bluuebunny/crossref_metadata_2025_split huggingface dataset:
Akt Phosphorylates p47phoxand Mediates Respiratory Burst Activity in Human Neutrophils
Authors: Chen Qingdan , Powell David W. , Rane Madhavi J. , Singh Saurabh , Butt Waseem , Klein Jon B. , McLeish Kenneth R. 
Published: April 2014

AbstractRespiratory burst activity and phosphorylation of an NADPH oxidase component, p47phox, during neutrophil stimulation are mediated by phosphatidylinositol 3-kinase (PI-3K) activation. Products of PI-3K activate several kinases, including the serine/threonine kinase Akt. The present study examined the ability of Akt to regulate neutrophil respiratory burst activity and to interact with and phosphorylate p47phox. Inhibition of Akt activity in human neutrophils by an inhibitory peptide significantly attenuated fMLP-stimulated, but not PMA-stimulated, superoxide release. Akt inhibitory peptide also inhibited hydrogen peroxide generation stimulated by bacterial phagocytosis. A direct interaction between p47phox and Akt was shown by the ability of GST-p47phox to precipitate recombinant Akt and to precipitate Akt from neutrophil lysates. Active recombinant Akt phosphorylated recombinant p47phox in vitro, as shown by 32P incorporation, by a mobility shift change detected by two-dimensional gel electrophoresis, and by immunoblotting with phospho-Akt substrate Ab. Mutation analysis indicated that 2 aa residues, Ser304 and Ser328, were phosphorylated by Akt. Inhibition of Akt activity also inhibited fMLP-stimulated neutrophil chemotaxis. We propose that Akt mediates PI-3K-dependent p47phox phosphorylation, which contributes to respiratory burst activity in human neutrophils.
Expression and Production of the CXC Chemokine Growth-Related Oncogene-α by Human Eosinophils
Authors: Persson-Dajotoy Terese , Andersson Pia , Bjartell Anders , Calafat Jero , Egesten Arne 
Published: April 2014

AbstractEosinophils are seen together with neutrophils at sites of inflammation. However, their roles are not clear. In addition, eosinophils infiltrate tumor tissue in some neoplastic diseases. In this study, we show that large amounts of the neutrophil-activating CXC chemokine growth-related oncogene (GRO)-α can be produced by human eosinophils. Eosinophils showed presence of preformed GRO-α in the crystalloid-containing specific granules (190 pg/2 × 106 cells). During incubation, a strong increase in GRO-α gene expression was seen. At a low cell density, addition of TNF-α or IL-1β increased the production of GRO-α in eosinophils, which was not the case at a higher cell density. Eosinophils can produce TNF-α themselves, and neutralizing Abs against TNF-α significantly inhibited GRO-α production. This suggests that autocrine and paracrine effects from TNF-α can be important when up-regulating GRO-α gene expression. In contrast, IFN-γ, a prototypic Th1-cytokine, down-regulated expression of GRO-α. This may be important during resolution of inflammation but also suggests different roles for eosinophils depending on the inflammatory context. Tumor-infiltrating eosinophils in Hodgkin’s disease of the nodular sclerosing type are associated with a poor prognosis. Eosinophils from such tumor tissue showed an abundant expression of GRO-α. The GRO-α receptor CXCR2 was also detected in tumor tissue, proposing interactions between eosinophils and the tumor. Our findings suggest that eosinophils can promote inflammation through recruitment of CXCR2-bearing cells. In addition, this feature of the eosinophils indicates a role for these cells in the biology of certain tumors.
Hybrids of Dendritic Cells and Tumor Cells Generated by Electrofusion Simultaneously Present Immunodominant Epitopes from Multiple Human Tumor-Associated Antigens in the Context of MHC Class I and Class II Molecules
Authors: Parkhurst Maria R. , DePan Cormac , Riley John P. , Rosenberg Steven A. , Shu Suyu 
Published: April 2014

