Fig. 2.

Anti-inflammatory cytokines in sepsis. Anti-inflammatory cytokines mainly include IL-4, IL-10 and IL-37. IL-4 can induce CD4⁺ T cells to differentiate into Th2 cells and promote autocrine signaling of mast cells through positive feedback. It can also stimulate the release of other anti-inflammatory cytokines and inhibit the release of pro-inflammatory cytokines such as IL-2 and IFN-γ by activated Th1. IL-10 may aggravate immunosuppression by decreasing the release of pro-inflammatory cytokines including TNF-α, inhibiting the proliferation of CD4⁺ T cells and promoting the differentiation of CD4⁺ T cells into Tregs and the proliferation of MDSCs. IL-37 is closely related to the severity of sepsis-induced immunosuppression by suppressing the pro-inflammatory cytokine release from monocytes and neutrophils. Inflammatory cytokines such as TNF-α, IFN-γ and IL-2 are represented by red dots whereas IL-10, IL-37 and IL-4 are represented by dots in other colors. Th1 T helper 1, Th2 T helper 2, MDSC myeloid-derived suppressor cell, TNF-α tumor necrosis factor-alpha, IFN-γ interferon-γ, IL interleukin, Mo/Mφ monocyte/macrophage