Article
作者: Dhawan, Vikas ; Kuyucak, Serdar ; Patil, Rahul ; Bednenko, Janna ; Luo, Dahai ; Ramasamy, Boominathan ; Charman, Susan A. ; Chen, Ming Wei ; Chandy, K. George ; Colussi, Paul ; Ng, Xuan Rui ; Ng, Jeremy Jun Heng ; Lescar, Julien ; Morales, Rodrigo A. V. ; Beeton, Christine ; El Sahili, Abbas ; Nguyen, Hai M. ; Robins, Edward G. ; Pennington, Michael W. ; Yasmin, Sabina ; Norton, Raymond S. ; Hartimath, Siddana V. ; Ong, Seow Theng ; Sadasivam, Pragalath ; Chang, Shih Chieh ; Goggi, Julian L. ; Zhuang, Zhong ; Tanner, Mark R. ; Krishnarjuna, Bankala ; Bajaj, Saumya ; Wulff, Heike ; Patel, Dharmeshkumar ; Tan, Peng Wen
We describe a cysteine-rich, membrane-penetrating, joint-targeting, and remarkably stable peptide, EgK5, that modulates voltage-gated KV1.3 potassium channels in T lymphocytes by a distinctive mechanism. EgK5 enters plasma membranes and binds to KV1.3, causing current run-down by a phosphatidylinositol 4,5-bisphosphate-dependent mechanism. EgK5 exhibits selectivity for KV1.3 over other channels, receptors, transporters, and enzymes. EgK5 suppresses antigen-triggered proliferation of effector memory T cells, a subset enriched among pathogenic autoreactive T cells in autoimmune disease. PET-CT imaging with 18F-labeled EgK5 shows accumulation of the peptide in large and small joints of rodents. In keeping with its arthrotropism, EgK5 treats disease in a rat model of rheumatoid arthritis. It was also effective in treating disease in a rat model of atopic dermatitis. No signs of toxicity are observed at 10-100 times the in vivo dose. EgK5 shows promise for clinical development as a therapeutic for autoimmune diseases.