Intracellular delivery of nuclear localization signal suppresses COVID-19 mediated inflammation by regulating expression of cytokines/chemokines

The outbreak of coronavirus disease 19 (COVID-19), caused by the recently identified coronavirus named SARS-CoV-2, is leading patients to death (mortality: ~7%) because of cytokine storm. COVID-19 induces excessive secretion of proinflammatory cytokines and chemokines accompanied by the disruption of the bronchi and alveoli, which could ultimately develop into permanent lung impairments such as pulmonary fibrosis. To regulate the uncontrolled expression of proinflammatory cytokines/chemokines, improved cell-permeable nuclear import inhibitor (iCP-NI) has been developed by fusing sequence-optimized hydrophobic cell-penetrating peptide (CPP), namely advanced macromolecule transduction domain (aMTD) with nuclear localization signal (NLS) of stress responsive transcription factors (SRTFs: NF-κB, STAT1/3, AP-1, and NFAT). Intracellularly delivered NLS is supposed to suppress expression of proinflammatory cytokines/chemokines by inhibiting transport of SRTFs from cytoplasm into nucleus. iCP-NI regulated expression of cytokines (TNF-α: -79%, IL-6: -91%, IL-12: -110% and IL-10: +574%) and chemokines (MCP-1: -89%) in bronchoalveolar lavage fluids (BALFs) from RNA virus infection mimetic pneumonitis animals that were induced with inhalation of RNA structure molecule, poly I:C. iCP-NI also significantly decreased pulmonary fibrosis (-61%) in bleomycin-induced pulmonary fibrosis animals. Moreover, iCP-NI protected leukocytes (CD3+ T cell: 100%, CD4+/CD3+ T cell: 96%, B220+ B cell: 85%, CD45+ macrophage: 100%) and reduced apoptotic splenocytes (-97%) in staphylococcal enterotoxin B (SEB) and poly I:C-induced acute pneumonitis animals. These results suggest that iCP-NI has potential as a novel therapeutic measurement for inflammation caused by various infectious diseases including COVID-19 accompanied with cytokine storm and severe sepsis. Citation Format: Danbi Lee, Sanghyeon Yu, Misuk Baek, Jieun Kim, Mingu Kang, Hakyoung Park, Jaewook Lee, Seokwon Lee, Junghun Kwak, Hyemin Yu, Seungwoo Lee, Sujeong Kim, Hyewon Lee, Dasom Shin, Boram Kim, Minyoung Jung, Youngsil Choi, Daewoong Jo, Gyunam Kim, Dongho Kim. Intracellular delivery of nuclear localization signal suppresses COVID-19 mediated inflammation by regulating expression of cytokines/chemokines [abstract]. In: Proceedings of the AACR Virtual Meeting: COVID-19 and Cancer; 2020 Jul 20-22. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(18_Suppl):Abstract nr PO-051.