Genome-wide CRISPR screens in T helper cells reveal pervasive cross-talk between activation and differentiation

Abstract

T helper type 2 (Th2) cells are important regulators of our adaptive immune response, particularly the response against parasites, and have relevance for auto-immunity as well as tumour progression. This classic T helper type has been studied intensively, but not systematically. Using newly developed, genome-wide retroviral CRISPR knock-out (KO) technology, combined with RNA-seq, ATAC-seq and ChIP-seq, we have dissected the regulatory circuitry governing differentiation in these cells. During Th2 activation/differentiation approximately 4000 genes are perturbed, with at least 200 genes specifically associated with the Th2 program in mouse and human. We confirm previously known Th2 driver genes and have discovered several novel genes, including transcription factors, metabolic genes and potential receptors/cytokines, critical for Th2 function. Our study provides an atlas for, but not limited to, the Th2 regulatory network, pinpointing the key players of Th2 differentiation.