bluuebunny/crossref_metadata_2025_split huggingface dataset:
6-Phosphogluconate Dehydrogenase and Glucose-6-Phosphate Dehydrogenase Form a Supramolecular Complex in Human Neutrophils That Undergoes Retrograde Trafficking during Pregnancy
Authors: Kindzelskii Andrei L. , Ueki Tatsuya , Michibata Hitoshi , Chaiworapongsa Tinnakorn , Romero Roberto , Petty Howard R. 
Published: April 2014

AbstractNeutrophils from pregnant women display reduced neutrophil-mediated effector functions, such as reactive oxygen metabolite (ROM) release. Because the NADPH oxidase and NO synthase produce ROMs and NO, the availability of their substrate NADPH is a potential regulatory factor. NADPH is produced by glucose-6-phosphate dehydrogenase (G-6-PDase) and 6-phosphogluconate dehydrogenase (6-PGDase), which are the first two steps of the hexose monophosphate shunt (HMS). Using immunofluorescence microscopy, we show that 6-PGDase, like G-6-PDase, undergoes retrograde transport to the microtubule-organizing centers in neutrophils from pregnant women. In contrast, 6-PGDase is found in an anterograde distribution in cells from nonpregnant women. However, lactate dehydrogenase distribution is unaffected by pregnancy. Cytochemical studies demonstrated that the distribution of 6-PGDase enzymatic activity is coincident with 6-PGDase Ag. The accumulation of 6-PGDase at the microtubule-organizing centers could be blocked by colchicine, suggesting that microtubules are important in this enzyme’s intracellular distribution. In situ kinetic studies reveal that the rates of 6-gluconate turnover are indistinguishable in samples from nonpregnant and pregnant women, suggesting that the enzyme is functionally intact. Resonance energy transfer experiments showed that 6-PGDase and G-6-PDase are in close physical proximity within cells, suggesting the presence of supramolecular enzyme complexes. We suggest that the retrograde trafficking of HMS enzyme complexes during pregnancy influences the dynamics of NADPH production by separating HMS enzymes from glucose-6-phosphate generation at the plasma membrane and, in parallel, reducing ROM and NO production in comparison with fully activated neutrophils from nonpregnant women.
Inactivation of C5a Anaphylatoxin by a Peptide That Is Complementary to a Region of C5a
Authors: Fujita Emiko , Farkas Imre , Campbell William , Baranyi Lajos , Okada Hidechika , Okada Noriko 
Published: April 2014

AbstractPL37 (RAARISLGPRCIKAFTE) is an antisense homology box peptide composed of aa 37–53 of C5a-anaphylatoxin and is considered to be the region essential for C5a function. Using a computer program, we designed the complementary peptides ASGAPAPGPAGPLRPMF (Pep-A) and ASTAPARAGLPRLPKFF (Pep-B). Pep-A bound to PL37 and to C5a with very slow dissociation as determined by analysis using surface plasmon resonance, whereas Pep-B failed to bind at all. C5a was inactivated by concentrations of 7 nM or more of Pep-A, and this concentration of Pep-A inhibited induction of intracellular Ca2+ influx in neutrophils. Patch clamp electrophysiology experiments also showed the effectiveness of Pep-A in C5aR-expressing neuroblastoma cells. Furthermore, Pep-A administration prevented rats from C5a-mediated rapid lethal shock induced by an Ab to a membrane inhibitor of complement after LPS sensitization.
The Functional Profile of Primary Human Antiviral CD8+ T Cell Effector Activity Is Dictated by Cognate Peptide Concentration
Authors: Betts Michael R. , Price David A. , Brenchley Jason M. , Loré Karin , Guenaga F. Javier , Smed-Sorensen Anna , Ambrozak David R. , Migueles Stephen A. , Connors Mark , Roederer Mario , Douek Daniel C. , Koup Richard A. 
Published: April 2014

