Effects of Tolerant Nanoparticles Loaded with Various Regulatory Molecules on the Development of Experimental Autoimmune Encephalomyelitis

Abstract

This research investigated the effects of tolerating nanoparticles (tNPs) loaded with multiple regulatory molecules on progression of experimental autoimmune encephalomyelitis (EAE). The polylactic acid-glycolic acid copolymer (PLGA), multiple regulatory molecular fragments (Fc) (programmed death receptor ligand 1-Fc (PD-L1-Fc), CD47-Fc), transforming growth factor (TGF-β1), and multiple oligodendrocyte glycoprotein (MOG) antigen peptides (p-MOG) were selected to prepare the tNPs (MRM-tNPs) loaded with various regulatory molecules. Then, the MRM-tNPs were applied in MOG35-55 polypeptide-induced EAE mouse model. According to the treatment methods, the mice were rolled into a group A (BS therapeutic agent), a group B (no-load-NPs), a group C (MOG-tNPs), and a group D (MRM-tNPs). The therapeutic effects were evaluated by the inflammatory infiltration degree (IID), demyelination loss degree (DLD), and apoptosis rate (AR) of CD4+ and CD8+ T cells. The Results showed that the encapsulation rate (ER) of TGF-β1 was 87.65%, and its cumulative release rate (RR) was 58.22%. There were obvious fluorescence signals on MRM-tNPs, MRM-tNPs without PD-L1, and MRM-tNPs without CD47. The neurological function (NF) score in the group D after MRM-tNPs treatment was less than 2 points (P <0.05). The scores of IID and DLD in the brain and spinal cord (SC) of EAE mice in the group D were much lower to those in groups A, B, and C, and the ARs of CD4+ and CD8+ T cells were higher (P <0.05). In conclusion, the tNPs loaded with various regulatory molecules can promote the apoptosis of antigen-specific T cells (AST) and reduce the infiltration and demyelination of inflammatory cells, thus alleviating the EAE.