NEAT-seq: Simultaneous profiling of intra-nuclear proteins, chromatin accessibility, and gene expression in single cells

Oligo-conjugated antibodies have allowed for joint measurement of surface protein abundance and the transcriptome in single cells using high-throughput sequencing. Extending these measurements to gene regulatory proteins in the nucleus would provide a powerful means to link changes in abundance of trans-acting TFs to changes in activity of cis-acting elements and expression of genes regulated by these factors and elements. Here, we introduce Nuclear protein Epitope, chromatin Accessibility, and Transcriptome sequencing (NEAT-seq), a technique to simultaneously measure nuclear protein abundance, chromatin accessibility, and the transcriptome in single cells. We apply this technique to profile CD4 memory T cells using a panel of master transcription factors (TFs) that drive distinct helper T cell subsets and regulatory T cells (Tregs) and identify examples of TFs with regulatory activity gated by three distinct mechanisms: transcription, translation, and regulation of chromatin binding. We further identify regulatory elements and target genes associated with each TF, which we use to link a non-coding GWAS SNP within a GATA motif to both strong allele-specific chromatin accessibility in cells expressing high levels of GATA, and a putative target gene. Overall design: Multiomic single cell profiling of mouse ESC and human K562 mixture, primary human CD4+CD45RO+ memory T cells