Characterization of a novel fusion protein from IpaB and IpaD of Shigella spp. and its potential as a pan-Shigella vaccine.
Shigellosis is an important disease in the developing world, where about 90 million people become infected with Shigella spp. each year. We previously demonstrated that the type three secretion apparatus (T3SA) proteins IpaB and IpaD are protective antigens in the mouse lethal pulmonary model. In order to simplify vaccine formulation and process development, we have evaluated a vaccine design that incorporates both of these previously tested Shigella antigens into a single polypeptide chain. To determine if this fusion protein (DB fusion) retains the antigenic and protective capacities of IpaB and IpaD, we immunized mice with the DB fusion and compared the immune response to that elicited by the IpaB/IpaD combination vaccine. Purification of the DB fusion required coexpression with IpgC, the IpaB chaperone, and after purification it maintained the highly α-helical characteristics of IpaB and IpaD. The DB fusion also induced comparable immune responses and retained the ability to protect mice against Shigella flexneri and S. sonnei in the lethal pulmonary challenge. It also offered limited protection against S. dysenteriae challenge. Our results show the feasibility of generating a protective Shigella vaccine comprised of the DB fusion.
Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA.
Francisco J
FJ
Martinez-Becerra
Xiaotong
X
Chen
Nicholas E
NE
Dickenson
Shyamal P
SP
Choudhari
Kelly
K
Harrison
John D
JD
Clements
William D
WD
Picking
Lillian L
LL
Van De Verg
Richard I
RI
Walker
Wendy L
WL
Picking
D000818:Animals; D000942:Antigens, Bacterial / Q000235:genetics / Q000276:immunology; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology*; D004405:Dysentery, Bacillary / Q000276:immunology* / Q000517:prevention & control*; D005260:Female; D007114:Immunization; D051379:Mice; D008807:Mice, Inbred BALB C; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology*; D022281:Shigella Vaccines / Q000276:immunology*; D012762:Shigella dysenteriae / Q000276:immunology; D012763:Shigella flexneri / Q000276:immunology; D012764:Shigella sonnei / Q000276:immunology; D014614:Vaccines, Synthetic / Q000276:immunology
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C095770:IpaD protein, Shigella flexneri; D011993:Recombinant Fusion Proteins; D022281:Shigella Vaccines; D014614:Vaccines, Synthetic; C087447:ipaB protein, Shigella