IL-10 / anti-inflammatory cytokines

Interleukin-10 is a pleiotropic anti-inflammatory cytokine produced primarily by macrophages, T regulatory cells, and B cells that restrains pro-inflammatory signalling by inhibiting the synthesis of cytokines including IL-6, TNF-α, and IL-12 in myeloid cells, partly through suppression of NF-κB and STAT1. In healthy immune homeostasis, IL-10 acts as a critical brake on inflammation, preventing immunopathology during infection and autoimmunity; it is distinct from pro-inflammatory biomarkers such as IL-6, which belongs to a separate conceptual framework. With aging, the balance between IL-10 and pro-inflammatory cytokines is dysregulated in a context-dependent manner, with some studies reporting impaired IL-10 induction in older individuals while others observe elevated levels, suggesting that the relationship is tissue- and stimulus-specific rather than uniformly declining.