Construction, Characterization, and Immunogenicity of an Attenuated Salmonella enterica Serovar Typhimurium pgtE Vaccine Expressing Fimbriae with Integrated Viral Epitopes from the spiC Promoter

AUTOR(ES)

Chen, Huaiqing

FONTE

American Society for Microbiology

RESUMO

Transmissible gastroenteritis virus (TGEV) is a porcine coronavirus that causes diarrhea, leading to near 100% mortality in neonatal piglets with corresponding devastating economic consequences. For the protection of neonatal and older animals, oral live vaccines present the attractive property of inducing desired mucosal immune responses, including colostral antibodies in sows—an effective means to passively protect suckling piglets. Newly attenuated Salmonella vaccine constructs expressing TGEV S protein epitopes were studied and evaluated for improved humoral immune response to TGEV. The macrophage-inducible Salmonella ssaH and spiC/ssaB promoters were compared for their ability to express the TGEV C and A epitopes in the context of the heterologous 987P fimbriae on Salmonella vaccines. Compared to the ssaH promoter, the Salmonella cya crp vector elicited significantly higher levels of mucosal and systemic antibodies in orally immunized mice when the chimeric fimbriae were expressed from the spiC promoter. The Salmonella spiC promoter construct induced the highest level of chimeric fimbriae after being taken up by the J774A.1 macrophagelike cells. The Salmonella cya crp vaccine vector was shown to incorporate into 987P partially degraded chimeric subunits lacking the TGEV epitopes. In contrast, its isogenic pgtE mutant produced fimbriae consisting exclusively of intact chimeric subunits. Mice immunized orally with the Salmonella pgtE vaccine expressing chimeric fimbriae from the spiC promoter elicited significantly higher systemic and mucosal antibody titers against the TGEV epitopes compared to the parental vaccine. This study indicates that the Salmonella cya crp pgtE vector and the spiC promoter can be used successfully to improve immune responses toward heterologous antigens.

Documentos Relacionados

• Construction, Genotypic and Phenotypic Characterization, and Immunogenicity of Attenuated ΔguaBA Salmonella enterica Serovar Typhi Strain CVD 915
• Levels of Expression and Immunogenicity of Attenuated Salmonella enterica Serovar Typhimurium Strains Expressing Escherichia coli Mutant Heat-Labile Enterotoxin
• Expression and Immunogenicity of Hemagglutinin A from Porphyromonas gingivalis in an Avirulent Salmonella enterica Serovar Typhimurium Vaccine Strain
• Salmonella enterica Serotype Typhimurium Elicits Cross-Immunity against a Salmonella enterica Serotype Enteritidis Strain Expressing LP Fimbriae from the lac Promoter
• Salmonella enterica Serovars Gallinarum and Pullorum Expressing Salmonella enterica Serovar Typhimurium Type 1 Fimbriae Exhibit Increased Invasiveness for Mammalian Cells