RACCOON POXVIRUS AS A GENE EXPRESSION AND VACCINE VECTOR FOR GENES OF RABIES VIRUS AND OTHER ORGANISMS

摘要

Raccoon poxvirus, an organism that may be indigenous in nature, is established as a suitable substrate for insertion and expression of nucleotide coding sequence of heterolgous organisms. Two infectious raccoon poxvirus recombinants for expressing rabies virus surface spike glycoprotein (G) were produced by homologous recombination between raccoon poxvirus DNA and chimeric plasmids previously used for production of vaccinia virus recombinants by thymidine kinase insertional inactivation. Raccoons that were fed polyurethane baits loaded with raccoon poxvirus recombinant quickly developed high levels of rabies virus neutralizing antibodies and were protected when challenged with an otherwise lethal dose of raccoon rabies street virus. Dogs developed rabies virus neutralizing antibodies after feeding a vectored raccoon poxvirus recombinant in contrast to feeding a vaccinia: G recombinant that induced no rabies neutralizing antibodies. Cotton rats, skunks, mice and rabbits that were fed recombinant raccoon poxvirus developed variable levels of rabies neutralizing antibodies. All vaccinated cotton rats were protected from otherwise lethal rabies challenge.