Rotavirus (RV) causes severe life-threatening diarrhea in young children and immunocompromised individuals. There are several licensed attenuated vaccines for young children, but there are no vaccines or antiviral therapeutics for immunocompromised patients of any age. Previously, our laboratory demonstrated that arachidin 1 (A1) and arachidin 3 (A3) decreases the number of infectious simian RV particles and RV non-structural protein 4 (NSP4) in a human intestinal cell line which suggests effects on RV replication. This study examined the effects of the arachidins on the human RV (Wa)-infected African green monkey kidney cell line, MA104. The addition of either A1 or A3 did not decrease the viability of MA104 cells, however plaque forming assays measured significant decreases in the number of infectious RV particles with the addition of the arachidins. Correspondingly, western blot analyses revealed a change in the presence of VP6 and NSP4 (structural and nonstructural RV proteins, respectively). This implies that like the simian RV, Wa replication is also affected by both A1 and A3. Additionally, tunable resistive pulse sensing technology (TRPS) measured changes in the population distribution of released nanoparticles between 60-140 nanometers. Additionally, TEM morphometric analyses showed ultrastructural changed in RV-infected cells treated with A1 or A3. This included nucleus to cytoplasm ratios that were determined by TEM and whole cell fluorescent assays that disclosed significant nuclear size alterations with the addition of RV which implied modifications of the apoptosis and autophagy pathways. Moreover, the increased presence of autophagic vesicles seen with RV+A1 reinforced the model of a switch from the apoptosis to the autophagy pathway. In addition, immunoblot assays reveal the presence of cannabinoid 1 and 2 receptors on MA104 cells. These receptors bind A1 and A3 and are important in signaling in the endocannabinoid system. This implies a role for Witcher et al.: Arachidin-1 and Arachidin-3 Modulation of Rotavirus-infected MA10 2 A1 and A3 in modulating cannabinoid receptor cell signaling in RV-infected cells which indicates a mechanism of action of A1 and A3 with potential RV therapeutic activity.
Witcher, Caleb M.; Napier-Jameson, Rebekah; Lockwood, Hannah N.; Mattila, Macie N.; Wisdom, Stormey B.; Saade Ferreira, Luanna L.; Taylor, Josephine; Clack, Beatrice; Medina-Bolivar, Fabricio; Ball, Judith M.; and Parr, Rebecca D., "Arachidin-1 and Arachidin-3 Modulation of Rotavirus-infected MA104 Cells" (2019). Faculty Publications. 164.