Abstract
Central and systemic inflammation play pivotal roles in epileptogenesis and proepileptogenesis in temporal lobe epilepsy (TLE). The interplay between peripheral CD4+ T cells and central microglia orchestrates the "systemic-central" immune response in TLE. However, the precise molecular mechanisms linking central and systemic inflammation in TLE remain unknown. This preliminary findings revealed an imbalance in Th1/Th2 subsets in the periphery，accompanied by related cytokines release in TLE patients. they proposed that this peripheral Th1/Th2 imbalance may influence central inflammation by mediating microglial state dynamics within epileptic foci and distant brain regions. In Li-pilocarpine-induced TLE rats, a peripheral Th1/Th2 imbalance and observed corresponding central and systemic responses is confirmed. Notably, CD4+ T cells infiltrated through the compromised blood-brain barrierand are spatially close to microglia around epileptic foci. Intravenous depletion and reinfusion of CD4+ T cells modulated microglia state dynamics and altered neuroinflammatory cytokines secretion. Moreover, mRNA sequencing of the human hippocampus identified Notch1 as a key regulator of Th1/Th2 differentiation, CD4+ T cell recruitment to brain infiltration sites, and the regulation of microglial responses, seizure frequency, and cognition. This study underscores the significance of Th1/Th2 imbalance in modulating the "systemic-central" response in TLE, highlighting Notch1 as a potential therapeutic target.