| Id |
Subject |
Object |
Predicate |
Lexical cue |
| T303 |
0-21 |
Sentence |
denotes |
MATERIALS AND METHODS |
| T304 |
23-37 |
Sentence |
denotes |
Human subjects |
| T305 |
38-180 |
Sentence |
denotes |
The study was approved by the Ethics Committee of Zhongshan Ophthalmic Center, China and the Ethics Committee of Wuhan Hankou Hospital, China. |
| T306 |
181-368 |
Sentence |
denotes |
A written informed consent was routinely obtained from all individuals participating in the study and all relevant ethical regulations regarding human research participants were followed. |
| T307 |
369-537 |
Sentence |
denotes |
Healthy non-frail individuals were recruited in the Zhongshan Ophthalmic Center, and divided by age into two groups in cohort-1: young adults (YA) and aged adults (AA). |
| T308 |
538-640 |
Sentence |
denotes |
The YA group ranged from ages 20 to 45 years old and the AA group ranged from ages 60 to 80 years old. |
| T309 |
641-829 |
Sentence |
denotes |
COVID-19 patients diagnosed by real-time fluorescent quantitative reverse transcription polymerase chain reaction (RT-qPCR) and CT images were enrolled in the Wuhan Hankou Hospital, China. |
| T310 |
830-1106 |
Sentence |
denotes |
Based on their clinical history, patients were divided into incipient and recovered groups in cohort-2 and cohort-3 respectively, and the incipient hospitalized patients were further divided by age into young COVID-19 patient onset (YCO) and aged COVID-19 patient onset (ACO). |
| T311 |
1107-1293 |
Sentence |
denotes |
Enrolled patients that tested negative with nucleic acid transfer in 7–14 days were further divided into young COVID-19 patient recovered (YCR) and aged COVID-19 patient recovered (ACR). |
| T312 |
1294-1434 |
Sentence |
denotes |
Individuals with comorbid conditions including cancer, immunocompromising disorders, hypertension, diabetes and steroid usage were excluded. |
| T313 |
1435-1657 |
Sentence |
denotes |
No significant gender differences were detected between YA group and AA group in cohort-1 (Table S1C–E), between YH, AH, YCO and ACO group in cohort-2 (Table S1F), between YH, AH, YCR and ACR group in cohort-3 (Table S1G). |
| T314 |
1659-1682 |
Sentence |
denotes |
Antibodies and reagents |
| T315 |
1683-1836 |
Sentence |
denotes |
Antibodies against the following markers in flow cytometric analysis were purchased from Biolegend, BD biosciences and Abcam: CD3 (clone SK7) BV785 (Cat. |
| T316 |
1837-1873 |
Sentence |
denotes |
344842), CD19 (clone HB19) APC (Cat. |
| T317 |
1874-1913 |
Sentence |
denotes |
302212), CD88 (clone S5/1) PE/Cy7 (Cat. |
| T318 |
1914-1952 |
Sentence |
denotes |
344307), CD89 (clone A59) PE/Cy7 (Cat. |
| T319 |
1953-1992 |
Sentence |
denotes |
354107), HLA-DR (clone L243) FITC (Cat. |
| T320 |
1993-2031 |
Sentence |
denotes |
307604), CD11c (clone 3.9) BV421 (Cat. |
| T321 |
2032-2080 |
Sentence |
denotes |
301627), FcεRIa (clone AER-37) PercP/Cy5.5 (Cat. |
| T322 |
2081-2119 |
Sentence |
denotes |
334622), CD1c (clone L161) BV650 (Cat. |
| T323 |
2120-2166 |
Sentence |
denotes |
331541), CD371 (CLEC12A) (clone 50C1) PE (Cat. |
| T324 |
2167-2233 |
Sentence |
denotes |
353603) were purchased from Biolegend, CD147 (clone HIM6) PE (Cat. |
| T325 |
2234-2276 |
Sentence |
denotes |
562552) was purchased from BD biosciences. |
| T326 |
2277-2307 |
Sentence |
denotes |
Fetal bovine serum (FBS) (Cat. |
| T327 |
2308-2349 |
Sentence |
denotes |
10270-106), penicillin/streptomycin (Cat. |
| T328 |
2350-2392 |
Sentence |
denotes |
15140-122), and Trypsin-EDTA (0.25%) (Cat. |
| T329 |
2393-2430 |
Sentence |
denotes |
25200-072) were purchased from GIBCO. |
| T330 |
2431-2448 |
Sentence |
denotes |
RT-qPCR kit (Cat. |
| T331 |
2449-2486 |
Sentence |
denotes |
25200-072) was purchased from TaKaRa. |
| T332 |
2488-2524 |
Sentence |
denotes |
