bluuebunny/crossref_metadata_2025_split huggingface dataset:
T-bet Down-Modulation in Tolerized Th1 Effector CD4 Cells Confers a TCR-Distal Signaling Defect That Selectively Impairs IFN-γ Expression
Authors: Long Meixiao , Slaiby Aaron M. , Hagymasi Adam T. , Mihalyo Marianne A. , Lichtler Alexander C. , Reiner Steven L. , Adler Adam J. 
Published: April 2014

Abstract
When Th1 effector CD4 cells encounter tolerizing Ag in vivo, their capacity to express the effector cytokines IFN-γ and TNF-α is lost more rapidly than noneffector functions such as IL-2 production and proliferation. To localize the relevant intracellular signaling defects, cytokine expression was compared following restimulation with Ag vs agents that bypass TCR-proximal signaling. IFN-γ and TNF-α expression were both partially rescued when TCR-proximal signaling was bypassed, indicating that both TCR-proximal and -distal signaling defects impair the expression of these two effector cytokines. In contrast, bypassing TCR-proximal signaling fully rescued IL-2 expression. T-bet, a transcription and chromatin remodeling factor that is required to direct the differentiation of naive CD4 cells into IFN-γ-expressing Th1 effectors, was partially down-modulated in tolerized Th1 effectors. Enforcing T-bet expression during tolerization selectively rescued the ability to express IFN-γ, but not TNF-α. Conversely, expression of a dominant-negative T-bet in Th1 effectors selectively impaired the ability to express IFN-γ, but not TNF-α. Analysis of histone acetylation at the IFN-γ promoter further suggested that down-modulation of T-bet expression during Th1 effector CD4 cell tolerization does not impair IFN-γ expression potential through alterations in chromatin structure.
Microglia Proliferation Is Regulated by Hydrogen Peroxide from NADPH Oxidase
Authors: Mander Palwinder K. , Jekabsone Aiste , Brown Guy C. 
Published: April 2014

Abstract
Microglia are resident brain macrophages that become activated and proliferate following brain damage or stimulation by immune mediators, such as IL-1β or TNF-α. We investigated the mechanisms by which microglial proliferation is regulated in primary cultures of rat glia. We found that basal proliferation of microglia was stimulated by proinflammatory cytokines IL-1β or TNF-α, and this proliferation was completely inhibited by catalase, implicating hydrogen peroxide as a mediator of proliferation. In addition, inhibitors of NADPH oxidase (diphenylene iodonium or apocynin) also prevented microglia proliferation, suggesting that this may be the source of hydrogen peroxide. IL-1β and TNF-α rapidly stimulated the rate of hydrogen peroxide produced by isolated microglia, and this was inhibited by diphenylene iodonium, implying that the cytokines were acting directly on microglia to stimulate the NADPH oxidase. Low concentrations of PMA or arachidonic acid (known activators of NADPH oxidase) or xanthine/xanthine oxidase or glucose oxidase (generating hydrogen peroxide) also increased microglia proliferation and this was blocked by catalase, showing that NADPH oxidase activation or hydrogen peroxide was sufficient to stimulate microglia proliferation. In contrast to microglia, the proliferation of astrocytes was unaffected by the presence of catalase. In conclusion, these findings indicate that microglial proliferation in response to IL-1β or TNF-α is mediated by hydrogen peroxide from NADPH oxidase.
Destructive Cleavage of Antigenic Peptides Either by the Immunoproteasome or by the Standard Proteasome Results in Differential Antigen Presentation
Authors: Chapiro Jacques , Claverol Stéphane , Piette Fanny , Ma Wenbin , Stroobant Vincent , Guillaume Benoît , Gairin Jean-Edouard , Morel Sandra , Burlet-Schiltz Odile , Monsarrat Bernard , Boon Thierry , Van den Eynde Benoît J. 
Published: April 2014

Abstract
The immunoproteasome (IP) is usually viewed as favoring the production of antigenic peptides presented by MHC class I molecules, mainly because of its higher cleavage activity after hydrophobic residues, referred to as the chymotrypsin-like activity. However, some peptides have been found to be better produced by the standard proteasome. The mechanism of this differential processing has not been described. By studying the processing of three tumor antigenic peptides of clinical interest, we demonstrate that their differential processing mainly results from differences in the efficiency of internal cleavages by the two proteasome types. Peptide gp100209–217 (ITDQVPSFV) and peptide tyrosinase369–377 (YMDGTMSQV) are destroyed by the IP, which cleaves after an internal hydrophobic residue. Conversely, peptide MAGE-C2336–344 (ALKDVEERV) is destroyed by the standard proteasome by internal cleavage after an acidic residue, in line with its higher postacidic activity. These results indicate that the IP may destroy some antigenic peptides due to its higher chymotrypsin-like activity, rather than favor their production. They also suggest that the sets of peptides produced by the two proteasome types differ more than expected. Considering that mature dendritic cells mainly contain IPs, our results have implications for the design of immunotherapy strategies.
I-Ep-Bound Self-Peptides: Identification, Characterization, and Role in Alloreactivity
Authors: Felix Nathan J. , Suri Anish , Walters James J. , Horvath Stephen , Gross Michael L. , Allen Paul M. 
Published: April 2014

