18 research outputs found
Multi-loci diagnosis of acute lymphoblastic leukaemia with high-throughput sequencing and bioinformatics analysis
International audienceHigh-throughput sequencing (HTS) is considered a technical revolution that has improved our knowledge of lymphoid and autoimmune diseases, changing our approach to leukaemia both at diagnosis and during follow-up. As part of an immunoglobulin/T cell receptor-based minimal residual disease (MRD) assessment of acute lymphoblastic leukaemia patients, we assessed the performance and feasibility of the replacement of the first steps of the approach based on DNA isolation and Sanger sequencing, using a HTS protocol combined with bioinformatics analysis and visualization using the Vidjil software. We prospectively analysed the diagnostic and relapse samples of 34 paediatric patients, thus identifying 125 leukaemic clones with recombinations on multiple loci (TRG, TRD, IGH and IGK), including Dd2/Dd3 and Intron/KDE rearrangements. Sequencing failures were halved (14% vs. 34%, P = 0.0007), enabling more patients to be monitored. Furthermore, more markers per patient could be monitored, reducing the probability of false negative MRD results. The whole analysis, from sample receipt to clinical validation, was shorter than our current diagnostic protocol, with equal resources. V(D)J recombination was successfully assigned by the software, even for unusual recombinations. This study emphasizes the progress that HTS with adapted bioinformatics tools can bring to the diagnosis of leukaemia patients
Fast multiclonal clusterization of V(D)J recombinations from high-throughput sequencing
International audienceBACKGROUND: V(D)J recombinations in lymphocytes are essential for immunological diversity. They are also usefulmarkers of pathologies. In leukemia, they are used to quantify the minimal residual disease duringpatient follow-up. However, the full breadth of lymphocyte diversity is not fully understood. RESULTS: We propose new algorithms that process high-throughput sequencing (HTS) data to extract unnamedV(D)J junctions and gather them into clones for quantification. This analysis is based on a seedheuristic and is fast and scalable because in the first phase, no alignment is performed with germlinedatabase sequences. The algorithms were applied to TR HTS data from a patient with acutelymphoblastic leukemia, and also on data simulating hypermutations. Our methods identified themain clone, as well as additional clones that were not identified with standard protocols. CONCLUSIONS: The proposed algorithms provide new insight into the analysis of high-troughput sequencing data forleukemia, and also to the quantitative assessment of any immunological profile. The methodsdescribed here are implemented in a C++ open-source program called Vidjil
Fast multiclonal clusterization of V(D)J recombinations from high-throughput sequencing
International audienceBACKGROUND: V(D)J recombinations in lymphocytes are essential for immunological diversity. They are also usefulmarkers of pathologies. In leukemia, they are used to quantify the minimal residual disease duringpatient follow-up. However, the full breadth of lymphocyte diversity is not fully understood. RESULTS: We propose new algorithms that process high-throughput sequencing (HTS) data to extract unnamedV(D)J junctions and gather them into clones for quantification. This analysis is based on a seedheuristic and is fast and scalable because in the first phase, no alignment is performed with germlinedatabase sequences. The algorithms were applied to TR HTS data from a patient with acutelymphoblastic leukemia, and also on data simulating hypermutations. Our methods identified themain clone, as well as additional clones that were not identified with standard protocols. CONCLUSIONS: The proposed algorithms provide new insight into the analysis of high-troughput sequencing data forleukemia, and also to the quantitative assessment of any immunological profile. The methodsdescribed here are implemented in a C++ open-source program called Vidjil
: Recueil de fiches peÌdagogiques du reÌseau MAPS
DoctoralLe reÌseau theÌmatique MAPS «ModeÌlisation multi-Agent appliqueÌe aux PheÌnomeÌnes SpatialiseÌs » propose depuis 2009 des eÌveÌnements scientifiques ayant pour but de diffuser les pratiques de modeÌlisations multi-agents au sein des Sciences de lâHomme et de la SocieÌteÌ (SHS). Ce collectif pluridisciplinaire de chercheurs, dâenseignants-chercheurs et de doctorants est labelliseÌ en tant que âȘ reÌseau theÌmatique » par le ReÌseau National des SysteÌmes Complexes (GIS RNSC) et beÌneÌficie du soutien du CNRS au titre de la Formation Permanente. Depuis 2009, plusieurs modĂšles ont Ă©tĂ© dĂ©veloppĂ©s au cours d'Ă©vĂ©nements MAPS. Ces modĂšles ont fait l'objet de fiches pĂ©dagogiques dĂ©taillĂ©es destineÌes aux communauteÌs eÌducatives et universitaires et en particulier aux enseignants qui souhaiteraient faire deÌcouvrir la modeÌlisation aÌ leurs eÌtudiants, mais aussi aÌ ceux qui envisagent dâapprofondir certains aspects avec un public plus averti. Elles sont eÌgalement destineÌes aÌ tous les curieux qui souhaiteraient deÌcouvrir ce que la modeÌlisation apporte aux SHS, du point de vue heuristique et du point de vue opeÌrationnel. Enfin, elles sont aussi des supports pour toutes les personnes qui souhaiteraient diffuser les reÌflexions scientifiques sur la modeÌlisation et la simulation qui ont preÌsideÌ aÌ la reÌdaction de ces fiches
