{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,24]],"date-time":"2026-10-24T04:07:25Z","timestamp":1792814845229,"version":"4.5.0"},"reference-count":30,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2026,5,15]],"date-time":"2026-05-15T00:00:00Z","timestamp":1778803200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Major Project of Guangzhou National Laboratory","award":["GZNL2023A01005"],"award-info":[{"award-number":["GZNL2023A01005"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["TropicalMed"],"abstract":"<jats:p>Human metapneumovirus (HPMV) is a significant pathogen that causes lower respiratory tract infections. Given the weak immunogenicity thereof, and the few relevant studies, the utility of the viral membrane protein G as a vaccine remains controversial. In this study, the G extracellular domain (RMG) of HMPV was expressed either alone or fused with the cholera toxin B subunit (CTB) and \u201ccross-reacting material 197\u201d (CRM197) carrier proteins (giving G-CTB\/G and CRM197), to enhance immunogenicity. The non-glycosylated G protein (REG) expressed in Escherichia coli served as a control. SDS-PAGE and anti-His tag Western blotting verified that each protein was successfully expressed and correctly identified. BALB\/c mice were immunized with each protein and subjected to challenge with HMPV. The results showed that, although immunization with RMG alone failed to induce potent neutralizing antibodies, it modestly reduced viral loads in the lungs of mice. However, the pathological damage caused by lung inflammation was more aggravated than that of the control challenge group. The level of specific IgG antibody induced by the recombinant G-CTB was significantly higher than that elicited by RMG. Compared to the RMG group, the viral load in the lungs of the G-CTB group tended to be reduced. Also, the damage caused by lung inflammation was significantly alleviated. Our study proves that HMPV G may be a valuable antigen in terms of HMPV vaccine development and offers a promising strategy for modulating the immunogenicity and safety thereof.<\/jats:p>","DOI":"10.3390\/tropicalmed11050135","type":"journal-article","created":{"date-parts":[[2026,5,15]],"date-time":"2026-05-15T14:19:29Z","timestamp":1778854769000},"page":"135","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Human Metapneumovirus G Protein Immunogenicity and Safety Explored via Carrier Protein Fusion"],"prefix":"10.3390","volume":"11","author":[{"given":"Tian","family":"Ren","sequence":"first","affiliation":[{"name":"State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China"},{"name":"Guangzhou National Laboratory, No. 9 XingDaoHuanBei Road, Guangzhou International Bio Island, Guangzhou 510005, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kailun","family":"Ma","sequence":"additional","affiliation":[{"name":"Guangzhou National Laboratory, No. 9 XingDaoHuanBei Road, Guangzhou International Bio Island, Guangzhou 510005, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xinmiao","family":"Lai","sequence":"additional","affiliation":[{"name":"Guangzhou National Laboratory, No. 9 XingDaoHuanBei Road, Guangzhou International Bio Island, Guangzhou 510005, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jizheng","family":"Chen","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China"},{"name":"Guangzhou National Laboratory, No. 9 XingDaoHuanBei Road, Guangzhou International Bio Island, Guangzhou 510005, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Changgui","family":"Li","sequence":"additional","affiliation":[{"name":"National Institutes for Food and Drug Control, Beijing 102629, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,5,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"135","DOI":"10.12688\/f1000research.12625.1","article-title":"Human metapneumovirus\u2014What we know now","volume":"7","author":"Shafagati","year":"2018","journal-title":"F1000Research"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1299","DOI":"10.1136\/bmj.p1299","article-title":"HMPV: The little known virus that\u2019s making its mark in intensive care","volume":"381","author":"Wise","year":"2023","journal-title":"BMJ"},{"key":"ref_3","first-page":"e85259","article-title":"The Re-emergence of Human Metapneumovirus: Virus Classification, Characteristics, Mechanisms of Infection, Clinical Features, Diagnosis, Epidemiology, Prevention, and Treatment","volume":"17","author":"Chittiprol","year":"2025","journal-title":"Cureus"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"719","DOI":"10.1038\/89098","article-title":"A newly discovered human pneumovirus isolated from young children with respiratory tract disease","volume":"7","author":"Groen","year":"2001","journal-title":"Nat. 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