DNA methylation dynamics during monocyte-to-macrophage differentiation and BCG vaccine induced trained immunity

Trained immunity is a phenomenon whereby innate immune cells such as monocytes or macrophages undergo functional reprogramming after exposure to certain microbial components, altering their responses to future exposures. This study profiled the transcriptomes of human monocytes responding to two different BCG vaccine strains. Time-course in vitro culture of human monocytes. Trained immunity was induced in culture through an initial exposure of primary human monocytes to BCG Denmark and BCG Bulgaria strains for 24 hours, followed by removal of stimulus and differentiation to macrophages for an additional 5 days. Cells were collected at baseline (day 0), 4 hour, 24 hour, 6 days and 6 days + 4h LPS re-stimulation.