bluuebunny/crossref_metadata_2025_split huggingface dataset:
Requirement for CD4 T Cell Help in Maintenance of Memory CD8 T Cell Responses Is Epitope Dependent
Authors: Ramsburg Elizabeth A. , Publicover Jean M. , Coppock Dagan , Rose John K. 
Published: April 2014

Abstract
CD4 Th cells play critical roles in stimulating Ab production and in generating primary or maintaining memory CTL. The requirement for CD4 help in generating and maintaining CTL responses has been reported to vary depending on the vector or method used for immunization. In this study, we examined the requirement for CD4 T cell help in generating and maintaining CTL responses to an experimental AIDS vaccine vector based on live recombinant vesicular stomatitis virus (VSV) expressing HIV Env protein. We found that primary CD8 T cell responses and short-term memory to HIV Env and VSV nucleocapsid (VSV N) proteins were largely intact in CD4 T cell-deficient mice. These responses were efficiently recalled at 30 days postinfection by boosting with vaccinia recombinants expressing HIV Env or VSV N. However, by 60 days postinfection, the memory/recall response to VSV N was lost in CD4-deficient mice, while the recall response HIV Env was partially maintained in the same animals for at least 90 days. This result indicates that there are epitope-specific requirements for CD4 help in the maintenance of memory CD8 T cell responses. Our results also suggest that choice of epitopes might be critical in an AIDS vaccine designed to protect against disease in the context of reduced or declining CD4 T cell help.
Cytoskeletal Protein Transformation in HIV-1-Infected Macrophage Giant Cells
Authors: Kadiu Irena , Ricardo-Dukelow Mary , Ciborowski Pawel , Gendelman Howard E. 
Published: April 2014

Abstract
The mechanisms linking HIV-1 replication, macrophage biology, and multinucleated giant cell formation are incompletely understood. With the advent of functional proteomics, the characterization, regulation, and transformation of HIV-1-infected macrophage-secreted proteins can be ascertained. To these ends, we performed proteomic analyses of culture fluids derived from HIV-1 infected monocyte-derived macrophages. Robust reorganization, phosphorylation, and exosomal secretion of the cytoskeletal proteins profilin 1 and actin were observed in conjunction with productive viral replication and giant cell formation. Actin and profilin 1 recruitment to the macrophage plasma membrane paralleled virus-induced cytopathicity, podosome formation, and cellular fusion. Poly-l-proline, an inhibitor of profilin 1-mediated actin polymerization, inhibited cytoskeletal transformations and suppressed, in part, progeny virion production. These data support the idea that actin and profilin 1 rearrangement along with exosomal secretion affect viral replication and cytopathicity. Such events favor the virus over the host cell and provide insights into macrophage defense mechanisms used to contain viral growth and how they may be affected during progressive HIV-1 infection.
Recombinant Human IFN-α Inhibits Cerebral Malaria and Reduces Parasite Burden in Mice
Authors: Vigário Ana Margarida , Belnoue Elodie , Grüner Anne Charlotte , Mauduit Marjorie , Kayibanda Michèle , Deschemin Jean-Christophe , Marussig Myriam , Snounou Georges , Mazier Dominique , Gresser Ion , Rénia Laurent 
Published: April 2014

Abstract
Most C57BL/6 mice infected i.p. with Plasmodium berghei ANKA (PbA) die between 7 and 14 days with neurologic signs, and the remainder die later (&gt;15 days) with severe anemia. Daily i.p. injections of a recombinant human IFN-α (active on mouse cells) prevented death by cerebral malaria (87% deaths in the control mice vs 6% in IFN-α-treated mice). The mechanisms of this IFN-α protective effect were multiple. IFN-α-treated, PbA-infected mice showed 1) a marked decrease in the number of PbA parasites in the blood mediated by IFN-γ, 2) less sequestered parasites in cerebral vessels, 3) reduced up-regulation of ICAM-1 expression in brain endothelial cells, 4) milder rise of blood levels of TNF, 5) increased levels of IFN-γ in the blood resulting from an increased production by splenic CD8+ T cells, and 6) fewer leukocytes (especially CD8+ T cells) sequestered in cerebral vessels. On the other hand, IFN-α treatment did not affect the marked anemia observed in PbA-infected mice. Survival time in IFN-α-treated mice was further increased by performing three blood transfusions over consecutive days.
The Yersinia Effector Protein YpkA Induces Apoptosis Independently of Actin Depolymerization
Authors: Park Heiyoung , Teja Kabir , O’Shea John J. , Siegel Richard M. 
Published: April 2014

