bluuebunny/crossref_metadata_2025_split huggingface dataset:
Porphyromonas gingivalisSelectively Up-Regulates the HIV-1 Coreceptor CCR5 in Oral Keratinocytes
Authors: Giacaman Rodrigo A. , Nobbs Angela H. , Ross Karen F. , Herzberg Mark C. 
Published: April 2014

AbstractPrimary infection of oral epithelial cells by HIV-1, if it occurs, could promote systemic infection. Most primary systemic infections are associated with R5-type HIV-1 targeting the R5-specific coreceptor CCR5, which is not usually expressed on oral keratinocytes. Because coinfection with other microbes has been suggested to modulate cellular infection by HIV-1, we hypothesized that oral keratinocytes may up-regulate CCR5 in response to the oral endogenous pathogen Porphyromonas gingivalis by cysteine-protease (gingipains) activation of the protease-activated receptors (PARs) or LPS signaling through the TLRs. The OKF6/TERT-2-immortalized normal human oral keratinocyte line expressed CXCR4, whereas CCR5 was not detectable. When exposed to P. gingivalis ATCC 33277, TERT-2 cells induced greater time-dependent expression of CCR5-specific mRNA and surface coreceptors than CXCR4. By comparing arg- (Rgp) and lys-gingipain (Kgp) mutants, a mutant deficient in both proteases, and the action of trypsin, P. gingivalis Rgp was strongly suggested to cleave PAR-1 and PAR-2 to up-regulate CCR5. CCR5 was also slightly up-regulated by an isogenic gingipain-deficient mutant, suggesting the presence of a nongingipain-mediated mechanism. Purified P. gingivalis LPS also up-regulated CCR5. Blocking TLR2 and TLR4 receptors with Abs attenuated induction of CCR5, suggesting LPS signaling through TLRs. P. gingivalis, therefore, selectively up-regulated CCR5 by two independent signaling pathways, Rgp acting on PAR-1 and PAR-2, and LPS on TLR2 and TLR4. By inducing CCR5 expression, P. gingivalis coinfection could promote selective R5-type HIV-1 infection of oral keratinocytes.
Cellular and Humoral Autoreactivity in Idiopathic Pulmonary Fibrosis
Authors: Feghali-Bostwick Carol A. , Tsai Christopher G. , Valentine Vincent G. , Kantrow Stephen , Stoner Michael W. , Pilewski Joseph M. , Gadgil Aneal , George M. Patricia , Gibson Kevin F. , Choi Augustine M. K. , Kaminski Naftali , Zhang Yingze , Duncan Steven R. 
Published: April 2014

Abstract
Idiopathic pulmonary fibrosis (IPF) is a morbid, refractory lung disorder with an unknown pathogenesis. To investigate potential adaptive immune mechanisms in IPF, we compared phenotypes and effector functions of peripheral CD4 T cells, autoantibody production, and proliferative responses of pulmonary hilar lymph node CD4 T cells to autologous lung extracts from afflicted patients and normals. Our results show that greater proportions of peripheral CD4 T lymphocytes in IPF subjects expressed MHC class II and CD154 (CD40L), and they more frequently elaborated TGF-β1, IL-10, and TNF-α. Abnormal CD4 T cell clonal expansions were found in all IPF patients, and 82% of these subjects also had IgG autoantibodies against cellular Ags. IPF lung extracts stimulated proliferations of autologous CD4 T cells, unlike preparations from normals or those with other lung diseases, and the IPF proliferative responses were enhanced by repeated cycles of stimulation. Thus, CD4 T cells from IPF patients have characteristics typical of cell-mediated pathologic responses, including augmented effector functions, provision of facultative help for autoantibody production, oligoclonal expansions, and proliferations driven by an Ag present in diseased tissues. Recognition that an autoreactive immune process is present in IPF can productively focus efforts toward identifying the responsible Ag, and implementing more effective therapies.
Fully MHC-Disparate Mixed Hemopoietic Chimeras Show Specific Defects in the Control of Chronic Viral Infections
Authors: Koehn Brent H. , Williams Matthew A. , Borom Keshawna , Gangappa Shivaprakash , Pearson Thomas C. , Ahmed Rafi , Larsen Christian P. 
Published: April 2014

