247 research outputs found

    PO and ID BCG vaccination in humans induce distinct mucosal and systemic immune responses and CD4(+) T cell transcriptomal molecular signatures.

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    Protective efficacy of Bacillus Calmette-Guérin (BCG) may be affected by the methods and routes of vaccine administration. We have studied the safety and immunogenicity of oral (PO) and/or intradermal (ID) administration of BCG in healthy human subjects. No major safety concerns were detected in the 68 healthy adults vaccinated with PO and/or ID BCG. Although both PO and ID BCG could induce systemic Th1 responses capable of IFN-γ production, ID BCG more strongly induced systemic Th1 responses. In contrast, stronger mucosal responses (TB-specific secretory IgA and bronchoalveolar lavage T cells) were induced by PO BCG vaccination. To generate preliminary data comparing the early gene signatures induced by mucosal and systemic BCG vaccination, CD4(+) memory T cells were isolated from subsets of BCG vaccinated subjects pre- (Day 0) and post-vaccination (Days 7 and 56), rested or stimulated with BCG infected dendritic cells, and then studied by Illumina BeadArray transcriptomal analysis. Notably, distinct gene expression profiles were identified both on Day 7 and Day 56 comparing the PO and ID BCG vaccinated groups by GSEA analysis. Future correlation analyses between specific gene expression patterns and distinct mucosal and systemic immune responses induced will be highly informative for TB vaccine development.Mucosal Immunology advance online publication 30 August 2017; doi:10.1038/mi.2017.67

    Peptide microarray-based characterization of antibody responses to host proteins after bacille Calmette-Guerin vaccination

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    BACKGROUND: Bacille Calmette–Guérin (BCG) is the world’s most widely distributed vaccine, used against tuberculosis (TB), in cancer immunotherapy, and in autoimmune diseases due to its immunomodulatory properties. To date, the effect of BCG vaccination on antibody responses to host proteins has not been reported. High-content peptide microarrays (HCPM) offer a unique opportunity to gauge specific humoral immune responses. METHODS: The sera of BCG-vaccinated healthy adults were tested on a human HCPM platform (4953 randomly selected epitopes of human proteins) to detect specific immunoglobulin gamma (IgG) responses. Samples were obtained at 56, 112, and 252 days after vaccination. Immunohistology was performed on lymph node tissue from patients with TB lymphadenitis. Results were analysed with a combination of existing and novel statistical methods. RESULTS: IgG recognition of host peptides exhibited a peak at day 56 post BCG vaccination in all study subjects tested, which diminished over time. Primarily, IgG responses exhibited increased reactivity to ion transporters (sodium, calcium channels), cytokine receptors (interleukin 2 receptor β (IL2Rβ), fibroblast growth factor receptor 1 (FGFR1)), other cell surface receptors (inositol, somatostatin, angiopoeitin), ribonucleoprotein, and enzymes (tyrosine kinases, phospholipase) on day 56. There was decreased IgG reactivity to transforming growth factor-beta type 1 receptor (TGFβR1) and, in agreement with the peptide microarray findings, immunohistochemical analysis of TB-infected lymph node samples revealed an overexpression of TGFβR in granulomatous lesions. Moreover, the vesicular monoamine transporter (VMAT2) showed increased reactivity on days 112 and 252, but not on day 56 post-vaccination. IgG to interleukin 4 receptor (IL4R) showed increased reactivity at 112 days post-vaccination, while IgG to IL2Rβ and FGFR1 showed decreased reactivity on days 112 and 252 as compared to day 56 post BCG vaccination. CONCLUSIONS: BCG vaccination modifies the host’s immune landscape after 56 days, but this imprint changes over time. This may influence the establishment of immunological memory in BCG-vaccinated individuals

    Th17 cells are more protective than Th1 cells against the intracellular parasite Trypanosoma cruzi

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    Th17 cells are a subset of CD4+ T cells known to play a central role in the pathogenesis of many autoimmune diseases, as well as in the defense against some extracellular bacteria and fungi. However, Th17 cells are not believed to have a significant function against intracellular infections. In contrast to this paradigm, we have discovered that Th17 cells provide robust protection against Trypanosoma cruzi, the intracellular protozoan parasite that causes Chagas disease. Th17 cells confer significantly stronger protection against T. cruzi-related mortality than even Th1 cells, traditionally thought to be the CD4+ T cell subset most important for immunity to T. cruzi and other intracellular microorganisms. Mechanistically, Th17 cells can directly protect infected cells through the IL-17A-dependent induction of NADPH oxidase, involved in the phagocyte respiratory burst response, and provide indirect help through IL-21-dependent activation of CD8+ T cells. The discovery of these novel Th17 cell-mediated direct protective and indirect helper effects important for intracellular immunity highlights the diversity of Th17 cell roles, and increases understanding of protective T. cruzi immunity, aiding the development of therapeutics and vaccines for Chagas disease