AbstractAntiviral CD8+ T cells can elaborate at least two effector functions, cytokine production and cytotoxicity. Which effector function is elaborated can determine whether the CD8+ T cell response is primarily inflammatory (cytokine producing) or antiviral (cytotoxic). In this study we demonstrate that cytotoxicity can be triggered at peptide concentrations 10- to 100-fold less than those required for cytokine production in primary HIV- and CMV-specific human CD8+ T cells. Cytolytic granule exocytosis occurs at peptide concentrations insufficient to cause substantial TCR down-regulation, providing a mechanism by which a CD8+ T cell could engage and lyse multiple target cells. TCR sequence analysis of virus-specific cells shows that individual T cell clones can degranulate or degranulate and produce cytokine depending on the Ag concentration, indicating that response heterogeneity exists within individual CD8+ T cell clonotypes. Thus, antiviral CD8+ T cell effector function is determined primarily by Ag concentration and is not an inherent characteristic of a virus-specific CD8+ T cell clonotype or the virus to which the response is generated. The inherent ability of viruses to induce high or low Ag states may be the primary determinant of the cytokine vs cytolytic nature of the virus-specific CD8+ T cell response.
CD4+CD25bright Regulatory T Cells Actively Regulate Inflammation in the Joints of Patients with the Remitting Form of Juvenile Idiopathic Arthritis
Authors: de Kleer Ismé M. , Wedderburn Lucy R. , Taams Leonie S. , Patel Alka , Varsani Hemlata , Klein Mark , de Jager Wilco , Pugayung Gisela , Giannoni Francesca , Rijkers Ger , Albani Salvatore , Kuis Wietse , Prakken Berent 
Published: April 2014

AbstractThis study investigates the role of CD4+CD25+ regulatory T cells during the clinical course of juvenile idiopathic arthritis (JIA). Persistent oligoarticular JIA (pers-OA JIA) is a subtype of JIA with a relatively benign, self-remitting course while extended oligoarticular JIA (ext-OA JIA) is a subtype with a much less favorable prognosis. Our data show that patients with pers-OA JIA display a significantly higher frequency of CD4+CD25bright T cells with concomitant higher levels of mRNA FoxP3 in the peripheral blood than ext-OA JIA patients. Furthermore, while numbers of synovial fluid (SF) CD4+CD25bright T cells were equal in both patient groups, pers-OA JIA patients displayed a higher frequency of CD4+CD25int T cells and therefore of CD4+CD25total in the SF than ext-OA JIA patients. Analysis of FoxP3 mRNA levels revealed a high expression in SF CD4+CD25bright T cells of both patient groups and also significant expression of FoxP3 mRNA in the CD4+CD25int T cell population. The CD4+CD25bright cells of both patient groups and the CD4+CD25int cells of pers-OA JIA patients were able to suppress responses of CD25neg cells in vitro. A markedly higher expression of CTLA-4, glucocorticoid-induced TNFR, and HLA-DR on SF CD4+CD25bright T regulatory (Treg) cells compared with their peripheral counterparts suggests that the CD4+CD25+ Treg cells may undergo maturation in the joint. In correlation with this mature phenotype, the SF CD4+CD25bright T cells showed an increased regulatory capacity in vitro compared with peripheral blood CD4+CD25bright T cells. These data suggest that CD4+CD25bright Treg cells play a role in determining the patient’s fate toward either a favorable or unfavorable clinical course of disease.
Antiviral Cytokines Induce Hepatic Expression of the Granzyme B Inhibitors, Proteinase Inhibitor 9 and Serine Proteinase Inhibitor 6
Authors: Barrie Mahmoud B. , Stout Heather W. , Abougergi Marwan S. , Miller Bonnie C. , Thiele Dwain L. 
Published: April 2014