Abstract
Hybrid cells generated by fusing dendritic cells with tumor cells (DC-TC) are currently being evaluated as cancer vaccines in preclinical models and human immunization trials. In this study, we evaluated the production of human DC-TC hybrids using an electrofusion protocol previously defined for murine cells. Human DCs were electrically fused with allogeneic melanoma cells (888mel) and were subsequently analyzed for coexpression of unique DC and TC markers using FACS and fluorescence microscopy. Dually fluorescent cells were clearly observed using both techniques after staining with Abs against distinct surface molecules suggesting that true cell fusion had occurred. We also evaluated the ability of human DC-TC hybrids to present tumor-associated epitopes in the context of both MHC class I and class II molecules. Allogeneic DCs expressing HLA-A*0201, HLA-DRβ1*0401, and HLA-DRβ1*0701 were fused with 888mel cells that do not express any of these MHC molecules, but do express multiple melanoma-associated Ags. DC-888mel hybrids efficiently presented HLA-A*0201-restricted epitopes from the melanoma Ags MART-1, gp100, tyrosinase, and tyrosinase-related protein 2 as evaluated by specific cytokine secretion from six distinct CTL lines. In contrast, DCs could not cross-present MHC class I-restricted epitopes after exogenously loading with gp100 protein. DC-888mel hybrids also presented HLA-DRβ1*0401- and HLA-DRβ1*0701-restricted peptides from gp100 to CD4+ T cell populations. Therefore, fusions of DCs and tumor cells express both MHC class I- and class II-restricted tumor-associated epitopes and may be useful for the induction of tumor-reactive CD8+ and CD4+ T cells in vitro and in human vaccination trials.
Immunization with a Xenobiotic 6-Bromohexanoate Bovine Serum Albumin Conjugate Induces Antimitochondrial Antibodies
Authors: Leung Patrick S. C. , Quan Chao , Park Ogyi , Van de Water Judy , Kurth Mark J. , Nantz Michael H. , Ansari Aftab A. , Coppel Ross L. , Lam Kit S. , Gershwin M. Eric 
Published: April 2014

Abstract
The E2 subunit of pyruvate dehydrogenase complex (PDC-E2) is the major autoantigen recognized by antimitochondrial Abs (AMA) in primary biliary cirrhosis (PBC). Recently, we replaced the lipoic acid moiety of PDC-E2 with a battery of synthetic structures designed to mimic a xenobiotically modified lipoyl hapten on a 12-aa peptide that was found within the immunodominant autoepitope of PDC-E2 and demonstrated that AMA in PBC reacted against several organic modified mimotopes as well as, or sometimes significantly better than, the native lipoyl domain. Based on this data, we immunized rabbits with one such xenobiotic organic compound, 6-bromohexanoate, coupled to BSA. One hundred percent of immunized rabbits developed AMA that have each and every characteristic of human AMAs with reactivity against PDC-E2, E2 subunit of branched chain 2-oxo-acid dehydrogenase, and E2 subunit of 2-oxoglutarate dehydrogenase complex. The rabbit AMA also inhibited enzymatic function of PDC-E2 and, importantly, binds to peptide sequences not present in the xenobiotic carrier immunogen. In contrast, BSA-immunized controls did not produce such activity. Our observation that animals immunized with a xenobiotic BSA complex produce autoantibodies that react not only with the xenobiotic, but also with mitochondrial autoantigens recognized by autoimmune PBC sera, suggests that environmental xenobiotic agents can be a risk factor for the induction of PBC.
Comparative Effects of Human Igα and Igβ in Inducing Autoreactive Antibodies Against B Cells in Mice
Authors: Sheu Jim J. C. , Cheng Tammy , Chen Huan Y. , Lim Carmay , Chang Tse-Wen 
Published: April 2014

AbstractHuman and mouse Igα molecules share only 58% amino acid sequence identity in their extracellular regions. However, mice immunized with a recombinant Fc fusion protein containing the extracellular portion of human Igα produced significant amounts of IgG capable of binding to Igα on mouse B cells. The induced auto/cross-reactive Abs could down-regulate B cell levels and the consequent humoral immune responses against an irrelevant Ag in treated mice. Analogous immunization with an Fc fusion protein containing the extracellular portion of human Igβ gave a much weaker response to mouse Igβ, although human and mouse Igβ, like their Igα counterparts, share 56% sequence identity in their extracellular regions. Protein sequence analyses indicated that a potential immunogenic segment, located at the C-terminal loop of the extracellular domain, has an amino acid sequence that is identical between human and mouse Igα. A mAb A01, which could bind to both human and mouse Igα, was found to be specific to a peptide encompassing this immunogenic segment. These findings suggest that specific auto/cross-reactivity against self Igα can be induced by a molecular mimicry presented by a foreign Igα.
Entry into the Thymic Microenvironment Triggers Notch Activation in the Earliest Migrant T Cell Progenitors
Authors: Harman Benjamin C. , Jenkinson Eric J. , Anderson Graham 
Published: April 2014

