Targeting the 2C protein of enteroviruses to develop broad-spectrum antivirals derived from Fluoxetine – Fluox2C

Enteroviruses (EVs) are pathogens of increasing public health concern with recurrent emerging agents. Although many EVs are associated with mild clinical manifestations, they can lead to serious complications such as encephalitis, meningitis, pneumonia, myocarditis and poliomyelitis. Given the large genotypic diversity among EVs, molecules targeting highly conserved viral proteins should be considered for the development of pan-enterovirus drugs. To this respect, the non-structural protein 2C, the most conserved enteroviral protein with essential functions in viral replication, is an attractive antiviral target. Recent studies demonstrated that the FDA-approved drug Fluoxetine (an antidepressant marketed as Prozac®) efficiently inhibits replication of human EVs by targeting an allosteric site of the viral protein 2C, making Fluoxetine a promising antiviral ‘starting point’. Because such drug-repurposing candidates often suffer from suboptimal efficacy and pharmacokinetic (PK) for viral diseases, we aim to optimize Fluoxetine into potent broad-spectrum antivirals to treat enterovirus infections and severe related disorders.
To maximize Fluoxetine optimization, we intend to apply ‘structure-based drug design’ (SBDD) and ‘targeted covalent inhibitors’ (TCI) approaches with close interaction of synthetic medicinal and computational chemistry, structural biology, biochemistry, and virology. Thus, an effective optimization strategy will be achieved through iterative cycles of (1) in silico design of Fluoxetine derivatives libraries and modeling-driven evaluation of these virtual libraries for synthesis, (2) conventional and parallel chemical synthesis of the selected derivatives, (3) in vitro and ex vivo efficacy evaluation of the synthetized derivatives on recombinant 2C proteins and EV infection models and (4) determining modes of action to explore Fluoxetine derivatives-2C protein interactions. Finally, the antiviral effect and pharmacokinetics properties of the most efficient candidate(s) will be assessed by in vivo preclinical trials on a relevant EV small-animal model.
This work will lay the foundation for a new antiviral strategy targeting specifically the 2C protein of EVs, a critical protein in viral replication, through the development of novel broad-spectrum antivirals with original modes of action.