The TASK1 channel inhibitor A293 shows efficacy in a mouse model of multiple sclerosis

The two-pore domain potassium channel TASK1 (KCNK3) has recently emerged as an important modulator in autoimmune CNS inflammation. Previously, it was shown that T lymphocytes obtained from TASK1−/− mice display impaired T cell effector functions and that TASK1−/− mice show a significantly reduced disease severity in myelin oligodendrocyte glycoprotein (MOG35-55) peptide induced experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. We here evaluate a potent and specific TASK1 channel inhibitor, A293, which caused a dose-dependent reduction of T cell effector functions (cytokine production and proliferation). This effect was abolished in CD4+ T cells from TASK1−/− mice but not in cells from TASK3−/− mice. In electrophysiological measurements, A293 application induced a significant reduction of the outward current of wildtype T lymphocytes, while there was no effect in TASK1−/− cells. Preventive and therapeutic application of A293 significantly ameliorated the EAE disease course in wildtype mice while it had no significant effect in TASK1−/− mice and was still partly effective in TASK3−/− mice. In summary, our findings support the concept of TASK1 as an attractive drug target for autoimmune disorders.

► A293, a selective TASK1 inhibitor, leads to a reduction of T cell effector functions. ► Application of A293 ameliorates the disease course in the MOG-induced EAE model. ► These effects were abolished in TASK1 knockout mice.