Exercise Activates Interferon Immune Response of the Liver via Gpld1 to Enhance Antiviral Innate Immunity

Healthy behavioral patterns could modulate organ functions to enhance the body’s immunity. However, whether exercise regulates antiviral innate immunity remains elusive. Here, we found that exercise promotes type-I IFN (IFN-I) production in the liver and enhances IFN-I immune activity of the body. Despite the possibility that many exercise-induced factors could regulate IFN-I production, we identified Gpld1 as a crucial molecule and the liver as the major organ to promote IFN-I production after exercise. Exercise largely loses the efficiency to induce IFN-I in Gpld1-/- mice. Further studies demonstrated that exercise-produced 3-hydroxybutanoic acid (3-HB) critically induces Gpld1 expression in the liver. Gpld1 blocks the PP2A-IRF3 interaction and therefore enhances IRF3 activation and IFN-I production, and improves the body’s antiviral ability. This study reveals that the exercise behavior improves antiviral innate immunity by linking the liver metabolism to systemic IFN-I activity, and uncovers an unknown function of liver cells in innate immunity.