A single-cell view on host immune transcriptional response to in vivo BCG-induced trained immunity

Cell Rep. 2023 May 30;42(5):112487. doi: 10.1016/j.celrep.2023.112487. Epub 2023 May 7.

Abstract

Bacillus Calmette-Guérin (BCG) vaccination is a prototype model for the study of trained immunity (TI) in humans, and results in a more effective response of innate immune cells upon stimulation with heterologous stimuli. Here, we investigate the heterogeneity of TI induction by single-cell RNA sequencing of immune cells collected from 156 samples. We observe that both monocytes and CD8+ T cells show heterologous transcriptional responses to lipopolysaccharide, with an active crosstalk between these two cell types. Furthermore, the interferon-γ pathway is crucial in BCG-induced TI, and it is upregulated in functional high responders. Data-driven analyses and functional experiments reveal STAT1 to be one of the important transcription factors for TI shared in all identified monocyte subpopulations. Finally, we report the role of type I interferon-related and neutrophil-related TI transcriptional programs in patients with sepsis. These findings provide comprehensive insights into the importance of monocyte heterogeneity during TI in humans.

Keywords: BCG; CP: Immunology; IFN-γ; STAT1; in vivo training; monocyte heterogeneity; single-cell RNA-seq; trained immunity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • BCG Vaccine
  • CD8-Positive T-Lymphocytes
  • Humans
  • Immunity, Innate
  • Interferon-gamma / metabolism
  • Mycobacterium bovis* / metabolism
  • Trained Immunity

Substances

  • BCG Vaccine
  • Interferon-gamma