induces NF-κB, as demonstrated by the activation of I-κB kinase (IKK), increased NF-κB DNA binding, and p65 nuclear translocation. CD40-activated IKK also phosphorylates a GST-p65 substrate at serine 536 in the transactivation domain 1. Concomitant with the activation of IKK, CD40L-transfected baby hamster kidney cell treatment strongly activates c-Jun N-terminal kinase. CD40 activation increases the secretion of IL-8 and monocyte chemoattractant protein-1 by HSCs 10- and 2-fold, respectively. Adenovirally delivered dominant negative (dn) IKK2 and TNFR-associated factor 2dn inhibit IKK-mediated GST-I-κB and GST-p65 phosphorylation, NF-κB binding, and IL-8 secretion, whereas IKK1dn and NF-κB-inducing kinase dominant negative do not have inhibitory effects. We conclude that the CD40-CD40L receptor-ligand pair is involved in a cross-talk between HSCs and immune effector cells that contributes to the perpetuation of HSC activation in liver fibrosis through TNFR-associated factor 2- and IKK2-dependent pathways.
Accelerated Nephrotoxic Nephritis Is Exacerbated in C1q-Deficient Mice
Authors: Robson Michael G. , Cook H. Terence , Botto Marina , Taylor Philip R. , Busso Nathalie , Salvi Roberto , Pusey Charles D. , Walport Mark J. , Davies Kevin A. 
Published: April 2014

AbstractC1q deficiency strongly predisposes to the development of systemic lupus erythematosus in humans and mice. We used the model of accelerated nephrotoxic nephritis in C1q-deficient mice to explore the mechanisms behind these associations. C1q-deficient mice developed severe glomerular thrombosis within 4 days of induction of disease, whereas wild-type mice developed mild injury. These findings suggest that C1q protects from immune-mediated glomerular injury. This exacerbated thrombosis was also seen in mice triply deficient in C1q, factor B, and C2, excluding a major pathogenic role for the alternative pathway of complement in this phenomenon. However, these mice did not develop elevated creatinine levels. No exacerbation of accelerated nephrotoxic nephritis was observed in mice doubly deficient in factor B and C2, suggesting a protective role for C1q against renal inflammation that is proximal to C2 activation. There were increased murine IgG deposits, neutrophil numbers, and apoptotic cells in the glomeruli of C1q-deficient mice compared with wild-type mice. Renal expression of genes encoding procoagulant proteins was also enhanced in C1q-deficient mice. The increased IgG deposits and apoptotic cells in the glomeruli of C1q-deficient mice suggest that the exacerbation of disease may be due to a defect in the clearance of immune complexes and/or apoptotic cells from their kidneys.
PU.1 and Multiple IFN Regulatory Factor Proteins Synergize to Mediate Transcriptional Activation of the Human IL-1β Gene
Authors: Marecki Sylvia , Riendeau Carrie J. , Liang Michael D. , Fenton Matthew J. 
Published: April 2014

AbstractBoth lymphoid and myeloid cells express two related members of the IFN regulatory factor (IRF) family of transcription factors, specifically IRF-4 and IFN consensus binding protein (ICSBP or IRF-8). We previously reported that macrophages express IRF-4 and in combination with the ETS-like protein PU.1 can synergistically activate a human IL-1β reporter gene. Here we report that this synergy is mediated by a composite PU.1/IRF element located within an upstream enhancer known to confer cytokine- and LPS-inducible expression. In macrophages, synergistic activation of IL-1β reporter gene expression was preferentially mediated by IRF-4, whereas IRF-4 and ICSBP were equally capable of synergizing with PU.1 when coexpressed in fibroblasts. Furthermore, coexpression of IRF-1 and IRF-2 dramatically increased the capacity of both PU.1/IRF-4 and PU.1/ICSBP to induce IL-1β reporter gene expression in fibroblasts. The additional synergy observed with IRF-1 and IRF-2 coexpression is mediated by a region of DNA distinct from either the IL-1β enhancer or promoter. We also assessed the capacity of these transcription factors to activate endogenous IL-1β gene when overexpressed in human embryonic kidney 293 cells. Although ectopic expression of PU.1 alone was sufficient to activate modest levels of IL-1β transcripts, endogenous IL-1β expression was markedly increased following coexpression of additional IRF proteins. Thus, maximal expression of both a human IL-1β reporter gene and the endogenous IL-1β gene was observed in cells that coexpressed PU.1, IRF-4 (or ICSBP), IRF1, and IRF2. Together, our observations suggest that these factors may function together as an enhanceosome.
Bacterial DNA and Lipopolysaccharide Induce Synergistic Production of TNF-α Through a Post-Transcriptional Mechanism
Authors: Gao Jian Jun , Xue Qiao , Papasian Christopher J. , Morrison David C. 
Published: April 2014

