Analyse de la spécificité antigénique des lymphocytes T auto-réactifs chez des patients atteints de la maladie de Vogt-Koyanagi-Harada.

Vogt-Koyanagi-Harada (VKH) disease is an autoimmune disease affecting the eye, the meninges, theinner ear and the skin. The melanocytes are the cells common to the four affected tissues and areconsidered as the source of self-antigens. Our objective was to identify the antigens targeted bypotentially autoreactive CD4 T lymphocytes obtained from VKH patients. In preliminary experiments,we failed to isolate self-reactive lymphocytes in the blood of two patients. For a third patient with anuntreated uveomeningitidis, we isolated 107 T cell clones from his cerebrospinal fluid. Each of the107 T cell clones, among which ninety percent were CD4+, was tested for its ability to secretecytokines upon contact with autologous presenting cells loaded with either of the followingmelanocytic proteins: TRP1, TRP2, tyrosinase, gp100, Melan-A or KU-MEL-1. None of the 107 Tcell clones was able to specifically secrete TNF- , IFN- , IL-5, or IL-17 upon contact withautologous B cells loaded with the above-mentioned melanocytic proteins. Nine clones were Th17, asthey secreted IL-17 upon non-specific stimulation. Contrary to what would be implied from previousreports, activation of these CD4 T cell clones was not triggered by antigens derived from the sixmelanocytic proteins. This suggests that still undefined self-antigens are involved during the earlyphase of VKH disease.La maladie de Vogt-Koyanagi-Harada (VKH) est une maladie auto-immune touchant les yeux, les méninges et la peau. Les mélanocytes sont des cellules communes aux 4 organes cibles et sont considérés comme la source des auto-antigènes. L'objectif de ce travail est de déterminer la spécificité antigénique de lymphocytes T CD4 potentiellement auto-réactifs obtenus chez des patients VKH. Lors d’expériences préliminaires, nous n’avons pas réussi à isoler de lymphocytes auto-réactifs dans le sang de 2 patients. Dans le cas d’un troisième patient ayant une uvéoméningite non traitée, 107 clones de lymphocytes T dont 90% étaient CD4 +, ont été isolés à partir du liquide cérébrospinal. Chacun d’eux a été testé pour sa capacité à sécréter des cytokines après stimulation avec des cellules présentatrices d'antigènes autologues chargées avec l'une des protéines recombinantes mélanocytaires TRP1, TRP2, tyrosinase, gp100, Melan-A ou KU-MEL-1. Aucun des clones de lymphocytes T n’a été capable de sécréter du TNF-α, de l'IFN-γ, de l’IL-5, ou de l ‘IL-17. Neuf clones secrétaient de l’IL-17 en réponse à une stimulation non spécifique. Contrairement aux données de la littérature, les clones de lymphocytes T CD4 issus du liquide cérébrospinal d'un patient VKH ne reconnaissaient donc pas l’une des six protéines mélanocytaires, suggérant qu’un autre antigène pourrait être impliqué dans le déclenchement de la maladie de VKH

Insights from quantitative and mathematical modelling on the proposed WHO 2030 goals for Chagas disease

article publié sur la plateforme Gates Open researchChagas disease (CD) persists as one of the neglected tropical diseases (NTDs) with a particularly large impact in the Americas. The World Health Organization (WHO) recently proposed goals for CD elimination as a public health problem to be reached by 2030 by means of achieving intradomiciliary transmission interruption (IDTI), blood transfusion and transplant transmission interruption, diagnostic and treatment scaling-up and prevention and control of congenital transmission. The NTD Modelling Consortium has developed mathematical models to study Trypanosoma transmission dynamics and the potential impact of control measures. cruzi Modelling insights have shown that IDTI is feasible in areas with sustained vector control programmes and no presence of native triatomine vector populations. However, IDTI in areas with native vectors it is not feasible in a sustainable manner. Combining vector control with trypanocidal treatment can reduce the timeframes necessary to reach operational thresholds for IDTI (<2% seroprevalence in children aged <5 years), but the most informative age groups for serological monitoring are yet to be identified. Measuring progress towards the 2030 goals will require availability of vector surveillance and seroprevalence data at a fine scale, and a more active surveillance system, as well as a better understanding of the risks of vector re-colonization and disease resurgence after vector control cessation. Also, achieving scaling-up in terms of access to treatment to the expected levels (75%) will require a substantial increase in screening asymptomatic populations, which is anticipated to become very costly as CD prevalence decreases. Further modelling work includes refining and extending mathematical models (including transmission dynamics and statistical frameworks) to predict transmission at a sub-national scale, and developing quantitative tools to inform IDTI certification, post-certification and re-certification protocols. Potential perverse incentives associated with operational thresholds are discussed. These modelling insights aim to inform discussions on the goals and treatment guidelines for CD

Modeling Biochemical Gradients In Vitro to Control Cell Compartmentalization in a Microengineered 3D Model of the Intestinal Epithelium

