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

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.

Roscovitine exacerbates Mycobacterium abscessus infection by reducing NADPH oxidase-dependent neutrophil trafficking

“…Mabs infections are associated with severe pneumonia and accelerated inflammatory lung damage in CF patients 70,71 . In line with results previously obtained 31,32 , Roscovitine reduces intracellular bacterial loads in both WT and CF macrophages infected with Mabs, likely by enhancing their ability to kill bacteria. As intracellular bacterial destruction by professional phagocytes is crucial to control Mabs infection 6,72 , perhaps stimulating antibacterial activity using Roscovitine and thereby precluding the establishment of an acute infection could be a therapeutic strategy in CF-related Mabs infection.…”

“…As intracellular bacterial destruction by professional phagocytes is crucial to control Mabs infection 6,72 , perhaps stimulating antibacterial activity using Roscovitine and thereby precluding the establishment of an acute infection could be a therapeutic strategy in CF-related Mabs infection. Roscovitine stimulates macrophage bactericidal activity by restoring intra-phagolysosome acidic pH 31,32 (which is abnormally high in CF macrophages 73 ). Having shown that professional phagocytes acidify phagosomes to efficiently control Mabs 72,74,75 , Roscovitine-mediated intra-phagosomal acidification could account for the Mabs infection phenotype.…”

“…Roscovitine also exerts anti-inflammatory actions on macrophages 26,27 , eosinophils 28,29 and lymphocytes 30 . Moreover, Roscovitine enhances bactericidal activity of CF alveolar macrophages 31,32 . However, Roscovitine has not been tested in CF infection models.…”

Role of RND Efflux Pumps in Drug Resistance of Cystic Fibrosis Pathogens

“…These molecules generally act by impairing bacterial growth, permeabilizing bacteria through the alteration of the structure of the outer membrane, inhibiting biofilm formation and eradicating established biofilms [114,116]. Alternative approaches based on molecules used for other diseases, natural products, quorum-sensing inhibitors and antimicrobial peptides are under investigation [118][119][120][121]. Finally, interest in the design of B. cenocepacia vaccines has recently risen [122].…”

Dysfunctional Inflammation in Cystic Fibrosis Airways: From Mechanisms to Novel Therapeutic Approaches

“…The different behavior of Orkambi® and Symdeko® unveils a novel anti-inflammatory property exclusive to coadministration of tezacaftor, which may thus exert a wide range of therapeutic effects against lung infection and inflammation, both associated with IL-1β. Furthermore, very recent results from Shrestha and colleagues identified a synergistic effect between R-roscovitine, a synthetic tri-substituted purine that has shown multiple benefits in CF [48,49], and Symdeko® in the killing of Burkholderia cenocepacia by CF macrophages [118], thus disclosing new encouraging perspectives on the use of the tezacaftor/ivacaftor combination to dampen CF inflammation.…”