bluuebunny/crossref_metadata_2025_split huggingface dataset:
J Chain in the Nurse Shark: Implications for Function in a Lower Vertebrate
Authors: Hohman Valerie S. , Stewart Sue E. , Rumfelt Lynn L. , Greenberg Andrew S. , Avila David W. , Flajnik Martin F. , Steiner Lisa A. 
Published: April 2014

AbstractJ chain is a small polypeptide covalently attached to polymeric IgA and IgM. In humans and mice, it plays a role in binding Ig to the polymeric Ig receptor for transport into secretions. The putative orthologue of mammalian J chain has been identified in the nurse shark by sequence analysis of cDNA and the polypeptide isolated from IgM. Conservation with J chains from other species is relatively poor, especially in the carboxyl-terminal portion, and, unlike other J chains, the shark protein is not acidic. The only highly conserved segment in all known J chains is a block of residues surrounding an N-linked glycosylation site. Of the eight half-cystine residues that are conserved in mammalian J chains, three are lacking in the nurse shark, including two in the carboxyl-terminal segment that have been reported to be required for binding of human J chain-containing IgA to secretory component. Taken together with these data, the relative abundance of J chain transcripts in the spleen and their absence in the spiral valve (intestine) suggest that J chain in nurse sharks may not have a role in Ig secretion. Analysis of J chain sequences in diverse species is in agreement with accepted phylogenetic relationships, with the exception of the earthworm, suggesting that the reported presence of J chain in invertebrates should be reassessed.
Caspase Activity Is Required for Stimulated B Lymphocytes to Enter the Cell Cycle
Authors: Olson N. Eric , Graves Jonathan D. , Shu Geraldine L. , Ryan Elizabeth J. , Clark Edward A. 
Published: April 2014

AbstractFollowing activation with proliferative stimuli, including ligation of CD40, dense human tonsillar B cells (&gt;98% cells in G0) have increased cleavage and activation of caspase-8 and -6 accompanied by decreased caspase-3 activation and apoptosis. Proliferation was blocked by either a broad specificity caspase inhibitor or inhibitors selective for caspase-6 or caspase-8. In contrast, an inhibitor selective for caspase-3 was without effect. Furthermore, induction of cyclin D and cyclin-dependent kinase 4 mRNA and protein was blocked upon inhibition of caspase-6, but not caspase-3. Thus, caspase-6-like activity is required for quiescent B cells to increase the expression of genes required for entry into G1. In support of this model, the transcriptional suppressor special AT-rich sequence-binding protein 1, a preferred caspase-6 substrate, was cleaved upon B cell stimulation. Caspase activity was not required for all signaling events, as caspase inhibitors did not affect the phosphorylation of p42/44 mitogen-activated protein kinase, the expression of the survival factor cellular inhibitor of apoptosis 2, or the production of IL-6 by stimulated G0 B cells. These findings suggest a mechanism by which caspase-6 may selectively allow entry of quiescent B cells into the cell cycle.
Different and Divergent Regulation of the KIR2DL4 and KIR3DL1 Promoters
Authors: Stewart C. Andrew , van Bergen Jeroen , Trowsdale John 
Published: April 2014

Abstract
The killer Ig-like receptors (KIR) are a family of highly related MHC class I receptors that show extreme genetic polymorphism both within the human population and between closely related primate species, suggestive of rapid evolutionary diversification. Most KIR are expressed in a variegated fashion by the NK population, giving rise to an NK repertoire of specificities for MHC class I. We compared the promoter for KIR3DL1, which exhibits variegated gene expression, with that for KIR2DL4, which is expressed by all NK cell clones. Maximum transcriptional activity of each was encoded within ∼270 bp upstream of the translation initiation codon. The KIR2DL4 promoter drove reporter gene expression only in NK cells, while the KIR3DL1 promoter was active in a range of cell types, suggesting that the latter requires other regulatory elements for physiological expression. In NK cells, reporter gene expression driven by the KIR2DL4 promoter was greater than that driven by the KIR3DL1 promoter. DNase I footprinting revealed that transcription factor binding sites differ between the two promoters. The data indicate that while the promoters of these two KIR genes share 67% nucleotide identity, they have evolved distinct properties consistent with different roles in regulating the generation of NK repertoire.
Polyvalent Antigens Stabilize B Cell Antigen Receptor Surface Signaling Microdomains
Authors: Thyagarajan Rathna , Arunkumar Nandini , Song Wenxia 
Published: April 2014