    Kerr Spinning Particle, Strings, and Superparticle Models

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    A combined model of the Kerr spinning particle and superparticle is considered. The structure of the Kerr geometry is presented in a complex form as being created by a complex source. A natural supergeneralization of this construction is obtained corresponding to a complex "supersource". Peforming a supershift to the Kerr and Kerr-Sen solutions we obtain metrics of supergravity black holes with a nonlinear realization of broken supersymmetry.Comment: minor revision, some grammatical changes and correction of the misprint before eq.(10); 13p., Latex, Talk at the International Seminar "Supersymmetry and quantum field theory" dedicated to the memory of D.V.Volkov, Kharkov, January 199

    Stability of scaling regimes in d2d\geq 2 developed turbulence with weak anisotropy

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    The fully developed turbulence with weak anisotropy is investigated by means of renormalization group approach (RG) and double expansion regularization for dimensions d2d\ge 2. Some modification of the standard minimal substraction scheme has been used to analyze stability of the Kolmogorov scaling regime which is governed by the renormalization group fixed point. This fixed point is unstable at d=2d=2; thus, the infinitesimally weak anisotropy destroyes above scaling regime in two-dimensional space. The restoration of the stability of this fixed point, under transition from d=2d=2 to d=3,d=3, has been demonstrated at borderline dimension 2<dc<3 2<d_c<3. The results are in qualitative agreement with ones obtained recently in the framework of the usual analytical regularization scheme.Comment: 23 pages, 2 figure

    An immunoinformatic approach for identification of Trypanosoma cruzi HLA-A2-restricted CD8\u3csup\u3e+\u3c/sup\u3e T cell epitopes

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    Chagas disease is a major neglected tropical disease caused by persistent chronic infection with the protozoan parasite Trypanosoma cruzi. An estimated 8 million people are infected with T. cruzi, however only 2 drugs are approved for treatment and no vaccines are available. Thus there is an urgent need to develop vaccines and new drugs to prevent and treat Chagas disease. In this work, we identify T cell targets relevant for human infection with T. cruzi. The trans-sialidase (TS) gene family is a large family of homologous genes within the T. cruzi genome encoding over 1,400 members. There are 12 highly conserved TS gene family members which encode enzymatically active TS (functional TS; F-TS), while the remaining TS family genes are less conserved, enzymatically inactive and have been hypothesized to be involved in immune evasion (non-functional TS; NF-TS). We utilized immunoinformatic tools to identify HLA-A2-restricted CD8+ T cell epitopes conserved within F-TS family members and NF-TS gene family members. We also utilized a whole-genome approach to identify T cell epitopes present within genes which have previously been shown to be expressed in life stages relevant for human infection (Non-TS genes). Thirty immunogenic HLA-A2-restricted CD8+ T cell epitopes were identified using IFN-γ ELISPOT assays after vaccination of humanized HLA-A2 transgenic mice with mature dendritic cells pulsed with F-TS, NF-TS, and Non-TS peptide pools. The immunogenic HLA-A2-restricted T cell epitopes identified in this work may serve as potential components of an epitope-based T cell targeted vaccine for Chagas disease

    First detection of frequency-dependent, time-variable dispersion measures

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    Donner J, Verbiest J, Tiburzi C, et al. First detection of frequency-dependent, time-variable dispersion measures. Astronomy &amp; Astrophysics. 2019;624: A22.Context. High-precision pulsar-timing experiments are affected by temporal variations of the dispersion measure (DM), which are related to spatial variations in the interstellar electron content and the varying line of sight to the source. Correcting for DM variations relies on the cold-plasma dispersion law which states that the dispersive delay varies with the squared inverse of the observing frequency. This may, however, give incorrect measurements if the probed electron content (and therefore the DM) varies with observing frequency, as is predicted theoretically due to the different refraction angles at different frequencies. Aims. We study small-scale density variations in the ionised interstellar medium. These structures may lead to frequency-dependent DMs in pulsar signals. Such an effect could inhibit the use of lower-frequency pulsar observations as tools to correct time-variable interstellar dispersion in higher-frequency pulsar-timing data. Methods. We used high-cadence, low-frequency observations with three stations from the German LOng-Wavelength (GLOW) consortium, which are part of the LOw-Frequency ARray (LOFAR). Specifically, 3.5 yr of weekly observations of PSR J2219+4754 are presented. Results. We present the first detection of frequency-dependent DMs towards any interstellar object and a precise multi-year time-series of the time- and frequency-dependence of the measured DMs. The observed DM variability is significant and may be caused by extreme scattering events. Potential causes for frequency-dependent DMs are quantified and evaluated. Conclusions. We conclude that frequency dependence of DMs has been reliably detected and is indeed caused by small-scale (up to tens of AUs) but steep density variations in the interstellar electron content. We find that long-term trends in DM variability equally affect DMs measured at both ends of our frequency band and hence the negative impact on long-term high-precision timing projects is expected to be limited

