T reg cells limit IFN-γ production to control macrophage accrual and phenotype during skeletal muscle regeneration

Significance Skeletal muscle relies on its regenerative capacity to recover after acute injury. Immune-system cells, notably macrophages and regulatory T cells, play critical roles during muscle regeneration. This study addressed the impact of regulatory T cells on macrophages during muscle repair. In a mouse model of acute injury, regulatory T cells controlled the composition and phenotype of muscle macrophages during muscle repair by limiting production of the inflammatory cytokine, interferon-γ, produced by natural killer and effector T cells. Thus, we uncovered an interferon-γ–centered regulatory loop that can be further explored as a gateway to improved muscle therapies.