AbstractLPS is well recognized for its potent capacity to activate mouse macrophages to produce TNF-α, an important inflammatory mediator in bacterial infection-related diseases such as septic shock. We demonstrate here that while inducing only low levels of TNF-α alone, DNA from both Gram-negative and Gram-positive bacteria synergizes with subthreshold concentrations of LPS (0.3 ng/ml) to induce TNF-α in the RAW 264.7 macrophage-like cell line. The bacterial DNA effects are mimicked by synthetic CpG-containing oligodeoxynucleotides, but not non-CpG-containing oligodeoxynucleotides. Pretreatment of macrophages with either DNA for 2–8 h inhibits macrophage TNF-α production in responses to DNA/LPS. However, when pretreatment was extended to 24 h, DNA/LPS synergy on TNF-α is further enhanced. RT-PCR analysis indicates that mRNA levels of the TNF-α gene, however, are not synergistically induced by bacterial DNA and LPS. Analyses of the half-life of TNF-α mRNA indicate that TNF-α message has a longer half-life in bacterial DNA- and LPS-treated macrophages than that in bacterial DNA- or LPS-treated macrophages. These findings indicate that the temporally controlled, synergistic induction of TNF-α by bacterial DNA and LPS is not mediated at the transcriptional level. Instead, this synergy may occur via a post-transcriptional mechanism.
Reversing Lipopolysaccharide Toxicity by Ligating the Macrophage Fcγ Receptors
Authors: Gerber Jeffrey S. , Mosser David M. 
Published: April 2014

AbstractOur laboratory has previously demonstrated that the ligation of phagocytic receptors on macrophages can influence cytokine production. In this study, we examine the cytokine responses to multiple inflammatory stimuli following FcγR ligation. Macrophages were stimulated in vitro with LPS, lipoteichoic acid, CD40 ligand, or low molecular mass hyaluronic acid. All of these stimuli were proinflammatory in character, inducing the production of high levels of IL-12, but only modest amounts of IL-10. The coligation of FcγR along with these stimuli resulted in an anti-inflammatory profile, abrogating IL-12 production and inducing high levels of IL-10. The modulation of these two cytokines occurred by two independent mechanisms. Whereas the abrogation of IL-12 biosynthesis was a property shared by several macrophage receptors, the induction of IL-10 was specific to the FcγR. The biological relevance of these observations was examined in murine models of endotoxemia, in which FcγR ligation induced the rapid production of IL-10 and prevented IL-12 synthesis. Mice could be passively immunized with Abs to LPS to reverse inflammatory cytokine production, and the transfer of macrophages whose FcγR had been ligated could rescue mice from lethal endotoxemia. Thus, the ligation of the macrophage FcγR can be exploited to prevent inappropriate inflammatory cytokine responses.
Blockade of CD40 Ligand Suppresses Chronic Experimental Myasthenia Gravis by Down-Regulation of Th1 Differentiation and Up-Regulation of CTLA-4
Authors: Im Sin-Hyeog , Barchan Dora , Maiti Prasanta Kumar , Fuchs Sara , Souroujon Miriam C. 
Published: April 2014

