Construction of new primer sets for corresponding to genetic evolution of human adenoviruses in major capsid genes through frequent recombination.

A number of novel recombinant human adenoviruses (HAdVs) have recently been identified through sequencing of the complete genomes. The recombinant HAdV sequences share similarity with other types in the major capsid genes, namely the hexon, penton base, and fiber genes, implying recombination events, which may result in escape from the immune response and the acquisition of different organotropisms. Therefore, a surveillance system of HAdVs that considers the effect of frequent recombination on genetic evolution in these genes must be constructed. In this study, we designed new primer sets that can amplify the partial penton base and fiber genes from species HAdV-A to HAdV-F and proteotype HAdVs on the basis of sequence analyses, including previously reported primers that amplify loop 1 of the hexon. Phylogenetic analysis through sequencing with these primers correctly classified clinical HAdV isolates in loop 1 of the hexon gene, the Arg-Gly-Asp (RGD) loop of the penton base gene, and the knob of the fiber gene, which contain neutralizing, hemagglutination, and receptor binding epitopes associated with immunogenicity and tissue tropisms of HAdVs. This study contributes to the accumulation of correct information regarding genetic diversity and evolution in the worldwide HAdV surveillance.