Immunization With Outer Membrane Vesicles Derived From Major Outer Membrane Protein-Deficient Salmonella Typhimurium Mutants for Cross Protection Against Salmonella Enteritidis and Avian Pathogenic Escherichia coli O78 Infection in Chickens

Abstract

Colibacillosis is an economically important infectious disease in poultry, caused by avian pathogenic Escherichia coli (APEC). Salmonella enterica serovar Enteritidis (S. Enteritidis) is a major cause of food-borne diseases in human circulated through poultry-derived products, including meat and chicken eggs. Vaccine control is the mainstream approach for combating these infections, but it is difficult to create a vaccine for the broad-spectrum protection of poultry due to multiple serotypes of these pathogens. Our previous studies have shown that outer membrane vesicles (OMVs) derived from S. enterica serovar Typhimurium mutants with a remodeled outer membrane could induce cross-protection against heteroserotypic Salmonella infection. Therefore, in this study, we further evaluated the potential of broadspectrum vaccines based on major outer membrane protein (OMP)-deficient OMVs, including ΔompA, ΔompC, and ΔompD, and determined the protection effectiveness of these candidate vaccines in murine and chicken infection models. The results showed that ΔompA led to an increase in the production of OMVs. Notably, ΔompAΔompCΔompD OMVs showed significantly better cross-protection against S. enterica serovar Choleraesuis, S. Enteritidis, APEC O78, and Shigella flexneri 2a than did other omp-deficient OMVs, with the exception of ΔompA OMVs. Subsequently, we verified the results in the chicken model, in which ΔompAΔompCΔompD OMVs elicited significant cross-protection against S. Enteritidis and APEC O78 infections. These findings further confirmed the feasibility of improving the immunogenicity of OMVs by remodeling the outer membrane and provide a new perspective for the development of broad-spectrum vaccines based on OMVs.

Outer membrane vesicles from genetically engineered Salmonella enterica serovar Typhimurium presenting Helicobacter pylori antigens UreB and CagA induce protection against Helicobacter pylori infection in mice

“…Typhimurium UK-1 [ 12 ] QS0071 S . Typhimurium UK-1 ∆ rfbP ∆ fliC ∆ fljB ∆ ompA [ 8 ] QS0072 Δ rfbP Δ fliC Δ fljB Δ ompA with plasmid pHbp+UreB-VacA-CagA This study QS0073 Δ rfbP Δ fliC Δ fljB Δ ompA with plasmid pHbp+UreB-VacA This study QS0074 Δ rfbP Δ fliC Δ fljB Δ ompA with plasmid pHbp+UreB- CagA This study QS0075 ΔrfbP ΔfliC ΔfljB Δ ompA with plasmid pHbp+VacA-CagA This study QS0076 Δ rfbP Δ fliC Δ fljB Δ ompA with pHbp+UreB This study QS0077 Δ rfbP Δ fliC Δ fljB Δ ompA with pHbp+VacA This study QS0078 Δ rfbP Δ fliC Δ fljB Δ ompA with pHbp+CagA This study QS0081 Δ rfbP Δ fliC Δ fljB Δ ompC [ 8 ] QS0082 Δ rfbP Δ fliC Δ fljB Δ ompC with plasmid Hbp+UreB-VacA-CagA This study QS0091 Δ rfbP Δ fliC Δ fljB Δ ompD [ 8 ] QS0092 …”

“…Native OMVs (without any detergent treatment) were collected and isolated from culture supernatants of S . Typhimurium χ3761 and its mutants as previously described [ 8 , 16 ]. Briefly, 2 L of bacteria culture supernatants in the logarithmic phase (OD 600 = 1) were collected and filtered using a 0.45 μm Steritop bottle-top filter unit (Millipore et al, USA).…”

“…The self-made rabbit serum antibodies corresponding to the protein, including UreB, VacA, and CagA were used for immunoblotting to detect the expression of different proteins in OMVs. The OMV particle size distribution and concentration were determined by nanoparticle tracking analyses (NanoSight NS300, Malvern Instruments, United Kingdom) as previously described [ 8 , 17 ]. The average of triplicate video statistics was taken for each sample.…”

“…Simultaneous deletion of Salmonella flagellar structural proteins FliC and FljB promoted humoral and mucosal immunity to a certain extent and markedly improved cross-protection effects [ 7 ]. In addition, OMVs cross-protected against the same Salmonella serotype and heterologous E. coli after the knockout of outer membrane proteins (OMPs) OmpA, OmpC, and OmpD [ 8 ]. These results indicate that Salmonella OMVs can serve as an antigen delivery vector with great potential for developing broad-spectrum vaccines.…”

Outer Membrane Vesicle Vaccine Platforms

“…For example, it has been shown that disruption of small noncoding RNA improves the protective efficacy of OMVs against Helicobacter pylori infection in a mouse model [ 72 ]. Both intranasal and intraperitoneal immunization with flagellin-deficient S. typhimurium OMVs resulted in efficient protection against heterologous S. choleraesuis and S. enteritidis challenge [ 73 ] and immunization with OMVs from major outer membrane protein-deficient S. typhimurium mutants enhanced cross-protection [ 74 ].…”