RT Journal Article T1 A Live Salmonella Vaccine Delivering PcrV through the Type III Secretion System Protects against Pseudomonas aeruginosa. A1 Aguilera-Herce, Julia A1 Garcia-Quintanilla, Meritxell A1 Romero-Flores, Rocio A1 McConnell, Michael J A1 Ramos-Morales, Francisco K1 PcrV K1 Pseudomonas aeruginosa K1 Salmonella-delivered vaccines K1 SseJ K1 type III secretion AB Pseudomonas aeruginosa is a common Gram-negative opportunistic pathogen that is intrinsically resistant to a wide range of antibiotics. The development of a broadly protective vaccine against P. aeruginosa remains a major challenge. Here, we used an attenuated strain of Salmonella enterica serovar Typhimurium as a vehicle to express P. aeruginosa antigens. A fusion between the S. enterica type III secretion effector protein SseJ and the P. aeruginosa antigen PcrV expressed under the control of the sseA promoter was translocated by Salmonella into host cells in vitro and elicited the generation of specific antibodies in mice. Mice immunized with attenuated Salmonella expressing this fusion had reduced bacterial loads in the spleens and lungs and lower serum levels of proinflammatory cytokines than control mice after P. aeruginosa infection. Importantly, immunized mice also showed significantly enhanced survival in this model. These results suggest that type III secretion effectors of S. enterica are appropriate carriers in the design of a live vaccine to prevent infections caused by P. aeruginosaIMPORTANCE The Gram-negative bacterium Pseudomonas aeruginosa is an important opportunistic pathogen that causes infections in cystic fibrosis and hospitalized patients. Therapeutic treatments are limited due to the emergence and spread of new antibiotic-resistant strains. In this context, the development of a vaccine is a priority. Here, we used an attenuated strain of Salmonella enterica serovar Typhimurium as a vehicle to express and deliver the Pseudomonas antigen PcrV. This vaccine induced the generation of specific antibodies in mice and protected them from lethal infections with P. aeruginosa This is an important step toward the development of an effective vaccine for the prevention of infections caused by P. aeruginosa in humans. PB American Society for Microbiology YR 2019 FD 2019-04-17 LK http://hdl.handle.net/10668/13846 UL http://hdl.handle.net/10668/13846 LA en NO Aguilera-Herce J, GarcĂ­a-Quintanilla M, Romero-Flores R, McConnell MJ, Ramos-Morales F. A Live Salmonella Vaccine Delivering PcrV through the Type III Secretion System Protects against Pseudomonas aeruginosa. mSphere. 2019 Apr 17;4(2):e00116-19. DS RISalud RD Apr 7, 2025