AbstractThe B cell Ag receptor (BCR) can distinguish subtle differences in Ag structure and trigger differential responses. In this study, we analyzed the effects of Ag valency on the signaling and Ag-targeting functions of the BCR. Although both paucivalent and polyvalent Ags induced the redistribution of the surface BCR into polarized caps, polyvalent Ag-induced BCR caps persisted. Ganglioside GM1, a lipid raft marker, and tyrosine-phosphorylated proteins, but not CD45 and transferrin receptor, were concentrated in BCR caps, suggesting BCR caps as surface-signaling microdomains. Prolonged BCR caps were concomitant with an increase in the level and duration of protein tyrosine phosphorylation and a reduction in BCR internalization and movement to late endosomes/lysosomes. Thus, Ag valency influences B cell responses by modulating the stability of BCR-signaling microdomains and BCR trafficking.
OX40 Ligation on Activated T Cells Enhances the Control ofCryptococcus neoformansand Reduces Pulmonary Eosinophilia
Authors: Humphreys Ian R. , Edwards Lorna , Walzl Gerhard , Rae Aaron J. , Dougan Gordon , Hill Sue , Hussell Tracy 
Published: April 2014

AbstractPulmonary eosinophilia induced in C57BL/6 mice after Cryptococcus neoformans infection is driven by CD4+ Th2 cells. The immunological mechanisms that protect against eosinophilia are not fully understood. Interaction of OX40 (CD134) and its ligand, OX40L, has been implicated in T cell activation and cell migration. Unlike CD28, OX40 is only expressed on T cells 1–2 days after Ag activation. Manipulation of this pathway would therefore target recently activated T cells, leaving the naive repertoire unaffected. In this study, we show that engagement of OX40 by an OX40L:Ig fusion protein drives IFN-γ production by CD4+ T cells and reduces eosinophilia and C. neoformans burden in the lung. Using gene-depleted mice, we show that reduction of eosinophilia and pathogen burden requires IL-12 and/or IFN-γ. C. neoformans infection itself only partially induces OX40L expression by APCs. Provision of exogenous OX40L reveals a critical role of this pathway in the prevention of C. neoformans-induced eosinophilia.
Central Role of Complement in Passive Protection by Human IgG1 and IgG2 Anti-pneumococcal Antibodies in Mice
Authors: Saeland Eirikur , Vidarsson Gestur , Leusen Jeanette H. W. , van Garderen Evert , Nahm Moon H. , Vile-Weekhout Henriette , Walraven Vanessa , Stemerding Annette M. , Verbeek J. Sjef , Rijkers Ger T. , Kuis Wietse , Sanders Elisabeth A. M. , van de Winkel Jan G. J. 
Published: April 2014

Abstract
Streptococcus pneumoniae is an important cause of morbitity and mortality worldwide. Capsule-specific IgG1 and IgG2 Abs are induced upon vaccination with polysaccharide-based vaccines that mediate host protection. We compared the protective capacity of human recombinant serogroup 6-specific IgG1 and IgG2 Abs in mice deficient for either leukocyte FcR or complement factors. Human IgG1 was found to interact with mouse leukocyte FcR in vitro, whereas human IgG2 did not. Both subclasses induced complement activation, resulting in C3c deposition on pneumococcal surfaces. Passive immunization of C57BL/6 mice with either subclass before intranasal challenge with serotype 6A induced similar degrees of protection. FcγRI- and III-deficient mice, as well as the combined FcγRI, II, and III knockout mice, were protected by passive immunization, indicating FcR not to be essential for protection. C1q or C2/factor B knockout mice, however, were not protected by passive immunization. Passively immunized C2/factor B−/− mice displayed higher bacteremic load than C1q−/− mice, supporting an important protective role of the alternative complement pathway. Spleens from wild-type and C1q−/− mice showed hyperemia and thrombotic vessel occlusion, as a result of septicemic shock. Notably, thrombus formation was absent in spleens of C2/factor B−/− mice, suggesting that the alternative complement pathway contributes to shock-induced intravascular coagulation. These studies demonstrate complement to play a central role in Ab-mediated protection against pneumococcal infection in vivo, as well as in bacteremia-associated thrombotic complications.
Proteins and Their Derived Peptides as Carriers in a Conjugate Vaccine forStreptococcus pneumoniae: Self-Heat Shock Protein 60 and Tetanus Toxoid
Authors: Amir-Kroll Hila , Nussbaum Gabriel , Cohen Irun R. 
Published: April 2014