AbstractT cell recognition of peptide/allogeneic MHC complexes is a major cause of transplant rejection. Both the presented self-peptides and the MHC molecules are involved; however, the molecular basis for alloreactivity and the contribution of self-peptides are still poorly defined. The murine 2.102 T cell is specific for hemoglobin(64–76)/I-Ek and is alloreactive to I-Ep. The natural self-peptide/I-Ep complex recognized by 2.102 remains unknown. In this study, we characterized the peptides that are naturally processed and presented by I-Ep and used this information to define the binding motif for the murine I-Ep class II molecule. Interestingly, we found that the P9 anchor residue preferred by I-Ep is quite distinct from the residues preferred by other I-E molecules, although the P1 anchor residue is conserved. A degree of specificity for the alloresponse was shown by the lack of stimulation of 2.102 T cells by 19 different identified self-peptides. The binding motif was used to search the mouse genome for candidate 2.102 reactive allopeptides that contain strong P1 and P9 anchor residues and possess previously identified allowable TCR contact residues. Two potential allopeptides were identified, but only one of these peptides, G protein-coupled receptor 128, was able to stimulate 2.102 T cells. Thus, the G protein-coupled receptor 128 peptide represents a candidate allopeptide that is specifically recognized by 2.102 T cells bound to I-Ep and was identified using bioinformatics. These studies highlight the specific involvement of self-peptides in alloreactivity.
The Ret Finger Protein Inhibits Signaling Mediated by the Noncanonical and Canonical IκB Kinase Family Members
Authors: Zha Jikun , Han Ke-Jun , Xu Liang-Guo , He Wei , Zhou Qianhe , Chen Danying , Zhai Zhonghe , Shu Hong-Bing 
Published: April 2014

Abstract
IFN regulatory factor-3 is a transcription factor that is required for the rapid induction of type I IFNs in the innate antiviral response. Two noncanonical IκB kinase (IKK) family members, IKKε and TRAF family-associated NF-κB activator-binding kinase-1, have been shown to phosphorylate IFN regulatory factor-3 and are critically involved in virus-triggered and TLR3-mediated signaling leading to induction of type I IFNs. In yeast two-hybrid screens for potential IKKε-interacting proteins, we identified Ret finger protein (RFP) as an IKKε-interacting protein. Coimmunoprecipitation experiments indicated that RFP interacted with IKKε and TRAF family-associated NF-κB activator-binding kinase-1 as well as the two canonical IKK family members, IKKβ and IKKα. RFP inhibited activation of the IFN-stimulated response element and/or NF-κB mediated by the IKK family members and triggered by TNF, IL-1, polyinosinic-polycytidylic acid (ligand for TLR3), and viral infection. Moreover, knockdown of RFP expression by RNA interference-enhanced activation of IFN-stimulated response element and/or NF-κB triggered by polyinosinic-polycytidylic acid, TNF, and IL-1. Taken together, our findings suggest that RFP negatively regulates signaling involved in the antiviral response and inflammation by targeting the IKKs.
Identification and Characterization of DC-SCRIPT, a Novel Dendritic Cell-Expressed Member of the Zinc Finger Family of Transcriptional Regulators
Authors: Triantis Vassilis , Trancikova Dagmar Eleveld , Looman Maaike W. G. , Hartgers Franca C. , Janssen Richard A. J. , Adema Gosse J. 
Published: April 2014

