title: Mutated and bacteriophage T4 nanoparticle arrayed F1-V immunogens from Yersinia pestis as next generation plague vaccines.
abstract: Pneumonic plague is a highly virulent infectious disease with 100% mortality rate, and its causative organism Yersinia pestis poses a serious threat for deliberate use as a bioterror agent. Currently, there is no FDA approved vaccine against plague. The polymeric bacterial capsular protein F1, a key component of the currently tested bivalent subunit vaccine consisting, in addition, of low calcium response V antigen, has high propensity to aggregate, thus affecting its purification and vaccine efficacy. We used two basic approaches, structure-based immunogen design and phage T4 nanoparticle delivery, to construct new plague vaccines that provided complete protection against pneumonic plague. The NH₂-terminal β-strand of F1 was transplanted to the COOH-terminus and the sequence flanking the β-strand was duplicated to eliminate polymerization but to retain the T cell epitopes. The mutated F1 was fused to the V antigen, a key virulence factor that forms the tip of the type three secretion system (T3SS). The F1mut-V protein showed a dramatic switch in solubility, producing a completely soluble monomer. The F1mut-V was then arrayed on phage T4 nanoparticle via the small outer capsid protein, Soc. The F1mut-V monomer was robustly immunogenic and the T4-decorated F1mut-V without any adjuvant induced balanced TH1 and TH2 responses in mice. Inclusion of an oligomerization-deficient YscF, another component of the T3SS, showed a slight enhancement in the potency of F1-V vaccine, while deletion of the putative immunomodulatory sequence of the V antigen did not improve the vaccine efficacy. Both the soluble (purified F1mut-V mixed with alhydrogel) and T4 decorated F1mut-V (no adjuvant) provided 100% protection to mice and rats against pneumonic plague evoked by high doses of Y. pestis CO92. These novel platforms might lead to efficacious and easily manufacturable next generation plague vaccines.
authors.affiliation: Department of Biology, The Catholic University of America, Washington, District of Columbia, United States of America.
authors.forename: Pan
authors.initials: P
authors.lastname: Tao
authors.forename: Marthandan
authors.initials: M
authors.lastname: Mahalingam
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Kirtley
authors.forename: Christina J
authors.initials: CJ
authors.lastname: van Lier
authors.forename: Jian
authors.initials: J
authors.lastname: Sha
authors.forename: Linsey A
authors.initials: LA
authors.lastname: Yeager
authors.forename: Ashok K
authors.initials: AK
authors.lastname: Chopra
authors.forename: Venigalla B
authors.initials: VB
authors.lastname: Rao
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000956:Antigens, Viral / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017122:Bacteriophage T4 / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism; D002213:Capsid / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism; D036022:Capsid Proteins / Q000235:genetics / Q000378:metabolism; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D050505:Mutant Proteins / Q000737:chemistry / Q000378:metabolism; D010316:Particle Size; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010930:Plague / Q000276:immunology* / Q000382:microbiology / Q000517:prevention & control / Q000821:virology; D010931:Plague Vaccine / Q000737:chemistry / Q000276:immunology; D052899:Pore Forming Cytotoxic Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D054730:Protein Interaction Domains and Motifs; D011897:Random Allocation; D051381:Rats; D011914:Rats, Inbred BN; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D058425:Vaccines, Virus-Like Particle / Q000737:chemistry / Q000276:immunology*; D015010:Yersinia pestis / Q000276:immunology / Q000821:virology*
chemical_list: D000942:Antigens, Bacterial; D000956:Antigens, Viral; D001426:Bacterial Proteins; D036022:Capsid Proteins; C043908:LcrV protein, Yersinia; D050505:Mutant Proteins; D010446:Peptide Fragments; D010931:Plague Vaccine; D052899:Pore Forming Cytotoxic Proteins; D011994:Recombinant Proteins; D058425:Vaccines, Virus-Like Particle; C505708:YscF protein, Yersinia pestis; C086725:caf1 protein, Yersinia pestis; C103392:small outer capsid protein, bacteriophage T4