VSV-G modification enhances engineered exosome SARS-CoV-2 vaccine to respiratory mucosal immunity
10.3867/j.issn.1000-3002.2025.08370
- VernacularTitle:VSV-G修饰增强工程化外泌体SARS-CoV2疫苗诱导呼吸道黏膜免疫
- Author:
Zehong CHEN
1
;
Haonan XING
;
Mei LU
;
Xiwei WANG
;
Meng LI
;
Xiuli GAO
;
Aiping ZHENG
Author Information
1. 贵州医科大学药学院,中药功效成分发掘与利用全国重点实验室,贵州 贵阳 561113;军事医学研究院,北京 100850;国家安全特需药品全国重点实验室,北京 100850;贵州省高校微生物生化药学工程中心,贵州 贵阳 561113
- Publication Type:Journal Article
- Keywords:
engineered exosomes;
severe acute respiratory syndrome coronavirus 2;
vesicular stomatitis virus envelope glycoprotein-G;
mucosal vaccine;
nasal mucosal immunity;
immune response induction
- From:
Chinese Journal of Pharmacology and Toxicology
2025;39(8):581-590
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVE To investigate the impact of vesicular stomatitis virus envelope glycopro-tein-G(VSV-G)modification on the mucosal immune efficacy of antigen-loaded engineered exosome vaccines.METHODS In vitro experiments:Dendritic cells(DCs)were divided into three groups:cell-control(treated with culture medium),receptor binding domain(RBD)(transfected with plasmid RBD),and RBD+VSV-G(co-transfected with plasmids RBD and VSV-G).Expression levels of RBD and VSV-G were assessed using Western blotting,flow cytometry,and immunofluorescence.Exosomes were extracted via ultracentrifugation,whose morphology,size distribution,and marker proteins were analyzed using transmission electron microscopy,nanoparticle tracking analysis,and Western blotting that confirmed the expressions of RBD and VSV-G in the exosomes.In vivo experiments:① Female BALB/c mice were divided into the control group Mock exosomes(Mock-Exo)(derived from the supernatant of cell-control),RBD decorated exosomes(RBD-Exo)(derived from the RBD cell supernatant),and RBD and VSV-G decorated exosomes(RBD+VSV-G-Exo)(derived from RBD+VSV-G cell supernatant).Follow-ing intranasal immunization with the respective vaccines,the nasal retention effects were evaluated using in vivo imaging.Flow cytometry was used to assess the ability to recruit immune cells to the nasal tissue.Serum RBD-specific immunoglobulin G(IgG)and mucosal immunoglobulin A(IgA)(bronchoal-veolar lavage fluid/nasal wash)were quantified at 7 and 21 d post-immunization by enzyme-linked immuno-sorbent assay.Body weight changes were monitored and key serum biochemical parameters along with histopathological damage to major organs were analyzed following immunization.② Female BALB/c mice were divided into the Mock-Exo group(intranasally inoculated with Mock-Exo),RBD+VSV-G-Exo group(intranasally inoculated with RBD+VSV-G-Exo),and RBD+VSV-G-Exo(im)group(intramus-cularly injected with RBD+VSV-G-Exo).RESULTS In vitro experiments:RBD and VSV-G were successfully expressed in cells,with positive rates of RBD+and VSV-G+cells at 64.4%and 31.2%,respectively.The extracted exosomes exhibited regular morphology and qualified purity,with a particle size of approximately 138 nm and successfully loaded RBD and VSV-G proteins.In vivo experiments:Compared to Mock-Exo and RBD-Exo,RBD+VSV-G-Exo prolonged nasal retention time to 96 h and markedly increased the numbers of CD49B+natural killer cells,CD11c+dendritic cells,and F4/80+macrophages in nasal tissues.RBD+VSV-G-Exo induced robust RBD-specific immune responses,with serum IgG titers,BALF IgA titers,and nasal wash IgA titers reaching 1∶5 215,1∶2 560,1∶1 114,respec-tively.In contrast,no RBD-specific IgA antibody titers were detected in the BALF and nasal wash of mice treated with RBD+VSV-G-Exo(im).Mice showed stable body weight gain during 30 d post-immu-nization.Major serum biochemical indices were within normal reference ranges,and no obvious patho-logical changes were observed in major organs or olfactory bulbs 7 d after immunization.CONCLU-SION VSV-G modification extends the retention time of engineered exosome vaccines in nasal tissues,enhance their ability to recruit immune cells,and induce a high-level antigen-specific respiratory mucosal immune response.