Detection of SARS-Cov-2 with RT-qPCR |
| T333 |
2525-2680 |
Sentence |
denotes |
Samples used for RT-qPCR were blood, upper respiratory tract sputum and throat swab obtained from patients at specified time-points during hospitalization. |
| T334 |
2681-2786 |
Sentence |
denotes |
The patient samples were collected, processed and analyzed following the guideline stipulated by the WHO. |
| T335 |
2787-2932 |
Sentence |
denotes |
To extract viral RNA, the specimens were treated with the QIAamp RNA Viral Kit (Qiagen, Heiden, Germany) following the manufacturer’s guidelines. |
| T336 |
2933-3148 |
Sentence |
denotes |
The presence of SARS-CoV-2 infection was confirmed with a China CDC recommended RT-qPCR kit (TaKaRa, Dalian, China). qPCR was performed as previously described (Zhang et al., 2019; Bi et al., 2020; Li et al., 2020). |
| T337 |
3150-3213 |
Sentence |
denotes |
Isolation of PBMCs for mass cytometry, scRNA-seq and scATAC-seq |
| T338 |
3214-3445 |
Sentence |
denotes |
For pipeline analysis, venous blood samples were derived from each healthy donor or patient using Ficoll-Hypaque density solution, heparinized and then processed by standard density gradient centrifugation methods to isolate PBMCs. |
| T339 |
3446-3543 |
Sentence |
denotes |
The viability and quantity of PBMCs in single-cell suspensions were determined using Trypan Blue. |
| T340 |
3544-3593 |
Sentence |
denotes |
For each sample, the cell viability exceeded 90%. |
| T341 |
3594-3773 |
Sentence |
denotes |
For each sample with more than 1 × 107 viable cells, a fraction of PBMCs was extracted for scRNA-seq analysis, a fraction of PBMCs was allocated for scATAC-seq and mass cytometry. |
| T342 |
3775-3799 |
Sentence |
denotes |
Flow cytometric analysis |
| T343 |
3800-4010 |
Sentence |
denotes |
PBMCs suspended in phosphate buffered saline (PBS) were cultured with Live/Dead yellow dye (Invitrogen) at 4 °C for 30 min and then washed once with 1 mL of PBS containing 1% FBS (GIBCO, Grand Island, NY, USA). |
| T344 |
4011-4079 |
Sentence |
denotes |
Subsequently, cells were treated with antibodies for 30 min at 4 °C. |
| T345 |
4080-4486 |
Sentence |
denotes |
These antibodies included: CD3-BV785 (clone SK7, Biolegend), CD19-APC (clone HB19, Biolegend), CD88-PE/Cy7 (clone S5/1, Biolegend), CD89-PE/Cy7 (clone A59, Biolegend), HLA-DR-FITC (clone L243, Biolegend), CD11c-BV421 (clone 3.9, Biolegend), FcεRIa- PercP/Cy5.5 (clone AER-37, Biolegend), CD1c-BV650 (clone L161, Biolegend), CD147-PE (clone HIM6, BD biosciences), CD371 (CLEC12A)-PE (clone 50C1, Biolegend). |
| T346 |
4487-4662 |
Sentence |
denotes |
Analysis of PBMCs with flow cytometry was conducted with BD Fortessa (BD Biosciences) and the results were evaluated with FlowJo (version 10.0.7, Tree Star, Ashland, OR, USA). |
| T347 |
4664-4719 |
Sentence |
denotes |
Mass cytometry live cell barcoding and surface staining |
| T348 |
4720-4859 |
Sentence |
denotes |
We made use of a live cell barcoding approach to minimize inter-sample staining variability, sample handling time and antibody consumption. |
| T349 |
4860-5018 |
Sentence |
denotes |
After incubating with anti-human CD45 loaded with different isotopes (89Y, 162Dy, 165Ho, 169Tm, 175Lu), all the samples were then pooled for surface staining. |
| T350 |
5019-5187 |
Sentence |
denotes |
The Maxpar Direct Immune Profiling Assay (Fluidigm) was used for cell surface staining and the monoclonal anti-human antibodies in the assay kit are listed as Table S2. |
| T351 |
5188-5610 |
Sentence |
denotes |
Barcoded and combined samples were washed and stained with viability dyes cisplatin-195pt (0.5 μmolL) (Fluidigm, 201064) and vortexed to mix thoroughly for 2 min at room temperature for cell viability, terminated with Maxpar Cell Staining buffer at room temperature (400 rcf.), washed, fixed with 1.6% paraformaldehyde (PFA; Electron Microscopy Sciences) in PBS for 10 min at room temperature on a rotary shaker (500 rpm). |
