Biology subjects

Nomaru, H.

Publications and source records attributed to Nomaru, H..

3 recordsLinked to original sources

bioRxiv2023

Label-free ghost cytometry for manufacturing of cell therapy products

Automation and quality control (QC) are critical in manufacturing safe and effective cell and gene therapy products. However, current QC methods, reliant on molecular staining, pose difficulty in in-line testing and can increase manufacturing costs. Here we demonstrate the potential of using label-free ghost cytometry (LF-GC), a machine learning-driven, multidimensional, high-content, and high-throughput flow cytometry approach, in various stages of the cell therapy manufacturing processes. LF-GC accurately quantified cell count and viability of human peripheral blood mononuclear cells (PBMCs) and identified non-apoptotic live cells and early apoptotic/dead cells in PBMCs, T cells and non-T cells in white blood cells (WBCs), activated T cells and quiescent T cells in PBMCs, and particulate impurities in PBMCs. The data support that LF-GC is a non-destructive label-free cell analytical method that can be used to monitor cell numbers, assess viability, identify specific cell subsets or phenotypic states, and remove impurities during cell therapy manufacturing. Thus, LF-GC holds the potential to enable full automation in the manufacturing of cell therapy products with reduced cost and increased efficiency.

cell biology↗

bioRxiv2022

An optimized approach for multiplexing single-nuclear ATAC-seq using oligonucleotide conjugated antibodies

BackgroundSingle-cell technologies to analyze transcription and chromatin structure have been widely used in many research areas to reveal the functions and molecular properties of cells at single-cell resolution. Sample multiplexing techniques are valuable when performing single-cell analysis, reducing technical variation and permitting cost efficiencies. Several commercially available methods are available and have been used in many scRNA-seq studies. On the other hand, while several methods have been published, the multiplexing techniques for single nuclear Assay for Transposase-Accessible Chromatin (snATAC)-seq assays remain under development. We developed a simple nucleus hashing method using oligonucleotide conjugated antibodies recognizing nuclear pore complex proteins, NuHash, to perform snATAC-seq library preparations by multiplexing. ResultsWe performed multiplexing snATAC-seq analyses on the mixture of human and mouse cell samples (two samples, 2-plex, and four samples, 4-plex) using NuHash. The demultiplexing accuracy of NuHash was high, and only ten out of 9,144 nuclei (2-plex) and 150 of 12,208 nuclei (4-plex) had discordant classifications between NuHash demultiplexing and discrimination using reference genome alignments. We compared results between snATAC-seq and deeply sequenced bulk ATAC-seq on the same samples and found that most of the peaks detected in snATAC-seq were also detected in deeply sequenced bulk ATAC-seq. The bulk ATAC-seq signal intensity was positively correlated with the number of cell subtype clusters detected in snATAC-seq, but not the subset of peaks detected in all clusters. These subsets of snATAC-seq peaks showed different distributions over different genomic features, suggesting that the peak intensities of bulk ATAC-seq can be used to identify different types of functional loci. ConclusionsOur multiplexing method using oligo-conjugated anti-nuclear pore complex proteins, NuHash, permits high accuracy demultiplexing of samples. The NuHash protocol is straightforward, it works on frozen samples, and requires no modifications for snATAC-seq library preparation.

genomics↗

bioRxiv2020

Single cell multi-omic analysis identifies a Tbx1-dependent multilineage primed population in the murine cardiopharyngeal mesoderm

The poles of the heart and branchiomeric muscles of the face and neck are formed from the cardiopharyngeal mesoderm (CPM) within the pharyngeal apparatus. The formation of the cardiac outflow tract and branchiomeric muscles are disrupted in patients with 22q11.2 deletion syndrome (22q11.2DS), due to haploinsufficiency of TBX1, encoding a T-box transcription factor. Here, using single cell RNA-sequencing, we identified a multilineage primed population (MLP) within the CPM, marked by the Tbx1 lineage, which has bipotent properties to form cardiac and skeletal muscle cells. The MLPs are localized within the nascent mesoderm of the caudal lateral pharyngeal apparatus and provide a continuous source of progenitors that undergo TBX1-dependent progression towards maturation. Tbx1 also regulates the balance between MLP maintenance and maturation while restricting ectopic non-mesodermal gene expression. We further show that TBX1 confers this balance by direct regulation of MLP enriched genes and downstream pathways, partly through altering chromatin accessibility. Our study thus uncovers a new cell population and reveals novel mechanisms by which Tbx1 directs the development of the pharyngeal apparatus, which is profoundly altered in 22q11.2DS.

developmental biology↗