AbstractMyasthenia gravis (MG) and experimental autoimmune MG (EAMG) are T cell-dependent Ab-mediated autoimmune disorders, in which the nicotinic acetylcholine receptor (AChR) is the major autoantigen. Th1-type cells and costimulatory factors such as CD40 ligand (CD40L) contribute to disease pathogenesis by producing proinflammatory cytokines and by activating autoreactive B cells. In this study we demonstrate the capacity of CD40L blockade to modulate EAMG, and analyze the mechanism underlying this disease suppression. Anti-CD40L Abs given to rats at the chronic stage of EAMG suppress the clinical progression of the autoimmune process and lead to a decrease in the AChR-specific humoral response and delayed-type hypersensitivity. The cytokine profile of treated rats suggests that the underlying mechanism involves down-regulation of AChR-specific Th1-regulated responses with no significant effect on Th2- and Th3-regulated AChR-specific responses. EAMG suppression is also accompanied by a significant up-regulation of CTLA-4, whereas a series of costimulatory factors remain unchanged. Adoptive transfer of splenocytes from anti-CD40L-treated rats does not protect recipient rats against subsequently induced EAMG. Thus it seems that the suppressed progression of chronic EAMG by anti-CD40L treatment does not induce a switch from Th1 to Th2/Th3 regulation of the AChR-specific immune response and does not induce generation of regulatory cells. The ability of anti-CD40L treatment to suppress ongoing chronic EAMG suggests that blockade of CD40L may serve as a potential approach for the immunotherapy of MG and other Ab-mediated autoimmune diseases.
Western and Chinese Antirheumatic Drug-Induced T Cell Apoptotic DNA Damage Uses Different Caspase Cascades and Is Independent of Fas/Fas Ligand Interaction
Authors: Lai Jenn-Haung , Ho Ling-Jun , Lu Kuo-Cheng , Chang Deh-Ming , Shaio Men-Fang , Han Shou-Hwa 
Published: April 2014

Abstract
Spontaneous or therapeutic induction of T cell apoptosis plays a critical role in establishing transplantation tolerance and maintaining remission of autoimmune diseases. We investigated the mechanisms of apoptosis induced by Chinese and Western antirheumatic drugs (ARDs) in human T cells. We found that hydroxychloroquine, Tripterygium wilfordii hook F, and tetrandrine (Tet), but not methotrexate, at therapeutic concentrations can cause T cell death. In addition, Tet selectively killed T cells, especially activated T cells. Although ARD-induced cytotoxicity was mediated through apoptotic mechanisms, Fas/Fas ligand interaction was not required. We further demonstrated that the processes of phosphatidylserine externalization and DNA damage along the ARD-induced T cell apoptotic pathway could operate independently, and that selective inhibition of DNA damage by caspase inhibitors did not prevent T cells from undergoing cell death. Moreover, we found that Tet- and Tripterygium wilfordii hook F-induced T cell DNA damage required caspase-3 activity, and hydroxychloroquine-induced T cell DNA damage was mediated through a caspase-3- and caspase-8-independent, but Z-Asp-Glu-Val-Asp-fluomethyl ketone-sensitive, signaling pathway. Finally, the observation that ARD-induced activation of caspase-3 in both Fas-sensitive and Fas-resistant Jurkat T cells indicates that Fas/Fas ligand interaction plays no role in ARD-induced T cell apoptosis. Our observations provide new information about the complex apoptotic mechanisms of ARDs, and have implications for combining Western and Chinese ARDs that have different immunomodulatory mechanisms in the therapy of autoimmune diseases and transplantation rejection.
A Glutamic Acid Decarboxylase 65-Specific Th2 Cell Clone Immunoregulates Autoimmune Diabetes in Nonobese Diabetic Mice
Authors: Tisch Roland , Wang Bo , Atkinson Mark A. , Serreze David V. , Friedline Randall 
Published: April 2014

