Bacterial strains designed for immunization frequently have
mutations that eliminate lipopolysaccharide O-antigen. These mutants are less
immunogenic, however they also have a lowered ability to colonize the intestinal
tract and invade intestinal mucosal cells. There is a need then, for a bacterium
that has a mutation allowing O-antigen synthesis, but that still reduces the
host immune response against the bacterium itself.
Researchers at the Biodesign Institute of Arizona State
University have developed a recombinant bacterium with a regulated rfaH nucleic
acid. Regulation of the expression of this gene can down regulate O-antigen
synthesis after an initial period of growth of the bacterium in a host. This
permits increased host immune responses to the exogenous antigen being carried
by the immunizing bacteria.
By combining attenuating mutations, one can produce a
Salmonella vaccine capable of delivering a heterologous antigen to induce
protective immunity. This feature may also enable the use of a Salmonella
vaccine vector for multiple vaccines to provide immunization against multiple
infectious diseases.
Potential Applications
Benefits and Advantages
- Excellent attenuation and safety with long-lasting
protective immunity
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For more information about the inventor(s) and their
research, please see
Dr.
Curtiss' directory webpage
Dr.
Curtiss' departmental webpage
