title: Activities of Pseudomonas aeruginosa effectors secreted by the Type III secretion system in vitro and during infection.
abstract: Pseudomonas aeruginosa utilizes a number of distinct pathways to secrete proteins that play various roles during infection. These include the type II secretion system, which is responsible for the secretion of the majority of exoproducts into the surrounding environment, including toxins and degradative enzymes. In contrast, the type III secretion system mediates the delivery of protein effectors directly into the cytoplasm of the host cell. Using tissue culture assays and a mouse acute-pneumonia model, we have determined the contribution of each of the type III effectors during infection. In strain PAK, ExoS is the major cytotoxin required for colonization and dissemination during infection. ExoT confers protection of tissue culture cells from type III-dependent lysis, while ExoY seemed to have little effect on cytotoxicity. ExoU is over 100-fold more cytotoxic than ExoS. The cytotoxicity of type II secretion was determined following deletion of the genes for the more toxic type III secretion system. The participation of these secretion systems during lifelong colonization of cystic fibrosis (CF) patients is unclear. By comparing clonal strains from the same patient isolated at the initial onset of P. aeruginosa infection and more than a decade later, after chronic colonization has been established, we show that initial strains are more cytotoxic than chronic strains that have evolved to reduce type III secretion. Constitutive expression of genes for the type III secretion system restored ExoS secretion but did not always reestablish cytotoxicity, suggesting that CF strains accumulate a number of mutations to reduce bacterial toxicity to the host.
authors.affiliation: Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Vincent T
authors.initials: VT
authors.lastname: Lee
authors.forename: Roger S
authors.initials: RS
authors.lastname: Smith
authors.forename: Burkhard
authors.initials: B
authors.lastname: Tümmler
authors.forename: Stephen
authors.initials: S
authors.lastname: Lory
mesh_terms: D036002:ADP Ribose Transferases / Q000235:genetics / Q000378:metabolism / Q000633:toxicity; D000208:Acute Disease; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism* / Q000633:toxicity*; D001427:Bacterial Toxins / Q000235:genetics / Q000633:toxicity; D016466:CHO Cells; D002908:Chronic Disease; D006224:Cricetinae; D003550:Cystic Fibrosis / Q000382:microbiology / Q000503:physiopathology*; D020690:GTPase-Activating Proteins; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism / Q000633:toxicity; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D009154:Mutation; D018410:Pneumonia, Bacterial / Q000382:microbiology* / Q000503:physiopathology; D011552:Pseudomonas Infections / Q000382:microbiology* / Q000503:physiopathology; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; C477521:ExoT protein, Pseudomonas aeruginosa; D020690:GTPase-Activating Proteins; C111749:pseudomonas exoprotein A protein, Pseudomonas aeruginosa; C111504:ExoY protein, bacteria; D005964:Glucosyltransferases; D036002:ADP Ribose Transferases; C444820:exoenzyme S
references.citation: J Biol Chem. 1999 Dec 17;274(51):36369-72
references.pmid: 10593930
references.citation: Antibiot Chemother (1971). 1989;42:130-53
references.pmid: 2512834
references.citation: Infect Immun. 2000 Oct;68(10):6066-8
references.pmid: 10992524
references.citation: Infect Immun. 2001 Jan;69(1):538-42
references.pmid: 11119548
references.citation: Infect Immun. 2001 Feb;69(2):1185-8
references.pmid: 11160019
references.citation: Burns. 2001 Mar;27(2):129-30
references.pmid: 11226648
references.citation: Mol Microbiol. 2001 Apr;40(1):76-85
references.pmid: 11298277
references.citation: J Infect Dis. 2001 Jun 15;183(12):1767-74
references.pmid: 11372029
references.citation: EMBO J. 2001 Oct 1;20(19):5373-82
references.pmid: 11574469
