Cationic lipid-modified PEG-PLGA nanoparticles facilitate effective dendritic cell reprogramming to alleviate T cell-mediated autoimmunity in EAE.

Abstract

Multiple sclerosis (MS) is a chronic autoimmune disorder characterized by aberrant T cell responses and central nervous system inflammation. Dendritic cells (DCs), as key regulators of T cell activation and differentiation, represent a promising therapeutic target for restoring immune homeostasis. In this study, we repurposed our previously developed cationic lipid-assisted PEG-PLGA nanoparticle (CLAN) platform for targeted dual-siRNA delivery to DCs. Specifically, CLAN was employed to co-deliver siRNAs against CD40 and LKB1-two critical mediators of DC costimulatory signaling and metabolic control. In vitro, CLAN_{siCD40+siLKB1} achieved efficient and simultaneous knockdown of both genes in primary DCs, matching the silencing efficacy of Lipofectamine while offering improved biocompatibility. Following a single systemic administration, CLAN preferentially targeted splenic CD11c⁺ DCs, achieving over 60 % siRNA uptake; this efficiency could be further enhanced through repeated dosing. Treated DCs suppressed Th1/Th17 differentiation and promoted Treg induction. In an experimental autoimmune encephalomyelitis (EAE) model, CLAN_{siCD40+siLKB1} significantly delayed disease onset and reduced clinical severity, with histological analyses confirming attenuated CNS inflammation and preserved spinal cord structure. This work highlights the therapeutic potential of CLAN as a modular nanocarrier for immune reprogramming via multiplexed gene silencing in dendritic cells, offering a novel strategy for treating MS and other T cell-mediated autoimmune diseases.