Evaluation of cell-to-cell transmission in Hepatitis B Virus

2020 Fiscal Year Final Research Report

• Project/Area Number: 17K15708
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Virology
• Research Institution: Meiji University (2019-2020); National Institute of Infectious Diseases (2017-2018)
• Principal Investigator: TAKEUCHI Junko S. (柴田潤子) 明治大学, 研究・知財戦略機構(生田), 特任講師 (80647488)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: B型肝炎ウイルス / Cell-to-cell感染

Outline of Final Research Achievements

Viruses such as human immunodeficiency virus (HIV) can spread via two types of replication strategies: cell-free infection and cell-to-cell infection. Viral cell-to-cell infection, in which viral particles transmit to adjacent uninfected cells, has shown to be more efficient than infection by cell-free virus particles. However, it is still controversial whether Hepatitis B virus (HBV) can propagate via cell-to-cell infection. To address this question, HBV producer cells were co-cultured with HBV susceptible cells in the presence or absence of
neutralizing antibodies (nAbs). In the absence of nAbs, HBV propagates by both cell-free and cell-to-cell infections. While, in the presence of nAbs, cell-free transmission is inhibited, thereby allowing HBV to replicate only by the cell-to-cell infection. Our co-culture experiments demonstrated that HBV may spread by the cell-to-cell infection mode.

Free Research Field

B型肝炎ウイルス

Academic Significance and Societal Importance of the Research Achievements

HIV-1の研究においては、cell-free感染では低コピー数のウイルスが細胞に感染するのに対し、cell-to-cell感染では大量のウイルスが細胞に受け渡されるため、薬剤感受性が低いと報告されている。
HBVにおいても、現行の治療法では持続感染者からウイルスを完全に排除できないが、HBV cell-to-cell 感染と薬剤感受性についての関連は不明である。本研究は、「抗HBV剤がcell-free 感染だけでなくcell-to-cell 感染も標的としているか？」を評価できるスクリーニング系開発の一助となることが期待される。