Abstract
The pathogenicity of the plague agent Yersinia pestis is largely due to the injection of effector proteins that potently block immune responses into host cells through a type III secretion apparatus. One Yersinia effector protein, YpkA, a putative serine/threonine kinase, has been reported to act by depolymerizing actin and disrupting actin microfilament organization. Using YpkA-GFP fusion proteins to directly visualize cells expressing YpkA, we found instead that YpkA triggered rapid cell death that can be blocked by caspase inhibitors and Bcl-xL, but was not dependent on caspase-8. The actin depolymerization promoted by YpkA was only seen in cells with other features of apoptosis, and was blocked by inhibiting apoptosis, indicating that actin filament disruption is likely to be a result, rather than a cause of YpkA-induced apoptosis. A region including aa 133–262 in YpkA was sufficient for inducing apoptosis independent of localization to the plasma membrane. These data suggest that YpkA can act as a direct inducer of cell death.
Perforin-Dependent Cryptococcal Microbicidal Activity in NK Cells Requires PI3K-Dependent ERK1/2 Signaling
Authors: Wiseman Jeremy C. D. , Ma Ling Ling , Marr Kaleb J. , Jones Gareth J. , Mody Christopher H. 
Published: April 2014

Abstract
Previously, NK cells have been reported to kill the opportunistic fungal pathogen Cryptococcus neoformans through a perforin-dependent mechanism; however, the receptor and signaling involved are unknown. In this report we sought to identify the signaling pathways activated and required for direct perforin-mediated killing of microbes. In this study, using the NK-like cell line YT and primary peripheral blood NK cells, it is demonstrated that YT cells kill C. neoformans and that the killing is accompanied by the activation of PI3K. We demonstrate that inhibition of either the catalytic subunit (using a pharmacological inhibitor) or the α-regulatory subunit (using small interfering RNA knockdown) of PI3K significantly inhibited the killing of C. neoformans. Downstream of PI3K, ERK1/2 was activated in a PI3K-dependent fashion and was required for cryptococcal killing. Furthermore, we demonstrate that perforin release from YT cells can be detected by 4 h after contact of the YT cells with C. neoformans and that the release of perforin is blocked by pharmacological inhibition of either PI3K or ERK1/2. Defective degranulation is rooted in the inability to polarize perforin-containing granules toward the target. Finally, we demonstrate that PI3K-ERK1/2-dependent signaling is activated and required for the killing of C. neoformans by primary NK cells. Taken together, these data identify a conserved PI3K-ERK1/2 pathway that is used by NK cells during the direct killing of C. neoformans and demonstrate that the pathway is essential in the formation and activation of the microbicidal mechanism.
The Relationship between Apoptosis and High-Mobility Group Protein 1 Release from Murine Macrophages Stimulated with Lipopolysaccharide or Polyinosinic-Polycytidylic Acid
Authors: Jiang Weiwen , Bell Charles W. , Pisetsky David S. 
Published: April 2014

