In vitro neutralization of yellow head virus infection in shrimp using recombinant PmYRP65 protein

Yellow head virus (YHV) is a major pathogen in the Southeast Asia shrimp aquaculture industry especially in Thailand, and YHV associated mortality results in significant economic loss. Although appropriate farm management strategies can decrease the YHV infection rate in shrimp, an epidemic of the virus remains, with no specific anti-YHV therapy. Previous reports have identified PmYRP65 as a protein that mediates YHV entry into susceptible cells, and studies using RNA interference have shown that systemic administration of double-stranded RNAs (dsRNAs) directed to PmYRP65 are able to provide protection against infection. This study sought to determine whether recombinant PmYRP65 protein (rPmYRP65) would be able to act as a competitive binding protein to neutralize YHV infection. To undertake this a cDNA encoding PmYRP65 was cloned, and rPmYRP65 was expressed, purified and characterized for its ability to neutralize YHV infection before injection into shrimp. The results showed that rPmYRP65 protein could significantly inhibit YHV infection by its receptor characteristic, through acting as a competitor to bind YHV. This study showed that rPmYRP65 has potential applications for neutralizing YHV infection of shrimp.