In:
Science, American Association for the Advancement of Science (AAAS), Vol. 385, No. 6704 ( 2024-07-05)
Abstract:
Enhancers are distal cis-regulatory elements that increase the expression of target genes. Active enhancers produce bidirectional enhancer RNAs (eRNAs). Transcription of eRNAs can be used to measure enhancer activity and to delineate enhancer architecture at nucleotide resolution. Profiling of transcribed enhancers in single human cells can provide insights into cell type–specific gene regulation and genetic predisposition to diseases. However, comprehensive maps of eRNAs in cell types relevant to diseases are still lacking. RATIONALE The 5′ cap is added to the first nucleotide of an RNA molecule. By leveraging a specific “cap signature,” we developed read-level prefiltering and transcribed enhancer call (ReapTEC), a method for simultaneously profiling gene expression and enhancer activity by using 5′-end single-cell RNA sequencing (5′ scRNA-seq). We applied ReapTEC and single-nucleus assay for transposase-accessible chromatin using sequencing (snATAC-seq) to a total of ~1 million single human CD4 + T cells and constructed a CD4 + T cell type–resolved multimodal atlas to pinpoint genetic and cellular causes of immune-mediated diseases. RESULTS By using ReapTEC, we accurately mapped the transcription start sites of mRNAs, long noncoding RNAs, and eRNAs in single cells, which allowed us to study the expression of not only genes but also bidirectionally transcribed candidate enhancers (btcEnhs). We characterized rare and uncharacterized cell types, including GPR25 -expressing regulatory T cells, along with the expression profiles of ~130 surface proteins. We identified 62,803 btcEnhs and 218,508 accessible chromatin regions active across diverse CD4 + T cells. We found higher cell type specificity for RNA transcription than for chromatin accessibility both at promoters and enhancers. We also showed that the heritability of immune-mediated diseases was enriched more in btcEnhs than in open chromatin regions. Using our CD4 + T cell type–resolved atlas of btcEnhs, we systematically interpreted genetic variants associated with a range of immune-mediated diseases. We found that btcEnhs harboring disease SNPs were often active in specific subsets of CD4 + T cells; generally, they were conserved across mammals but in some cases were primate specific. We investigated the target genes of disease-relevant btcEnhs by generating fine-scale chromatin contact maps derived from ultradeep Micro-C data; we further performed CRISPR activation of selected disease-relevant btcEnhs to validate their target genes. CONCLUSION Our study establishes a platform for integrating and elucidating CD4 + T cell diversity and genetic risk of immune-mediated diseases. Although 3′ scRNA-seq is widely used as a major tool for single-cell gene expression analysis, our study demonstrates the strength of 5′ scRNA-seq. We anticipate the utility of our multimodal atlas in addressing variant-to-function challenges. CD4 + T cell type–resolved atlas of btcEnhs for systematic interpretation of the genetic basis of immune-mediated diseases. ( A ) ReapTEC allows us to detect transcription start sites (TSSs) and active enhancers using 5′ scRNA-seq. ( B ) Disease-relevant btcEnhs containing genetic variants associated with immune-mediated diseases were linked to target genes by using fine-scale chromatin contact maps. CITE-seq, cellular indexing of transcriptomes and epitopes by sequencing; Ref, reference allele; Alt, alternative allele.
Type of Medium:
Online Resource
ISSN:
0036-8075
,
1095-9203
DOI:
10.1126/science.add8394
Language:
English
Publisher:
American Association for the Advancement of Science (AAAS)
Publication Date:
2024
detail.hit.zdb_id:
128410-1
detail.hit.zdb_id:
2066996-3
SSG:
11
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