Abstract
High-mobility group protein 1 (HMGB1) is a nonhistone nuclear protein whose function depends on cellular location. Inside the cell, HMGB1 modulates a variety of important cellular processes, including transcription, whereas outside the cell, HMGB1 acts as a cytokine that can promote inflammation and mediate sepsis and arthritis in animal models. In in vitro studies, proinflammatory molecules such as LPS, lipoteichoic acid, polyinosinic-polycytidylic acid (poly(I:C)), TNF-α, and type I and II IFNs can induce HMGB1 release from macrophages. Although these agents can activate cells, they can also induce apoptosis under certain circumstances. Therefore, because of evidence that apoptotic as well as necrotic cells can contribute to HMGB1-mediated events in sepsis, we have investigated the relationship between apoptosis and HMGB1 release in macrophages and other cells. In these experiments, using RAW 264.7 cells as a model, LPS and poly(I:C) caused HMGB1 release into the medium whereas CpG ODN failed to induce this response. With both LPS and poly(I:C), the extent of HMGB1 release correlated with the occurrence of apoptosis as measured by caspase 3 activation, lactate dehydrogenase release, and TUNEL staining. Similar results were obtained with primary murine macrophages as well as human Jurkat T cells. For Jurkat cells, poly(I:C) and NO donors induced apoptosis as well as HMGB1 release. Together, these results indicate that HMGB1 release from macrophages is correlated with the occurrence of apoptosis and suggest that these processes reflect common mechanisms and can occur concomitantly.
Airway Epithelium Controls Lung Inflammation and Injury through the NF-κB Pathway
Authors: Cheng Dong-sheng , Han Wei , Chen Sabrina M. , Sherrill Taylor P. , Chont Melissa , Park Gye-Young , Sheller James R. , Polosukhin Vasiliy V. , Christman John W. , Yull Fiona E. , Blackwell Timothy S. 
Published: April 2014

Abstract
Although airway epithelial cells provide important barrier and host defense functions, a crucial role for these cells in development of acute lung inflammation and injury has not been elucidated. We investigated whether NF-κB pathway signaling in airway epithelium could decisively impact inflammatory phenotypes in the lungs by using a tetracycline-inducible system to achieve selective NF-κB activation or inhibition in vivo. In transgenic mice that express a constitutively active form of IκB kinase 2 under control of the epithelial-specific CC10 promoter, treatment with doxycycline induced NF-κB activation with consequent production of a variety of proinflammatory cytokines, high-protein pulmonary edema, and neutrophilic lung inflammation. Continued treatment with doxycycline caused progressive lung injury and hypoxemia with a high mortality rate. In contrast, inducible expression of a dominant inhibitor of NF-κB in airway epithelium prevented lung inflammation and injury resulting from expression of constitutively active form of IκB kinase 2 or Escherichia coli LPS delivered directly to the airways or systemically via an osmotic pump implanted in the peritoneal cavity. Our findings indicate that the NF-κB pathway in airway epithelial cells is critical for generation of lung inflammation and injury in response to local and systemic stimuli; therefore, targeting inflammatory pathways in airway epithelium could prove to be an effective therapeutic strategy for inflammatory lung diseases.
Gnotobiotic IL-10−/−;NF-κBEGFP Mice Reveal the Critical Role of TLR/NF-κB Signaling in Commensal Bacteria-Induced Colitis
Authors: Karrasch Thomas , Kim Joo-Sung , Muhlbauer Marcus , Magness Scott T. , Jobin Christian 
Published: April 2014

