The development of biologically contained Sudan virus as an alternative and safe tool for fundamental filovirus research

Filoviruses, including Ebola virus, Sudan virus, and Marburg virus, cause severe diseases with high fatality rates and require BSL-4 containment, which significantly restricts research. Although several BSL-2 surrogate systems have been developed, they often fail to fully reproduce viral replication and the complete life cycle. VP30 is a transcriptional activator essential for initiating viral mRNA synthesis in filoviruses and is functionally exchangeable among related viruses. VP30-deficient filovirus systems have been reported; however, a VP30-deficient Sudan virus (SUDV) system has not previously been established. In the reported study, a SUDV genome in which the VP30 gene was replaced with GFP was transfected into Vero cells expressing SUDV VP30. GFP fluorescence confirmed successful virus rescue. The rescued virus was passaged, and a VP30-deficient SUDV was isolated. Sequencing confirmed no unintended mutations, and no VP30 reversion was observed after 10 passages. Growth analysis showed replication only in VP30-expressing cells, while no replication occurred in VP30-negative cells. VP30 proteins from EBOV, RESTV, and SUDV showed high functional compatibility, whereas MARV VP30 showed little complementation. This system provides a platform that may reduce reliance on BSL-4 containment and facilitate safer studies of SUDV biology, antiviral development, and filovirus evolution.
(AI)