references.citation: Microbiology. 2001 Oct;147(Pt 10):2659-69
references.pmid: 11577145
references.citation: J Infect Dis. 2002 Jan 15;185(2):269-70
references.pmid: 11807706
references.citation: Biochem Biophys Res Commun. 2002 Feb 15;291(1):91-100
references.pmid: 11829467
references.citation: Infect Immun. 2002 Apr;70(4):2198-205
references.pmid: 11895987
references.citation: Biochem J. 2002 Nov 1;367(Pt 3):617-28
references.pmid: 12132999
references.citation: J Bacteriol. 2003 Feb;185(3):1071-81
references.pmid: 12533483
references.citation: Dev Cell. 2003 Feb;4(2):253-63
references.pmid: 12586068
references.citation: J Bacteriol. 2003 Apr;185(7):2066-79
references.pmid: 12644476
references.citation: Invest Ophthalmol Vis Sci. 2003 Sep;44(9):3892-8
references.pmid: 12939306
references.citation: J Biol Chem. 2003 Oct 17;278(42):41326-32
references.pmid: 12915403
references.citation: Infect Immun. 2004 Mar;72(3):1677-84
references.pmid: 14977975
references.citation: J Bacteriol. 2004 Jun;186(12):3837-47
references.pmid: 15175297
references.citation: J Infect Dis. 1966 Feb;116(1):112-6
references.pmid: 4956054
references.citation: Proc Natl Acad Sci U S A. 1992 Jan 1;89(1):47-51
references.pmid: 1309616
references.citation: Mol Microbiol. 1992 May;6(9):1121-31
references.pmid: 1588814
references.citation: Science. 1993 May 21;260(5111):1127-30
references.pmid: 8493556
references.citation: Am J Physiol. 1994 Nov;267(5 Pt 1):L551-6
references.pmid: 7977765
references.citation: J Infect Dis. 1994 Dec;170(6):1616-21
references.pmid: 7996008
references.citation: Biochemistry. 1996 Feb 27;35(8):2754-8
references.pmid: 8611582
references.citation: Infect Immun. 1996 Jun;64(6):2288-94
references.pmid: 8675339
references.citation: Microbiol Rev. 1996 Sep;60(3):539-74
references.pmid: 8840786
references.citation: Mol Microbiol. 1996 Dec;22(5):991-1003
references.pmid: 8971719
references.citation: Gene. 1997 Feb 20;186(1):29-35
references.pmid: 9047341
references.citation: Mol Microbiol. 1997 Aug;25(3):547-57
references.pmid: 9302017
references.citation: Infect Immun. 1997 Oct;65(10):4061-7
references.pmid: 9317008
references.citation: Behring Inst Mitt. 1997 Feb;(98):249-55
references.pmid: 9382747
references.citation: Mol Microbiol. 1998 Feb;27(4):807-18
references.pmid: 9515706
references.citation: Infect Immun. 1998 Jun;66(6):2521-8
references.pmid: 9596711
references.citation: Infect Immun. 1998 Jul;66(7):3242-9
references.pmid: 9632591
references.citation: Gene. 1998 May 28;212(1):77-86
references.pmid: 9661666
references.citation: Proc Natl Acad Sci U S A. 1998 Nov 10;95(23):13899-904
references.pmid: 9811898
references.citation: Infect Immun. 1999 Apr;67(4):2040-4
references.pmid: 10085057
references.citation: J Bacteriol. 1964 Sep;88:745-57
references.pmid: 14208514
references.citation: J Bacteriol. 2003 Apr;185(7):2080-95
references.pmid: 12644477
references.citation: Infect Immun. 2003 May;71(5):2404-13
references.pmid: 12704110
references.citation: EMBO J. 2003 Jun 16;22(12):2959-69
references.pmid: 12805211
references.citation: Proc Natl Acad Sci U S A. 2003 Jul 8;100(14):8484-9
references.pmid: 12815109
references.citation: J Biol Chem. 2003 Aug 29;278(35):32794-800
references.pmid: 12807879
references.citation: Genetics. 1967 Mar;55(3):513-24
references.pmid: 6068403
references.citation: J Infect Dis. 1972 Jun;125(6):631-6
references.pmid: 4624815
references.citation: Proc Natl Acad Sci U S A. 1975 Jun;72(6):2284-8
references.pmid: 166383
references.citation: Infect Immun. 1980 May;28(2):546-56
references.pmid: 6772562
references.citation: Infect Immun. 1982 Aug;37(2):662-9
references.pmid: 6811437
references.citation: Rev Infect Dis. 1983 Nov-Dec;5 Suppl 5:S998-1004
references.pmid: 6419322
references.citation: Can J Microbiol. 1985 Apr;31(4):387-92
references.pmid: 2988728
references.citation: J Clin Microbiol. 1986 Aug;24(2):260-4
references.pmid: 3018037
references.citation: Nature. 2000 Aug 31;406(6799):959-64
references.pmid: 10984043