Abstract
Commensal bacteria and TLR signaling have been associated with the maintenance of intestinal homeostasis in dextran sodium sulfate-induced intestinal injury. The aim of this study was to determine the in vivo role of TLR/NF-κB activation in a model of commensal bacteria-induced T cell-mediated colitis. A NF-κB reporter gene mouse (NF-κBEGFP) (EGFP, enhanced GFP) was crossed to the colitogenic susceptible strain IL-10−/− and derived into germfree conditions using embryo-transfer technology. Germfree IL-10wt/wt;NF-κBEGFP and IL-10−/−;NF-κBEGFP mice (wt, wild type) were dual associated with the nonpathogenic commensal bacteria strains Enterococcus faecalis and Escherichia coli. EGFP was detected using macroimaging, confocal microscopy, and flow cytometry. IL-10−/−;MyD88−/− mice were used to assess E. faecalis/E. coli-induced TLR-dependent signaling and IL-23 gene expression. Dual-associated IL-10−/−;NF-κBEGFP mice developed severe inflammation by 7 wk. Macroscopic analysis showed elevated EGFP expression throughout the colon of bacteria-associated IL-10−/−;NF-κBEGFP mice. Confocal microscopy analysis revealed EGFP-positive enterocytes during the early phase of bacterial colonization (1 wk) in both IL-10wt/wt and IL-10−/− mice, while the signal shifted toward lamina propria T cells, dendritic cells, neutrophils, and macrophages in IL-10−/− mice during colitis (7 wk). The NF-κB inhibitor BAY 11-7085 attenuated E. faecalis/E. coli-induced EGFP expression and development of colitis. Additionally, E. faecalis/E. coli-induced NF-κB signaling and IL-23 gene expression were blocked in bone marrow-derived dendritic cells derived from IL-10−/−;MyD88−/− mice. We conclude that bacteria-induced experimental colitis involves the activation of TLR-induced NF-κB signaling derived mostly from mucosal immune cells. Blocking TLR-induced NF-κB activity may represent an attractive strategy to treat immune-mediated intestinal inflammation.
Peripherin Is a Relevant Neuroendocrine Autoantigen Recognized by Islet-Infiltrating B Lymphocytes
Authors: Puertas Maria Carmen , Carrillo Jorge , Pastor Xavier , Ampudia Rosa Maria , Planas Raquel , Alba Aurora , Bruno Roxana , Pujol-Borrell Ricardo , Estanyol Josep Maria , Vives-Pi Marta , Verdaguer Joan 
Published: April 2014

Abstract
Most of our knowledge of the antigenic repertoire of autoreactive B lymphocytes in type 1 diabetes (T1D) comes from studies on the antigenic specificity of both circulating islet-reactive autoantibodies and peripheral B lymphocyte hybridomas generated from human blood or rodent spleen. In a recent study, we generated hybridoma cell lines of infiltrating B lymphocytes from different mouse strains developing insulitis, but with different degrees of susceptibility to T1D, to characterize the antigenic specificity of islet-infiltrating B lymphocytes during progression of the disease. We found that many hybridomas produced mAbs restricted to the peripheral nervous system (PNS), thus indicating an active B lymphocyte response against PNS elements in the pancreatic islet during disease development. The aim of this study was to identify the autoantigen recognized by these anti-PNS mAbs. Our results showed that peripherin is the autoantigen recognized by all anti-PNS mAbs, and, therefore, a relevant neuroendocrine autoantigen targeted by islet-infiltrating B lymphocytes. Moreover, we discovered that the immune dominant epitope of this B lymphocyte immune response is found at the C-terminal end of Per58 and Per61 isoforms. In conclusion, our study strongly suggests that peripherin is a major autoantigen targeted during T1D development and poses a new question on why peripherin-specific B lymphocytes are mainly attracted to the islet during disease.
Lysophospholipids of Different Classes Mobilize Neutrophil Secretory Vesicles and Induce Redundant Signaling through G2A
Authors: Frasch S. Courtney , Zemski-Berry Karin , Murphy Robert C. , Borregaard Niels , Henson Peter M. , Bratton Donna L. 
Published: April 2014