AbstractThe establishment of mixed allogeneic chimerism can induce donor-specific transplantation tolerance across full MHC barriers. However, a theoretical disadvantage of this approach is the possibility that the state of mixed chimerism might negatively affect the recipient’s immune competence to control pathogens. Previous studies using murine models have not supported this hypothesis, because they indicate that acute viral infections are cleared by chimeric animals with similar kinetics to that of unmanipulated controls. However, chronic or persistent viral infections often require a more complex and sustained response with cooperation between CD4 Th cells, CTL, and B cells for effective control. The current study indicates that profound defects become manifest in the control of chronic pathogenic infections in MHC-disparate mixed allogeneic chimeric mice. Furthermore, we show that ineffective priming of the donor-restricted CTL response leads to virus persistence, as well as severe T cell exhaustion. Our results further suggest that either T cell adoptive immunotherapy or selected MHC haplotype matching partially restore immune competence. These approaches may facilitate the translation of mixed chimerism therapeutic regimens.
Induction of Primary Biliary Cirrhosis in Guinea Pigs following Chemical Xenobiotic Immunization
Authors: Leung Patrick S. C. , Park Ogyi , Tsuneyama Koichi , Kurth Mark J. , Lam Kit S. , Ansari Aftab A. , Coppel Ross L. , Gershwin M. Eric 
Published: April 2014

Abstract
Although significant advances have been made in dissecting the effector mechanisms in autoimmunity, the major stumbling block remains defining the etiological events that precede disease. Primary biliary cirrhosis (PBC) illustrates this paradigm because of its high degree of heritability, its female predominance, and its extraordinarily specific and defined immune response and target destruction. In PBC, the major autoantigens belong to E2 components of the 2-oxo-acid dehydrogenase family of mitochondrially located enzymes that share a lipoylated peptide sequence that is the immunodominant target. Our previous work has demonstrated that synthetic mimics of the lipoate molecule such as 6-bromohexoanate demonstrate a high degree of reactivity with PBC sera prompted us to immunize groups of guinea pigs with 6-bromohexoanate conjugated to BSA. In this study, we provide serologic and immunohistochemical evidence that such immunized guinea pigs not only develop antimitochondrial autoantibody responses similar to human PBC, but also develop autoimmune cholangitis after 18 mo. Xenobiotic-immunized guinea pigs are the first induced model of PBC and suggest an etiology that has implications for the causation of other human autoimmune diseases. The data also reflect the likelihood that, in PBC, the multilineage antimitochondrial response is a pathogenic mechanism and that loss of tolerance and subsequent development of biliary lesions depends on either modification of the host mitochondrial Ag or a similar breakdown due to molecular mimicry.
Cutting Edge: Complement (C3d)-Linked Antigens Break B Cell Anergy
Authors: Lyubchenko Taras , Dal Porto Joseph M. , Holers V. Michael , Cambier John C. 
Published: April 2014

Abstract
C3dg adducts of Ag can coligate complement receptor type 2 (CR2; CD21) and the B cell Ag receptor. This interaction significantly amplifies BCR-mediated signals in Ag-naive wild-type mice, lowering the threshold for B cell activation and the generation of humoral immune responses as much as 1000-fold. In this study we demonstrate that CR2-mediated complementation of BCR signals can also overcome B cell anergy. Unlike Ag alone, BCR/CR2 costimulation (Ars-CCG/C3dg complexes) of anergic Ars/A1 B cells led to Ca2+ mobilization in vitro and the production of autoantibodies in vivo. Interestingly, the in vivo immune response of anergic cells occurs without the formation of germinal centers. These results suggest that the Ag unresponsiveness of anergic B cells can be overcome by cross-reactive (self-mimicking) Ags that have been complement-opsonized. This mechanism may place individuals exposed to complement-fixing bacteria at risk for autoimmunity.
CD154 Tone Sets the Signaling Pathways and Transcriptome Generated in Model CD40-Pluricompetent L3055 Burkitt’s Lymphoma Cells
Authors: Stewart Ross , Wei Wenbin , Challa Anita , Armitage Richard J. , Arrand John R. , Rowe Martin , Young Lawrence S. , Eliopoulos Aristides , Gordon John 
Published: April 2014

