Research Theme

• Development of a mosquito-borne flavivirus vaccine that does not induce antibody-dependent enhancement of infection (ADE)
• Mechanism of tetramer formation of IgA antibodies induced by intranasal vaccination.

Keyword

• Vaccine
• Recombinant protein
• Antibody

Overview of Research

• Antibodies induced by flavivirus infection or vaccination shows cross-reactivity to diverse of flaviviruses. These cross-reactive antibodies are causative agent for ADE, resulting in severe diseases. We will evaluate the ADE epitopes using monoclonal antibodies induced by flaviviral infection or viral protein immunization. Based on information of the ADE epitopes, we aim to develop safe and effective vaccines that do not cause ADE.
• Secreted IgA antibody on mucosal epithelium plays a critical role in protecting from invasive pathogens. The secreted IgA antibody includes dimer and tetramer in addition to monomer. Since tetrameric IgA antibody is known to exhibit higher neutralizing activity than monomeric or dimeric IgA antibodies, intranasal vaccines that can efficiently induce tetrameric IgA antibody on mucosal epithelium are expected to show high vaccine efficacy. However, the mechanisms of IgA tetramerization and of effective induction of tetrameric IgA antibody are still unknown. Therefore, we aim to elucidate the mechanism of tetrameric IgA antibody formation in order to develop an effective intranasal vaccine.