Nanovesicle-targeted Kv1.3 knockdown in memory T cells suppresses CD40L expression and memory phenotype

Ca2+ signaling controls activation and effector functions of T lymphocytes. Ca2+ levels also regulate NFAT activation and CD40 ligand (CD40L) expression in T cells. CD40L in activated memory T cells binds to its cognate receptor, CD40, on other cell types resulting in the production of antibodies and pro inflammatory mediators. The CD40L/CD40 interaction is implicated in the pathogenesis of autoimmune disorders and CD40L is widely recognized as a therapeutic target. Ca2+ signaling in T cells is regulated by Kv1.3 channels. We have developed lipid nanoparticles that deliver Kv1.3 siRNAs (Kv1.3-NPs) selectively to CD45RO(+) memory T cells and reduce the activation-induced Ca2+ influx. Herein we report that Kv1.3-NPs reduced NFAT activation and CD40L expression exclusively in CD45RO(+) T cells. Furthermore, Kv1.3-NPs suppressed cytokine release and induced a phenotype switch of T cells from predominantly memory to naive. These findings indicate that Kv1.3-NPs operate as targeted immune suppressive agents with promising therapeutic potentials. (C) 2016 Elsevier Ltd. All rights reserved.