Abstract
Activated B cells reacting to small amounts of CD40L (CD154) maintain homeostasis by suppressing default apoptosis. Additional outcomes, particularly differentiation, demand higher CD40 occupancy. Here, focusing on survival, we compared changes in the transcriptome of pleiotropically competent, early passage L3055 Burkitt’s lymphoma cells confronted with low (picomolar) and high (nanomolar) concentrations of CD154 to gain insight into how a single receptor sets these distinct phenotypes. Of 267 genes altering transcriptional activity in response to strong CD154 tone, only 25 changed coordinately on low receptor occupancy. Seven of the top nine common up-regulated genes were targets of NF-κB. Direct measurement and functional inhibition of the NF-κB pathway revealed it to be central to a CD40-dependent survival signature. Although the canonical NF-κB axis was engaged by both signaling strengths equally, robust alternative pathway activation was a feature selective to a strong CD40 signal. Discriminatory exploitation of the two separate arms of NF-κB activation may indicate a principle whereby a cell senses and reacts differentially to shifting ligand availability. Identifying components selectively coupling CD40 to each axis could indicate targets for disruption in B cell pathologies underpinned by ectopic and/or hyper-CD154 activity such as neoplasia and some autoimmunities.
Proteinase-Activated Receptor-2 Promotes Allergic Sensitization to an Inhaled Antigen through a TNF-Mediated Pathway
Authors: Ebeling Cory , Lam Tong , Gordon John R. , Hollenberg Morley D. , Vliagoftis Harissios 
Published: April 2014

Abstract
The reason why particular inhaled Ags induce allergic sensitization while others lead to immune tolerance is unclear. Along with a genetic predisposition to atopy, intrinsic characteristics of these Ags must be important. A common characteristic of many allergens is that they either possess proteinase activity or are inhaled in particles rich in proteinases. Many allergens, such as house dust mite and cockroach allergens, have the potential to activate the proteinase-activated receptor (PAR)-2. In this study, we report that PAR-2 activation in the airways at the same time as exposure to inhaled Ags induces allergic sensitization, whereas exposure to Ag alone induces tolerance. BALB/c mice were administered OVA with a PAR-2 activating peptide intranasally. Upon allergen re-exposure mice developed airway inflammation and airway hyperresponsiveness, as well as OVA-specific T cells with a Th2 cytokine profile when restimulated with OVA in vitro. Conversely, mice given OVA alone or OVA with a PAR-2 control peptide developed tolerance. These tolerant mice did not develop airway inflammation or airway hyperresponsiveness, and developed OVA-specific T cells that secreted high levels of IL-10 when restimulated with OVA in vitro. Furthermore, pulmonary dendritic cell trafficking was altered in mice following intranasal PAR-2 activation. Finally, we showed that PAR-2-mediated allergic sensitization was TNF-dependent. Thus, PAR-2 activation in the airways could be a critical factor in the development of allergic sensitization following mucosal exposure to allergens with serine proteinase activity. Interfering with this pathway may prove to be useful for the prevention or treatment of allergic diseases.
Identification of an IL-7-Dependent Pre-T Committed Population in the Spleen
Authors: Gautreau Laetitia , Arcangeli Marie-Laure , Pasqualetto Valérie , Joret Anne-Marie , Garcia-Cordier Corinne , Mégret Jérôme , Schneider Elke , Ezine Sophie 
Published: April 2014

Abstract
Several extrathymic T cell progenitors have been described but their various contributions to the T cell lineage puzzle are unclear. In this study, we provide evidence for a splenic Lin−Thy1.2+ T cell-committed population, rare in B6 mice, abundant in TCRα−/−, CD3ε−/−, and nude mice, and absent in IL-7- and Rag-2-deficient mice. Neither B nor myeloid cells are generated in vivo and in vitro. The incidence of these pre-T cells is under the control of thymus and/or mature T cells, as revealed by graft experiments. Indeed, IL-7 consumption by mature T cells inhibits the growth of these pre-T cells. Moreover, the nude spleen contains an additional Lin−Thy1.2+CD25+ subset which is detected in B6 mice only after thymectomy. We establish that the full pre-T cell potential and proliferation capacity are only present in the c-kitlow fraction of progenitors. We also show that most CCR9+ progenitors are retained in the spleen of nude mice, but present in the blood of B6 mice. Thus, our data describe a new T cell lineage restricted subset that accumulates in the spleen before migration to the thymus.
Severe Depletion of Mucosal CD4+ T Cells in AIDS-Free Simian Immunodeficiency Virus-Infected Sooty Mangabeys
Authors: Gordon Shari N. , Klatt Nichole R. , Bosinger Steven E. , Brenchley Jason M. , Milush Jeffrey M. , Engram Jessica C. , Dunham Richard M. , Paiardini Mirko , Klucking Sara , Danesh Ali , Strobert Elizabeth A. , Apetrei Cristian , Pandrea Ivona V. , Kelvin David , Douek Daniel C. , Staprans Silvija I. , Sodora Donald L. , Silvestri Guido 
Published: April 2014

