Development of an Ad5H3 Chimera Using the “Antigen Capsid-Incorporation” Strategy for an Alternative Vaccination Approach
Linlin Gu1, Mert Icyuz2, Valentina Krendelchtchikova1, Alexandre Krendelchtchikov1, Alison E. Johnston3, Qiana L. Matthews1, 4, *
Identifiers and Pagination:Year: 2016
First Page: 10
Last Page: 20
Publisher Id: TOVJ-10-10
Article History:Received Date: 18/10/2015
Revision Received Date: 10/2/2016
Acceptance Date: 23/02/2016
Electronic publication date: 26/04/2016
Collection year: 2016
open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution-Non-Commercial 4.0 International Public License (CC BY-NC 4.0) (https://creativecommons.org/licenses/by-nc/4.0/legalcode), which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.
Adenovirus type 5 (Ad5) achieved success as a conventional transgene vaccine vector in preclinical trials, however; achieved poor efficiency in some of the clinical trials, due to the major hurdle associated with Ad5 pre-existing immunity (PEI) in the majority of the human population.
We sought to generate Ad5-based chimeras to assess their capabilities to bypass this bottleneck and to induce antigen-specific humoral immune response.
A His6 tag was incorporated into the hypervariable region 2 (HVR2) of hexon3 (H3) capsid protein using the “Antigen Capsid-Incorporation” strategy. This lead to the construction of a viral chimera, Ad5H3-HVR2-His. Ad5H3 was generated previously by substituting the hexon of Ad5 (hexon5) with the hexon from adenovirus type 3 (Ad3).
His6 was presented on the viral capsid surface and recognized by a His6 antibody. An in vitro neutralization assay with Ad5 sera indicated the ability of Ad5 chimeras to partially escape Ad5 immunity. Immunization with Ad5H3-HVR2-His generated significant humoral response to the incorporated tagged peptide, when compared to the immunizations with controls.
Based on our in vitro studies the data suggested that Ad5H3 as a novel chimeric vaccine platform yields the possibility to escape Ad5 neutralization, and the potential to generate robust humoral immunity against incorporated antigens using the “Antigen Capsid-Incorporation” strategy.