| T352 |
5611-5701 |
Sentence |
denotes |
The fixed cells were resuspended in pre-cooling Maxpar Cell Staining to slow fix reaction. |
| T353 |
5702-5858 |
Sentence |
denotes |
Fixed samples were washed twice with PBS/bovine serum albumin and once with double-distilled water before resuspended in 400 μL of surface-antibody mixture. |
| T354 |
5859-5941 |
Sentence |
denotes |
Surface staining was performed for 30 min at 37 °C on a rotating shaker (500 rpm). |
| T355 |
5942-6129 |
Sentence |
denotes |
The samples then stored in freshly diluted 2% formaldehyde (Electron Microscopy Sciences) in PBS containing 0.125 nmol/L iridium 191/193 intercalator (Fluidigm, 201192) at 4 °C overnight. |
| T356 |
6131-6190 |
Sentence |
denotes |
scRNA-seq data alignment, processing and sample aggregation |
| T357 |
6191-6426 |
Sentence |
denotes |
The Chromium Single Cell 5′ Library (the 10x Genomics chromium platform Illumina NovaSeq6000), Gel Bead and Multiplex Kit, and Chip Kit (10x Genomics) were used to convert single-cell suspension samples to barcoded scRNA-seq libraries. |
| T358 |
6427-6575 |
Sentence |
denotes |
Single-cell RNA libraries were prepared using the Chromium Single Cell 5′ v2 Reagent (10x Genomics, 120237) kit as per the manufacturer’s protocols. |
| T359 |
6576-6643 |
Sentence |
denotes |
The quality of the libraries was checked using the FastQC software. |
| T360 |
6644-6774 |
Sentence |
denotes |
Initial processing of the sequenced data was performed using CellRanger software (https://support.10xgenomics.com, version 3.1.0). |
| T361 |
6775-6958 |
Sentence |
denotes |
The command Cell Ranger count in CellRanger Software Suite (10x Genomics) was used to demultiplex and barcode the sequences derived from the 10x Genomics single-cell RNA-seq platform. |
| T362 |
6959-7263 |
Sentence |
denotes |
The data was filtered, normalized, dimensionality was reduced, clustered, and differential gene expression analysis were performed after calculation of the single-cell expression matrix by CellRanger using Python (version 3.7.7) Scanpy (https://scanpy.readthedocs.io/en/stable/index.html, version 1.4.6). |
| T363 |
7264-7403 |
Sentence |
denotes |
Data collection and the subsequent analyses were performed in an unsupervised manner, but not blinded to the conditions of the experiments. |
| T364 |
7404-7605 |
Sentence |
denotes |
For quality control, the filtered cell population was mainly those cells that express HBB, HBA1, and several light and heavy chain transcripts, which identified as the RBC-contaminated cell population. |
| T365 |
7606-7751 |
Sentence |
denotes |
Likewise, several clusters expressing genes has no significance (P ≥ 0.1, calculate by 10x genomics Loupe Cell Browser with it default algorithm. |
| T366 |
7752-7847 |
Sentence |
denotes |
P values are adjusted using the Benjamini-Hochberg correction for multiple tests) were removed. |
| T367 |
7848-7989 |
Sentence |
denotes |
A total of 16 libraries were sequenced, and 166,609 cells (YA 77,652 cells, AA 88,957 cells) were analyzed after quality control in cohort-1. |
| T368 |
7990-8148 |
Sentence |
denotes |
For cohort-3, 22 libraries and 205,434 cells (YH 79,039 cells, AH 88,750 cells, YCR 19,533 cells, ACR 18,112 cells) were remained for the subsequent analysis. |
| T369 |
8149-8448 |
Sentence |
denotes |
The genes used in principal component analysis (PCA) analysis have eliminated mitochondria (MT), and ribosomes (RPL and RPS) genes with 50 principal components, and then aligned together, followed by t-distributed stochastic neighbor embedding (t-SNE) are both used after the results of the aligned. |
| T370 |
8449-8631 |
Sentence |
denotes |