Abstract
HIV-infected humans and SIV-infected rhesus macaques experience a rapid and dramatic loss of mucosal CD4+ T cells that is considered to be a key determinant of AIDS pathogenesis. In this study, we show that nonpathogenic SIV infection of sooty mangabeys (SMs), a natural host species for SIV, is also associated with an early, severe, and persistent depletion of memory CD4+ T cells from the intestinal and respiratory mucosa. Importantly, the kinetics of the loss of mucosal CD4+ T cells in SMs is similar to that of SIVmac239-infected rhesus macaques. Although the nonpathogenic SIV infection of SMs induces the same pattern of mucosal target cell depletion observed during pathogenic HIV/SIV infections, the depletion in SMs occurs in the context of limited local and systemic immune activation and can be reverted if virus replication is suppressed by antiretroviral treatment. These results indicate that a profound depletion of mucosal CD4+ T cells is not sufficient per se to induce loss of mucosal immunity and disease progression during a primate lentiviral infection. We propose that, in the disease-resistant SIV-infected SMs, evolutionary adaptation to both preserve immune function with fewer mucosal CD4+ T cells and attenuate the immune activation that follows acute viral infection protect these animals from progressing to AIDS.
Polymorphisms in Genes Involved in Innate Immunity Predispose Toward Mycetoma Susceptibility
Authors: van de Sande Wendy W. J. , Fahal Ahmed , Verbrugh Henri , van Belkum Alex 
Published: April 2014

Abstract
Madurella mycetomatis is the main causative agent of mycetoma, a tumorous fungal infection characterized by the infiltration of large numbers of neutrophils at the site of infection. In endemic areas the majority of inhabitants have Abs to M. mycetomatis, although only a small proportion of individuals actually develop mycetomal disease. It therefore appears that neutrophils are unable to clear the infection in some individuals. To test this hypothesis, 11 single nucleotide polymorphisms involved in neutrophil function were studied in a population of Sudanese mycetoma patients vs geographically and ethnically matched controls. Significant differences in allele distribution for IL-8 (CXCL8), its receptor CXCR2, thrombospondin-4 (TSP-4), NO synthase 2 (NOS2), and complement receptor 1 (CR1) were found. Further, the NOS2Lambaréné polymorphism was clearly associated with lesion size. The genotypes obtained for CXCL8, its receptor CXCR2, and TSP-4 all predisposed to a higher CXCL8 expression in patients, which was supported by the detection of significantly elevated levels of CXCL8 in patient serum. The NOS2 genotype observed in healthy controls was correlated with an increase in NOS2 expression and higher concentrations of nitrate and nitrite in control serum. We present the first evidence of human genetic predisposition toward susceptibility to mycetoma, a neglected infection of the poor.
A Role for Dietary Selenium and Selenoproteins in Allergic Airway Inflammation
Authors: Hoffmann Peter R. , Jourdan-Le Saux Claude , Hoffmann Fukun W. , Chang Peter S. , Bollt Oana , He Qingping , Tam Elizabeth K. , Berry Marla J. 
Published: April 2014

Abstract
Asthma is driven by allergic airway inflammation and involves increased levels of oxidative stress. This has led to speculation that antioxidants like selenium (Se) may play important roles in preventing or treating asthma. We fed diets containing low (0.08 parts per million), medium (0.25 parts per million), or high (2.7 parts per million) Se to female C57BL/6 mice and used an established OVA challenge protocol to determine the relationship between Se intake and the development of allergic airway inflammation. Results demonstrated that mice fed medium levels of Se had robust responses to OVA challenge in the lung as measured by lung cytokine levels, airway cellular infiltrate, eosinophilia, serum anti-OVA IgE, airway hyperreactivity, goblet cell hyperplasia, and phosphorylated STAT-6 levels in the lung. In contrast, responses to OVA challenge were less robust in mice fed low or high levels of Se. In particular, mice fed low Se chow showed significantly lower responses compared with mice fed medium Se chow for nearly all readouts. We also found that within the medium Se group the expression of lung glutathione peroxidase-1 and liver selenoprotein P were increased in OVA-challenged mice compared with PBS controls. These data suggest that Se intake and allergic airway inflammation are not related in a simple dose-response manner, which may explain the inconsistent results obtained from previous descriptive studies in humans. Also, our results suggest that certain selenoproteins may be induced in response to Ag challenges within the lung.
Effects of Gamma Radiation on FcεRI and TLR-Mediated Mast Cell Activation
Authors: Soule Benjamin P. , Brown Jared M. , Kushnir-Sukhov Nataliya M. , Simone Nicole L. , Mitchell James B. , Metcalfe Dean D. 
Published: April 2014