Abstract
Several studies have provided indirect evidence in support of a role for β cell-specific Th2 cells in regulating insulin-dependent diabetes (IDDM). Whether a homogeneous population of Th2 cells having a defined β cell Ag specificity can prevent or suppress autoimmune diabetes is still unclear. In fact, recent studies have demonstrated that β cell-specific Th2 cell clones can induce IDDM. In this study we have established Th cell clones specific for glutamic acid decarboxylase 65 (GAD65), a known β cell autoantigen, from young unimmunized nonobese diabetic (NOD) mice. Adoptive transfer of a GAD65-specific Th2 cell clone (characterized by the secretion of IL-4, IL-5, and IL-10, but not IFN-γ or TGF-β) into 2- or 12-wk-old NOD female recipients prevented the progression of insulitis and subsequent development of overt IDDM. This prevention was marked by the establishment of a Th2-like cytokine profile in response to a panel of β cell autoantigens in cultures established from the spleen and pancreatic lymph nodes of recipient mice. The immunoregulatory function of a given Th cell clone was dependent on the relative levels of IFN-γ vs IL-4 and IL-10 secreted. These results provide direct evidence that β cell-specific Th2 cells can indeed prevent and suppress autoimmune diabetes in NOD mice.
Vascular Adhesion Protein 1 Mediates Binding of Immunotherapeutic Effector Cells to Tumor Endothelium
Authors: Irjala Heikki , Salmi Marko , Alanen Kalle , Grénman Reidar , Jalkanen Sirpa 
Published: April 2014

AbstractTumor-infiltrating lymphocytes (TIL) can be used as an immunotherapeutic tool to treat cancer. Success of this therapy depends on the homing and killing capacity of in vitro-activated and -expanded TIL. Vascular adhesion protein 1 (VAP-1) is an endothelial molecule that mediates binding of lymphocytes to vessels of inflamed tissue. Here, we studied whether VAP-1 is involved in binding of TIL, lymphokine-activated killer (LAK) cells, and NK cells to vasculature of the cancer tissue. We demonstrated that VAP-1 is expressed on the endothelium of cancer vasculature. The intensity and number of positive vessels varied greatly between the individual specimens, but it did not correlate with the histological grade of the cancer. Using an in vitro adhesion assay we showed that VAP-1 mediates adhesion of TIL, LAK, and NK cells to cancer vasculature. Treatment of the tumor sections with anti-VAP-1 Abs diminished the number of adhesive cells by 60%. When binding of different effector cell types was compared, it was evident that different cancer tissues supported the adhesion of TIL to a variable extent and LAK cells were more adhesive than TIL and NK cells to tumor vasculature. These data suggest that VAP-1 is an important interplayer in the antitumor response. Thus, by up-regulating the expression of VAP-1 in tumor vasculature, it can be possible to improve the effectiveness of TIL therapy.
Fas Ligand Overexpression on Allograft Endothelium Inhibits Inflammatory Cell Infiltration and Transplant-Associated Intimal Hyperplasia
Authors: Sata Masataka , Luo Zhengyu , Walsh Kenneth 
Published: April 2014

AbstractDespite recent advances in immunosuppressive therapy, accelerated coronary atherosclerosis remains a major problem in the long-term survival of transplant recipients. Chronic graft vasculopathy is believed to result from recipient inflammatory responses, and it is characterized by early mononuclear cell infiltration of the transplanted vessel. Here we show that endothelial cells can be genetically modified to overexpress functional, cell-surface Fas ligand (FasL) by adenovirus-mediated gene transfer without undergoing self-destruction. In a rodent model of transplant graft vasculopathy, endothelial overexpression of FasL attenuated T cell and macrophage infiltration at 1 wk posttransplantation. These vessels also displayed reduced neointima formation at one and 2 mo posttransplantation. These results indicate that inhibition of the early inflammatory response to allografted vessels by endothelial cell-specific overexpression of FasL may have utility in the treatment of transplant arteriosclerosis.
The Allergen-Induced Airway Hyperresponsiveness in a Human-Mouse Chimera Model of Asthma Is T Cell and IL-4 and IL-5 Dependent
Authors: Tournoy Kurt G. , Kips Johan C. , Pauwels Romain A. 
Published: April 2014