Abstract
Interactions between T cell precursors and thymic stromal cells are essential during thymocyte development. However, the role of the thymus in initial commitment of lymphoid progenitors to the T lineage remains controversial, with data providing evidence for both extra- and intrathymic commitment mechanisms. In this context, it is clear that Notch1 is an important mediator during initiation of T cell development. Here we have analyzed the mechanisms regulating Notch activation in lymphoid precursors at extrathymic sites and in the thymus, including stages representing the first wave of embryonic thymus colonization on embryonic day 12 of gestation. We show that Notch activation in migrant lymphoid precursors requires entry into the thymic microenvironment where they are exposed to Notch ligands expressed by immature thymic epithelial cells. Moreover, continued Notch signaling in such precursors requires sustained interactions with Notch ligands. Collectively, these findings suggest a role for Notch in an intrathymic mechanism of T cell lineage commitment involving sustained interactions with Notch ligand bearing thymic epithelium.
Human Intestinal Epithelial Cells Are Broadly Unresponsive to Toll-Like Receptor 2-Dependent Bacterial Ligands: Implications for Host-Microbial Interactions in the Gut
Authors: Melmed Gil , Thomas Lisa S. , Lee Nahee , Tesfay Samuel Y. , Lukasek Katie , Michelsen Kathrin S. , Zhou Yuehua , Hu Bing , Arditi Moshe , Abreu Maria T. 
Published: April 2014

Abstract
Intestinal epithelial cells (IEC) interact with a high density of Gram-positive bacteria and are active participants in mucosal immune responses. Recognition of Gram-positive organisms by Toll-like receptor (TLR)2 induces proinflammatory gene expression by diverse cells. We hypothesized that IEC are unresponsive to Gram-positive pathogen-associated molecular patterns and sought to characterize the functional responses of IEC to TLR2-specific ligands. Human colonic epithelial cells isolated by laser capture microscopy and IEC lines (Caco-2, T84, HT-29) were analyzed for expression of TLR2, TLR6, TLR1, and Toll inhibitory protein (Tollip) mRNA by RT-PCR and quantitative real-time PCR. Response to Gram-positive bacterial ligands was measured by NF-κB reporter gene activation and IL-8 secretion. TLR2 protein expression was analyzed by immunofluorescence and flow cytometry. Colonic epithelial cells and lamina propria cells from both uninflamed and inflamed tissue demonstrate low expression of TLR2 mRNA compared with THP-1 monocytes. IECs were unresponsive to TLR2 ligands including the staphylococcal-derived Ags phenol soluble modulin, peptidoglycan, and lipotechoic acid and the mycobacterial-derived Ag soluble tuberculosis factor. Transgenic expression of TLR2 and TLR6 restored responsiveness to phenol soluble modulin and peptidoglycan in IEC. In addition to low levels of TLR2 protein expression, IEC also express high levels of the inhibitory molecule Tollip. We conclude that IEC are broadly unresponsive to TLR2 ligands secondary to deficient expression of TLR2 and TLR6. The relative absence of TLR2 protein expression by IEC and high level of Tollip expression may be important in preventing chronic proinflammatory cytokine secretion in response to commensal Gram-positive bacteria in the gut.
Differential Expression of the Murine Mannose-Binding Lectins A and C in Lymphoid and Nonlymphoid Organs and Tissues
Authors: Wagner Swen , Lynch Nicholas J. , Walter Wolfgang , Schwaeble Wilhelm J. , Loos Michael 
Published: April 2014

Abstract
Mannose-binding lectin (MBL), a member of the collectin family, binds to carbohydrate structures on the surfaces of micro-organisms and may serve as a recognition molecule of the lectin pathway of complement activation. In rodents two forms, MBL-A and MBL-C, were described and shown to be products of two related, but uncoupled, genes. The liver is the main source of MBL biosynthesis. For rat MBL-A, expression has also been described in the kidney. Here we report that the two forms of murine MBL are differentially expressed in a number of nonhepatic tissues. Real-time RT-PCR revealed that the liver is the major site of expression for both MBL genes. Lower copy numbers were found in kidney, brain, spleen, and muscle. In testis, only the MBL-A gene is expressed, whereas MBL-C is exclusively expressed in small intestine. Using in situ hybridization and immunohistochemistry, we demonstrate that both MBLs are synthesized by hepatocytes and show MBL expression in cells of the monocyte/macrophage lineage. In the kidney MBL-A, but not MBL-C, was found to be synthesized. Vice versa, only MBL-C biosynthesis was detected in endothelial cells of the small intestine. The latter finding may support the view that MBL-C, as part of the innate immune system, may be a counterpart of secretory IgA of the acquired immune system in preventing, for example, microbial invasion and colonization. Our findings demonstrate that MBL-A and MBL-C are differentially expressed, implying distinct biological roles for both recognition molecules of the murine lectin pathway of complement.
The Long Pentraxin Ptx3 Is Synthesized in IgA Glomerulonephritis and Activates Mesangial Cells
Authors: Bussolati Benedetta , Peri Giuseppe , Salvidio Gennaro , Verzola Daniela , Mantovani Alberto , Camussi Giovanni 
Published: April 2014

