Protection against P. aeruginosa with an adenovirus vector containing an OprF epitope in the capsid
Stefan Worgall, … , Imre Kovesdi, Ronald G. Crystal
Stefan Worgall, … , Imre Kovesdi, Ronald G. Crystal
Published May 2, 2005
Citation Information: J Clin Invest. 2005;115(5):1281-1289. https://doi.org/10.1172/JCI23135.
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Article

Protection against P. aeruginosa with an adenovirus vector containing an OprF epitope in the capsid

Abstract

Pseudomonas aeruginosa is an important opportunistic pathogen that can cause chronic and often life-threatening infections of the respiratory tract, particularly in individuals with cystic fibrosis (CF). Because infections with P. aeruginosa remain the major cause of the high morbidity and mortality of CF, a vaccine against P. aeruginosa would be very useful for preventing this disorder. The outer membrane protein F (OprF) of P. aeruginosa is a promising vaccine candidate and various B cell epitopes within OprF have been identified. Given that adenovirus (Ad) vectors have strong immunogenic potential and can function as adjuvants for genetic vaccines, the present study evaluates the immunogenic and protective properties of a novel replication-deficient Ad vector in which the Ad hexon protein was modified to include a 14–amino acid epitope of P. aeruginosa OprF (Epi8) in loop 1 of the hypervariable region 5 of the hexon (AdZ.Epi8). Immunization of C57BL/6 mice with AdZ.Epi8 resulted in detectable serum anti–P. aeruginosa and anti-OprF humoral responses. These responses were haplotype dependent, with higher serum anti-OprF titers in CBA mice than in BALB/c or C57BL/6 mice. AdZ.Epi8 induced Epi8-specific IFN-γ–positive CD4 and CD8 T cell responses and resulted in protection against a lethal pulmonary challenge with agar-encapsulated P. aeruginosa. Importantly, repeated administration of AdZ.Epi8 resulted in boosting of the anti-OprF humoral and anti-Epi8 cellular response, whereas no boosting effect was present in the response against the transgene β-galactosidase. These observations suggest that Ad vectors expressing pathogen epitopes in their capsid will protect against an extracellular pathogen and will allow boosting of the epitope-specific humoral response with repeated administration, a strategy that should prove useful in developing Ad vectors as vaccines where humoral immunity will be protective.

Authors

Stefan Worgall, Anja Krause, Michael Rivara, Kyung-Kim Hee, Enrico V. Vintayen, Neil R. Hackett, Peter W. Roelvink, Joseph T. Bruder, Thomas J. Wickham, Imre Kovesdi, Ronald G. Crystal

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Repeated administration of AdZ.Epi8 results in boosting of the Epi8-spec...
Repeated administration of AdZ.Epi8 results in boosting of the Epi8-specific cellular immune response. (A and B) C57BL/6 mice were immunized via the subcutaneous route with AdZ.Epi8 or AdZ at a dose of 1 × 1010 pu/animal. Some mice were not immunized further (×1); others received a second immunization 2 weeks later (×2). Ten days after the second immunization, CD4 and CD8 cells were isolated from spleens and the IL-4 and IFN-γ responses after in vitro stimulation with Epi8 or β-galactosidase were assessed by ELISPOT assay. Shown are data for CD4 IL-4 (A), CD4 IFN-γ (B), and CD8 IFN-γ (C) after in vitro stimulation with DCs plus β-galactosidase or DCs plus Epi8. For each condition, data were normalized to the total number of polyclonal cells stimulated with PMA/ionomycin.