Infection with flaviviruses requires BCLXL for cell survival

2017 Fiscal Year Final Research Report

• Project/Area Number: 16K19139
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Virology
• Research Institution: Osaka University
• Principal Investigator: TORU OKAMOTO 大阪大学, 微生物病研究所, 准教授 (80628595)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: フラビウイルス / アポトーシス / BCL2

Outline of Final Research Achievements

In this study, we examined the roles of BCL2 proteins in the induction of apoptosis in cells upon infection with flaviviruses, such as Japanese encephalitis virus, Dengue virus and Zika virus. We showed that survival of the infected cells depends on BCLXL, a pro-survival BCL2 protein due to suppression of the expression of another pro-survival protein, MCL1. Treatment with BCLXL inhibitors, as well as deficient BCLXL gene expression, induced BAX/BAK-dependent apoptosis upon infection with flaviviruses. Furthermore, we examined the roles of BCLXL in the death of JEV-infected cells during in vivo infection. Haploinsufficiency of the BCLXL gene, as well as administration of BH3 mimetic compounds, produced resistance to the lethal challenge of JEV infection and suppressed inflammation. These results suggest that BCLXL plays a crucial role in the survival of cells infected with flaviviruses.

Free Research Field

ウイルス学