Molecular Mechanisms of White Spot Syndrome Virus Infection and Perspectives on Treatments

Abstract

Since its emergence in the 1990s, White Spot Disease (WSD) has had major economic and societal impact in the crustacean aquaculture sector. Over the years shrimp farming alone has experienced billion dollar losses through WSD. The disease is caused by the White Spot Syndrome Virus (WSSV), a large dsDNA virus and the only member of the Nimaviridae family. Susceptibility to WSSV in a wide range of crustacean hosts makes it a major risk factor in the translocation of live animals and in commodity products. Currently there are no effective treatments for this disease. Understanding the molecular basis of disease processes has contributed significantly to the treatment of many human and animal pathogens, and with a similar aim considerable efforts have been directed towards understanding host–pathogen molecular interactions for WSD. Work on the molecular mechanisms of pathogenesis in aquatic crustaceans has been restricted by a lack of sequenced and annotated genomes for host species. Nevertheless, some of the key host–pathogen interactions have been established: between viral envelope proteins and host cell receptors at initiation of infection, involvement of various immune system pathways in response to WSSV, and the roles of various host and virus miRNAs in mitigation or progression of disease. Despite these advances, many fundamental knowledge gaps remain; for example, the roles of the majority of WSSV proteins are still unknown. In this review we assess current knowledge of how WSSV infects and replicates in its host, and critique strategies for WSD treatment.

Two White Spot Syndrome Virus MicroRNAs Target the Dorsal Gene To Promote Virus Infection in Marsupenaeus japonicus Shrimp

“…WSSV, a virus with a 305-kb circular double-stranded genomic DNA, is a new member of the genus Whispovirus belonging to the family Nimaviridae (20). WSSV is a major pathogen in shrimp and causes great economic losses in crustacean aquaculture industries worldwide (21). The results showed that WSSV genome-encoded miRNAs (WSSV-miR-N13 and WSSV-miR-N23) could simultaneously target the Dorsal gene of its host shrimp.…”

Sustainable farming of the mealworm Tenebrio molitor for the production of food and feed

“…In shrimp farming, vaccine-like approaches to combat the white spot syndrome virus (WSSV) have been reported as being very successful [140,141]. Vaccination with inactivated viruses or recombinant virus proteins lead to an improved survival rate upon WSSV infection [142][143][144]. The application of transgenerational immune priming to reduce disease outbreaks has also been considered in the aquaculture industry [145].…”

Hesperetin protects crayfish Procambarus clarkii against white spot syndrome virus infection

“…Mortality rates are usually very high and cumulative mortality can reach 100% within 3-10 days from the onset of visible gross signs [3,4]. The clinical symptoms of white spot syndrome include loss of appetite, lethargy, and the appearance of white spots on the exoskeleton [5]. White spot disease had been reported from several Asian countries since the early 1990s, and then from South America and from the south-eastern coast of the USA [6][7][8][9].…”

“…During the breeding process, disease prevention and control measures are mostly based on prevention. Once the white spot disease breaks out, the crayfish's mortality rate is extremely high, which leads to the farmers' blood loss [5]. Therefore, there is an urgent need to develop a therapeutic drug that is less harmful to crayfish cells and could effectively reduce the mortality rate after infected WSSV.…”