OBJECTIVETo observe the protection against periodontal bone loss in the Sprague-Dawley (SD) rats periodontitis model, with the recombined plasmid pcDNA3.1+/kgpcd as DNA gene vaccine.

METHODSPcDNA3.1+/kgpcd was delivered into rats by submandibular gland-targeted injection. The anti-KGPcd sIgA in saliva was measured by indirect ELISA method. Immunohistochemistry staining was used to assess the protection in the animal model.

RESULTSThe level of specific anti-KGPcd sIgA in saliva of the experimental group was significantly higher than that of control group. HE staining showed that immunization with recombined plasmid pcDNA3.1+/kgpcd could protect or minimize tissue destruction caused by subsequent P. gingivalis challenge in the rat model.

CONCLUSIONSThe results indicate that pcDNA3.1+/kgpcd was a good candidate for anti-periodontitis gene vaccine and could provide protection against Porphyromonas gingivalis-caused periodontitis in rat lesion model.

Animals ; Bacterial Vaccines ; immunology ; therapeutic use ; Immunoglobulin A, Secretory ; analysis ; Periodontitis ; immunology ; microbiology ; prevention & control ; Porphyromonas gingivalis ; genetics ; immunology ; Rats ; Rats, Sprague-Dawley ; Vaccines, DNA ; immunology ; therapeutic use

The emergence of multidrug-resistant Klebsiella pneumoniae highlights the need to develop preventive measures to ameliorate Klebsiella infections. Bacteria-derived extracellular vesicles (EVs) are spherical nanometer-sized proteolipids enriched with outer membrane proteins. Gram-negative bacteria-derived EVs have gained interest for use as nonliving complex vaccines. In the present study, we evaluated whether K. pneumoniae-derived EVs confer protection against bacteria-induced lethality. K. pneumoniae-derived EVs isolated from in vitro bacterial culture supernatants induced innate immunity, including the upregulation of co-stimulatory molecule expression and proinflammatory mediator production. EV vaccination via the intraperitoneal route elicited EV-reactive antibodies and interferon-gamma-producing T-cell responses. Three vaccinations with the EVs prevented bacteria-induced lethality. As verified by sera and splenocytes adoptive transfer, the protective effect of EV vaccination was dependent on both humoral and cellular immunity. Taken together, these findings suggest that K. pneumoniae-derived EVs are a novel vaccine candidate against K. pneumoniae infections.
Animals ; Bacterial Vaccines/immunology/*microbiology/*therapeutic use ; Extracellular Vesicles/immunology/*microbiology ; Female ; Humans ; Immunity, Cellular ; Immunity, Innate ; Interferon-gamma/immunology ; Klebsiella Infections/immunology/*prevention &control ; Klebsiella pneumoniae/*immunology ; Mice, Inbred C57BL ; Vaccination