Proposed Mechanistic Axis of Infections and mTOR Hyperactivation: A Multidisciplinary Review of Immune, Rheumatologic, and Psychiatric Links.

Early-life infections can produce durable changes in immune function and behavior. We propose a mechanistic hypothesis positioning the mechanistic target of rapamycin (mTOR) as the link between peripheral inflammation and central nervous system dysfunction in pediatric post-infectious syndromes. Based on clinical, translational, and experimental literature, we outline a stepwise pathway. First, sustained mTOR activation skews T-cell and macrophage differentiation toward pro-inflammatory and autoimmune states. Second, endothelial mTOR signaling weakens tight junctions and increases vesicular transport, compromising blood-brain barrier integrity. Third, cytokines and sometimes autoreactive cells enter the brain and engage mTOR in microglia and neurons, driving neuroinflammation, impaired synaptic maintenance and plasticity, and neurotransmitter disruption. This framework accounts for features observed in Long COVID, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and pediatric acute neuropsychiatry syndrome (PANS/PANDAS) and yields testable predictions on pathway activity and barrier permeability. It also motivates targeted interventions that modulate mTOR-related processes in immune and endothelial compartments and within neural circuits in children. So, this article aims to outline a mechanistic framework linking infection-driven mTOR activation to post-infectious neuropsychiatric syndromes.