And using the run_harmony function (in pyharmony package, version 1.0.7) and combat function (in Scanpy) methods to deal with batch effect issues if batch effect existing in dataset. |
| T371 |
8632-8701 |
Sentence |
denotes |
Genes not detected in any cell were removed from subsequent analysis. |
| T372 |
8703-8773 |
Sentence |
denotes |
Dimensionality reduction and clustering analysis of scRNA-seq datasets |
| T373 |
8774-9020 |
Sentence |
denotes |
To analyze the scRNA-seq data, we log normalized data (1 + counts per 10,000) with the ‘‘sc.pp.normalize_total’’ function before clustering, reduction and performing 2-dimensional t-SNE algorithm clustering with the first 50 principal components. |
| T374 |
9021-9168 |
Sentence |
denotes |
This was done following PCA on top 5,000 most variable genes by using “sc.pp.highly_variable_genes” function in Scanpy with the default parameters. |
| T375 |
9169-9375 |
Sentence |
denotes |
Dimensionality method and identification of significant clusters and was performed using Leiden clustering algorithm which uses a shared nearest neighbour modularity optimization-based clustering algorithm. |
| T376 |
9376-9496 |
Sentence |
denotes |
Marker genes for each significant cluster were found using the function sc.tl.rank_genes_groups with default parameters. |
| T377 |
9498-9530 |
Sentence |
denotes |
Differential expression analysis |
| T378 |
9531-9780 |
Sentence |
denotes |
Differential expression analysis for each cell type between different groups (YA and AA in cohort-1 and YH, AH, YCR and ACR in cohort-3) was performed using the t-test as implemented in the ‘‘sc.tl.rank_genes_groups’’ function of the Scanpy package. |
| T379 |
9781-9918 |
Sentence |
denotes |
For each cluster, differentially-expressed genes (DEGs) were performed using the t-test and generated relative to all of the other cells. |
| T380 |
9919-10078 |
Sentence |
denotes |
Before executing the differential expression analysis, we filtered out the cell types that were missing or had fewer than three cells in the comparison groups. |
| T381 |
10079-10348 |
Sentence |
denotes |
An aging-associated and disease-related DEG dataset was established (adjusted P value < 0.05, |Log2FC| > 0.25) after identification of DEGs between AA and YA groups in cohort-1, AH and YH groups in cohort-3, ACR and AH groups in cohort-3, YCR and YH groups in cohort-3. |
| T382 |
10349-10465 |
Sentence |
denotes |
The ‘‘upregulated DEGs during aging’’ were defined as the DEGs that increased in AA group and decreased in YA group. |
| T383 |
10466-10580 |
Sentence |
denotes |
The ‘‘downregulated DEGs in aging’’ were defined as the DEGs that decreased in AA group and increased in YA group. |
| T384 |
10582-10608 |
Sentence |
denotes |
Gene functional annotation |
| T385 |
10609-10829 |
Sentence |
denotes |
The Metascape webtool (www.metascape.org) (Zhou et al., 2019) that allow visualization of functional patterns of gene clusters and statistical analysis was used to conduct DEGs gene ontology, pathway enrichment analyses. |
| T386 |
10830-10993 |
Sentence |
denotes |
Among the top 30 enriched GO terms or pathways across various types of cells and tissues, 10 GO terms or pathways which were associated with aging were visualized. |
| T387 |
10994-11169 |
Sentence |
denotes |
Gene expression profile cluster plots and heatmaps were established using the pheatmap R package (https://cran.r-project.org/web/packages/pheatmap/index.html, version 1.0.12). |
| T388 |
11171-11191 |
Sentence |
denotes |
Aging score analysis |
| T389 |
11192-11335 |
Sentence |
denotes |
To assess the impact of aging in circulating immune cells, we selected the top 20 genes out of 60 common upregulated genes in all immune cells. |
| T390 |
11336-11458 |
Sentence |
denotes |
Aging scores were estimated for all cells as the average of the scaled (Z-normalized) expression of the genes in the list. |
