In vitro assembly of Penaeus monodon densovirus (PmDNV)‐like particles produced in a prokaryote expression system

Viral diseases are a significant problem in the shrimp aquaculture industry as outbreaks can cause significant mortality and economic loss. While it has been shown that triggering the shrimp RNA interference pathway through dsRNA is a potentially viable treatment pathway, this approach is hampered by the lack of a suitable delivery mechanism. Virus‐like particles (VLPs), which are structurally similar to native viruses but lack the genetic material, could possibly be developed as a delivery vehicle. To generate a candidate VLP, the Penaeus monodon densovirus (PmDNV) capsid protein was cloned with an added histidine tag and expressed in an E. coli expression system. While the protein was expressed in inclusion bodies, the recombinant PmDNV capsid protein could be dissolved and subsequently purified by nickel affinity column chromatography. The formation of VLP from this purified rPmDNV capsid protein was investigated by transmission electron microscopy, and PmDNV‐VLPs were observed that looked similar to the native PmDNV virion. Our results suggest that the PmDNV‐like particle could be promisingly applied towards vaccination and that this PmDNV‐like particle can potentially serve as a system for delivery of nucleic acids to trigger innate immunity in shrimp.