Browsing by Author "Bourn, William"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Open Access
    An oral recombinant Salmonella enterica serovar Typhimurium mutant elicits systemic antigen-specific CD8+ T cell cytokine responses in mice
    (BioMed Central Ltd, 2009) Chin'ombe, Nyasha; Bourn, William; Williamson, Anna-Lise; Shephard, Enid
    BACKGROUND:The induction of antigen-specific CD8+ T cell cytokine responses against an attenuated, oral recombinant Salmonella enterica serovar Typhimurium vaccine expressing a green fluorescent protein (GFP) model antigen was investigated. A GFP expression plasmid was constructed in which the gfp gene was fused in-frame with the 5' domain of the Escherichia coli beta-galactosidase alpha-gene fragment with expression under the lac promoter. Groups of mice were orally immunized three times with the bacteria and systemic CD8+ T cell cytokine responses were evaluated. RESULTS: High level of the GFP model antigen was expressed by the recombinant Salmonella vaccine vector. Systemic GFP-specific CD8+ T cell cytokine (IFN-gamma and IL-4) immune responses were detected after mice were orally vaccinated with the bacteria. It was shown that 226 net IFN-gamma and 132 net IL-4 GFP-specific SFUs/10e6 splenocytes were formed in an ELISPOT assay. The level of IFN-gamma produced by GFP peptide-stimulated cells was 65.2-fold above background (p < 0.05). The level of IL-4 produced by the cells was 10.4-fold above background (p < 0.05). CONCLUSION: These results suggested that a high expressing recombinant Salmonella vaccine given orally to mice would elicit antigen-specific CD8+ T cell responses in the spleen. Salmonella bacteria may, therefore, be used as potential mucosal vaccine vectors.
  • Thumbnail Image
    Item
    Open Access
    Recombinant Salmonella enterica serovar Typhimurium vaccine vector expressing green fluorescent protein as a model antigen or human immunodeficiency virus type 1 subtype C Gag
    (2007) Chin'ombe, Nyasha; Williamson, Anna-Lise; Shephard, Enid G; Bourn, William
    Includes bibliographical references (leaves 172-200).