Targeted delivery of siRNAs against ion channels by lipid nanoparticles in T cell subsets

P. Hajdu
University of Cincinnati, US

Keywords: ion channel, siRNA, T cell, autoimmunity

Summary:

Effector memory T cells (TEM) play an essential role in the autoimmune diseases. Kv1.3 channels regulate the function of TEM’s and their inhibition suppresses their activity. This study was undertaken to determine whether silencing the Kv1.3 gene in TEM’s can be a new therapeutic approach in autoimmunity. We demonstrated that lipid nanoparticles (NPs) encapsulating Kv1.3specific siRNAs were delivered exclusively to TEM cells, reduced the Kv1.3 expression and impaired Ca2+-signaling. 100nm-NPs were fabricated from a mixture of PC, PE-PEG-biotin and cholesterol. NPs were functionalized with biotin-conjugated CD45RO antibodies via chromophore-labeled streptavidin. Kv1.3-siRNAs were introduced by lyophilization (Kv1.3-NPs). The efficiency and off-target effects of Kv1.3 siRNAs were determined by RT-qPCR and electrophysiology. Human T and MOLT-4 cells were used to test the specificity of NPs binding to CD45RO positive TEM’s. The effect of Kv1.3-NPs on the Ca2+ response in T cells was monitored by flow cytometry. Incubation of T/MOLT-4 cells with CD45RO-coated NPs showed the selective binding and endocytosis of NPs into TEM’s. Consequently, Kv1.3-siRNA in the Kv1.3-NPs was released into the cytosol, Kv1.3 expression decreased and T cells showed impaired Ca2+ influx as compared to the control cells. These findings may open novel therapy in autoimmune diseases.