Abstract
Dendritic cells (DC) compose a heterogeneous population of cells that hold a leading role in initiating and directing immune responses. Although their function in recognizing, capturing, and presenting Ags is well defined, the molecular mechanisms that control their differentiation and immune functions are still largely unknown. In this study, we report the isolation and characterization of DC-SCRIPT, a novel protein encoded by an 8-kb mRNA that is preferentially expressed in DC. DC-SCRIPT is expressed in multiple DC subsets in vivo, including myeloid DC, plasmacytoid DC, and Langerhans cells. At the protein level, DC-SCRIPT consists of a proline-rich region, 11 C2H2-type zinc fingers, and an acidic region. Localization studies reveal that DC-SCRIPT resides in the nucleus and that nuclear localization is critically dependent on the zinc fingers. The protein displays no transcriptional activation properties according to assorted transactivation assays, but interacts with the corepressor C-terminal binding protein 1. Taken together, our results show that we have isolated a novel DC marker that could be involved in transcriptional repression. In contrast to other DC molecules, DC-SCRIPT identifies all DC subsets tested to date.
Aspartic Acid Homozygosity at Codon 57 of HLA-DQ β Is Associated with Susceptibility to Pulmonary Tuberculosis in Cambodia
Authors: Delgado Julio C. , Baena Andres , Thim Sok , Goldfeld Anne E. 
Published: April 2014

Abstract
After infection with Mycobacterium tuberculosis, clinical disease usually remains latent, contained by the host immune response. Although polymorphisms of HLA loci have been hypothesized to play a major role in the breakdown of latency, a functional link has not been established. Molecular-based HLA-typing methods were used to test the association of sets of HLA alleles encoding an aspartic acid at codon 57 of the HLA-DQ β-chain (HLA-DQ β57-Asp) with susceptibility to tuberculosis in a cohort of 436 pulmonary tuberculosis patients and 107 healthy controls from Cambodia. HLA class II null cells were transduced with HLA-DQ β57-Asp or HLA-DQ β57-Ala and evaluated for their ability to bind peptides from two immunogenic M. tuberculosis specific proteins, ESAT-6 and CFP-10. In this study, we report a highly significant association between progressive pulmonary tuberculosis and homozygosity for HLA-DQ β57-Asp alleles. The presence of HLA-DQ β57-Asp resulted in a significantly reduced ability to bind a peptide from the central region of the ESAT-6 protein. Furthermore, when this peptide was presented by an HLA-DQ β57-Asp allele, Ag-specific IFN-γ production from CD4+ T cells from tuberculosis patients was significantly less than when this peptide was presented by an HLA-DQ-β allele encoding an alanine at codon 57. Multiple genetic loci and ethnic-specific factors are likely involved in the human immune response to tuberculosis. The data presented here provide a functional explanation for a highly significant association between an HLA polymorphism and tuberculosis in a highly characterized group of patients with susceptibility to progressive tuberculosis infection in Cambodia.
IL-23 Enhances the Inflammatory Cell Response in Cryptococcus neoformans Infection and Induces a Cytokine Pattern Distinct from IL-12
Authors: Kleinschek Melanie A. , Muller Uwe , Brodie Scott J. , Stenzel Werner , Kohler Gabriele , Blumenschein Wendy M. , Straubinger Reinhard K. , McClanahan Terrill , Kastelein Robert A. , Alber Gottfried 
Published: April 2014

Abstract
IL-23, a heterodimeric cytokine composed of the p40 subunit of IL-12 and a novel p19 subunit, has been shown to be a key player in models of autoimmune chronic inflammation. To investigate the role of IL-23 in host resistance during chronic fungal infection, wild-type, IL-12- (IL-12p35−/−), IL-23- (IL-23p19−/−), and IL-12/IL-23- (p40-deficient) deficient mice on a C57BL/6 background were infected with Cryptococcus neoformans. Following infection, p40-deficient mice demonstrated higher mortality than IL-12p35−/− mice. Reconstitution of p40-deficient mice with rIL-23 prolonged their survival to levels similar to IL-12p35−/− mice. IL-23p19−/− mice showed a moderately reduced survival time and delayed fungal clearance in the liver. Although IFN-γ production was similar in wild-type and IL-23p19−/− mice, production of IL-17 was strongly impaired in the latter. IL-23p19−/− mice produced fewer hepatic granulomata relative to organ burden and showed defective recruitment of mononuclear cells to the brain. Moreover, activation of microglia cells and expression of IL-1β, IL-6, and MCP-1 in the brain was impaired. These results show that IL-23 complements the more dominant role of IL-12 in protection against a chronic fungal infection by an enhanced inflammatory cell response and distinct cytokine regulation.
Innate Immune Dysfunction in HIV Infection: Effect of HIV Envelope-NK Cell Interactions
Authors: Kottilil Shyam , Shin Kyungmin , Jackson Julia O. , Reitano Kristin N. , O’Shea Marie Angeline , Yang Jun , Hallahan Claire W. , Lempicki Richard , Arthos James , Fauci Anthony S. 
Published: April 2014

