Visualization of immune cell-to-cell transmission of SFTS virus

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K20768
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0803:Pathology, infection/immunology, and related fields
• Research Institution: National Institute of Infectious Diseases
• Principal Investigator: Sho Miyamoto 国立感染症研究所, 感染病理部, 研究員 (30881792)
• Project Period (FY): 2021-08-30 – 2023-03-31
• Keywords: SFTS virus / B cell / preplasmablast

Outline of Final Research Achievements

The B cells that are the target of SFTS virus infection in humans are activated B cells that differentiated into plasmablasts. To elucidate how the target cells are induced, we performed SFTS virus infection of human peripheral blood cells, verified whether activated B cells are induced, and searched for cell types and secreted factors required for the induction. After infecting peripheral blood cells with SFTS virus, we observed the induction of the activated B cells with a phenotype similar to that of atypical lymphocytes in SFTS patients. Notably, infection of peripheral blood B cells alone induced similar activated B cell propagation. Cytokine quantification revealed secreted factors specific to B cells that were not secreted by the virus-infected monocytes.

Free Research Field

ウイルス学

Academic Significance and Societal Importance of the Research Achievements

末梢血B細胞へのウイルス感染のみで活性化B細胞が増殖することから、その誘導にはSFTSウイルスのB細胞感染が重要であると考えられた。また、B細胞感染によって分泌されるサイトカイン・ケモカインが活性化B細胞の増殖を促すことが示唆された。これらの成果はSFTS患者の生体内におけるウイルス増殖と標的免疫細胞の動態の解明に寄与し、SFTS重症化機構の解明に貢献すると考えられる。