Macrophages are innate immune cells involved in host defense. Dissecting the regulatory landscape that enables their swift and specific response to pathogens, we performed time-series analysis of gene expression and chromatin accessibility in murine macrophages exposed to various immune stimuli, and we functionally evaluated gene knockouts at scale using a combined CROP-seq and CITE-seq assay. We identified new roles of transcription regulators such as Spi1/PU.1 and JAK-STAT pathway members in immune cell homeostasis and response to pathogens. Macrophage activity was modulated by splicing proteins SFPQ and SF3B1, histone acetyltransferase EP300, cohesin subunit SMC1A, and mediator complex proteins MED8 and MED14. We further observed crosstalk among immune signaling pathways and identified molecular drivers of pathogen-induced dynamics. In summary, this study establishes a time-resolved regulatory map of pathogen response in macrophages, and it describes a broadly applicable method for dissecting immune-regulatory programs through integrative time-series analysis and high-content CRISPR screening. A record of this paper's transparent peer review process is included in the supplemental information.
Traxler et al. (Fri,) studied this question.