Abstract
We have previously described a number of NK cell dysfunctions in HIV-viremic individuals. In the present study, we performed DNA microarray analysis followed by phenotypic and functional characterization in an effort to investigate which HIV envelope glycoproteins (gp120) affect the physiologic functions of NK cells. Upon treatment of NK cells with HIV gp120, DNA microarray analyses indicated up-regulation of several categories of genes that are associated with apoptosis, suppression of both cellular proliferation and survival, as well as down-regulation of genes that play a vital role in cell proliferation, innate immune defense mechanism, and cell survival. Both subtypes of gp120 suppressed NK cell cytotoxicity, proliferation, and the ability to secrete IFN-γ. NK cells exposed to X4-subtype HIV gp120 showed a significant decrease in the levels of CC chemokines, while exposure to R5-subtype HIV gp120 had minimal effect. Extended exposure to HIV gp120 resulted in apoptosis of NK cells, further validating the microarray data. Our data demonstrate that exposure of NK cells to HIV envelope proteins results in profound cellular abnormalities at the level of gene expression as well as generic cell functions. These findings are likely to be a consequence of a direct HIV gp120-mediated effect on NK cells. Identification of specific surface receptors on NK cells that interact with HIV envelope proteins might explain how HIV is capable of circumventing innate immune defense mechanisms and establishing infection in susceptible individuals.
Impairment of Alternative Macrophage Activation Delays Cutaneous Leishmaniasis in Nonhealing BALB/c Mice
Authors: Hölscher Christoph , Arendse Berenice , Schwegmann Anita , Myburgh Elmarie , Brombacher Frank 
Published: April 2014

AbstractExpressed on various cell types, the IL-4Rα is a component of both receptors for IL-4 and IL-13. Susceptibility of BALB/c mice to Leishmania major is believed to be dependent on the development of IL-4- and IL-13-producing Th2 cells, while IFN-γ secretion by Th1 cells is related to resistance. Despite a sustained development of Th2 cells, IL-4Rα-deficient BALB/c mice are able to control acute cutaneous leishmaniasis, suggesting that IL-4Rα-bearing cells other than Th2 cells contribute to susceptibility. To analyze the contribution of the IL-4Rα on macrophages, recently generated macrophage/neutrophil-specific IL-4Rα-deficient mice on a susceptible BALB/c genetic background were infected with L. major. Strikingly, macrophage/neutrophil-specific IL-4Rα-deficient mice showed a significantly delayed disease progression with normal Th2 and type 2 Ab responses but improved macrophage leishmanicidal effector functions and reduced arginase activity. Together, these results suggest that alternative macrophage activation contributes to susceptibility in cutaneous leishmaniasis.
Modified Pulmonary Surfactant Is a Potent Adjuvant That Stimulates the Mucosal IgA Production in Response to the Influenza Virus Antigen
Authors: Mizuno Dai , Ide-Kurihara Mikiko , Ichinomiya Tomoko , Kubo Itsuka , Kido Hiroshi 
Published: April 2014

Abstract
The intranasal administration of influenza hemagglutinin (HA) vaccine with Surfacten, a modified pulmonary surfactant free of antigenic c-type lectins, as a mucosal adjuvant induced the highest protective mucosal immunity in the airway. The intranasal immunization of mice with HA vaccine (0.2 μg)-Surfacten (0.2 μg) selectively induced the neutralizing anti-HA IgA, but not IgG, and conferred nearly maximal protection in the airway, without inducing a systemic response. In contrast, intranasal inoculation of vaccine with 0.2 μg of the potent mucosal adjuvant cholera toxin B* (CT-B*), prepared by adding 0.2% native CT to the B subunit of CT, induced both anti-HA IgA and IgG in the airway and in the serum. The intranasal administration of HA vaccine alone induced a limited amount of mucosal IgA against influenza virus. Although the s.c. administration of HA vaccine prominently induced serum IgG and IgA, Surfacten and CT-B* did not enhance their induction, and the concentrations of Abs leaking into the airways were insufficient to prevent viral multiplication. The intranasal administration of HA-Surfacten stimulated the expression of MHC class II, CD40, and CD86 molecules in the CD11c-positive cells isolated from the nasal mucosa, but not the expression of cells from the lungs or spleens. Lymphocytes isolated from the airway mucosa after intranasal HA-Surfacten immunization prominently induced TGF-β1 which, compared with inoculation without Surfacten, promoted an Ag-specific mucosal IgA response. Surfacten alone, however, did not induce TGF-β1. Our observations suggest that Surfacten, by mimicking the natural surfactant, is an effective mucosal adjuvant in the process of airway immunization.
Selectin Ligand-Independent Priming and Maintenance of T Cell Immunity during Airborne Tuberculosis
Authors: Schreiber Tanja , Ehlers Stefan , Aly Sahar , Hölscher Alexandra , Hartmann Sven , Lipp Martin , Lowe John B. , Hölscher Christoph 
Published: April 2014