Abstract
The long pentraxin PTX3 has been recently involved in amplification of the inflammatory reactions and regulation of innate immunity. In the present study we evaluated the expression and role of PTX3 in glomerular inflammation. PTX3 expression was investigated in the IgA, type I membranoproliferative, and diffuse proliferative lupus glomerulonephritis, which are characterized by inflammatory and proliferative lesions mainly driven by resident mesangial cells, and in the membranous glomerulonephritis and the focal segmental glomerular sclerosis, where signs of glomerular inflammation are usually absent. We found an intense staining for PTX3 in the expanded mesangial areas of renal biopsies obtained from patients with IgA glomerulonephritis. The pattern of staining was on glomerular mesangial and endothelial cells. Scattered PTX3-positive cells were also detected in glomeruli of type I membranoproliferative glomerulonephritis. The concomitant expression of CD14 suggests an inflammatory origin of these cells. Normal renal tissue and biopsies from patients with the other glomerular nephropathies studied were mainly negative for PTX3 expression in glomeruli. However, PTX3-positive cells were detected in the interstitium of nephropathies showing inflammatory interstitial injury. In vitro, cultured human mesangial cells synthesized PTX3 when stimulated with TNF-α and IgA and exhibited specific binding for recombinant PTX3. Moreover, stimulation with exogenous PTX3 promoted mesangial cell contraction and synthesis of the proinflammatory lipid mediator platelet-activating factor. In conclusion, we provide the first evidence that mesangial cells may both produce and be a target for PTX3. The detection of this long pentraxin in the renal tissue of patients with glomerulonephritis suggests its potential role in the modulation of glomerular and tubular injury.
Lack of a Functional Alternative Complement Pathway Ameliorates Ischemic Acute Renal Failure in Mice
Authors: Thurman Joshua M. , Ljubanovic Danica , Edelstein Charles L. , Gilkeson Gary S. , Holers V. Michael 
Published: April 2014

Abstract
Ischemia/reperfusion (I/R) injury of the kidney is a common cause of acute renal failure (ARF) and is associated with high morbidity and mortality in the intensive care unit. The mechanisms underlying I/R injury are complex. Studies have shown that complement activation contributes to the pathogenesis of I/R injury in the kidney, but the exact mechanisms of complement activation have not been defined. We hypothesized that complement activation in this setting occurs via the alternative pathway and that mice deficient in complement factor B, an essential component of the alternative pathway, would be protected from ischemic ARF. Wild-type mice suffered from a decline in renal function and had significant tubular injury, particularly in the outer medulla, after I/R. We found that factor B-deficient mice (fB−/−) developed substantially less functional and morphologic renal injury after I/R. Furthermore, control wild-type mice had an increase in tubulointerstitial complement C3 deposition and neutrophil infiltration in the outer medulla after I/R, whereas fB−/− mice demonstrated virtually no C3 deposition or neutrophil infiltration. Our results demonstrate that complement activation in the kidney after I/R occurs exclusively via the alternative pathway, and that selective inhibition of this pathway provides protection to the kidneys from ischemic ARF.
Oral Feeding with Ethinyl Estradiol Suppresses and Treats Experimental Autoimmune Encephalomyelitis in SJL Mice and Inhibits the Recruitment of Inflammatory Cells into the Central Nervous System
Authors: Subramanian Sandhya , Matejuk Agata , Zamora Alex , Vandenbark Arthur A. , Offner Halina 
Published: April 2014

