title: Laser-mediated rupture of chlamydial inclusions triggers pathogen egress and host cell necrosis.
abstract: Remarkably little is known about how intracellular pathogens exit the host cell in order to infect new hosts. Pathogenic chlamydiae egress by first rupturing their replicative niche (the inclusion) before rapidly lysing the host cell. Here we apply a laser ablation strategy to specifically disrupt the chlamydial inclusion, thereby uncoupling inclusion rupture from the subsequent cell lysis and allowing us to dissect the molecular events involved in each step. Pharmacological inhibition of host cell calpains inhibits inclusion rupture, but not subsequent cell lysis. Further, we demonstrate that inclusion rupture triggers a rapid necrotic cell death pathway independent of BAK, BAX, RIP1 and caspases. Both processes work sequentially to efficiently liberate the pathogen from the host cytoplasm, promoting secondary infection. These results reconcile the pathogen's known capacity to promote host cell survival and induce cell death.
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia.
authors.forename: Markus C
authors.initials: MC
authors.lastname: Kerr
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia.
authors.forename: Guillermo A
authors.identifier: 0000-0002-0494-2404
authors.initials: GA
authors.lastname: Gomez
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia.
authors.forename: Charles
authors.initials: C
authors.lastname: Ferguson
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.|Department of Medical Biology, University of Melbourne, Parkville, Victoria 3052, Australia.
authors.forename: Maria C
authors.initials: MC
authors.lastname: Tanzer
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.|Department of Medical Biology, University of Melbourne, Parkville, Victoria 3052, Australia.
authors.forename: James M
authors.initials: JM
authors.lastname: Murphy
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia.
authors.forename: Alpha S
authors.initials: AS
authors.lastname: Yap
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia.
authors.forename: Robert G
authors.identifier: 0000-0002-7494-5248
authors.initials: RG
authors.lastname: Parton
authors.affiliation: School of Life Sciences, University of Technology Sydney, Ultimo, New South Wales 2007, Australia.
authors.forename: Wilhelmina M
authors.initials: WM
authors.lastname: Huston
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia.
authors.forename: Rohan D
authors.initials: RD
authors.lastname: Teasdale
mesh_terms: D064113:CRISPR-Cas Systems; D002154:Calpain / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D016923:Cell Death / Q000528:radiation effects; D002692:Chlamydia trachomatis / Q000472:pathogenicity / Q000502:physiology; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D000072669:Gene Editing; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D054884:Host-Pathogen Interactions; D006801:Humans; D053685:Laser Therapy; D007930:Leucine / Q000031:analogs & derivatives / Q000494:pharmacology; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D018715:Microscopy, Video; D009336:Necrosis / Q000201:enzymology / Q000235:genetics / Q000469:parasitology*; D059008:Time-Lapse Imaging; D000097573:Red Fluorescent Protein
chemical_list: D002154:Calpain; D015853:Cysteine Proteinase Inhibitors; D049452:Green Fluorescent Proteins; D007930:Leucine; D008164:Luminescent Proteins; D000097573:Red Fluorescent Protein; C024974:E 64