title: Listeria monocytogenes exploits efferocytosis to promote cell-to-cell spread.
abstract: Efferocytosis, the process by which dying or dead cells are removed by phagocytosis, has an important role in development, tissue homeostasis and innate immunity. Efferocytosis is mediated, in part, by receptors that bind to exofacial phosphatidylserine (PS) on cells or cellular debris after loss of plasma membrane asymmetry. Here we show that a bacterial pathogen, Listeria monocytogenes, can exploit efferocytosis to promote cell-to-cell spread during infection. These bacteria can escape the phagosome in host cells by using the pore-forming toxin listeriolysin O (LLO) and two phospholipase C enzymes. Expression of the cell surface protein ActA allows L. monocytogenes to activate host actin regulatory factors and undergo actin-based motility in the cytosol, eventually leading to formation of actin-rich protrusions at the cell surface. Here we show that protrusion formation is associated with plasma membrane damage due to LLO's pore-forming activity. LLO also promotes the release of bacteria-containing protrusions from the host cell, generating membrane-derived vesicles with exofacial PS. The PS-binding receptor TIM-4 (encoded by the Timd4 gene) contributes to efficient cell-to-cell spread by L. monocytogenes in macrophages in vitro and growth of these bacteria is impaired in Timd4(-/-) mice. Thus, L. monocytogenes promotes its dissemination in a host by exploiting efferocytosis. Our results indicate that PS-targeted therapeutics may be useful in the fight against infections by L. monocytogenes and other bacteria that use similar strategies of cell-to-cell spread during infection.
authors.affiliation: 1] Cell Biology Program, Hospital for Sick Children, Toronto, Ontario M5G0A4, Canada [2] Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S1A8, Canada.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Czuczman
authors.affiliation: Cell Biology Program, Hospital for Sick Children, Toronto, Ontario M5G0A4, Canada.
authors.forename: Ramzi
authors.initials: R
authors.lastname: Fattouh
authors.affiliation: Department of Cell Biology and Institute of Biomembranes, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands.
authors.forename: Jorik M
authors.initials: JM
authors.lastname: van Rijn
authors.affiliation: Cell Biology Program, Hospital for Sick Children, Toronto, Ontario M5G0A4, Canada.
authors.forename: Veronica
authors.initials: V
authors.lastname: Canadien
authors.affiliation: Cell Biology Program, Hospital for Sick Children, Toronto, Ontario M5G0A4, Canada.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Osborne
authors.affiliation: 1] Cell Biology Program, Hospital for Sick Children, Toronto, Ontario M5G0A4, Canada [2] Division of Gastroenterology, Hepatology, and Nutrition, Department of Paediatrics, Hospital for Sick Children, Toronto, Ontario M5G1X8, Canada [3] Institute of Medical Science, University of Toronto, Toronto, Ontario M5S1A8, Canada [4] Sickkids IBD Centre, Hospital for Sick Children, Toronto, Ontario M5G1X8, Canada.
authors.forename: Aleixo M
authors.initials: AM
authors.lastname: Muise
authors.affiliation: Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: Vijay K
authors.initials: VK
authors.lastname: Kuchroo
authors.affiliation: Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: Darren E
authors.initials: DE
authors.lastname: Higgins
authors.affiliation: 1] Cell Biology Program, Hospital for Sick Children, Toronto, Ontario M5G0A4, Canada [2] Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S1A8, Canada [3] Institute of Medical Science, University of Toronto, Toronto, Ontario M5S1A8, Canada [4] Sickkids IBD Centre, Hospital for Sick Children, Toronto, Ontario M5G1X8, Canada.
