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de Bourcy, C. F. A.

Publications and source records attributed to de Bourcy, C. F. A..

2 recordsLinked to original sources

IDseq - An Open Source Cloud-based Pipeline and Analysis Service for Metagenomic Pathogen Detection and Monitoring

BackgroundMetagenomic next generation sequencing (mNGS) has enabled the rapid, unbiased detection and identification of microbes without pathogen-specific reagents, culturing, or a priori knowledge of the microbial landscape. mNGS data analysis requires a series of computationally intensive processing steps to accurately determine the microbial composition of a sample. Existing mNGS data analysis tools typically require bioinformatics expertise and access to local server-class hardware resources. For many research laboratories, this presents an obstacle, especially in resource limited environments. FindingsWe present IDseq, an open source cloud-based metagenomics pipeline and service for global pathogen detection and monitoring (https://idseq.net). The IDseq Portal accepts raw mNGS data, performs host and quality filtration steps, then executes an assembly-based alignment pipeline which results in the assignment of reads and contigs to taxonomic categories. The taxonomic relative abundances are reported and visualized in an easy-to-use web application to facilitate data interpretation and hypothesis generation. Furthermore, IDseq supports environmental background model generation and automatic internal spike-in control recognition, providing statistics which are critical for data interpretation. IDseq was designed with the specific intent of detecting novel pathogens. Here, we benchmark novel virus detection capability using both synthetically evolved viral sequences, and real-world samples, including IDseq analysis of a nasopharyngeal swab sample acquired and processed locally in Cambodia from a tourist from Wuhan, China, infected with the recently emergent SARS-CoV-2. ConclusionThe IDseq Portal reduces the barrier to entry for mNGS data analysis and enables bench scientists, clinicians, and bioinformaticians to gain insight from mNGS datasets for both known and novel pathogens.

bioinformatics↗

Dynamics Of The Human Antibody Repertoire Following B-cell Depletion In Systemic Sclerosis

Systemic sclerosis with pulmonary arterial hypertension (SSc-PAH) is a debilitating and frequently lethal disease of unknown cause lacking effective treatment options. Lymphocyte anomalies and autoantibodies observed in systemic sclerosis have suggested an autoimmune character. Here we study the clonal structure of the B-cell repertoire in SSc-PAH using immunoglobulin heavy-chain sequencing before and after B-cell depletion. We found SSc-PAH to be associated with anomalies in B-cell development, namely altered VDJ rearrangement frequencies (reduced IGHV2-5 segment usage) and an increased somatic mutation-fixation probability in expanded B-cell lineages. SSc-PAH was also characterized by anomalies in B-cell homeostasis, namely an expanded IgD+ proportion with reduced mutation loads and an expanded proportion of highly antibody-secreting cells. Disease signatures pertaining to IGHV2-5 segment usage, IgD proportions and mutation loads were temporarily reversed after B-cell depletion. Analyzing the time course of B-cell depletion, we find that the kinetics of naive replenishment are predictable from baseline measurements alone, that release of plasma cells into the periphery can precede naive replenishment and that modes of B-cell receptor diversity are highly elastic. Our findings shed light on the humoral immune basis of SSc-PAH and provide insights into the effect of B-cell depletion on the antibody repertoire.\n\nAbbreviations

immunology↗