Epigenome analysis links gene regulatory elements in group 2 innate lymphocytes to asthma susceptibility

J Allergy Clin Immunol. 2018 Dec;142(6):1793-1807. doi: 10.1016/j.jaci.2017.12.1006. Epub 2018 Mar 2.


Background: Group 2 innate lymphoid cells (ILC2s) are major producers of the cytokines driving allergic asthma, and increased ILC2 numbers have been detected in blood and sputum of asthmatic patients. Asthma susceptibility has a strong genetic component, but the underlying mechanisms and whether asthma genetics affect ILC2 biology remain unclear.

Objective: We sought to study the ILC2 transcriptome and epigenome during airway inflammation (AI) to couple these to genes and genetic variants associated with asthma pathogenesis.

Methods: Mice harboring a reporter for the key ILC2 transcription factor GATA-3 were subjected to IL-33-driven AI, and ILC2s were isolated from bronchoalveolar lavage fluid and mediastinal lymph nodes. Human ILC2s were purified from peripheral blood and activated in vitro. We used RNA sequencing, genome-wide identification of histone-3 lysine-4 dimethylation-marked chromatin, and computational approaches to study the ILC2 transcriptome and epigenome.

Results: Activated ILC2s in mice displayed a tissue-specific gene expression signature that emerged from remarkably similar epigenomes. We identified superenhancers implicated in controlling ILC2 identity and asthma-associated genes. More than 300 asthma-associated genetic polymorphisms identified in genome-wide association studies localized to H3K4Me2+ gene regulatory elements in ILC2s. A refined set of candidate causal asthma-associated variants was uniquely enriched in ILC2, but not TH2 cell, regulatory regions.

Conclusions: ILC2s in AI use a flexible epigenome that couples adaptation to new microenvironments with functional plasticity. Importantly, we reveal strong correlations between gene regulatory mechanisms in ILC2s and the genetic basis of asthma, supporting a pathogenic role for ILC2s in patients with allergic asthma.

Keywords: GATA-3; Group 2 innate lymphoid cell; T(H)2 cell; airway inflammation; asthma; epigenetics; epigenome; genome-wide association study; superenhancer; transcription factor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Asthma / genetics*
  • Asthma / immunology*
  • Epigenesis, Genetic
  • GATA3 Transcription Factor / genetics
  • Genetic Predisposition to Disease*
  • Genome
  • Humans
  • Immunity, Innate
  • Lymphocytes / immunology*
  • Mice
  • Regulatory Sequences, Nucleic Acid
  • Transcriptome


  • GATA3 Transcription Factor
  • Gata3 protein, mouse