Flagellin-F1-V fusion protein is an effective plague vaccine in mice and two species of nonhuman primates.
A number of studies have clearly demonstrated that flagellin is a potent adjuvant that promotes robust immune responses when it is given with a protein antigen. In view of the potential biological and practical benefits of a recombinant protein vaccine composed of a single fusion protein containing flagellin and antigen, we have evaluated the efficacy of a fusion protein composed of flagellin and two protective antigens of Yersinia pestis (F1 and V) in eliciting protection against respiratory challenge with Y. pestis. Flagellin-F1-V was produced and purified in high yield under good manufacturing practices conditions. The fusion protein retains full Toll-like receptor 5-stimulating activity in vitro. Using a prime-boost immunization protocol, we found that flagellin-F1-V elicits robust antigen-specific humoral immunity in mice and two species of nonhuman primates. Immune mice were fully protected against intranasal challenge with 150 mean tolerated doses of Y. pestis CO92. In immune mice, the bacteria were completely cleared within 3 days after challenge. Flagellin-F1-V exhibited full stability for at least 297 days at 4 degrees C and at least 168 days at 25 degrees C. At between 29 and 84 days at 37 degrees C, the protein exhibited a loss of biological activity that appeared to be associated with a substantial change in protein diameter, possibly due to oligomerization. On the basis of our results, we believe that flagellin-F1-V is an outstanding candidate for evaluation in studies with humans.
Mizel
Steven B
SB
Department of Microbiology and Immunology, Wake Forest University School of Medicine, Medical Center Blvd., Winston-Salem, NC 27157-1064, USA. smizel@wfubmc.edu
Graff
Aaron H
AH
Sriranganathan
Nammalwar
N
Ervin
Sean
S
Lees
Cynthia J
CJ
Lively
Mark O
MO
Hantgan
Roy R
RR
Thomas
Michael J
MJ
Wood
James
J
Bell
Brian
B
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000235:genetics / Q000276:immunology*; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology*; D002522:Chlorocebus aethiops; D004355:Drug Stability; D004356:Drug Storage; D005260:Female; D005408:Flagellin / Q000235:genetics / Q000276:immunology*; D007117:Immunization, Secondary; D008252:Macaca fascicularis; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010931:Plague Vaccine / Q000235:genetics / Q000276:immunology*; D052899:Pore Forming Cytotoxic Proteins / Q000235:genetics / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology; D016019:Survival Analysis; D013696:Temperature; D013997:Time Factors; D051198:Toll-Like Receptor 5 / Q000276:immunology; D037521:Virulence Factors / Q000235:genetics / Q000276:immunology; D015010:Yersinia pestis / Q000276:immunology
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C043908:LcrV protein, Yersinia; D010931:Plague Vaccine; D052899:Pore Forming Cytotoxic Proteins; D011993:Recombinant Fusion Proteins; D051198:Toll-Like Receptor 5; D037521:Virulence Factors; C086725:caf1 protein, Yersinia pestis; D005408:Flagellin