Viral hemorrhagic septicemia virus (VHSV) is a serious disease impacting wild and cultured fish worldwide. Hence, an effective therapeutic method against VHSV
infection needs to be developed. Aptamer technology is a new and promising method for diagnostics and
therapeutics. It revolves around the use of an aptamer molecule, an artificial
ligand (
nucleic acid or
protein), which has the capacity to recognize target molecules with high affinity and specificity. Here, we aimed at selecting
RNA aptamers that can specifically bind to and inhibit the growth of a strain of fish VHSV both in vitro and in vivo. Three VHSV-specific
RNA aptamers (F1, F2, and C6) were selected from a pool of artificially and randomly produced
oligonucleotides using systematic evolution of ligands by exponential enrichment. The three
RNA aptamers showed obvious binding to VHSV in an electrophoretic mobility shift assay but not to other tested viruses. The
RNA aptamers were tested for their ability to inhibit VHSV in vitro using hirame natural embryo (HINAE) cells. Cytopathic effect and plaque assays showed that all aptamers inhibited the growth of VHSV in HINAE cells. In vivo tests using
RNA aptamers produced by Rhodovulum sulfidophilum showed that extracellular
RNA aptamers inhibited VHSV
infection in Japanese flounder. These results suggest that the
RNA aptamers are a useful tool for protection against VHSV
infection in Japanese flounder.