Abstract
Ionizing gamma radiation has several therapeutic indications including bone marrow transplantation and tumor ablation. Among immune cells, susceptibility of lymphocytes to gamma radiation is well known. However, there is little information on the effects of gamma radiation on mast cells, which are important in both innate and acquired immunity. Previous studies have suggested that mast cells may release histamine in response to high doses of gamma radiation, whereas other reports suggest that mast cells are relatively radioresistant. No strong link has been established between gamma radiation and its effect on mast cell survival and activation. We examined both human and murine mast cell survival and activation, including mechanisms related to innate and acquired immune responses following gamma radiation. Data revealed that human and murine mast cells were resistant to gamma radiation-induced cytotoxicity and, importantly, that irradiation did not directly induce β-hexosaminidase release. Instead, a transient attenuation of IgE-mediated β-hexosaminidase release and cytokine production was observed which appeared to be the result of reactive oxygen species formation after irradiation. Mast cells retained the ability to phagocytose Escherichia coli particles and respond to TLR ligands as measured by cytokine production after irradiation. In vivo, there was no decrease in mast cell numbers in skin of irradiated mice. Additionally, mast cells retained the ability to respond to Ag in vivo as measured by passive cutaneous anaphylaxis in mice after irradiation. Mast cells are thus resistant to the cytotoxic effects and alterations in function after irradiation and, despite a transient inhibition, ultimately respond to innate and acquired immune activation signals.
Urokinase-Type Plasminogen Activator Stimulation of Monocyte Matrix Metalloproteinase-1 Production Is Mediated by Plasmin-Dependent Signaling through Annexin A2 and Inhibited by Inactive Plasmin
Authors: Zhang Yahong , Zhou Zhao-Hua , Bugge Thomas H. , Wahl Larry M. 
Published: April 2014

Abstract
Chronic inflammatory diseases are associated with connective tissue turnover that involves a series of proteases, which include the plasminogen activation system and the family of matrix metalloproteinases (MMPs). Urokinase-type plasminogen activator (uPA) and plasmin, in addition to their role in fibrinolysis and activation of pro-MMPs, have been shown to transduce intracellular signals through specific receptors. The potential for uPA and plasmin to also contribute to connective tissue turnover by directly regulating MMP production was examined in human monocytes. Both catalytically active high m.w. uPA, which binds to the uPAR, and low m.w. uPA, which does not, significantly enhanced MMP-1 synthesis by activated human monocytes. In contrast, the N-terminal fragment of uPA, which binds to uPAR, but lacks the catalytic site, failed to induce MMP-1 production, indicating that uPA-stimulated MMP-1 synthesis was plasmin dependent. Endogenous plasmin generated by the action of uPA or exogenous plasmin increased MMP-1 synthesis by signaling through annexin A2, as demonstrated by inhibition of MMP-1 production with Abs against annexin A2 and S100A10, a dimeric protein associated with annexin A2. Interaction of plasmin with annexin A2 resulted in the stimulation of ERK1/2 and p38 MAPK, cyclooxygenase-2, and PGE2, leading to increased MMP-1 production. Furthermore, binding of inactive plasmin to annexin A2 inhibited plasmin induction of MMP-1, suggesting that inactive plasmin may be useful in suppressing inflammation.
“Cytokine Storm” in the Phase I Trial of Monoclonal Antibody TGN1412: Better Understanding the Causes to Improve PreClinical Testing of Immunotherapeutics
Authors: Stebbings Richard , Findlay Lucy , Edwards Cherry , Eastwood David , Bird Chris , North David , Mistry Yogesh , Dilger Paula , Liefooghe Emily , Cludts Isabelle , Fox Bernard , Tarrant Gill , Robinson Jane , Meager Tony , Dolman Carl , Thorpe Susan J. , Bristow Adrian , Wadhwa Meenu , Thorpe Robin , Poole Stephen 
Published: April 2014

Abstract
The CD28-specific mAb TGN1412 rapidly caused a life-threatening “cytokine storm” in all six healthy volunteers in the Phase I clinical trial of this superagonist, signaling a failure of preclinical safety testing. We report novel in vitro procedures in which TGN1412, immobilized in various ways, is presented to human white blood cells in a manner that stimulates the striking release of cytokines and profound lymphocyte proliferation that occurred in vivo in humans. The novel procedures would have predicted the toxicity of this superagonist and are now being applied to emerging immunotherapeutics and to other therapeutics that have the potential to act upon the immune system. Data from these novel procedures, along with data from in vitro and in vivo studies in nonhuman primates, suggest that the dose of TGN1412 given to human volunteers was close to the maximum immunostimulatory dose and that TGN1412 is not a superagonist in nonhuman primates.