| T391 |
11459-11587 |
Sentence |
denotes |
The score of aging for all immune cell types can be used to predict the effect of aging on single cells and cell subtype levels. |
| T392 |
11588-11855 |
Sentence |
denotes |
Calculation of the scores was done as follows: the score of the aging gene set in the given cell-subset (named as X) was computed as the sum of all UMI for all the aging genes expressed in X cell, divided by the sum of all UMI expressed by X cell (Pont et al., 2019). |
| T393 |
11857-11901 |
Sentence |
denotes |
Sequencing and analysis of TCR and BCR V(D)J |
| T394 |
11902-12082 |
Sentence |
denotes |
PCR amplification was done to enrich the full-length TCR/BCR V(D)J segments for the amplified cDNA from 5′ libraries with a Chromium Single-Cell V(D)J Enrichment kit (10 Genomics). |
| T395 |
12083-12260 |
Sentence |
denotes |
The TCR/BCR sequences of each T/B cell were clustered using the CellRanger vdj pipeline (version 3.1.0, allowing identification of CDR3 sequence and the rearranged TCR/BCR gene. |
| T396 |
12261-12372 |
Sentence |
denotes |
Analysis was performed using Loupe V(D)J Browser version 2.0.1 (https://support.10xgenomics.com, 10x Genomics). |
| T397 |
12373-12481 |
Sentence |
denotes |
In summary, barcode information a containing clonotype frequency and TCR/BCR diversity metric were obtained. |
| T398 |
12482-12600 |
Sentence |
denotes |
We projected T /B cells with dominant TCR/BCR clonotypes on a t-SNE plot using barcode information (Wen et al., 2020). |
| T399 |
12602-12640 |
Sentence |
denotes |
Determination of cell-cell interaction |
| T400 |
12641-12763 |
Sentence |
denotes |
We employed the expression of immune-related ligands and receptors to assess the cell-cell interactions (Ma et al., 2020). |
| T401 |
12764-13034 |
Sentence |
denotes |
The possible ligand-receptor interactions between one set of receptor-expressing cells and then next ligand-expressing cells were determined as the average of the product of receptor and ligand expression (respectively from set one and two) across all single-cell pairs: |
| T402 |
13035-13783 |
Sentence |
denotes |
\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$I = \mathop \sum \limits_{i}^{n} I_{i} \times \mathop \sum \limits_{j}^{m} r_{j} \left(\frac{1}{m*n}\right)$$\end{document}I=∑inIi×∑jmrj1m∗nwhere I refers to the interaction score between receptor expressing cells in set one and ligand-expressing cells in set two, Ii stands for the ligand expression of cell i in cell set one, rj represents the receptor expression of cell j in cell set two, n stands for the number of cells in set one and m denotes the number of cells in set two. |
| T403 |
13784-13922 |
Sentence |
denotes |
In the gene list, there were 168 pairs of well-annotated ligands and receptors, among which were co-stimulators, chemokines and cytokines. |
| T404 |
13923-14145 |
Sentence |
denotes |
The possible interactions between two cell types were orchestrated by receptor-ligand pairs by the product of the average expression levels of the ligand in one cell type and the respective receptor in the other cell type. |
| T405 |
14147-14192 |
Sentence |
denotes |
Mass cytometry processing and quality control |
| T406 |
14193-14416 |
Sentence |
denotes |
CyTOF data were acquired with a CyTOF2 system using a SuperSampler fluidics system (Victorian Airships) at an event rate of < 400 events per second and normalized with Helios normalizer software (Fluidigm version 6.7.1016). |
| T407 |
14417-14550 |
Sentence |
denotes |
Acquisitions from different days (three independent acquisitions were performed) were normalized using five-element beads (Fluidigm). |
| T408 |
14551-14653 |
Sentence |
denotes |
Barcoded samples were deconvoluted and cross-sample doublets were filtered using cytobank application. |