AbstractThe cellular and molecular mechanisms involved in the airway hyperresponsiveness (AHR) of patients with allergic asthma remain unclear. A role for Th2 inflammatory cells was suggested based on murine asthma models. No direct evidence exists on the role of these cells in human asthma. The development of a mouse-human chimera might be useful, allowing the in vivo study of the components of the human immune system relevant to asthma. We investigated the role of allergen-reactive T lymphocytes in a human-mouse SCID model. SCID mice were reconstituted intratracheally with human PBMC from healthy, nonallergic, nonasthmatic donors and exposed to an aerosol of house dust mite allergen after i.p. injection with Dermatophagoides pteronyssinus I Ag and alum. The donor T lymphocytes had a Th1 cytokine phenotype. The reconstituted and allergen-challenged mice developed AHR to carbachol. The mouse airways and lungs were infiltrated with human T lymphocytes. No eosinophils or increases in human IgE were observed. The intrapulmonary human T lymphocytes demonstrated an increase in intracytoplasmic IL-4 and IL-5 and a decrease in IFN-γ after exposure to allergen adjuvant. Antagonizing human IL-4/IL-13 or IL-5 resulted in a normalization of the airway responsiveness, despite a sustained intracellular Th2 cytokine production. These results provide evidence that the activated human allergen-reactive Th2 cells producing IL-4 or IL-5 are pivotal in the induction of AHR, whereas no critical role for eosinophils or IgE could be demonstrated. They also demonstrate that human allergen-specific Th1 lymphocytes can be driven to a Th2 phenotype.
Quantitative and Qualitative Influences of Tapasin on the Class I Peptide Repertoire
Authors: Purcell Anthony W. , Gorman Jeffrey J. , Garcia-Peydró Marína , Paradela Alberto , Burrows Scott R. , Talbo Gert H. , Laham Nihay , Peh Chen Au , Reynolds Eric C. , López de Castro José A. , McCluskey James 
Published: April 2014

AbstractTapasin is critical for efficient loading and surface expression of most HLA class I molecules. The high level surface expression of HLA-B*2705 on tapasin-deficient 721.220 cells allowed the influence of this chaperone on peptide repertoire to be examined. Comparison of peptides bound to HLA-B*2705 expressed on tapasin-deficient and -proficient cells by mass spectrometry revealed an overall reduction in the recovery of B*2705-bound peptides isolated from tapasin-deficient cells despite similar yields of B27 heavy chain and β2-microglobulin. This indicated that a proportion of suboptimal ligands were associated with B27, and they were lost during the purification process. Notwithstanding this failure to recover these suboptimal peptides, there was substantial overlap in the repertoire and biochemical properties of peptides recovered from B27 complexes derived from tapasin-positive and -negative cells. Although many peptides were preferentially or uniquely isolated from B*2705 in tapasin-positive cells, a number of species were preferentially recovered in the absence of tapasin, and some of these peptide ligands have been sequenced. In general, these ligands did not exhibit exceptional binding affinity, and we invoke an argument based on lumenal availability and affinity to explain their tapasin independence. The differential display of peptides in tapasin-negative and -positive cells was also apparent in the reactivity of peptide-sensitive alloreactive CTL raised against tapasin-positive and -negative targets, demonstrating the functional relevance of the biochemical observation of changes in peptide repertoire in the tapasin-deficient APC. Overall, the data reveal that tapasin quantitatively and qualitatively influences ligand selection by class I molecules.