Abstract
Expression of the granzyme B inhibitors, human proteinase inhibitor 9 (PI-9), or the murine orthologue, serine proteinase inhibitor 6 (SPI-6), confers resistance to CTL or NK killing by perforin- and granzyme-dependent effector mechanisms. In light of prior studies indicating that virally infected hepatocytes are selectively resistant to this CTL effector mechanism, the present studies investigated PI-9 and SPI-6 expression in hepatocytes and hepatoma cells in response to adenoviral infection and to cytokines produced during antiviral immune responses. Neither PI-9 nor SPI-6 expression was detected by immunoblotting in uninfected murine or human hepatocytes. Similarly, human Huh-7 hepatoma cells were found to express only very low levels of PI-9 relative to levels detected in perforin- and granzyme-resistant CTL or lymphokine-activated killer cells. Following in vivo adenoviral infection or in vitro culture with IFN-αβ or IFN-γ, SPI-6 expression was induced in murine hepatocytes. Similarly, after culture with IFN-α, induction of PI-9 mRNA and protein expression was observed in human hepatocytes and Huh-7 cells. IFN-γ and TNF-α also induced 4- to 10-fold higher levels of PI-9 mRNA expression in Huh-7 cells, whereas levels of mRNA encoding a related serine proteinase inhibitor, proteinase inhibitor 8, were unaffected by culture of Huh-7 cells with IFN-α, IFN-γ, or TNF-α. These findings indicate that cytokines that promote antiviral cytopathic responses also regulate expression of the cytoprotective molecules, PI-9 and SPI-6, in hepatocytes that are potential targets of CTL and NK effector mechanisms.
Lack of Galactose-α-1,3-Galactose Expression on Porcine Endothelial Cells Prevents Complement-Induced Lysis but Not Direct Xenogeneic NK Cytotoxicity
Authors: Baumann Bettina C. , Forte Pietro , Hawley Robert J. , Rieben Robert , Schneider Mårten K. J. , Seebach Jörg D. 
Published: April 2014

AbstractThe galactose-α-1,3-galactose (αGal) carbohydrate epitope is expressed on porcine, but not human cells, and therefore represents a major target for preformed human anti-pig natural Abs (NAb). Based on results from pig-to-primate animal models, NAb binding to porcine endothelial cells will likely induce complement activation, lysis, and hyperacute rejection in pig-to-human xenotransplantation. Human NK cells may also contribute to innate immune responses against xenografts, either by direct recognition of activating molecules on target cells or by FcγRIII-mediated xenogeneic Ab-dependent cellular cytotoxicity (ADCC). The present study addressed the question as to whether the lack of αGal protects porcine endothelial cells from NAb/complement-induced lysis, direct xenogeneic NK lysis, NAb-dependent ADCC, and adhesion of human NK cells under shear stress. Homologous recombination, panning, and limiting dilution cloning were used to generate an αGal-negative porcine endothelial cell line, PED2*3.51. NAb/complement-induced xenogeneic lysis of PED2*3.51 was reduced by an average of 86% compared with the αGal-positive phenotype. PED2*3.51 resisted NK cell-mediated ADCC with a reduction of lysis ranging from 30 to 70%. However, direct xenogeneic lysis of PED2*3.51, mediated either by freshly isolated or IL-2-activated human NK cells or the NK cell line NK92, was not reduced. Furthermore, adhesion of IL-2-activated human NK cells did not rely on αGal expression. In conclusion, removal of αGal leads to a clear reduction in complement-induced lysis and ADCC, but does not resolve adhesion of NK cells and direct anti-porcine NK cytotoxicity, indicating that αGal is not a dominant target for direct human NK cytotoxicity against porcine cells.
Cutting Edge: NTB-A Activates NK Cells via Homophilic Interaction
Authors: Flaig Ruediger M. , Stark Sebastian , Watzl Carsten 
Published: April 2014