authors.forename: John H
authors.initials: JH
authors.lastname: Brumell
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D001427:Bacterial Toxins / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D022081:Cell Surface Extensions / Q000378:metabolism / Q000382:microbiology*; D003593:Cytoplasm / Q000378:metabolism / Q000382:microbiology; D005260:Female; D006367:HeLa Cells; D006360:Heat-Shock Proteins / Q000378:metabolism; D006460:Hemolysin Proteins / Q000378:metabolism; D006801:Humans; D008089:Listeria monocytogenes / Q000472:pathogenicity / Q000502:physiology*; D008264:Macrophages / Q000166:cytology / Q000378:metabolism / Q000382:microbiology; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D010587:Phagocytosis; D010588:Phagosomes / Q000378:metabolism / Q000382:microbiology; D010718:Phosphatidylserines / Q000378:metabolism; D010738:Type C Phospholipases / Q000378:metabolism; D014617:Vacuoles / Q000378:metabolism / Q000382:microbiology
chemical_list: D000199:Actins; D001427:Bacterial Toxins; D006360:Heat-Shock Proteins; D006460:Hemolysin Proteins; D008565:Membrane Proteins; D010718:Phosphatidylserines; C500399:TIM-4 protein, mouse; D010738:Type C Phospholipases; C038705:hlyA protein, Listeria monocytogenes
references.citation: Trends Microbiol. 2012 Aug;20(8):360-8
references.pmid: 22652164
references.citation: Infect Immun. 2000 Feb;68(2):912-4
references.pmid: 10639462
references.citation: Infect Immun. 1994 Dec;62(12):5608-13
references.pmid: 7960143
references.citation: Biochem Pharmacol. 2011 Mar 15;81(6):703-12
references.pmid: 21219882
references.citation: Microbes Infect. 2007 Aug;9(10):1176-87
references.pmid: 17720603
references.citation: Infect Immun. 1999 Jul;67(7):3512-7
references.pmid: 10377133
references.citation: Infect Immun. 1995 Nov;63(11):4231-7
references.pmid: 7591052
references.citation: J Immunol. 1987 Sep 15;139(6):2005-9
references.pmid: 3114382
references.citation: J Cell Biol. 1999 Sep 20;146(6):1333-50
references.pmid: 10491395
references.citation: Microbiol Mol Biol Rev. 2012 Dec;76(4):707-20
references.pmid: 23204363
references.citation: Trends Cell Biol. 2008 Nov;18(11):552-9
references.pmid: 18848451
references.citation: J Bacteriol. 2003 Nov;185(21):6295-307
references.pmid: 14563864
references.citation: Proc Natl Acad Sci U S A. 2007 Jul 3;104(27):11430-5
references.pmid: 17592133
references.citation: Cell Microbiol. 2007 Jan;9(1):179-95
references.pmid: 17222191
references.citation: J Cell Sci. 2011 Jul 15;124(Pt 14):2414-23
references.pmid: 21693578
references.citation: J Cell Biol. 2000 Aug 7;150(3):527-38
references.pmid: 10931865
references.citation: Cell Microbiol. 2006 Feb;8(2):353-64
references.pmid: 16441444
references.citation: PLoS Pathog. 2012;8(7):e1002628
references.pmid: 22807671
references.citation: PLoS Pathog. 2011 Mar;7(3):e1001326
references.pmid: 21455492
references.citation: Science. 2009 Mar 27;323(5922):1729-33
references.pmid: 19325115
references.citation: Science. 2008 Apr 25;320(5875):531-5
references.pmid: 18436786
references.citation: Cell Death Differ. 2011 Jan;18(1):80-9
references.pmid: 20596076
references.citation: Infect Immun. 2000 Feb;68(2):999-1003
references.pmid: 10639481
references.citation: Nature. 2007 Nov 15;450(7168):435-9
references.pmid: 17960135
references.citation: Crit Rev Biochem Mol Biol. 2009 Sep-Oct;44(5):264-77
references.pmid: 19780638
references.citation: Microbiology (Reading). 2007 Jul;153(Pt 7):2250-2258
references.pmid: 17600069
references.citation: Proc Natl Acad Sci U S A. 2010 May 11;107(19):8706-11
references.pmid: 20368430
references.citation: Cell Microbiol. 2001 Feb;3(2):75-84
references.pmid: 11207622
references.citation: Traffic. 2010 May;11(5):675-87
references.pmid: 20136776
references.citation: J Immunol. 2008 Apr 1;180(7):4706-13
references.pmid: 18354194
references.citation: Cell Host Microbe. 2012 Oct 18;12(4):544-57
references.pmid: 23084921
references.citation: Immunity. 2011 Oct 28;35(4):445-55
references.pmid: 22035837
references.citation: J Cell Biol. 2002 Mar 18;156(6):1029-38
references.pmid: 11901168
references.citation: J Bacteriol. 2002 Aug;184(15):4177-86
references.pmid: 12107135
references.citation: Mol Microbiol. 2005 Sep;57(5):1460-73
references.pmid: 16102013
references.citation: Nat Methods. 2009 May;6(5):317
references.pmid: 19404250
references.citation: EMBO J. 2005 Mar 23;24(6):1287-300
references.pmid: 15729356
references.citation: Cell Host Microbe. 2012 Sep 13;12(3):289-300
references.pmid: 22980326
references.citation: Adv Immunol. 2012;113:19-32
references.pmid: 22244577