Project description:The sequence assembly of the human gut virome encounters several difficulties. A high proportion of human and bacterial matches is detected in purified viral samples. Viral DNA extraction results in a low DNA concentration, which does not reach the minimal limit required for sequencing library preparation. Therefore, the viromes are usually enriched by whole genome amplification (WGA), which is, however, prone to the development of chimeras and amplification bias. In addition, as there is a very wide diversity of gut viral species, very extensive sequencing efforts must be made for the assembling of whole viral genomes. We present an approach to improve human gut virome assembly by employing a more precise preparation of a viral sample before sequencing. Particles present in a virome previously filtered through 0.2 ?m pores were further divided into groups in accordance with their size and DNA content by fluorescence activated cell sorting (FACS). One selected viral fraction was sequenced excluding the WGA step, so that unbiased sequences with high reliability were obtained. The DNA extracted from the 314 viral particles of the selected fraction was assembled into 34 contigs longer than 1,000 bp. This represents an increase to the number of assembled long contigs per sequenced Gb in comparison with other studies where non-fractioned viromes are sequenced. Seven of these contigs contained open reading frames (ORFs) with explicit matches to proteins related to bacteriophages. The remaining contigs also possessed uncharacterized ORFs with bacteriophage-related domains. When the particles that are present in the filtered viromes are sorted into smaller groups by FACS, large pieces of viral genomes can be recovered easily. This approach has several advantages over the conventional sequencing of non-fractioned viromes: non-viral contamination is reduced and the sequencing efforts required for viral assembly are minimized.
Project description:This study was designed to investigate the efficacy of flow cytometry to accurately identify between normal and cancer cells in colon epithelium in humans diagnosed with colorectal cancer.
Project description:To investigate a non-invasive strategy for immune monitoring the peripheral blood by flow cytometry, to address the critical need to itdentify predictive immunological biomarkers that correlate with treatment response Peripheral blood mononuclear cells (PBMCs) from 19 non–small-cell lung cancer (NSCLC) patients before and after ICI treatment and four healthy human donors were evaluated, utilizing spectral flow to monitor 24 immune cell markers simultaneously over the course of treatment. We performed immune cell profiling analysis using data obtained from RNA-seq of 19 different patients before and after immunotherapy, to validate the multi-color flow based immune profiling
Project description:We have developed a methodology for isolation of high-quality RNA from cells that are fixed, stained and sorted by flow cytometry that allows routine transcriptomic analysis of highly purified cell populations and single cells. This method, essentially developed by modifying existing staining and sorting protocols, involves fixation of cells with glyoxal, an alternative fixative to commonly used formaldehyde, followed by methanol permeabilization, a 2-step primary and secondary antibody staining and sorting by flow cytometry. The advantage of using glyoxal is that it does not crosslink RNA to proteins nor form stable RNA adducts, ensuring that RNA remains accessible and amenable to enzymatic manipulation after glyoxal fixation. The dataset comprising mRNA seq libraries from unprocessed or fixed and stained human cancer cells demonstrate that RNA recovered from glyoxal-fixed cells does not retain sufficient glyoxal adducts to impair reverse transcription, and also reveal very few differentially expressed genes between the 2 groups. The dataset derived from fixed and stained cells that were sorted into CCNB1 positive or negative fractions show the applicability of this method for sorting highly purified cell fractions as the CCNB1 positive fractions show strong enrichment for G2-phase cells according to the GO analysis.
Project description:New techniques for single-cell analysis have led to insights into hematopoiesis and the immune system, but the ability of these techniques to cross-validate and reproducibly identify the biological variation in diverse human samples is currently unproven. We therefore performed a comprehensive assessment of human bone marrow cells using both single-cell RNA sequencing and multiparameter flow cytometry from twenty healthy adult human donors across a broad age range. These data characterize variation between healthy donors as well as age-associated changes in cell population frequencies. Direct comparison of techniques revealed discrepancy in the quantification of T lymphocyte and natural killer cell populations. Orthogonal validation of immunophenotyping using mass cytometry demonstrated good correlation with flow cytometry. Technical replicates using single-cell RNA sequencing matched robustly, while biological replicates showed variation. Given the increasing use of single-cell technologies in translational research, this resource serves as an important reference dataset and highlights opportunities for further refinement. [Funding source] Project Number: 1ZIAHL006163-05 Contact PI / Project Leader: HOURIGAN, CHRISTOPHER Title: DETECTION, PREVENTION AND TREATMENT OF ACUTE MYELOID LEUKEMIA (AML) RELAPSE. Awardee Organization: NATIONAL HEART, LUNG, AND BLOOD INSTITUTE
