Construction of an African Swine Fever Virus phagemid library through non-homologues random recombination

Abstract

African swine fever (ASF) is a haemorrhagic disease that affects swine in ongoing epidemics around the world. The etiologic agent of ASF, the African Swine Fever virus (ASFV), is a large multi-layered icosahedral dsDNA virus that encodes over 170 proteins, many of which have yet unknown functions. Partly because of its complexity, commercially available vaccines against ASF remain unavailable. Experimental attenuated-, subunit-, vector-, and DNA-vaccines have been developed previously, however, all fail to induce protective immunity outside of experimental conditions. Therefore, to aid the development of a multi-epitope chimeric vaccine against ASF, we attempted to construct a random multi-epitope library that can subsequently be screened for antigenic ASFV epitopes. To develop a randomized library of multi-epitope ASFV chimeras, gene fragment libraries were constructed using non-homologues recombination (NRR). Subsequently, we attempted to clone ASFV chimeras into phagemid vectors, to identify antigenic B-cell epitopes using phage-display.

Although this study did not successfully recombine ASFV-derived epitope fragments, we offer valuable insight into the development of randomized DNA libraries. Our results demonstrate that NRR can be used for the construction of randomly recombined dsDNA libraries. Additionally, we identified conformational B-cell epitopes on the surface of ASFV chimeras using in silico prediction tools. In conclusion, further research should optimize these methods to generate a diverse randomized multi-epitope chimeric library. Any antigenic multi-epitope chimera that arises from such study could contribute to the development of a multi-epitope-based ASFV vaccine.