| T409 |
14654-14939 |
Sentence |
denotes |
CyTOF data was pre-processed with Cytobank (https://mtsinai.cytobank.org; Cytobank, 7.0) to sequentially remove calibration beads, dead cells, debris and barcodes for CD45+ PBMCs based on event length, DNA (191Ir and 193Ir) and live cell (195Pt) channels and then export the FCS files. |
| T410 |
14940-15051 |
Sentence |
denotes |
We analyzed 200,000 PBMCs in cohort-1 and 160,000 PBMC in cohort-2, with an average of 20,000 cells per sample. |
| T411 |
15053-15094 |
Sentence |
denotes |
Mass cytometry visualizing and clustering |
| T412 |
15095-15206 |
Sentence |
denotes |
We created mass cytometry datasets for analysis by concatenating cells from all individuals for each cell type. |
| T413 |
15207-15418 |
Sentence |
denotes |
In this way, we created downsampled datasets of 95,316 TCs, 35,254 NKs, 22,042 BCs, 39,144 MCs and 8,244 DCs in cohort-1 and 57,910 TCs, 34,857 NKs, 13,812 BCs, 45,431 MCs and 7,990 DCs in cohort-2 for analysis. |
| T414 |
15419-15449 |
Sentence |
denotes |
We used FlowCore (65 flowCore: |
| T415 |
15450-15544 |
Sentence |
denotes |
Basic structures for flow cytometry data.) to read and process FCS files for further analysis. |
| T416 |
15545-15667 |
Sentence |
denotes |
For sample with more than 20,000 cells, we randomly selected 20,000 cells to ensure that samples were equally represented. |
| T417 |
15668-15866 |
Sentence |
denotes |
At last, we run the t-SNE dimensionality reduction algorithm on a combined data sample using the Seurat package based on harmony embedding (https://github.com/immunogenomics/harmony, version 1.0.0). |
| T418 |
15868-15907 |
Sentence |
denotes |
Batch correction of mass cytometry data |
| T419 |
15908-16049 |
Sentence |
denotes |
PBMC mass cytometry data from 10 subjects of cohort-1 or 8 subjects of cohort-2 was combined and batch normalized using harmony respectively. |
| T420 |
16050-16142 |
Sentence |
denotes |
First, mass cytometry data from each cohort all subjects was combined into a single dataset. |
| T421 |
16143-16215 |
Sentence |
denotes |
Second, harmony batch correction was performed using one of the samples. |
| T422 |
16216-16331 |
Sentence |
denotes |
Third, mass cytometry data were lognormalized in the Seurat’s NormalizeData function across the aggregated dataset. |
| T423 |
16333-16411 |
Sentence |
denotes |
Single-cell assay for transposase-accessible chromatin sequencing (scATAC-seq) |
| T424 |
16412-16551 |
Sentence |
denotes |
scATAC-seq targeting 4,000 cells per sample was performed using Chromium Single Cell ATAC Library and Gel Bead kit (10x Genomics, 1000110). |
| T425 |
16552-16620 |
Sentence |
denotes |
Each sample library was uniquely barcoded and quantified by RT-qPCR. |
| T426 |
16621-16854 |
Sentence |
denotes |
Libraries were then pooled and loaded on an Illumina Novaseq 6000 sequencer (3.5 pmol/L loading concentration, 50 + 8 + 16 + 49 bp read configuration) and sequenced to either 90% saturation or 30,000 unique reads per cell on average. |
| T427 |
16855-17086 |
Sentence |
denotes |
All protocols to generate scATAC-seq data on the 10x Chromium platform, including sample preparation, library preparation and instrument and sequencing settings, are available here: https://support.10xgenomics.com/single-cell-atac. |
| T428 |
17088-17114 |
Sentence |
denotes |
scATAC-seq data processing |
| T429 |
17116-17137 |
Sentence |
denotes |
scATAC-seq processing |
| T430 |
17138-17273 |
Sentence |
denotes |
scATAC-seq reads were aligned to the GRCh38 (hg38) reference genome and quantified using CellRanger-ATAC count (10x Genomics, v.1.0.0). |
| T431 |
17275-17301 |
Sentence |
denotes |
scATAC-seq quality control |
| T432 |
17302-17483 |
Sentence |
denotes |
To ensure that each cell was both adequately sequenced and had a high signal-to-background ratio, we filtered cells with less than 1,000 unique fragments and enrichment at TSSs < 8. |