AbstractWe induced T cell help for vaccination against Streptococcus pneumoniae (Pn) using self and foreign peptides and their source proteins conjugated to the capsular polysaccharide (CPS) of type 4 Pn; the carriers were self-heat shock protein 60 (HSP60) and tetanus toxoid (TT). We measured the production of IgG Abs to the CPS and the carriers, and tested resistance to challenge with highly lethal amounts of Pn injected i.p. (LD50 × 103–106). We now report that vaccination protects old and young mice from bacterial challenge; however, there were significant differences in vaccine efficacy based on the carrier. Self-HSP60 peptide p458m was more effective than the whole HSP60 molecule and was equally effective compared with TT. Both p458m and TT were more protective than the TT-derived peptide p30 after a single vaccination. However, peptide p30 was effective in more MHC genotypes than was p458m. Unlike other vaccines, protection conferred by p458m was not related to the amount of anti-CPS Ab: mice that produced very little Ab were still protected from highly lethal doses of bacteria (LD50 × 105–106). Furthermore, unlike the other carriers, there was no Ab response to the p458m carrier. Thus, peptides, self as well as foreign, can provide T cell help that differs functionally from that provided by the whole parent protein.
Genetic Engineering of a Suboptimal Islet Graft with A20 Preserves β Cell Mass and Function
Authors: Grey Shane T. , Longo Christopher , Shukri Tala , Patel Virendra I. , Csizmadia Eva , Daniel Soizic , Arvelo Maria B. , Tchipashvili Vaja , Ferran Christiane 
Published: April 2014

Abstract
Transplantation of an excessive number of islets of Langerhans (two to four pancreata per recipient) into patients with type I diabetes is required to restore euglycemia. Hypoxia, nutrient deprivation, local inflammation, and the β cell inflammatory response (up-regulation of NF-κB-dependent genes such as inos) result in β cell destruction in the early post-transplantation period. Genetic engineering of islets with anti-inflammatory and antiapoptotic genes may prevent β cell loss and primary nonfunction. We have shown in vitro that A20 inhibits NF-κB activation in islets and protects from cytokine- and death receptor-mediated apoptosis. In vivo, protection of newly transplanted islets would reduce the number of islets required for successful transplantation. Transplantation of 500 B6/AF1 mouse islets into syngeneic, diabetic recipients resulted in a cure rate of 100% within 5 days. Transplantation of 250 islets resulted in a cure rate of only 20%. Transplantation of 250 islets overexpressing A20 resulted in a cure rate of 75% with a mean time to cure of 5.2 days, comparable to that achieved with 500 islets. A20-expressing islets preserve functional β cell mass and are protected from cell death. These data demonstrate that A20 is an ideal cytoprotective gene therapy candidate for islet transplantation.
Aspirin-Triggered Lipoxin A4 and B4 Analogs Block Extracellular Signal-Regulated Kinase-Dependent TNF-α Secretion from Human T Cells
Authors: Ariel Amiram , Chiang Nan , Arita Makoto , Petasis Nicos A. , Serhan Charles N. 
Published: April 2014

AbstractLipoxins (LX) and their aspirin-triggered 15-epimer endogenous isoforms are endogenous anti-inflammatory and pro-resolution eicosanoids. In this study, we examined the impact of LX and aspirin-triggered LXA4-stable analogs (ATLa) on human T cell functions. 15-epi-16-(p-fluoro)phenoxy-LXA4 (ATLa1) blocked the secretion of TNF-α from human PBMC after stimulation by anti-CD3 Abs, with the IC50 value of ≈0.05 nM. A similar action was also exerted by the native aspirin-triggered 15-epi-LXA4, a new 15-epi-16-(p-trifluoro)phenoxy-LXA4 analog (ATLa2), as well as LXB4, and its analog 5-(R/S)-methyl-LXB4. The LXA4 receptor (ALX) is expressed in peripheral blood T cells and mediates the inhibition of TNF-α secretion from activated T cells by ATLa1. This action was accomplished by inhibition of the anti-CD3-induced activation of extracellular signal-regulated kinase, which is essential for TNF-α secretion from anti-CD3-activated T cells. These results demonstrate novel roles for LX and aspirin-triggered LX in the regulation of T cell-mediated responses relevant in inflammation and its resolution. Moreover, they provide potential counterregulatory signals in communication(s) between the innate and acquired immune systems.
Transepithelial Migration of Neutrophils in Response to Leukotriene B4 Is Mediated by a Reactive Oxygen Species-Extracellular Signal-Regulated Kinase-Linked Cascade
Authors: Woo Chang-Hoon , Yoo Min-Hyuk , You Hye-Jin , Cho Sung-Hoon , Mun Yeung-Chul , Seong Chu-Myong , Kim Jae-Hong 
Published: April 2014

