Transformed Bacteria Produce HCV-Specific Immune Response In Mice.(Brief Article)

2001 NOV 21 - (NewsRx.com & NewsRx.net) -- by Sonia Nichols, senior medical writer - U.S. National Institutes of Health (NIH) researchers report they have transformed Salmonella bacteria so that it elicits an immune response against hepatitis C virus (HCV) DNA in HLA-A2.1 transgenic mice.

"We used an oral immunization strategy with attenuated HCV-NS3-transformed Salmonella typhimurium to deliver DNA directly to the gut-associated lymphoid tissue," described H. Wedemeyer and coauthors in the November 2001 issue of Gastroenterology.

After murine immunization, Wedemeyer and colleagues collected and analyzed any detectable HCV epitope-specific CD8[superscript]+ T cells, using laboratory assays and challenge with recombinant vaccinia virus bearing HCV-NS3 to study specific immune response activity.

Salmonella plasmid DNA vectors produced CD8[superscript]+ T cell-specific immunity against the HCV epitope NS3-1073 that lasted for up to 10 months in more than 80% of the mice, Wedemeyer and team reported. The cells were cytotoxic and produced IFN-gamma, they added.

"A second epitope (NS3-1169) was also recognized by cytotoxic and IFN-gamma producing T cells, whereas a third one (NS3-1406) stimulated IFN-gamma production ...