{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,1]],"date-time":"2026-04-01T10:32:49Z","timestamp":1775039569821,"version":"3.50.1"},"reference-count":37,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,3,31]],"date-time":"2026-03-31T00:00:00Z","timestamp":1774915200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2023YFC2307703"],"award-info":[{"award-number":["2023YFC2307703"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["82373779, 92478116"],"award-info":[{"award-number":["82373779, 92478116"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100005090","name":"Beijing Nova Program","doi-asserted-by":"publisher","award":["20240484724"],"award-info":[{"award-number":["20240484724"]}],"id":[{"id":"10.13039\/501100005090","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nanomaterials"],"abstract":"<jats:p>Klebsiella pneumoniae poses a severe global health threat due to its extensive antibiotic resistance. However, to date, no vaccine against this pathogen has been approved for clinical use worldwide. Although self-assembling nanocarriers present distinct advantages for vaccine design, their ability to effectively load polysaccharide antigens and further elicit mucosal immunity remains unclear. Here, we developed a modular, self-assembling nanovaccine (CNP-OPSKpO1) against K. pneumoniae by loading of K. pneumoniae O1 polysaccharide antigen onto a cholera toxin B subunit (CTB)-based nanoparticle (CNP). After determining the safety of the vaccine via intranasal immunization, we further evaluated its immune efficacy. CNP-OPSKpO1 elicited stronger systemic IgG and mucosal sIgA responses than non-nanoparticulate controls. In a non-lethal pulmonary infection model, CNP-OPSKpO1 vaccination reduced lung bacterial burden by over 5 logs compared to controls, achieving near-complete bacterial clearance. Histopathological analysis further confirmed minimal lung damage in vaccinated animals. In addition, in a lethal pulmonary challenge model, it conferred 90% survival, whereas all mice in the antigen-alone control group died within 4 days. Our work not only provides a safe, effective, and adjuvant-free candidate vaccine against K. pneumoniae but also advances a versatile platform for developing broad-spectrum mucosal vaccines against other pathogens.<\/jats:p>","DOI":"10.3390\/nano16070428","type":"journal-article","created":{"date-parts":[[2026,4,1]],"date-time":"2026-04-01T08:08:34Z","timestamp":1775030914000},"page":"428","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Modular Development of a Klebsiella pneumoniae Bioconjugate Nanovaccine Elicits Robust Protection via Intranasal Immunization"],"prefix":"10.3390","volume":"16","author":[{"given":"Zhenshi","family":"Li","sequence":"first","affiliation":[{"name":"College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China"},{"name":"National Key Laboratory of Advanced Biotechnology, Academy of Military Medical Science, Beijing 100071, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lingli","family":"Chen","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Advanced Biotechnology, Academy of Military Medical Science, Beijing 100071, China"},{"name":"School of Basic Medical Sciences, Fujian Medical University, Fuzhou 350108, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Canran","family":"Liu","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Advanced Biotechnology, Academy of Military Medical Science, Beijing 100071, China"},{"name":"School of Basic Medical Sciences, Fujian Medical University, Fuzhou 350108, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kangfeng","family":"Wang","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Advanced Biotechnology, Academy of Military Medical Science, Beijing 100071, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Juntao","family":"Li","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Advanced Biotechnology, Academy of Military Medical Science, Beijing 100071, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xue","family":"Yan","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Advanced Biotechnology, Academy of Military Medical Science, Beijing 100071, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yuqing","family":"Jiang","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Advanced Biotechnology, Academy of Military Medical Science, Beijing 100071, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yan","family":"Guo","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Advanced Biotechnology, Academy of Military Medical Science, Beijing 100071, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9975-8978","authenticated-orcid":false,"given":"Li","family":"Zhu","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Advanced Biotechnology, Academy of Military Medical Science, Beijing 100071, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8476-4320","authenticated-orcid":false,"given":"Hengliang","family":"Wang","sequence":"additional","affiliation":[{"name":"College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China"},{"name":"State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing 100071, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chao","family":"Pan","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Advanced Biotechnology, Academy of Military Medical Science, Beijing 100071, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,3,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"52","DOI":"10.1017\/S0195941700062603","article-title":"Habitat association of Klebsiella species","volume":"6","author":"Bagley","year":"1985","journal-title":"Infect. 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