Abstract
NK cells are an important component of the innate immune system. Their activity is tightly regulated by activating and inhibitory surface receptors. However, the exact functions of many activating surface receptors, as well as their ligands, still remain to be elucidated. NTB-A is a receptor on the surfaces of human NK, T, and B cells, mediating a signal whose malfunction may be involved in X-linked lymphoproliferative disease. However, the ligand of NTB-A has remained elusive so far. Using trimeric recombinant proteins, we now show that NTB-A is its own ligand. Homophilic interaction of NTB-A enhances NK cell cytotoxicity and influences NK cell proliferation and IFN-γ secretion. We suggest that NTB-A is an interlymphocyte signaling molecule, which serves to orchestrate the activities of immune cells.
Cutting Edge: Effector Memory CD8+ T Cells Play a Prominent Role in Recall Responses to Secondary Viral Infection in the Lung
Authors: Roberts Alan D. , Woodland David L. 
Published: April 2014

Abstract
The relative contributions of CD62Lhigh (central) memory and CD62Llow (effector) memory T cell populations to recall responses are poorly understood, especially in the respiratory tract. In this study, we took advantage of a dual-adoptive transfer system in the mouse to simultaneously follow the recall response of effector and central memory subpopulations to intranasal parainfluenza virus infection. Using MHC class I and class II multimers, we tracked the responses of Ag-specific CD8+ and CD4+ memory T cells in the same animals. The data show that effector memory T cells mounted recall responses that were equal to, or greater than, those mounted by central memory T cells. Moreover, effector memory T cells were more efficient at subsequently establishing a second generation of memory T cells. These data contrast with other studies indicating that central memory CD8+ T cells are the prominent contributors to systemic virus infections.
Small Interfering RNAs Mediate Sequence-Independent Gene Suppression and Induce Immune Activation by Signaling through Toll-Like Receptor 3
Authors: Karikó Katalin , Bhuyan Prakash , Capodici John , Weissman Drew 
Published: April 2014

Abstract
Small interfering (si) and short hairpin (sh) RNAs induce robust degradation of homologous mRNAs, making them a potent tool to achieve gene silencing in mammalian cells. Silencing by siRNAs is used widely because it is considered highly specific for the targeted gene, although a recent report suggests that siRNA also induce signaling through the type I IFN system. When human embryonic kidney 293 (HEK293) or keratinocyte (HaCaT) cell lines or human primary dendritic cells or macrophages were transfected with siRNA or shRNAs, suppression of nontargeted mRNA expression was detected. Additionally, siRNA and shRNA, independent of their sequences, initiated immune activation, including IFN-α and TNF-α production and increased HLA-DR expression, in transfected macrophages and dendritic cells. The siRNAs induced low, but significant, levels of IFN-β in HEK293 and HaCaT cells. Secretion of these cytokines increased tremendously when HEK293 cells overexpressed Toll-like receptor 3 (TLR3), and the increased secretion of IFN-β was inhibited by coexpression of an inhibitor of TIR domain-containing adapter-inducing IFN-β, the TLR3 adaptor protein linked to IFN regulatory factor 3 signaling. Although siRNA and shRNA knockdown of genes represents a new and powerful tool, it is not without nonspecific effects, which we demonstrate are mediated in part by signaling through TLR3.
A Spontaneously Arising Pancreatic Tumor Does Not Promote the Differentiation of Naive CD8+ T Lymphocytes into Effector CTL
Authors: Lyman Michael A. , Aung Sandra , Biggs Judith A. , Sherman Linda A. 
Published: April 2014