Abstract
There is much interest in the possible ameliorating effects of estrogen on various autoimmune diseases. We previously established the protective effects of 17β-estradiol (E2) on experimental autoimmune encephalomyelitis (EAE). In the current study we investigated the effectiveness of oral treatment with ethinyl estradiol (EE) on EAE and the mechanisms involved. Ethinyl estradiol is a semisynthetic estrogen compound found in birth control pills, and its chemical structure allows this compound to retain activity when given orally. We found that oral EE, like E2, drastically suppressed EAE induced by proteolipid protein 139–151 peptide when given at initiation of EAE. However, unlike E2, EE reduced clinical severity when given after the onset of clinical signs. Treatment with EE significantly decreased the secretion of proinflammatory cytokines (IFN-γ, TNF-α, and IL-6) by activated T cells as well as the expression of a key matrix metalloproteinase, disease-mediating chemokines/receptors, and IgG2a levels, but increased the expression of TGF-β3 in the CNS. The absence of infiltrating lymphocytes together with the suppression of cytokines, matrix metalloproteinase, and chemokines/receptors suggests that EE, like E2, protects mice from EAE by inhibiting the recruitment of T cells and macrophages into the CNS. These results suggest that oral ethinyl estradiol might be a successful candidate as therapy for multiple sclerosis.
Cutting Edge: A Toll-Like Receptor 2 Polymorphism That Is Associated with Lepromatous Leprosy Is Unable to Mediate Mycobacterial Signaling
Authors: Bochud Pierre-Yves , Hawn Thomas R. , Aderem Alan 
Published: April 2014

Abstract
Toll-like receptors (TLRs) are key mediators of the innate immune response to microbial pathogens. We investigated the role of TLRs in the recognition of Mycobacterium leprae and the significance of TLR2Arg677Trp, a recently discovered human polymorphism that is associated with lepromatous leprosy. In mice, TNF-α production in response to M. leprae was essentially absent in TLR2-deficient macrophages. Similarly, human TLR2 mediated M. leprae-dependent activation of NF-κB in transfected Chinese hamster ovary and human embryonic kidney 293 cells, with enhancement of this signaling in the presence of CD14. In contrast, activation of NF-κB by human TLR2Arg677Trp was abolished in response to M. leprae and Mycobacterium tuberculosis. The impaired function of this TLR2 variant provides a molecular mechanism for the poor cellular immune response associated with lepromatous leprosy and may have important implications for understanding the pathogenesis of other mycobacterial infections.
Cutting Edge: CD40-Induced Expression of Recombination Activating Gene (RAG) 1 and RAG2: A Mechanism for the Generation of Autoaggressive T Cells in the Periphery
Authors: Vaitaitis Gisela M. , Poulin Michelle , Sanderson Richard J. , Haskins Kathryn , Wagner David H. 
Published: April 2014

AbstractIt has been speculated that autoimmune diseases are caused by failure of central tolerance. However, this remains controversial. We have suggested that CD40 expression identifies autoaggressive T cells in the periphery of autoimmune prone mice. In this study, we report that CD40 was cloned from autoaggressive T cells and that engagement induces expression and nuclear translocation of the recombinases, recombination activating gene (RAG) 1 and RAG2 in the autoaggressive, but not in the nonautoaggressive, peripheral T cell population. Furthermore, we demonstrate that CD40 engagement induces altered TCR Vα, but not Vβ, expression in these cells. Therefore, CD40-regulated expression of RAG1 and RAG2 in peripheral T cells may constitute a novel pathway for the generation of autoaggressive T cells.
IL-9 Enhances the Growth of Human Mast Cell Progenitors Under Stimulation with Stem Cell Factor
Authors: Matsuzawa Shigeyuki , Sakashita Kazuo , Kinoshita Tatsuya , Ito Susumu , Yamashita Tetsuji , Koike Kenichi 
Published: April 2014

AbstractWe examined the effects of IL-9 on human mast cell development from CD34+ cord blood (CB) and peripheral blood cells in serum-deprived cultures. IL-9 apparently enhanced cell production under stimulation with stem cell factor (SCF) from CD34+ CB cells. A great majority of the cultured cells grown with SCF + IL-9 became positive for tryptase at 4 wk. In methylcellulose cultures of CD34+ CB cells, IL-9 increased both the number and size of mast cell colonies grown with SCF. Furthermore, SCF + IL-9 caused an exclusive expansion of mast cell colony-forming cells in a 2-wk liquid culture of CD34+ CB cells, at a level markedly greater than for SCF alone. Clonal cell cultures and RT-PCR analysis showed that the targets of SCF + IL-9 were the CD34+CD38+ CB cells rather than the CD34+CD38− CB cells. IL-9 neither augmented the SCF-dependent generation of progeny nor supported the survival of 6-wk-cultured mast cells. Moreover, there was no difference in the appearance of tryptase+ cells and histamine content in the cultured cells between SCF and SCF + IL-9. The addition of IL-9 increased numbers of mast cell colonies grown with SCF from CD34+ peripheral blood cells in children with or without asthma. It is of interest that mast cell progenitors of asthmatic patients responded to SCF + IL-9 to a greater extent than those of normal controls. Taken together, IL-9 appears to act as a potent enhancer for the SCF-dependent growth of mast cell progenitors in humans, particularly asthmatic patients.