biostudies-literatureCaldwell BANational Institutes of Health113894https://www.ebi.ac.uk/biostudies/studies/S-EPMC11654472biostudies-literatureUnknown43(3)Monocytes can develop an exhausted memory state characterized by reduced differentiation, pathogenic inflammation, and immune suppression that drives immune dysregulation during sepsis. Chromatin alterations, notably via histone modifications, underlie innate immune memory, but the contribution of DNA methylation remains poorly understood. Using an ex vivo sepsis model, we show altered DNA methylation throughout the genome of exhausted monocytes, including genes implicated in immune dysregulation during sepsis and COVID-19 infection (e.g., Plac8). These changes are recapitulated in septic mice induced by cecal slurry injection. Methylation profiles developed in septic mice are maintained during ex vivo culture, supporting the involvement of DNA methylation in stable monocyte exhaustion memCell reportsAltered DNA methylation underlies monocyte dysregulation and immune exhaustion memory in sepsis.PMC11654472R01-AI-1721335TL1DK132771Wang JLi LCaldwell BAWu YfalseAltered DNA methylation underlies monocyte dysregulation and immune exhaustion memory in sepsis.Monocytes can develop an exhausted memory state characterized by reduced differentiation, pathogenic inflammation, and immune suppression that drives immune dysregulation during sepsis. Chromatin alterations, notably via histone modifications, underlie innate immune memory, but the contribution of DNA methylation remains poorly understood. Using an ex vivo sepsis model, we show altered DNA methylation throughout the genome of exhausted monocytes, including genes implicated in immune dysregulation during sepsis and COVID-19 infection (e.g., Plac8). These changes are recapitulated in septic mice induced by cecal slurry injection. Methylation profiles developed in septic mice are maintained during ex vivo culture, supporting the involvement of DNA methylation in stable monocyte exhaustion mem2024-01-01T00:00:00Z2024 Mar2025-04-04T00:38:50.643Z2025-04-04T00:38:50.643ZS-EPMC116544723844201710.1016/j.celrep.2024.113894