251. Hcp1-loaded staphylococcal membrane vesicle vaccine protects against acute melioidosis.
- Author
-
Zhu K, Li G, Li J, Zheng M, Peng X, Rao Y, Li M, Zhou R, and Rao X
- Subjects
- Animals, Mice, Hemolysin Proteins, Interleukin-6, Tumor Necrosis Factor-alpha, Antibodies, Bacterial, Bacterial Vaccines, Melioidosis prevention & control
- Abstract
Burkholderia pseudomallei is the causal agent of melioidosis, a deadly tropical infectious disease that lacks a vaccine. On the basis of the attenuated Staphylococcus aureus RN4220-Δ agr (RN), we engineered the RN4220-Δ agr / pdhB-hcp1 strain (RN-Hcp1) to generate B. pseudomallei hemolysin-coregulated protein 1 (Hcp1)-loaded membrane vesicles (
hcp1 MVs). The immunization of BALB/c mice withhcp1 MVs mixed with adjuvant by a three-dose regimen increased the serum specific IgG production. The serum levels of inflammatory factors, including TNF-α and IL-6, inhcp1 MV-vaccinated mice were comparable with those in PBS-challenged mice. The partial adjuvant effect of staphylococcal MVs was observed with the elevation of specific antibody titer inhcp1 MV-vaccinated mice relative to those that received the recombinant Hcp1 protein (rHcp1) or MVs derived from RN strain (Δagr MVs). Thehcp1 MVs/adjuvant vaccine protected 70% of mice from lethal B. pseudomallei challenge. Immunization withhcp1 MVs only protected 60% of mice, whereas vaccination with rHcp1 orΔagr MVs conferred no protection. Moreover, mice that receivedhcp1 MVs/adjuvant andhcp1 MVs immunization had low serum TNF-α and IL-6 levels and no inflammatory infiltration in comparison with other groups. In addition, all surviving mice inhcp1 MVs/adjuvant andhcp1 MVs groups exhibited no culturable bacteria in their lungs, livers, and spleens five days postinfection. Overall, our data highlighted a new strategy for developing B. pseudomallei vaccine and showed that Hcp1-incorporated staphylococcal MV is a promising candidate for the prevention of acute melioidosis., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Zhu, Li, Li, Zheng, Peng, Rao, Li, Zhou and Rao.)- Published
- 2022
- Full Text
- View/download PDF