Rotavirus-Mediated Prostaglandin E(2) Production in MA104 Cells Promotes Virus Attachment and Internalisation, Resulting in an Increased Viral Load

Rotaviruses are one of the leading causes of severe dehydrating diarrhoea in infants and children under the age of five. Despite the introduction of vaccines, disease burden remains high in sub-Saharan Africa, with no known anti-viral treatments available. During early infection rotavirus attaches to several cellular receptors and enters the cells by either clathrin-dependent or -independent endocytosis. Prostaglandin E(2,) an abundant eicosanoid, is produced from arachidonic acid during rotavirus infection and inhibition of prostaglandin E(2) formation have a deleterious effect on rotavirus infection. In this study, MA104 cells were supplemented with γ-linolenic acid (GLA), a precursor of arachidonic acid. Infection of supplemented cells with rotavirus SA11 led to a depletion in the relative percentages of GLA and arachidonic acid which coincided with an increased production of prostaglandin E(2) as monitored by ELISA. Confocal microscopy demonstrated that prostaglandin E(2) co-localises with the viroplasm-forming proteins, NSP5 and NSP2. Due to the known association of viroplasms with lipid droplets and the fact that lipid droplets are sites for prostaglandin E(2) production, our results indicate a possible role for viroplasms in the production of rotavirus-induced prostaglandin E(2). Replication kinetics showed that inhibitors, targeting the biosynthesis of prostaglandin E(2), had negative effects on rotavirus yield, especially during the early stages of infection. Using flow cytometry and prostaglandin E(2) addback experiments, we show that prostaglandin E(2) enhances the attachment and internalisation of rotavirus in MA104 cells indicating a possible role for prostaglandin E(2) during clathrin-mediated rotavirus entry. The production of prostaglandin E(2) during rotavirus infection could serve as a possible target for anti-viral treatment.