AbstractImmunity to Mycobacterium tuberculosis infection is critically dependent on the timely priming of T effector lymphocytes and their efficient recruitment to the site of mycobacterial implantation in the lung. E-, P-, and L-selectin counterreceptors control lymphocyte homing to lymph nodes and leukocyte trafficking to peripheral sites of acute inflammation, their adhesive function depending on fucosylation by fucosyltransferases (FucT) IV and VII. To address the relative importance of differentially glycosylated selectin counterreceptors for priming of T cell effector functions in a model of mycobacteria-induced granulomatous pulmonary inflammation, we used aerosol-borne M. tuberculosis to infect FucT-IV−/−, FucT-VII−/−, FucT-IV−/−/FucT-VII−/−, or wild-type control mice. In lymph nodes, infected FucT-IV−/−/FucT-VII−/− and, to a lesser extent, FucT-VII−/− mice had severely reduced numbers of T cells and reduced Ag-specific effector responses. By contrast, recruitment of activated T cells into the lungs was similar in all four groups of mice during infection and expression of T cell, and macrophage effector functions were only delayed in lungs of FucT-IV−/−/FucT-VII−/− mice. Importantly, lungs from all groups expressed CXCL13, CCL21, and CCL19 and displayed organized follicular neolymphoid structures after infection with M. tuberculosis, which suggests that the lung served as a selectin ligand-independent priming site for immune responses to mycobacterial infection. All FucT-deficient strains were fully capable of restricting M. tuberculosis growth in infected organs until at least 150 days postinfection. Our observations indicate that leukocyte recruitment functions dictated by FucT-IV and FucT-VII-dependent selectin ligand activities are not critical for inducing or maintaining T cell effector responses at levels necessary to control pulmonary tuberculosis.
The Inhibitory Receptor NKG2A Determines Lysis of Vaccinia Virus-Infected Autologous Targets by NK Cells
Authors: Brooks Collin R. , Elliott Tim , Parham Peter , Khakoo Salim I. 
Published: April 2014

Abstract
Signals transduced by inhibitory receptors that recognize self-MHC class I molecules prevent NK cells from being activated by autologous healthy target cells. In order for NK cells to be activated upon contact with an infected cell, the balance between the activating and inhibitory signals that regulate NK cell function must be altered in favor of activation. By studying liver-derived NK cells, we show that only a subpopulation of NK cells expressing high levels of the inhibitory receptor NKG2A are able to lyse autologous vaccinia-infected targets, and that this is due to selective down-regulation of HLA-E. These data demonstrate that release from an inhibitory receptor:ligand interaction is one mechanism that permits NK cell recognition of a virally infected target, and that the variegated expression of inhibitory receptors in humans generates a repertoire of NK cells with different antiviral potentials.
Polyoma Virus-Like Particles Elicit Polarized Cytokine Responses in APCs from Tumor-Susceptible and -Resistant Mice
Authors: Velupillai Palanivel , Garcea Robert L. , Benjamin Thomas L. 
Published: April 2014

Abstract
PERA/Ei (PE) mice are highly susceptible to tumor induction by polyoma virus, whereas C57BR/cdj (BR) mice are highly resistant. PE mice respond to viral infection with a type 2 (IL-10) and BR mice with a type 1 (IL-12) cytokine response, underlining the importance of a sustained T cell response for effective antitumor immunity. PE and BR mice showed comparable Ab responses to the virus, indicating that a Th1 response is fully compatible with strong humoral immunity. Tumor susceptibility is dominant, and a type 2 response prevails in F1 mice derived from these strains. In this study, we show that the different cytokine responses of virus-infected hosts are recapitulated in vitro by exposure of APCs from uninfected PE, BR, and F1 animals to the virus. Importantly, virus-like particles formed from recombinant VP1, the major viral capsid protein, elicited the same host-specific cytokine responses as infectious virus. Assembly of VP1 pentamers into capsid shells is required because unassembled VP1 pentamers were ineffective. Binding of virus-like particles to sialic acid is required because pretreatment of APCs with neuraminidase prevented the response. Expression of TLR2 and TLR4 differed among different subpopulations of APCs and also between resistant and susceptible mice. Evidence is presented indicating that these TLRs play a role in mediating the host-specific cytokine responses to the virus.