AbstractThe epithelial cells that form a barrier lining the lung airway are key regulators of neutrophil trafficking into the airway lumen in a variety of lung inflammatory diseases. Although the lipid mediator leukotriene B4 (LTB4) is known to be a principal chemoattractant for recruiting neutrophils to inflamed sites across the airway epithelium, the precise signaling mechanism involved remains largely unknown. In the present study, therefore, we investigated the signaling pathway through which LTB4 induces transepithelial migration of neutrophils. We found that LTB4 induces concentration-dependent transmigration of DMSO-differentiated HL-60 neutrophils and human polymorphonuclear neutrophils across A549 human lung epithelium. This effect was mediated via specific LTB4 receptors and was inhibited by pretreating the cells with N-acetylcysteine (NAC), an oxygen free radical scavenger, with diphenylene iodonium (DPI), an inhibitor of NADPH oxidase-like flavoproteins, or with PD98059, an extracellular signal-regulated kinase (ERK) inhibitor. Consistent with those findings, LTB4-induced ERK phosphorylation was completely blocked by pretreating cells with NAC or DPI. Taken together, our observations suggest LTB4 signaling to transepithelial migration is mediated via generation of reactive oxygen species, which leads to downstream activation of ERK. The physiological relevance of this signaling pathway was demonstrated in BALB/c mice, in which intratracheal instillation of LTB4 led to acute recruitment of neutrophils into the airway across the lung epithelium. Notably, the response to LTB4 was blocked by NAC, DPI, PD98059, or CP105696, a specific LTB4 receptor antagonist.
An Inducible Nitric Oxide Synthase-Luciferase Reporter System for In Vivo Testing of Anti-inflammatory Compounds in Transgenic Mice
Authors: Zhang Ning , Weber Aneil , Li Bonnie , Lyons Richard , Contag Pamela R. , Purchio Anthony F. , West David B. 
Published: April 2014

Abstract
The inducible NO synthase gene (iNOS) plays a role in a number of chronic and acute conditions, including septic shock and contact hypersensitivity autoimmune diseases, such as rheumatoid arthritis, gastrointestinal disorders, and myocardial ischemia. The iNOS gene is primarily under transcriptional control and is induced in a variety of conditions. The ability to monitor and quantify iNOS expression in vivo may facilitate a better understanding of the role of iNOS in different diseases. In this study, we describe a transgenic mouse (iNos-luc) in which the luciferase reporter is under control of the murine iNOS promoter. In an acute sepsis model produced by injection of IFN-γ and LPS, we observed an induction of iNOS-driven luciferase activity in the mouse liver. This transgene induction is dose and time dependent and correlated with an increase of liver iNOS protein and iNOS mRNA levels. With this model, we tested 11 compounds previously shown to inhibit iNOS induction in vitro or in vivo. Administration of dexamethasone, epigallocatechin gallate, α-phenyl-N-tert-butyl nitrone, and ebselen significantly suppressed iNOS transgene induction by IFN-γ and LPS. We further evaluated the use of the iNos-luc transgenic mice in a zymosan-induced arthritis model. Intra-articular injection of zymosan induced iNos-luc expression in the knee joint. The establishment of the iNos-luc transgenic model provides a valuable tool for studying processes in which the iNOS gene is induced and for screening anti-inflammatory compounds in vivo.
Immunoglobulin Activation of T Cell Chemoattractant Expression in Fibroblasts from Patients with Graves’ Disease Is Mediated Through the Insulin-Like Growth Factor I Receptor Pathway
Authors: Pritchard Jane , Han Rui , Horst Noah , Cruikshank William W. , Smith Terry J. 
Published: April 2014