    Oxide‐Based Solid‐State Batteries: A Perspective on Composite Cathode Architecture

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    The garnet-type phase Li7_7La3_3Zr2_2O12_{12} (LLZO) attracts significant attention as an oxide solid electrolyte to enable safe and robust solid-state batteries (SSBs) with potentially high energy density. However, while significant progress has been made in demonstrating compatibility with Li metal, integrating LLZO into composite cathodes remains a challenge. The current perspective focuses on the critical issues that need to be addressed to achieve the ultimate goal of an all-solid-state LLZO-based battery that delivers safety, durability, and pack-level performance characteristics that are unobtainable with state-of-the-art Li-ion batteries. This perspective complements existing reviews of solid/solid interfaces with more emphasis on understanding numerous homo- and heteroionic interfaces in a pure oxide-based SSB and the various phenomena that accompany the evolution of the chemical, electrochemical, structural, morphological, and mechanical properties of those interfaces during processing and operation. Finally, the insights gained from a comprehensive literature survey of LLZO–cathode interfaces are used to guide efforts for the development of LLZO-based SSBs

    Surprisingly High Specificity of the PPD Skin Test for M. tuberculosis Infection from Recent Exposure in The Gambia

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    BACKGROUND: Options for intervention against Mycobacterium tuberculosis infection are limited by the diagnostic tools available. The Purified Protein Derivative (PPD) skin test is thought to be non-specific, especially in tropical settings. We compared the PPD skin test with an ELISPOT test in The Gambia. METHODOLOGY/PRINCIPAL FINDINGS: Household contacts over six months of age of sputum smear positive TB cases and community controls were recruited. They underwent a PPD skin test and an ELISPOT test for the T cell response to PPD and ESAT-6/CFP10 antigens. Responsiveness to M. tuberculosis exposure was analysed according to sleeping proximity to an index case using logistic regression. 615 household contacts and 105 community controls were recruited. All three tests assessed increased significantly in positivity with increasing M. tuberculosis exposure, the PPD skin test most dramatically (OR 15.7; 95% CI 6.6–35.3). While the PPD skin test positivity continued to trend downwards in the community with increasing distance from a known case (61.9% to 14.3%), the PPD and ESAT-6/CFP-10 ELISPOT positivity did not. The PPD skin test was more in agreement with ESAT-6/CFP-10 ELISPOT (75%, p = 0.01) than the PPD ELISPOT (53%, p<0.0001). With increasing M. tuberculosis exposure, the proportion of ESAT-6/CFP-10 positive contacts who were PPD skin test positive increased (p<0.0001), and the proportion of ESAT-6/CFP-10 negative contacts that were PPD skin test negative decreased (p<0.0001); the converse did not occur. CONCLUSIONS/SIGNIFICANCE: The PPD skin test has surprisingly high specificity for M. tuberculosis infection from recent exposure in The Gambia. In this setting, anti-tuberculous prophylaxis in PPD skin test positive individuals should be revisited

    Role of GP82 in the Selective Binding to Gastric Mucin during Oral Infection with Trypanosoma cruzi

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    Oral infection by Trypanosoma cruzi has been the primary cause of recent outbreaks of acute Chagas' diseases. This route of infection may involve selective binding of the metacyclic trypomastigote surface molecule gp82 to gastric mucin as a first step towards invasion of the gastric mucosal epithelium and subsequent systemic infection. Here we addressed that question by performing in vitro and in vivo experiments. A recombinant protein containing the complete gp82 sequence (J18), a construct lacking the gp82 central domain (J18*), and 20-mer synthetic peptides based on the gp82 central domain, were used for gastric mucin binding and HeLa cell invasion assays, or for in vivo experiments. Metacyclic trypomastigotes and J18 bound to gastric mucin whereas J18* failed to bind. Parasite or J18 binding to submaxillary mucin was negligible. HeLa cell invasion by metacyclic forms was not affected by gastric mucin but was inhibited in the presence of submaxillary mucin. Of peptides tested for inhibition of J18 binding to gastric mucin, the inhibitory peptide p7 markedly reduced parasite invasion of HeLa cells in the presence of gastric mucin. Peptide p7*, with the same composition as p7 but with a scrambled sequence, had no effect. Mice fed with peptide p7 before oral infection with metacyclic forms developed lower parasitemias than mice fed with peptide p7*. Our results indicate that selective binding of gp82 to gastric mucin may direct T. cruzi metacyclic trypomastigotes to stomach mucosal epithelium in oral infection
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