Interaction of brain endothelial cells with T cells: implications for progression and therapeutic strategies of multiple sclerosis

The dynamic interplay between brain endothelial cells (BECs) and T cells is a key event in the pathogenesis of multiple sclerosis (MS). This process allows the extravasation of T cells from the peripheral circulation into the central nervous system (CNS), thereby triggering neuroinflammation and tissue damage. In MS, activated BECs facilitate T cell activation, recruitment, and CNS infiltration by upregulating major histocompatibility complex (MHC) molecules, cell adhesion molecules (CAMs), and chemokines. In response, T cells interact with BECs by expressing corresponding ligands, thereby modulating the immunoregulatory and barrier functions of BECs. This cross-talk between BECs and T cells significantly increases the complexity of MS treatment. Therefore, this review systematically summarizes the mutually reinforcing interactions between BECs and T cells based on existing research and highlights recent therapeutic strategies for either BECs or T cells that show promise in achieving favorable outcomes for treating MS.