AbstractGraves’ disease (GD) is associated with T cell infiltration, but the mechanism for lymphocyte trafficking has remained uncertain. We reported previously that fibroblasts from patients with GD express IL-16, a CD4-specific chemoattractant, and RANTES, a C-C chemokine, in response to GD-specific IgG (GD-IgG). We unexpectedly found that these responses result from a functional interaction between GD-IgG and the insulin-like growth factor (IGF)-I receptor (IGF-IR). IGF-I and the IGF-IR-specific IGF-I analog, des(1–3), mimic the effects of GD-IgG. Neither GD-IgG nor IGF-I activates chemoattractant expression in control fibroblasts from donors without GD. Interrupting IGF-IR function with specific receptor-blocking Abs or by transiently transfecting fibroblasts with a dominant negative mutant IGF-IR completely attenuates signaling provoked by GD-IgG. Moreover, GD-IgG displaces specific 125I-labeled IGF-I binding to fibroblasts and attenuates IGF-IR detection by flow cytometry. These findings identify a novel disease mechanism involving a functional GD-IgG/IGF-IR bridge, which potentially explains T cell infiltration in GD. Interrupting this pathway may constitute a specific therapeutic strategy.
Failure of Monocytes of Trauma Patients to Convert to Immature Dendritic Cells is Related to Preferential Macrophage-Colony-Stimulating Factor-Driven Macrophage Differentiation
Authors: De Asit K. , Laudanski Krzysztof , Miller-Graziano Carol L. 
Published: April 2014

Abstract
Following trauma, increased inflammatory monokine activation and depressed APC function can occur simultaneously. These contradictory monocyte (Mφ) dysfunctions could result if postinjury Mφ differentiation preferentially favored inflammatory macrophage (Mac) differentiation over development into the most potent APC, dendritic cells (DC). In this report, Mφ of trauma patients with a depressed MLR induction capacity are, for the first time, shown to be unable to differentiate in vitro to immature CD1a+ DC under the influence of GM-CSF and IL-4. Trauma patient Mφ that retained MLR-inducing capacity had a nonsignificant reduction in DC differentiation capacity. Only patient Mφ populations with depressed differentiation to immature DC (iDC) demonstrated depressed IL-12 and IL-15 production and a continued reduced MLR induction capacity. Neither increased IL-10 production nor decreased CD11c+ DC precursor numbers correlated with depressed Mφ-to-DC differentiation. Instead, these patients’ APC-dysfunctional Mφ populations had increased expression of inflammatory Mac phenotypes (CD64+, CD86low, HLA-DRlow) and up-regulated secretion of M-CSF. M-CSF combined with IL-6 inhibits Mφ-to-iDC differentiation and promotes Mφ-to-Mac differentiation by down-regulating GM-CSFR expression and increasing DC apoptosis. Both depressed GM-CSFR expression and increased Mφ iDC apoptosis, as well as increased expression of CD126 (IL-6R) and CD115 (M-CSFR), were detected in APC-defective patient Mφ. In vitro addition of anti-M-CSF enhanced the IL-4 plus GM-CSF-induced Mφ-to-DC differentiation of these patients. This suggests that, in trauma patients, enhanced Mφ-to-Mac differentiation with concomitant inhibited iDC development is partially due to increased circulating Mφ sensitivity to and production of M-CSF and contributes to postinjury immunoaberrations.
Characterization of the Antigen Specificity and TCR Repertoire, and TCR-Based DNA Vaccine Therapy in Myelin Basic Protein-Induced Autoimmune Encephalomyelitis in DA Rats
Authors: Miyakoshi Akira , Yoon Won Kee , Jee Youngheun , Matsumoto Yoh 
Published: April 2014

AbstractLike Lewis rats, DA rats are an experimental autoimmune encephalomyelitis (EAE)-susceptible strain and develop severe EAE upon immunization with myelin basic protein (MBP). However, there are several differences between the two strains. In the present study we induced acute EAE in DA rats by immunization with MBP and MBP peptides and examined the Ag specificity and TCR repertoire of encephalitogenic T cells. It was found that although immunization with MBP and a peptide corresponding to its 62–75 sequence (MBP62–75) induced clinical EAE, the responses of lymph node T cells isolated from MBP-immunized rats to MBP62–75 was marginal, indicating that this peptide contains major encephalitogenic, but not immunodominant, epitopes. The TCR analysis by CDR3 spectratyping of spinal cord T cells revealed that Vβ10 and Vβ15 spectratype expansion was always found in MBP62–75-immunized symptomatic rats. On the basis of these findings, we examined the encephalitogenicity of Vβ10- and Vβ15-positive T cells. First, the adoptive transfer experiments revealed that Vβ10-positive T line cells derived from MBP62–75-immunized rats induced clinical EAE in recipients. Second, administration of DNA vaccines encoding Vβ10 and Vβ15, alone or in combination, ameliorated MBP62–75-induced EAE. Collectively, it was strongly suggested that Vβ10- and Vβ15-positive T cells are encephalitogenic. Analyses of the Ag specificity and T cell repertoire of pathogenic T cells performed in this study provide useful information for designing specific immunotherapies against autoimmune diseases.