| T433 |
17484-17632 |
Sentence |
denotes |
To calculate TSS enrichment > 2, genome-wide Tn5-corrected insertions were aggregated ± 2,000 bp relative (TSS-strand-corrected) to each unique TSS. |
| T434 |
17633-17806 |
Sentence |
denotes |
This profile was normalized to the mean accessibility ± 1,900–2,000 bp from the TSS, smoothed every 51 bp and the maximum smoothed value was reported as TSS enrichment in R. |
| T435 |
17807-17937 |
Sentence |
denotes |
To construct a counts matrix for each cell by each feature (peaks), we read each fragment.tsv.gz fill into a GenomicRanges object. |
| T436 |
17938-18107 |
Sentence |
denotes |
For each Tn5 insertion, which can be thought of as the “start” and “end” of the ATAC fragments, we used findOverlaps to find all overlaps with the feature by insertions. |
| T437 |
18108-18234 |
Sentence |
denotes |
Then we added a column with the unique id (integer) cell barcode to the overlaps object and fed this into a sparseMatrix in R. |
| T438 |
18235-18416 |
Sentence |
denotes |
To calculate the fraction of reads/insertions in peaks, we used the colSums of the sparseMatrix and divided it by the number of insertions for each cell id barcode using table in R. |
| T439 |
18418-18461 |
Sentence |
denotes |
scATAC-seq visualization in genomic regions |
| T440 |
18462-18547 |
Sentence |
denotes |
To visualize scATAC-seq data, we read the fragments into a GenomicRanges object in R. |
| T441 |
18548-18676 |
Sentence |
denotes |
We then computed sliding windows across each region we wanted to visualize for every 100 bp “slidingWindows (region, 100, 100)”. |
| T442 |
18677-18784 |
Sentence |
denotes |
We computed a counts matrix for Tn5-corrected insertions as described above and then binarized this matrix. |
| T443 |
18785-18930 |
Sentence |
denotes |
We then returned all non-zero indices (binarization) from the matrix (cell × 100-bp intervals) and plotted them in ggplot2 in R with “geom_tile”. |
| T444 |
18931-19027 |
Sentence |
denotes |
For visualizing aggregate scATAC-seq data, the binarized matrix above was summed and normalized. |
| T445 |
19028-19137 |
Sentence |
denotes |
Scale factors were computed by taking the binarized sum in the global peak set and normalizing to 10,000,000. |
| T446 |
19138-19460 |
Sentence |
denotes |
Tracks were then plotted in Loupe Cell Browser, an interactive visualization software that shows scATAC-seq peak profiles for scATAC-seq cell clusters, similar to the analysis done in this manuscript and described at https://support.10xgenomics.com/single-cellatac/software/visualization/latest/what-is-loupe-cell-browser. |
| T447 |
19462-19470 |
Sentence |
denotes |
chromVAR |
| T448 |
19471-19519 |
Sentence |
denotes |
We measured global TF activity using chromVAR15. |
| T449 |
19520-19701 |
Sentence |
denotes |
We used the cell-by-peaks and the Catalog of Inferred Sequence Binding Preferences (CIS-BP) motif (from chromVAR motifs “human_pwms_v1”) matches within these peaks from motifmatchr. |
| T450 |
19702-19804 |
Sentence |
denotes |
We then computed the GC-bias-corrected deviation scores using the chromVAR “deviationScores” function. |
| T451 |
19806-19826 |
Sentence |
denotes |
Statistical analysis |
| T452 |
19827-19919 |
Sentence |
denotes |
The GraphPad Prism Software (version 8.0.2) was employed for data analysis and presentation. |
| T453 |
19920-19961 |
Sentence |
denotes |
All results are presented as means ± SEM. |
| T454 |
19962-20088 |
Sentence |
denotes |
Groups were compared with two-tailed Mann-Whitney-Wilcoxon tests and FDR was corrected using the Benjamini-Hochberg procedure. |
| T455 |
20089-20174 |
Sentence |
denotes |
P value was derived by a hypergeometric test in representative GO terms and pathways. |