AbstractLysophosphatidylcholine has been shown to enhance neutrophil functions through a mechanism involving the G protein-coupled receptor G2A. Recent data support an indirect effect of lysophosphatidylcholine on G2A rather than direct ligand binding. These observations prompted the hypothesis that other lysophospholipids (lyso-PLs) may also signal for human neutrophil activation through G2A. To this end, 1-oleoyl-2-hydroxy-sn-glycero-3-[phospho-l-choline], but also C18:1/OH lyso-PLs bearing the phosphoserine and phosphoethanolamine head groups, presented on albumin, were shown to signal for calcium flux in a self- and cross-desensitizing manner, implicating a single receptor. Blocking Abs to G2A inhibited calcium signaling by all three lyso-PLs. Furthermore, inhibition by both pertussis toxin and U-73122 established signaling via the Gαi/phospholipase C pathway for calcium mobilization. Altered plasma membrane localization of G2A has been hypothesized to facilitate signaling. Accordingly, an increase in detectable G2A was demonstrated by 1 min after lyso-PL stimulation and was followed by visible patching of the receptor. Western blotting showed that G2A resides in the plasma membrane/secretory vesicle fraction and not in neutrophil primary, secondary, or tertiary granules. Enhanced detection of G2A induced by lyso-PLs was paralleled by enhanced detection of CD45, confirming mobilization of the labile secretory vesicle pool. Together, these data show that lyso-PLs bearing various head groups redundantly mobilize G2A latent within secretory vesicles and result in G2A receptor/Gαi/phospholipase C signaling for calcium flux in neutrophils.
Gpnmb Is Induced in Macrophages by IFN-γ and Lipopolysaccharide and Acts as a Feedback Regulator of Proinflammatory Responses
Authors: Ripoll Vera M. , Irvine Katharine M. , Ravasi Timothy , Sweet Matthew J. , Hume David A. 
Published: April 2014

Abstract
The process of inflammation requires the selective expression of a suite of genes in cells of the macrophage lineage. To identify candidate regulators of inflammation, we used cDNA microarrays to compare the transcriptome of inflammatory macrophages (thioglycolate-elicited peritoneal macrophages), bone marrow-derived macrophages, nonadherent spleen cells, and fibroblasts. We identified genes that were macrophage restricted and further elevated in inflammatory macrophages, and characterized the function of one such gene, gpnmb. Gpnmb mRNA expression was enriched in myelomonocytic cell lines and macrophage-related tissues and strongly up-regulated during macrophage differentiation. Epitope-tagged GPNMB expressed in RAW264.7 cells exhibited a perinuclear distribution and colocalized with the Golgi marker coat protein β. Upon activation of macrophages with IFN-γ and LPS, GPNMB translocated from the Golgi apparatus to vesicular compartments scattered toward the periphery. Gpnmb overexpression in RAW264.7 cells caused a 2-fold reduction in the production of the cytokines IL-6 and IL-12p40 and the inflammatory mediator NO in response to LPS. DBA mice, which have an inactivating point mutation in the gpnmb gene, exhibited reduced numbers of myeloid cells, elevated numbers of thioglycolate-elicited peritoneal macrophages, and higher levels of proinflammatory cytokines in response to LPS. Thus, GPNMB acts as a negative regulator of macrophage inflammatory responses.
Osteopontin Aggravates Experimental Autoimmune Uveoretinitis in Mice
Authors: Kitamura Mizuki , Iwabuchi Kazuya , Kitaichi Nobuyoshi , Kon Shigeyuki , Kitamei Hirokuni , Namba Kenichi , Yoshida Kazuhiko , Denhardt David T. , Rittling Susan R. , Ohno Shigeaki , Uede Toshimitsu , Onoé Kazunori 
Published: April 2014

Abstract
Human endogenous uveitis is a common sight-threatening intraocular inflammatory disease and has been studied extensively using a murine model of experimental autoimmune uveoretinitis (EAU). It is possibly mediated by Th1 immune responses. In the present study, we investigated the role of osteopontin (OPN), a protein with pleiotropic functions that contributes to the development of Th1 cell-mediated immunity. Accompanying EAU progression, OPN was elevated in wild-type (WT) mice that had been immunized with human interphotoreceptor retinoid-binding protein (hIRBP) peptide 1–20. OPN-deficient (OPN−/−) mice showed milder EAU progression in clinical and histopathological scores compared with those of WT mice. The T cells from hIRBP-immunized OPN−/− mice exhibited reduced Ag-specific proliferation and proinflammatory cytokine (TNF-α and IFN-γ) production compared with those of WT T cells. When hIRBP-immunized WT mice were administered M5 Ab reacting to SLAYGLR sequence, a cryptic binding site to integrins within OPN, EAU development was significantly ameliorated. T cells from hIRBP-immunized WT mice showed significantly reduced proliferative responses and proinflammatory cytokine production upon stimulation with hIRBP peptide in the presence of M5 Ab in the culture. Our present results demonstrate that OPN may represent a novel therapeutic target to control uveoretinitis.
Hemorrhagic Shock Induces NAD(P)H Oxidase Activation in Neutrophils: Role of HMGB1-TLR4 Signaling
Authors: Fan Jie , Li Yuehua , Levy Ryan M. , Fan Janet J. , Hackam David J. , Vodovotz Yoram , Yang Huan , Tracey Kevin J. , Billiar Timothy R. , Wilson Mark A. 
Published: April 2014