Abstract
In this report, we address whether a growing tumor provides sufficient inflammatory signals to promote activation, clonal expansion, and acquisition of effector functions by naive tumor-specific CD8+ T lymphocytes. CD8+ T lymphocytes obtained from hemagglutinin (HA)-specific clone 4 TCR-transgenic mice were injected into recipient mice that spontaneously develop pancreatic tumors expressing HA as a tumor-associated Ag (RIP-Tag2-HA mice). When 3 × 106 clone 4 CD8+ T cells were transferred into tumor-bearing mice, the cells became activated in the pancreatic lymph nodes where they proliferated and acquired effector functions such as cytolytic activity and IFN-γ production. Surprisingly, reducing the number of adoptively transferred CD8+ T cells led to a parallel reduction in the proportion of the activated cells that exhibited effector functions, suggesting that CTL differentiation was induced by the large numbers of activated CD8+ T cells and not the tumor environment. Provision of tumor-specific CD4+ helper cells provided the signals required to promote both the development of CTL effector functions and increased clonal expansion, resulting in tumor eradication. Considering that only small numbers of tumor-specific CD8+ T cells would be present in a conventional T cell repertoire, these data suggest that tumor growth alone may not provide the inflammatory signals necessary to support the development of CD8+ T cell effector functions.
Tolerance to DNA in (NZB × NZW)F1 Mice That Inherit an Anti-DNA VH as a Conventional μ H Chain Transgene but Not as a VH Knock-in Transgene
Authors: Steeves Meredith A. , Marion Tony N. 
Published: April 2014

AbstractLupus-prone (NZB × NZW)F1 (BWF1) mice were made transgenic (Tg) for an anti-DNA Ab inherited either as a conventional VH3H9-μ H chain Tg (3H9-μ) with or without a conventional Vκ8-κ Tg, or a VH3H9 VH knock-in Tg allele (3H9R) with or without a Vκ4 Vκ knock-in Tg allele (Vκ4R). VH3H9 yields an anti-DNA Ab with most L chains including an anti-ssDNA with the Vκ8 Tg and an anti-dsDNA with the Vκ4 Tg. BWF1 mice that inherited the conventional 3H9-μ had normal serum IgM, little to none of which was encoded by 3H9-μ, and only a small percentage of those mice had serum anti-DNA, none of which was transgene encoded. B cells expressing the conventional 3H9-μ Tg were anergic. BWF1 mice that inherited the knock-in 3H9R Tg allele also had normal serum IgM, one-half of which was encoded by 3H9R, and produced anti-DNA encoded by the Tg allele. Most B cells expressing the knock-in 3H9R Tg also had an anergic phenotype. The results indicate that autoimmune-prone BWF1 mice initially develop effective B cell tolerance to DNA through anergy, and anergy was sustained in 3H9-μ Tg peripheral B cells but not in 3H9R Tg B cells. B cells expressing the 3H9R knock-in Tg allele were able to achieve an activation threshold that B cells expressing the 3H9-μ conventional Tg could not. The maintenance of B cell tolerance to DNA in autoimmune-prone BWF1 mice appears to differ from both normal mice and autoimmune-prone MRLlpr/lpr mice.
Mechanisms of Vδ1 γδ T Cell Activation by Microbial Components
Authors: Das Hiranmoy , Sugita Masahiko , Brenner Michael B. 
Published: April 2014

Abstract
There are two major subsets of γδ T cell in humans. Vγ2Vδ2 T cells predominate in the circulation and significantly expand in vivo during a variety of infectious diseases. Ags identified for the Vδ2 T cells are nonpeptide phosphate, amine, and aminobisphosphonate compounds. In contrast, Vδ1-encoded TCRs account for the vast majority of γδ T cells in tissues such as intestine and spleen. Some of these T cells recognize CD1c and MHC class I-related chain B molecules. These T cells are cytotoxic and use both perforin- and Fas-mediated cytotoxicity. A fundamental question is how these γδ T cells are activated during microbial exposure to carry out effector functions. In this study, we provide evidence for a mechanism by which Vδ1 γδ T cells are activated by inflammatory cytokines in the context of the Vδ1 TCR. Dendritic cells are necessary as accessory cells for microbial Ag-mediated Vδ1 γδ T cell activation. Cytokine (IL-12), adhesion (LFA3/CD2, LFA1/ICAM1) and costimulatory (MHC class I-related chain B molecule/NK-activating receptor G2D) molecules play a significant role along with Vδ1 TCR in this activation.
Activation-Induced Cell Death Limits Effector Function of CD4 Tumor-Specific T Cells
Authors: Saff Rebecca R. , Spanjaard Elena S. , Hohlbaum Andreas M. , Marshak-Rothstein Ann 
Published: April 2014

