Expression of heterologous antigens in Salmonella Typhimurium vaccine vectors using the in vivo-inducible, SPI-2 promoter, ssaG

Nicola D. McKelvie, Richard Stratford, Tao Wu, Trevor Bellaby, Emma Aldred, Nicky J. Hughes, Steven N. Chatfield, Derek Pickard, Christine Hale, Gordon Dougan, Shahid A. Khan

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18 Citations (Scopus)


DNA derived from regions upstream of the Salmonella enterica serovar Typhimurium ssaG gene were used to drive expression of different reporter genes in putative Salmonella vaccine strains. Expression from ssaG was shown to be significantly upregulated once Salmonella had entered murine or human macrophages, and levels of expression were dependent on the length of the ssaG 5′ sequence incorporated. S. Typhimurium derivatives harbouring the Escherichia coli heat labile toxin B subunit (LT-B) fused to various lengths of the ssaG promoter region were also constructed as single copy chromosomal integrations. Expression of LT-B by these Salmonella derivatives was detected at significant levels after intra-macrophage survival and mice immunised with these derivatives mounted marked anti-LT-B humoral antibody responses.

Original languageEnglish
Pages (from-to)3243-3255
Number of pages13
Issue number25-26
Publication statusPublished - 3 Sep 2004
Externally publishedYes


  • Chromosomal expression
  • E. coli heat labile toxin
  • In vivo-inducible expression
  • S. Typhimurium
  • Salmonella Pathogenicity Island-2
  • ssaG promoter

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