3D otolith shape for the main commercial species (flatfish and roundfish) in the Eastern Channel and the North Sea
Otolith shape analysis is commonly used in fisheries sciences to validate the relationship with fish length, to discriminate between stock units of fish, and to identify fish species from archeological data or stomach contents. However, all otolith studies have used two-dimensional (2D) images, a partial representation of the whole shape of the otolith. This study presents a comparative analysis of 2D and three-dimensional (3D) otolith shape data for many commercial species (flatfish: Lepidorhombus whiffiagonis, Scophthalmus maximus, Scophthalmus rhombus, Solea solea, Limanda limanda, Microstomus kitt, Platichthys flesus, Pleuronectes platessa and roundfish: Clupea harengus, Sardina pilchardus, Sprattus sprattus, Engraulis encrasicolus, Gadus morhua, Melanogrammus aeglefinus, Merlangius merlangus, Trisopterus luscus, Mullus surmuletus, Eutrigla gurnardus, Chelidonichthys cuculus, Chelidonichthys lucerna, Trachurus trachurus, Zeus faber) in the Eastern English Channel and the North Sea. 2D otolith images were made with an optical scanner, and 3D otolith images with an X-ray microtomograph. For each species, several specimens were selected from the complete size range. Otolith shape was assessed by analyzing several descriptors from 2D and 3D images from the otolith size parameters (Length, Width, Perimeter, Area and Volume). The relationship between fish length and otolith shape parameters are not the same within species and/or among species for 2D versus 3D data. Moreover, the relationship between 2D otolith size parameters and 3D otolith parameters are different among species. These results demonstrate the importance of 3D otolith shape analysis. In the future, the number of studies using otolith shape analysis in three dimensions must be increased strongly to validate previous studies on 2D images.  Â
A dataset of sequences with manually curated V(D)J designations
Workshop Immune Repertoire Sequencing : Bioinformatics and Applications in Hematology and Immunology (RepSeq 2016
Diagnostic et suivi des leucémies aiguës lymphoblastiques (LAL) par séquençage haut-débit (HTS)
National audienceLe diagnostic molĂ©culaire des LAL permet, par la recherche de rĂ©arrangements V (D) J sur lâADN des lymphoblastes, de mettre en Ă©vidence des marqueurs de clonalitĂ© dans 95% des cas. Ces marqueurs servent aussi Ă quantifier la maladie rĂ©siduelle par Q-PCR en temps rĂ©el (chimie Taqman) afin dâadapter au mieux la thĂ©rapeutique. Cette stratĂ©gie peut Ă©chouer dans les cas suivants : absence de marqueur initial, Ă©chec du sĂ©quençage ou enfin Ă©mergence Ă la rechute dâun clone non observĂ© au diagnostic ou trĂšs minoritaire. Le HTS autorise dĂ©sormais le sĂ©quençage profond d'une population lymphoĂŻde et permet de contourner ces Ă©cueils. Ce travail explore l'utilisation de cette technologie pour le diagnostic et le suivi des LAL.La clonalitĂ© de 8 patients pĂ©diatriques (5 LAL-B et 3 LAL-T, 2F/6M, 2 Ă 14 ans), au diagnostic et en suivi (37 points) a Ă©tĂ© Ă©tudiĂ©e . La sensibilitĂ© a Ă©tĂ© Ă©valuĂ©e par une gamme de dilution dâADN tumoral en ADN de PBL (de 10-2 Ă 10-5). Pour chaque Ă©chantillon, 500ng dâADN mĂ©dullaire sont extraits sur colonne QiagenÂź, dosĂ©s sur NanoDropÂź et amplifiĂ©s par les systĂšmes de PCR classiques, non fluorescents pour la cible TCRg et les IgH, systĂšmes dĂ©crits ou dĂ©rivĂ©s des travaux du Biomed-2. Les librairies de sĂ©quençages sont rĂ©alisĂ©es Ă partir des produits de PCR vĂ©rifiĂ©s sur gel dâagarose puis barre-codĂ©es et sĂ©quencĂ©es avec un sĂ©quenceur Ion Torrent (puce 318).Les sĂ©quences obtenues sont classĂ©es sur la base de leur rĂ©arrangement V (D) J par le logiciel Vidjil dĂ©diĂ© (http : //bioinfo.lifl.fr/vidjil). Nous avons identifiĂ© les clones et leurs proportions respectives au diagnostic, et Ă©tudiĂ© leur Ă©volution aux diffĂ©rents points de suivi. Nous avons retrouvĂ© les clones dĂ©tectĂ©s par les mĂ©thodes classiques mais aussi mis en Ă©vidence des clones minoritaires. Les rechutes ont Ă©tĂ© retrouvĂ©es, et, pour un patient, un clone Ă©mergent a Ă©tĂ© observĂ©. L'ensemble de l'analyse validĂ©e, incluant la prĂ©paration, le sĂ©quençage et l'analyse informatique, semble plus rapide que par les protocoles actuels.Par la reconstruction de rĂ©pertoires lymphoĂŻdes, le HTS prĂ©figure des avancĂ©es dans la connaissance des pathologies lymphomateuses et auto-immunes. Notre objectif est dâintĂ©grer cette technologie dans le processus molĂ©culaire de diagnostic et de suivi des LAL, ce qui pose aussi des dĂ©fis de formation Ă lâanalyse et lâinterprĂ©tation des rĂ©sultats et de praticitĂ© au sein d'un laboratoire d'hĂ©matologie. Le sĂ©quençage haut-dĂ©bit, couplĂ© Ă une analyse bioinformatique, donne une cartographie plus complĂšte de la population blastique au diagnostic dâune LAL et permet d'observer lâĂ©volution de cette population