Intermittent fasting modulates immune signatures but not TNF-dependent pathology in mice with constitutive STING activation

Abstract The cGAS–STING pathway is a central mediator of antiviral immunity, yet its constitutive activation causes severe systemic autoinflammatory disease and neurodegeneration. Intermittent fasting (IF) has been proposed as a non-pharmacological strategy to attenuate inflammation and neurodegeneration. We therefore performed a comprehensive study of how IF reshapes immune phenotypes and assessed whether IF mitigates pathology in mice carrying a constitutively active STING mutation ( Sting N153S⁺/⁻). Sting N153S⁺/⁻ mice and wild-type littermates were subjected to either an IF regimen (two 24-h fasting periods per week for 3 months) or ad libitum (AL) feeding and analyzed using gene expression profiling, cytokine and chemokine quantification, flow cytometry, histopathology, and machine-learning–based analyses across blood, lung, thymus, spleen, kidney, and brain. IF induced tissue-specific immunological changes, partially normalizing STING-induced alterations in immune cell composition, gene expression and cytokine levels in select peripheral organs. However, key TNF-dependent disease manifestations, especially lung pathology and dopaminergic neuron loss in the midbrain, were not ameliorated. Furthermore, exploratory supervised and unsupervised multivariate analyses revealed distinct signaling patterns associated with genotype and diet. These findings demonstrate that IF modulates specific immune signatures at the levels of gene expression, cytokine production, and immune cell composition. Nonetheless, these changes were insufficient to ameliorate TNF-associated disease features driving pulmonary pathology and neurodegeneration in Sting N153S⁺/⁻ mice. Together, these results underscore the importance of tailoring dietary interventions to the underlying disease mechanisms.