title: Legionella pneumophila infection of Drosophila S2 cells induces only minor changes in mitochondrial dynamics.
abstract: During infection of cells by Legionella pneumophila, the bacterium secretes a large number of effector proteins into the host cell cytoplasm, allowing it to alter many cellular processes and make the vacuole and the host cell into more hospitable environments for bacterial replication. One major change induced by infection is the recruitment of ER-derived vesicles to the surface of the vacuole, where they fuse with the vacuole membrane and prevent it from becoming an acidified, degradative compartment. However, the recruitment of mitochondria to the region of the vacuole has also been suggested by ultrastructural studies. In order to test this idea in a controlled and quantitative experimental system, and to lay the groundwork for a genome-wide screen for factors involved in mitochondrial recruitment, we examined the behavior of mitochondria during the early stages of Legionella pneumophila infection of Drosophila S2 cells. We found that the density of mitochondria near vacuoles formed by infection with wild type Legionella was not different from that found in dotA(-) mutant-infected cells during the first 4 hours after infection. We then examined 4 parameters of mitochondrial motility in infected cells: velocity of movement, duty cycle of movement, directional persistence and net direction. In the 4 hours following infection, most of these measures were indistinguishable between wild type and dotA(-).infection. However, wild type Legionella did induce a modest shift in the velocity distribution toward faster movement compared dotA(-) infection, and a small downward shift in the duty cycle distribution. In addition, wild type infection produced mitochondrial movement that was biased in the direction of the bacterial vacuole relative to dotA-, although not enough to cause a significant accumulation within 10 um of the vacuole. We conclude that in this host cell, mitochondria are not strongly recruited to the vacuole, nor is their motility dramatically affected.
authors: Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America.
authors: Elizabeth Wen
authors: EW
authors: Sun
authors: Monica L
authors: ML
authors: Wagner
authors: Amanda
authors: A
authors: Maize
authors: Doris
authors: D
authors: Kemler
authors: Elisabeth
authors: E
authors: Garland-Kuntz
authors: Li
authors: L
authors: Xu
authors: Zhao-Qing
authors: ZQ
authors: Luo
authors: Peter J
authors: PJ
authors: Hollenbeck
mesh_terms: D000818:Animals; D002460:Cell Line; D004330:Drosophila / Q000166:cytology / Q000382:microbiology*; D054884:Host-Pathogen Interactions; D006801:Humans; D016952:Legionella pneumophila / Q000502:physiology*; D007877:Legionnaires' Disease / Q000473:pathology*; D008928:Mitochondria / Q000382:microbiology* / Q000473:pathology
references: Nat Protoc. 2008;3(4):606-11
references: 18388942
references: PLoS One. 2011 Mar 09;6(3):e17638
references: 21408005
references: Front Microbiol. 2011 Feb 23;2:36
references: 21687427
references: J Cell Sci. 2012 May 1;125(Pt 9):2095-104
references: 22619228
references: Appl Environ Microbiol. 1996 Jun;62(6):2022-8
references: 8787400
references: Infect Immun. 2009 Nov;77(11):4724-39
references: 19687203
references: Arch Intern Med. 1986 Aug;146(8):1607-12
references: 3524495
references: J Cell Biol. 2003 Sep 15;162(6):1079-88
references: 12975351
references: Annu Rev Microbiol. 2000;54:567-613
references: 11018138
references: Front Microbiol. 2011 Oct 28;2:208
references: 22059087
references: Cell Microbiol. 2009 Aug;11(8):1219-35
references: 19438520
references: J Cell Biol. 2003 Sep 15;162(6):1003-16
references: 12975346
references: Science. 2004 Feb 6;303(5659):832-5
references: 14764878
references: Cell Microbiol. 2003 Dec;5(12):875-85
references: 14641173
references: J Bacteriol. 2010 Nov;192(22):6001-16
references: 20833813
references: Science. 2005 Aug 19;309(5738):1248-51
references: 16020693
references: Nature. 2000 Mar 16;404(6775):293-6
references: 10749213
references: Mol Microbiol. 1993 Jan;7(1):7-19
references: 8382332
references: J Cell Sci. 2001 Dec;114(Pt 24):4637-50
references: 11792828
references: Proc Natl Acad Sci U S A. 2011 Sep 20;108(38):16032-7
references: 21903925
references: Trends Microbiol. 2006 Mar;14(3):101-4
references: 16473012
references: Nat Cell Biol. 1999 Nov;1(7):451-3
references: 10559990
references: Cell Microbiol. 2006 May;8(5):793-805
references: 16611228
references: Nat Rev Microbiol. 2009 Jan;7(1):13-24
references: 19011659
references: Mol Microbiol. 2004 Jan;51(1):63-72
references: 14651611
references: Genes Dev. 2005 Feb 15;19(4):445-52
references: 15713840
references: Dis Model Mech. 2009 Sep-Oct;2(9-10):479-89
references: 19638422
references: J Exp Med. 1983 Dec 1;158(6):2108-26
references: 6644240
references: J Exp Biol. 2003 Jun;206(Pt 12):1985-92
references: 12756280
references: PLoS Pathog. 2012 Jan;8(1):e1002459
references: 22241989
references: J Clin Microbiol. 1979 Oct;10(4):437-41
references: 393713
references: Cell Microbiol. 2008 Jun;10(6):1209-20
references: 18363881
references: Proc Natl Acad Sci U S A. 2011 Mar 1;108(9):3612-7
references: 21321208
references: Infect Immun. 1999 May;67(5):2117-24
references: 10225863
references: Cell Microbiol. 2012 Jan;14(1):19-27
references: 21985602
references: Cell Microbiol. 2006 Mar;8(3):438-56
references: 16469056
references: PLoS Pathog. 2006 Apr;2(4):e34
references: 16652170