Gradients of signaling pathways within the intestinal stem cell (ISC) niche are instrumental for cellular compartmentalization and tissue function, yet how are they sensed by the epithelium is still not fully understood. Here a new in vitro model of the small intestine based on primary epithelial cells (i), apically accessible (ii), with native tissue mechanical properties and controlled mesh size (iii), 3D villus-like architecture (iv), and precisely controlled biomolecular gradients of the ISC niche (v) is presented. Biochemical gradients are formed through hydrogel-based scaffolds by free diffusion from a source to a sink chamber. To confirm the establishment of spatiotemporally controlled gradients, light-sheet fluorescence microscopy and in-silico modeling are employed. The ISC niche biochemical gradients coming from the stroma and applied along the villus axis lead to the in vivo-like compartmentalization of the proliferative and differentiated cells, while changing the composition and concentration of the biochemical factors affects the cellular organization along the villus axis. This novel 3D in vitro intestinal model derived from organoids recapitulates both the villus-like architecture and the gradients of ISC biochemical factors, thus opening the possibility to study in vitro the nature of such gradients and the resulting cellular response.© 2022 The Authors. Advanced Healthcare Materials published by Wiley-VCH GmbH

A Deep Insight into the Sialome of Rhodnius neglectus, a vector of chagas disease

Background Triatomines are hematophagous insects that act as vectors of Chagas disease. Rhodnius neglectus is one of these kissing bugs found, contributing to the transmission of this American trypanosomiasis. The saliva of hematophagous arthropods contains bioactive molecules responsible for counteracting host haemostatic, inflammatory, and immuneresponses. Methods/Principal Findings Next generation sequencing and mass spectrometry-based protein identification were performed to investigate the content of triatomine R. neglectus saliva.We deposited 4,230 coding DNA sequences (CDS) in GenBank. A set of 636 CDS of proteins of putative secretory nature was extracted from the assembled reads, 73 of them confirmed by proteomic analysis. The sialome of R. neglectus was characterized and serine protease transcripts detected. The presence of ubiquitous protein families was revealed, including lipocalins, serine protease inhibitors, and antigen-5. Metalloproteases, disintegrins, and odorant binding protein families were less abundant. Conclusions/Significance The data presented improve our understanding of hematophagous arthropod sialomes, and aid in understanding hematophagy and the complex interplay among vectors and their vertebrate hosts

Measurement of differential cross sections for top quark pair production using the lepton plus jets final state in proton-proton collisions at 13 TeV

National Science Foundation (U.S.

Identification of heavy-flavour jets with the CMS detector in pp collisions at 13 TeV

Many measurements and searches for physics beyond the standard model at the LHC rely on the efficient identification of heavy-flavour jets, i.e. jets originating from bottom or charm quarks. In this paper, the discriminating variables and the algorithms used for heavy-flavour jet identification during the first years of operation of the CMS experiment in proton-proton collisions at a centre-of-mass energy of 13 TeV, are presented. Heavy-flavour jet identification algorithms have been improved compared to those used previously at centre-of-mass energies of 7 and 8 TeV. For jets with transverse momenta in the range expected in simulated $\mathrm{t}\overline{\mathrm{t}}$ events, these new developments result in an efficiency of 68% for the correct identification of a b jet for a probability of 1% of misidentifying a light-flavour jet. The improvement in relative efficiency at this misidentification probability is about 15%, compared to previous CMS algorithms. In addition, for the first time algorithms have been developed to identify jets containing two b hadrons in Lorentz-boosted event topologies, as well as to tag c jets. The large data sample recorded in 2016 at a centre-of-mass energy of 13 TeV has also allowed the development of new methods to measure the efficiency and misidentification probability of heavy-flavour jet identification algorithms. The heavy-flavour jet identification efficiency is measured with a precision of a few per cent at moderate jet transverse momenta (between 30 and 300 GeV) and about 5% at the highest jet transverse momenta (between 500 and 1000 GeV)

Particle-flow reconstruction and global event description with the CMS detector

The CMS apparatus was identified, a few years before the start of the LHC operation at CERN, to feature properties well suited to particle-flow (PF) reconstruction: a highly-segmented tracker, a fine-grained electromagnetic calorimeter, a hermetic hadron calorimeter, a strong magnetic field, and an excellent muon spectrometer. A fully-fledged PF reconstruction algorithm tuned to the CMS detector was therefore developed and has been consistently used in physics analyses for the first time at a hadron collider. For each collision, the comprehensive list of final-state particles identified and reconstructed by the algorithm provides a global event description that leads to unprecedented CMS performance for jet and hadronic tau decay reconstruction, missing transverse momentum determination, and electron and muon identification. This approach also allows particles from pileup interactions to be identified and enables efficient pileup mitigation methods. The data collected by CMS at a centre-of-mass energy of 8 TeV show excellent agreement with the simulation and confirm the superior PF performance at least up to an average of 20 pileup interactions

Search for heavy resonances decaying to a top quark and a bottom quark in the lepton+jets final state in proton–proton collisions at 13 TeV

info:eu-repo/semantics/publishe

Evidence for the Higgs boson decay to a bottom quark–antiquark pair

info:eu-repo/semantics/publishe

Pseudorapidity and transverse momentum dependence of flow harmonics in pPb and PbPb collisions

info:eu-repo/semantics/publishe