Abstract
Hemorrhagic shock/resuscitation (HS/R)-induced generation of reactive oxygen species (ROS) plays an important role in posthemorrhage inflammation and tissue injury. We have recently reported that HS/R-activated neutrophils (PMN), through release of ROS, serve an important signaling function in mediating alveolar macrophage priming and lung inflammation. PMN NAD(P)H oxidase has been thought to be an important source of ROS following HS/R. TLR4 sits at the interface of microbial and sterile inflammation by mediating responses to both bacterial endotoxin and multiple endogenous ligands, including high-mobility group box 1 (HMGB1). Recent studies have implicated HMGB1 as an early mediator of inflammation after HS/R and organ ischemia/reperfusion. In the present study, we tested the hypothesis that HS/R activates NAD(P)H oxidase in PMN through HMGB1/TLR4 signaling. We demonstrated that HS/R induced PMN NAD(P)H oxidase activation, in the form of phosphorylation of p47phox subunit of NAD(P)H oxidase, in wild-type mice; this induction was significantly diminished in TLR4-mutant C3H/HeJ mice. HMGB1 levels in lungs, liver, and serum were increased as early as 2 h after HS/R. Neutralizing Ab to HMGB1 prevented HS/R-induced phosphorylation of p47phox in PMN. In addition, in vitro stimulation of PMN with recombinant HMGB1 caused TLR4-dependent activation of NAD(P)H oxidase as well as increased ROS production through both MyD88-IRAK4-p38 MAPK and MyD88-IRAK4-Akt signaling pathways. Thus, PMN NAD(P)H oxidase activation, induced by HS/R and as mediated by HMGB1/TLR4 signaling, is an important mechanism responsible for PMN-mediated inflammation and organ injury after hemorrhage.
Immune Cross-Reactivity in Celiac Disease: Anti-Gliadin Antibodies Bind to Neuronal Synapsin I
Authors: Alaedini Armin , Okamoto Haruka , Briani Chiara , Wollenberg Kurt , Shill Holly A. , Bushara Khalafalla O. , Sander Howard W. , Green Peter H. R. , Hallett Mark , Latov Norman 
Published: April 2014

Abstract
Celiac disease is an immune-mediated disorder triggered by ingestion of wheat gliadin and related proteins in genetically susceptible individuals. In addition to the characteristic enteropathy, celiac disease is associated with various extraintestinal manifestations, including neurologic complications such as neuropathy, ataxia, seizures, and neurobehavioral changes. The cause of the neurologic manifestations is unknown, but autoimmunity resulting from molecular mimicry between gliadin and nervous system proteins has been proposed to play a role. In this study, we sought to investigate the immune reactivity of the anti-gliadin Ab response toward neural proteins. We characterized the binding of affinity-purified anti-gliadin Abs from immunized animals to brain proteins by one- and two-dimensional gel electrophoresis, immunoblotting, and peptide mass mapping. The major immunoreactive protein was identified as synapsin I. Anti-gliadin Abs from patients with celiac disease also bound to the protein. Such cross-reactivity may provide clues into the pathogenic mechanism of the neurologic deficits that are associated with gluten sensitivity.