Fig. 2
From: Regulatory T cells-centered regulatory networks of skeletal muscle inflammation and regeneration
Schematic summary of the Treg-centered regulatory system in skeletal muscle repair. Treg cells can secrete IL-2 to inhibit Tconv and indirectly inhibit pro-inflammatory macrophages; they are stimulated by IL-2 and GLN secreted by pro-inflammatory macrophages, and in turn secrete TGF-β, HMOX-1, IL-10 and PD-1 for completing the phenotype switch of macrophages; Treg cells are also stimulated by IL-33 secreted by FAPs, which is inhibited by TNF-α secreted by pro-inflammatory macrophages and promoted by TGF-β secreted by anti-inflammatory macrophages; besides, Treg cells can directly secrete Areg or indirectly control the proliferation and differentiation of MuSCs by affecting the phenotype switch of macrophages.