title: Functional drug screening reveals anticonvulsants as enhancers of mTOR-independent autophagic killing of Mycobacterium tuberculosis through inositol depletion.
abstract: Mycobacterium tuberculosis (MTB) remains a major challenge to global health made worse by the spread of multidrug resistance. We therefore examined whether stimulating intracellular killing of mycobacteria through pharmacological enhancement of macroautophagy might provide a novel therapeutic strategy. Despite the resistance of MTB to killing by basal autophagy, cell-based screening of FDA-approved drugs revealed two anticonvulsants, carbamazepine and valproic acid, that were able to stimulate autophagic killing of intracellular M. tuberculosis within primary human macrophages at concentrations achievable in humans. Using a zebrafish model, we show that carbamazepine can stimulate autophagy in vivo and enhance clearance of M. marinum, while in mice infected with a highly virulent multidrug-resistant MTB strain, carbamazepine treatment reduced bacterial burden, improved lung pathology and stimulated adaptive immunity. We show that carbamazepine induces antimicrobial autophagy through a novel, evolutionarily conserved, mTOR-independent pathway controlled by cellular depletion of myo-inositol. While strain-specific differences in susceptibility to in vivo carbamazepine treatment may exist, autophagy enhancement by repurposed drugs provides an easily implementable potential therapy for the treatment of multidrug-resistant mycobacterial infection.
authors.affiliation: Department of Medicine, Cambridge Institute for Medical Research University of Cambridge, Cambridge, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Schiebler
authors.affiliation: Department of Medicine, Cambridge Institute for Medical Research University of Cambridge, Cambridge, UK Cambridge Centre for Lung Infection, Papworth Hospital, Cambridge, UK.
authors.forename: Karen
authors.initials: K
authors.lastname: Brown
authors.affiliation: Department of Medicine, Cambridge Institute for Medical Research University of Cambridge, Cambridge, UK.
authors.forename: Krisztina
authors.initials: K
authors.lastname: Hegyi
authors.affiliation: Department of Paediatric Infectious Diseases and Allergy, Imperial College London, London, UK.
authors.forename: Sandra M
authors.initials: SM
authors.lastname: Newton
authors.affiliation: Department of Medical Genetics, Cambridge Institute for Medical Research University of Cambridge, Cambridge, UK.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Renna
authors.affiliation: Department of Medicine, Cambridge Institute for Medical Research University of Cambridge, Cambridge, UK.
authors.forename: Lucy
authors.initials: L
authors.lastname: Hepburn
authors.affiliation: Department of Medicine, Cambridge Institute for Medical Research University of Cambridge, Cambridge, UK.
authors.forename: Catherine
authors.initials: C
authors.lastname: Klapholz
authors.affiliation: Department of Medicine, Cambridge Institute for Medical Research University of Cambridge, Cambridge, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Coulter
authors.affiliation: Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, USA.
authors.forename: Andres
authors.initials: A
authors.lastname: Obregón-Henao
authors.affiliation: Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, USA.
authors.forename: Marcela
authors.initials: M
authors.lastname: Henao Tamayo
authors.affiliation: Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, USA.
authors.forename: Randall
authors.initials: R
authors.lastname: Basaraba
authors.affiliation: Department of Paediatric Infectious Diseases and Allergy, Imperial College London, London, UK.
authors.forename: Beate
authors.initials: B
authors.lastname: Kampmann
authors.affiliation: Department of Infection and Immunity, University of Sheffield Western Bank, Sheffield, UK.
authors.forename: Katherine M
authors.initials: KM
authors.lastname: Henry
authors.affiliation: Department of Infection and Immunity, University of Sheffield Western Bank, Sheffield, UK.
authors.forename: Joseph
authors.initials: J
authors.lastname: Burgon
authors.affiliation: Department of Infection and Immunity, University of Sheffield Western Bank, Sheffield, UK.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Renshaw
authors.affiliation: Department of Medical Genetics, Cambridge Institute for Medical Research University of Cambridge, Cambridge, UK.
authors.forename: Angeleen
authors.initials: A
authors.lastname: Fleming
authors.affiliation: MRC Laboratory of Molecular Biology, Cambridge, UK.
authors.forename: Robert R
authors.initials: RR
authors.lastname: Kay
authors.affiliation: The Inositide Laboratory, Babraham Institute Babraham Research Campus, Cambridge, UK.
authors.forename: Karen E
authors.initials: KE
authors.lastname: Anderson
authors.affiliation: The Inositide Laboratory, Babraham Institute Babraham Research Campus, Cambridge, UK.
authors.forename: Phillip T
authors.initials: PT
authors.lastname: Hawkins
authors.affiliation: Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, USA arf27@cam.ac.uk dcr1000@cam.ac.uk D.Ordway@colostate.edu.
authors.forename: Diane J
authors.initials: DJ
authors.lastname: Ordway
authors.affiliation: Department of Medical Genetics, Cambridge Institute for Medical Research University of Cambridge, Cambridge, UK arf27@cam.ac.uk dcr1000@cam.ac.uk D.Ordway@colostate.edu.
authors.forename: David C
authors.initials: DC
authors.lastname: Rubinsztein
authors.affiliation: Department of Medicine, Cambridge Institute for Medical Research University of Cambridge, Cambridge, UK Cambridge Centre for Lung Infection, Papworth Hospital, Cambridge, UK arf27@cam.ac.uk dcr1000@cam.ac.uk D.Ordway@colostate.edu.
authors.forename: Rodrigo Andres
authors.initials: RA
authors.lastname: Floto
mesh_terms: D000818:Animals; D000927:Anticonvulsants / Q000008:administration & dosage*; D000995:Antitubercular Agents / Q000008:administration & dosage*; D001343:Autophagy / Q000187:drug effects*; D002220:Carbamazepine / Q000008:administration & dosage*; D002460:Cell Line; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical; D005260:Female; D006801:Humans; D007294:Inositol / Q000378:metabolism*; D008264:Macrophages / Q000187:drug effects / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000378:metabolism; D058570:TOR Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D014376:Tuberculosis / Q000188:drug therapy* / Q000276:immunology / Q000378:metabolism / Q000503:physiopathology*; D015027:Zebrafish
chemical_list: D000927:Anticonvulsants; D000995:Antitubercular Agents; D002220:Carbamazepine; D007294:Inositol; D058570:TOR Serine-Threonine Kinases
keywords: autophagy; multidrug‐resistant; myo‐inositol; tuberculosis