sIL-2RA Exacerbates Multiple Sclerosis by Activating Microglia and Upregulating Fc Receptors on MicrogliaOA

Objective:Multiple sclerosis(MS)is a chronic inflammatory demyelinating disease of the central nervous system(CNS).Soluble interleukin-2 receptor alpha(sIL-2Rα)has been implicated inMS pathogenesis,but its mechanisms remain unclear.This study investigates how sIL-2Rαexacerbates MS by modulating microglial activation and antibody-dependent cellular cytotoxicity(ADCC)in an experimental autoimmune encephalomyelitis(EAE)mouse model.Methods:Female C57BL/6J mice were induced with EAE and treated with sIL-2Rα.Clinical symptoms,histopathology,and molecular changes were analyzed.Microglial activation was assessed via immunohistochemistry,Western blot,and RNA sequencing.In vitro,ADCC-mediated oligodendrocyte injury was evaluated using Fc receptor inhibition and PI3K-Akt pathway blockade.Results:sIL-2Rα accelerated EAE onset and severity,increasingmicroglial M1 polarization and CNS inflammation.RNA-seq revealed PI3K-Akt pathway activation,upregulating Fc receptors(FcγR)on microglia,which enhanced ADCC against oligodendrocytes(p<0.001).Inhibiting FcγR or PI3K-Akt reduced oligodendrocyte damage.Conclusion:sIL-2Rαexacerbates MS by activating microglia via the PI3K-Aktaxis,promoting ADCC and demyelination.Targeting this pathway may offer novel therapeutic strategies for MS.