(R)-Roscovitine and CFTR modulators enhance killing of multi-drug resistant Burkholderia cenocepacia by cystic fibrosis macrophages

Chandra L Shrestha,Shuzhong Zhang,Stephanie Häfner,Jonathan Elie,Laurent Meijer,Benjamin T Kopp,Benjamin Wisniewski

doi:10.1038/s41598-020-78817-x

Chandra L Shrestha, Shuzhong Zhang + Show 5 more

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https://doi.org/10.1038/s41598-020-78817-x

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Abstract

Cystic fibrosis (CF) is characterized by chronic bacterial infections and heightened inflammation. Widespread ineffective antibiotic use has led to increased isolation of drug resistant bacterial strains from respiratory samples. (R)-roscovitine (Seliciclib) is a unique drug that has many benefits in CF studies. We sought to determine roscovitine’s impact on macrophage function and killing of multi-drug resistant bacteria. Human blood monocytes were isolated from CF (F508del/F508del) and non-CF persons and derived into macrophages (MDMs). MDMs were infected with CF clinical isolates of B. cenocepacia and P. aeruginosa. MDMs were treated with (R)-roscovitine or its main hepatic metabolite (M3). Macrophage responses to infection and subsequent treatment were determined. (R)-roscovitine and M3 significantly increased killing of B. cenocepacia and P. aeruginosa in CF MDMs in a dose-dependent manner. (R)-roscovitine-mediated effects were partially dependent on CFTR and the TRPC6 channel. (R)-roscovitine-mediated killing of B. cenocepacia was enhanced by combination with the CFTR modulator tezacaftor/ivacaftor and/or the alternative CFTR modulator cysteamine. (R)-roscovitine also increased MDM CFTR function compared to tezacaftor/ivacaftor treatment alone. (R)-roscovitine increases CF macrophage-mediated killing of antibiotic-resistant bacteria. (R)-roscovitine also enhances other macrophage functions including CFTR-mediated ion efflux. Effects of (R)-roscovitine are greatest when combined with CFTR modulators or cysteamine, justifying further clinical testing of (R)-roscovitine or optimized derivatives.

Highlights

Abbreviations CF Cystic fibrosis CFTR Cystic fibrosis transmembrane conductance regulator colony forming unit (CFU) Colony-forming unit assay IBMX 3-Isobutyl-1-methylxanthine MDM Monocyte-derived macrophage MQAE N-[Ethoxycarbonylmethyl]-6-methoxy-quinolinium bromide
We demonstrated the ability of roscovitine to enhance macrophagemediated killing of Burkholderia cenocepacia as well as multi-drug resistant Pseudomonas aeruginosa
We demonstrated efficacy of roscovitine alone or in combination with the CFTR modulator tezacaftor/ivacaftor, the strongest effect of roscovitine was in combination with the transglutaminase 2 inhibitor cysteamine

Summary

Introduction

Abbreviations CF Cystic fibrosis CFTR Cystic fibrosis transmembrane conductance regulator CFU Colony-forming unit assay IBMX 3-Isobutyl-1-methylxanthine MDM Monocyte-derived macrophage MQAE N-[Ethoxycarbonylmethyl]-6-methoxy-quinolinium bromide. Of further concern is the growing incidence of multi-drug resistant bacterial strains isolated from CF respiratory s amples[1,2] While new medications such as cystic fibrosis transmembrane conductance regulator (CFTR) modulators are improving outcomes in CF, their high cost[3,4] prohibits widespread use in many countries and in those without (sufficient) insurance. (R)-roscovitine (Seliciclib, hereafter refered to as roscovitine) is a synthetic, low molecular weight, tri-substituted purine (Fig. 1), initially developed as a cyclin-dependent kinase inhibitor for the treatment of lung, breast, and nasopharyngeal c ancers[8,9,10,11] It has undergone many preclinical studies as well as phase 1 and phase 2 clinical trials in more than 520 patients, mostly as a potential anti-cancer drug. We sought to build upon this trial and further determine the efficacy of roscovitine in CF, through examination of its impact upon restoration of macrophage function, including the ability to kill multi-drug resistant Burkholderia cenocepacia

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