Utilizing the Antigen Capsid-Incorporation Strategy for the Development of Adenovirus Serotype 5-Vectored Vaccine Approaches

作者：Gu Linlin; Farrow Anitra L; Krendelchtchikov Alexandre; Matthews Qiana L^*

来源：Jove-Journal of Visualized Experiments, 2015, (99): e52655.

DOI：10.3791/52655

• Immunology
• Issue 99
• Antigen Capsid-Incorporation strategy
• transgene method
• Adenovirus (Ad)
• vaccine
• capsid proteins
• dual modification
• pre-existing immunity (PEI)

Adenovirus serotype 5 (Ad5) has been extensively modified with traditional transgene methods for the vaccine development. The reduced efficacies of these traditionally modified Ad5 vectors in clinical trials could be primarily correlated with Ad5 pre-existing immunity (PEI) among the majority of the population. To promote Ad5-vectored vaccine development by solving the concern of Ad5 PEI, the innovative Antigen Capsid-Incorporation strategy has been employed. By merit of this strategy, Ad5-vectored we first constructed the hexon shuttle plasmid HVR1-KWAS-HVR5-His(6)/pH5S by subcloning the hypervariable region (HVR) 1 of hexon into a previously constructed shuttle plasmid HVR5-His(6)/pH5S, which had His(6) tag incorporated into the HVR5. This HVR1 DNA fragment containing a HIV epitope ELDKWAS was synthesized. HVR1-KWAS-HVR5-His(6)/pH5S was then linearized and co-transformed with linearized backbone plasmid pAd5/Delta H5 (GL), for homologous recombination. This recombined plasmid pAd5/H5-HVR1-KWAS-HVR5-His(6) was transfected into cells to generate the viral vector Ad5/H5-HVR1-KWAS-HVR5-His(6). This vector was validated to have qualitative fitness indicated by viral physical titer (VP/ml), infectious titer (IP/ml) and corresponding VP/IP ratio. Both the HIV epitope and His(6) tag were surface-exposed on the Ad5 capsid, and retained epitope-specific antigenicity of their own. A neutralization assay indicated the ability of this divalent vector to circumvent neutralization by Ad5-positive sera in vitro. Mice immunization demonstrated the generation of robust humoral immunity specific to the HIV epitope and His(6). This proof-of-principle study suggested that the protocol associated with the Antigen Capsid-Incorporation strategy could be feasibly utilized for the generation of Ad5-vectored vaccines by modifying different capsid proteins. This protocol could even be further modified for the generation of rare-serotype adenovirus-vectored vaccines.

• 出版日期2015-5