O-GlcNAcylation drives macrophage IL-4 responsiveness and tissue residency through metabolic and cell cycle calibration

The metabolic requirements for macrophage IL-4 polarization remain contentious, while immunometabolic studies of tissue resident macrophages are still sparse. Hexosamine biosynthesis has gained attention regarding its immune regulatory potential via downstream O-GlcNAcylation. Here we identify protein O-GlcNAcylation as a requirement for IL-4 polarization in vitro and proliferative expansion in vivo during cytokine challenge or infection. We further show that O-GlcNAcylation is critical for controlling tissue residency. By enforcing metabolic and cell cycle quiescence during differentiation, O-GlcNAcylation is needed for adult monocytes to establish a long-live residency program. In this context, its absence leads to perpetual DNA vulnerability and damage via reactive oxygen species, resulting in a senescent-like state poised for cell death. Conversely, long-lived populations instead require O-GlcNAcylation for self-renewal and inflammatory expansion. Our findings altogether suggest O-GlcNAcylation, fueled by hexosamine biosynthesis, serves as a central metabolic rheostat for resident macrophage formation and maintenance during homeostasis and disease.