Protection against anthrax with recombinant virus-expressed protective antigen in experimental animals.
We previously described the cloning and expression of the protective antigen (PA) gene of Bacillus anthracis in both vaccinia virus and a baculovirus. The antigenicity of the PA products was characterized. PA expressed by the recombinant vaccinia viruses elicited a partial protective immune response against a lethal B. anthracis spore challenge in guinea pigs and mice. The WR strain vaccinia virus recombinant (WR-PA) protected 60% of male mice and 50% of guinea pigs. WR-PA elicited high anti-PA antibody titers in mice but not in guinea pigs. Connaught strain vaccinia virus recombinants failed to protect any immunized animals. PA purified from baculovirus recombinant-infected cultures plus adjuvant partially protected male CBA/J mice and completely protected female Hartley guinea pigs from challenge. Both the recombinant and nonrecombinant PA preparations combined with adjuvant elicited high anti-PA antibody titers in Hartley guinea pigs and CBA/J mice. These data demonstrate that the recombinant baculovirus- and vaccinia virus-produced PAs were immunogenic in both guinea pigs and mice, that the baculovirus-PA recombinant was a useful source of immunogenic PA, and that vaccinia virus-PA recombinants may be feasible live anthrax vaccine candidates worthy of consideration for further development as live vaccines.
Iacono-Connors
L C
LC
Virology Division, U.S. Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland 21702-5011.
Welkos
S L
SL
Ivins
B E
BE
Dalrymple
J M
JM
D000818:Animals; D000881:Anthrax / Q000517:prevention & control*; D000942:Antigens, Bacterial / Q000276:immunology*; D001408:Bacillus anthracis / Q000254:growth & development / Q000276:immunology*; D005260:Female; D006168:Guinea Pigs; D008297:Male; D051379:Mice; D008808:Mice, Inbred CBA; D011993:Recombinant Fusion Proteins / Q000276:immunology; D014614:Vaccines, Synthetic; D014616:Vaccinia virus / Q000235:genetics
D000942:Antigens, Bacterial; D011993:Recombinant Fusion Proteins; D014614:Vaccines, Synthetic