Abstract
A number of studies have documented a critical role for tumor-specific CD4+ cells in the augmentation of immunotherapeutic effector mechanisms. However, in the context of an extensive tumor burden, chronic stimulation of such CD4+ T cells often leads to the up-regulation of both Fas and Fas ligand, and coexpression of these molecules can potentially result in activation-induced cell death and the subsequent loss of effector activity. To evaluate the importance of T cell persistence in an experimental model of immunotherapy, we used DO11 Th1 cells from wild-type, Fas-deficient, and Fas ligand-deficient mice as effector populations specific for a model tumor Ag consisting of an OVA-derived transmembrane fusion protein. We found that the prolonged survival of Fas-deficient DO11 Th1 cells led to a more sustained tumor-specific response both in vitro and in vivo. Importantly, both Fas- and Fas ligand-deficient Th1 cells delayed tumor growth and cause regression of established tumors more effectively than wild-type Th1 cells, indicating that resistance to activation-induced cell death significantly enhances T cell effector activity.
Differential Requirements for Endosomal Reduction in the Presentation of Two H2-Ed-Restricted Epitopes from Influenza Hemagglutinin
Authors: Sinnathamby Gomathinayagam , Maric Maja , Cresswell Peter , Eisenlohr Laurence C. 
Published: April 2014

Abstract
We examined the role of reduction in the presentation of two H2-Ed-restricted epitopes (site 1 epitope (S1) and site 3 epitope (S3)) occupying distinct domains of the influenza hemagglutinin major subunit that contains four intrachain disulfide bonds and is connected to the virion by one interchain bond. S3 is situated within the stalk region that unfolds in response to mild acidification, and loads onto recycling H2-Ed in the early endosome, while S1, located in the structurally constrained globular domain, loads onto nascent H2-Ed in the late endosome. Predicting dependence upon reduction for either epitope seemed plausible but the results from several approaches were clear: presentation of S1 but not S3 is reduction dependent. Surprisingly, IFN-γ-inducible lysosomal thiol reductase (GILT), the only reductase thus far known to be involved in MHC class II-restricted processing, is not necessary for the generation of S1. However, GILT is necessary for presentation of either epitope when the virus is pretreated with a reducible cross-linker. The results suggest that unfolding of the Ag, perhaps a prerequisite for proteolytic processing in many cases, proceeds either spontaneously in the early endosome or via reduction in a later endosome. They further imply mechanisms for GILT-independent reduction in the late endosome, with GILT perhaps being reserved for more intractable Ags.
Enhanced T Cell Proliferation in Mice Lacking the p85β Subunit of Phosphoinositide 3-Kinase
Authors: Deane Jonathan A. , Trifilo Matthew J. , Yballe Claudine M. , Choi Sangdun , Lane Thomas E. , Fruman David A. 
Published: April 2014

Abstract
Phosphoinositide 3-kinase activation is important for lymphocyte proliferation and survival. Disrupting the gene that encodes the major phosphoinositide 3-kinase regulatory isoform p85α impairs B cell development and proliferation. However, T cell functions are intact in the absence of p85α. In this study, we test the hypothesis that the related isoform p85β is an essential regulatory subunit for T cell signaling. Unexpectedly, T cells lacking p85β showed a marked increase in proliferation and decreased death when stimulated with anti-CD3 plus IL-2. Both CD4+ and CD8+ T cells completed more cell divisions. Transcriptional profiling revealed reduced levels of caspase-6 mRNA in p85β-deficient T cells, which was paralleled by reduced caspase-6 enzyme activity. Increased T cell accumulation was also observed in vivo following infection of p85β-deficient mice with mouse hepatitis virus. Together, these results suggest a unique role for p85β in limiting T cell expansion.