Polyamine Analog Diethylnorspermidine Restricts Coxsackievirus B3 and Is Overcome by 2A Protease Mutation In Vitro.

Bridget M Hulsebosch,Bryan C Mounce

doi:10.3390/v13020310

Abstract

Enteroviruses, including Coxsackievirus B3 (CVB3), are pervasive pathogens that cause significant disease, including cardiomyopathies. Unfortunately, no treatments or vaccines are available for infected individuals. We identified the host polyamine pathway as a potential drug target, as inhibiting polyamine biosynthesis significantly reduces enterovirus replication in vitro and in vivo. Here, we show that CVB3 is sensitive to polyamine depletion through the polyamine analog diethylnorspermidine (DENSpm), which enhances polyamine catabolism through induction of polyamine acetylation. We demonstrate that CVB3 acquires resistance to DENSpm via mutation of the 2A protease, which enhances proteolytic activity in the presence of DENSpm. Resistance to DENSpm occurred via mutation of a non-catalytic site mutation and results in decreased fitness. These data demonstrate that potential for targeting polyamine catabolism as an antiviral target as well as highlight a potential mechanism of resistance.

Highlights

Viruses 2021, 13, 310. https://Enterovirus infections are one of the most abundant viral infections in the United States and cause a wide range of diseases, ranging from mild to severe [1,2,3]
Polyamines are small, flexible, positively charged carbon chains crucial for mammalian cell function [7,8,9]. They have been known to be crucial for DNA and RNA structure, protein–RNA interactions, and translation and are found in all cell types [7,8]. Their biosynthesis pathway begins with the polyamine precursor molecule, ornithine, which is converted to the first polyamine, putrescine, via the rate-limiting enzyme ornithine decarboxylase 1 (ODC1) [7,8]
Because DENSpm and DFMO both reduce cellular polyamine levels, we investigated whether the mutant was resistant to DFMO treatment as well

Summary

Introduction

Viruses 2021, 13, 310. https://Enterovirus infections are one of the most abundant viral infections in the United States and cause a wide range of diseases, ranging from mild to severe [1,2,3]. CVB3 infection has a wide range of symptoms, including fever, dilated cardiomyopathy, aseptic meningitis, and is the leading cause of viral myocarditis. Polyamines are small, flexible, positively charged carbon chains crucial for mammalian cell function [7,8,9]. They have been known to be crucial for DNA and RNA structure, protein–RNA interactions, and translation and are found in all cell types [7,8]. Putrescine is further converted to spermidine and spermine (Figure 1A), which can both be catabolized back to putrescine or marked for degradation and export via spermidine/spermine acetyltransferase 1 (SAT1) [7,8] These two enzymes, ODC1 and SAT1, are critical in the synthesis and degradation of polyamines

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Conclusion