Our research project on human metapneumovirus (Principal Investigator: Makoto Takeda) has been selected for the research area "Global Research Infrastructure, Collaborative Research via Overseas Research Centers" of Japan Program for Infectious Diseases Research and Infrastructure of the Japan Agency for Medical Research and Development (AMED). 

https://www.amed.go.jp/en/program/list/15/01/001_003.html

https://www.amed.go.jp/en/program/list/15/01/001.html

https://www.amed.go.jp/koubo/03004/01/C_00005.html

Research title "Emergence and Spread of Human Metapneumovirus Strains with Major Genetic Alterations: Epidemiological and Molecular Characterization(Nagasaki University)" 

Background: Human metapneumovirus (HMPV) is a major cause of respiratory tract infections across all age groups and is one of the leading viral pathogens requiring hospitalization, particularly in young children and older adults. In recent years, HMPV strains carrying large duplications of 111 or 180 nucleotides in the G protein gene have spread globally. From late 2024 to early 2025, a marked increase in HMPV infections was reported, particularly in northern China. Similar G gene duplication variants have previously emerged and become globally dominant in respiratory syncytial virus (RSV), suggesting that these genetic alterations may enhance immune evasion and viral transmissibility.

Objective: This study aims to elucidate the mechanisms underlying the emergence and global spread of HMPV strains carrying G gene duplications, as well as to define the molecular basis of their pathogenicity and immune evasion.

Methods: We will utilize approximately 300 clinical HMPV specimens and associated epidemiological data collected over more than 18 years through the Nagasaki University research site in Vietnam. These resources will be used to investigate the timing of emergence, epidemiological dynamics, and clinical characteristics of duplication variants. In parallel, we will combine our reverse genetics system for HMPV duplication variants—the first established worldwide—with human iPSC-derived respiratory organoids developed at the Institute of Science Tokyo to determine how G gene duplications influence viral replication, innate immune evasion, and pathogenicity.

Expected Outcomes: By integrating long-term epidemiological data with functional virological analyses, this project will reveal the molecular basis of HMPV evolution and immune evasion. The findings will provide a scientific foundation for predicting future outbreaks and for developing vaccines and antiviral therapies. Furthermore, this integrated research framework will serve as an international platform applicable to studies of other respiratory viruses and emerging infectious diseases.