Phosphatidylinositol 4-kinase III beta is essential for the replication of human rhinovirus and its inhibition causes a lethal phenotype in vivo
Spickler, Catherine × Lippens, Julie Laberge, Marie-Kristine Desmeules, Sophie Bellavance, Edith Garneau, Michel Guo, Tim Hucke, Oliver Leyssen, Pieter Neyts, Johan Vaillancourt, Fréderic H Décor, Anne O'Meara, Jeff Franti, Michael Gauthier, Annick #
American Society for Microbiology (ASM)
Antimicrobial Agents and Chemotherapy vol:57. pages:3358.-68.
Human rhinovirus (HRV) is the predominant cause of the common cold, but more importantly infection may have serious repercussions in asthmatics and COPD patients. A cell-based antiviral screen against HRV was performed with a subset of our proprietary compound collection, and an aminothiazole series with pan-HRV species and enteroviral activity was identified. The series was found to act at the level of replication in the HRV infectious cycle. In vitro selection and sequencing of aminothiazole series-resistant HRV variants revealed a single nucleotide mutation leading to the amino acid change I42V in the essential HRV 3A protein. This same mutation has been previously implicated in resistance to enviroxime, a former clinical-stage anti-picornaviral agent. Enviroxime-like compounds have recently been shown to target the lipid kinase phophatidylinositol 4-kinase III beta (PI4KIIIβ). A good correlation between PI4KIIIβ activity and HRV antiviral potency was found when analyzing the data over 80 compounds of the aminothiazole series, covering a 750-fold potency range. The mechanism of action through PI4KIIIβ inhibition was further demonstrated by siRNA knockdown of PI4KB, which reduced HRV replication and also increased the potency of the PI4KIIIβ inhibitors. Inhibitors from two different structural classes with promising pharmacokinetic profiles and with very good selectivity for PI4KIIIβ were used to dissociate compound-related toxicity from target-related toxicity. Mortality was seen in all dosing groups of mice treated with either compound, therefore suggesting that short term inhibition of PI4KIIIβ is deleterious.