Investigation of a vaccine to prevent HTLV-1 infection by mother-to-child immunization

2023 Fiscal Year Final Research Report

• Project/Area Number: 18K07054
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 49030:Experimental pathology-related
• Research Institution: National Institute of Infectious Diseases
• Principal Investigator: Ainai Akira 国立感染症研究所, 感染病理部, 室長 (10572133)
• Project Period (FY): 2018-04-01 – 2024-03-31
• Keywords: HTLV-1 / ワクチン / 母子免疫

Outline of Final Research Achievements

Vaccination is a possible strategy for preventing new HTLV-1 infections, as HTLV-1 infection is neutralized by antibodies against the Env protein, and vaccination with the Env protein as antigen is expected to have a protective effect against infection. Female BALB/c mice were vaccinated with recombinant Env protein (rEnv) as antigen by a baculovirus expression system, subcutaneously with adjuvant twice at 3-week intervals, followed by an additional vaccination with rEnv only, and then mated. IgG antibody titers in sera obtained over time from the mother and pups after birth and birth revealed that the pups' sera had higher rEnv-specific antibody titers than the mother's sera.

Free Research Field

ワクチン学

Academic Significance and Societal Importance of the Research Achievements

HTLV-1は、成人T細胞白血病（Adult T-cell leukemia：ATL）等のHTLV-1関連疾患を引き起こす。ATLの発症は1年あたりキャリア1000~3000人に1人の割合で起こり、生涯発症率は約4~5%と考えられている。マウスにおいて、バキュロウイルス発現系による組換えEnvタンパク質（rEnv）を用いたワクチン接種により、仔マウスにおいて移行抗体が認められたことから、感染防御効果が期待できる。本成果は、HTLV-1感染症を制御しうるワクチンの可能性を明らかにしたと考える。