The Pseudomonas aeruginosa type III secretion system (T3SS) is known to be a very important virulence factor in acute human infections, but it is less important in maintaining chronic infections in which T3SS genes are downregulated. In vitro, the activation of T3SS expression involves a positive activating loop that acts on the transcriptional regulator ExsA. We have observed that in vivo T3SS expression is cell density-dependent in a manner that does not need known quorum-sensing (QS) signals. In addition, stationary-phase culture supernatants added to exponential-phase growing strains can inhibit T3SS expression. The analysis of transposon insertion mutants showed that the production of such T3SS-inhibiting signals might depend on tryptophan synthase and hence tryptophan, which is the precursor of signalling molecules such as indole-3-acetic acid (IAA), kynurenine and Pseudomonas quinolone signal (PQS). Commercially available tryptophan-derived molecules were tested for their role in the regulation of T3SS expression. At millimolar concentrations, IAA, 1-naphthalacetic acid (NAA) and 3-hydroxykynurenine inhibited T3SS expression. Inactivation of the tryptophan dioxygenase-encoding kynA gene resulted in a decrease in the T3SS-inhibiting activity of supernatants. These observations suggest that tryptophan catabolites are involved in the downregulation of T3SS expression in the transition from a low- to a high-cell-density state.
AyyaduraiN.,
Ravindra NaikP.,
Sreehari RaoM.,
Sunish KumarR.,
SamratS. K.,
ManoharM.,
SakthivelN.2006; Isolation and characterization of a novel banana rhizosphere bacterium as fungal antagonist and microbial adjuvant in micropropagation of banana. J Appl Microbiol 100:926–937
CalfeeM. W.,
ColemanJ. P.,
PesciE. C.2001; Interference with Pseudomonas quinolone signal synthesis inhibits virulence factor expression by Pseudomonas aeruginosa. Proc Natl Acad Sci U S A 98:11633–11637
CohenJ. D.,
SlovinJ. P.,
HendricksonA. M.2003; Two genetically discrete pathways convert tryptophan to auxin: more redundancy in auxin biosynthesis. Trends Plant Sci 8:197–199
DacheuxD.,
AttreeI.,
SchneiderC.,
ToussaintB.1999; Cell death of human polymorphonuclear neutrophils induced by a Pseudomonas aeruginosa cystic fibrosis isolate requires a functional type III secretion system. Infect Immun 67:6164–6167
DacheuxD.,
AttreeI.,
ToussaintB.2001; Expression of ExsA in trans confers type III secretion system-dependent cytotoxicity on noncytotoxic Pseudomonas aeruginosa cystic fibrosis isolates. Infect Immun 69:538–542
DacheuxD.,
EpaulardO.,
de GrootA.,
GueryB.,
LeberreR.,
AttreeI.,
PolackB.,
ToussaintB.2002; Activation of the Pseudomonas aeruginosa type III secretion system requires an intact pyruvate dehydrogenase aceAB operon. Infect Immun 70:3973–3977
DasguptaN.,
LykkenG. L.,
WolfgangM. C.,
YahrT. L.2004; A novel anti-anti-activator mechanism regulates expression of the Pseudomonas aeruginosa type III secretion system. Mol Microbiol 53:297–308
Delic-AttreeI.,
ToussaintB.,
VignaisP. M.1995; Cloning and sequence analyses of the genes coding for the integration host factor (IHF) and HU proteins of Pseudomonas aeruginosa. Gene 154:61–64
Della ChiesaM.,
CarlomagnoS.,
FrumentoG.,
BalsamoM.,
CantoniC.,
ConteR.,
MorettaL.,
MorettaA.,
VitaleM.2006; The tryptophan catabolite l-kynurenine inhibits the surface expression of NKp46- and NKG2D-activating receptors and regulates NK-cell function. Blood 108:4118–4125
Diaz-PerezA. L.,
Zavala-HernandezA. N.,
CervantesC.,
Campos-GarciaJ.2004; The gnyRDBHAL cluster is involved in acyclic isoprenoid degradation in Pseudomonas aeruginosa. Appl Environ Microbiol 70:5102–5110
EpaulardO.,
ToussaintB.,
QueneeL.,
DerouaziM.,
BoscoN.,
VilliersC.,
Le BerreR.,
GueryB.,
FiloponD.other authors2006; Anti-tumor immunotherapy via antigen delivery from a live attenuated genetically engineered Pseudomonas aeruginosa type III secretion system-based vector. Mol Ther 14:656–661
FaucherS. P.,
PorwollikS.,
DozoisC. M.,
McClellandM.,
DaigleF.2006; Transcriptome of Salmonella enterica serovar Typhi within macrophages revealed through the selective capture of transcribed sequences. Proc Natl Acad Sci U S A 103:1906–1911
FeltmanH.,
SchulertG.,
KhanS.,
JainM.,
PetersonL.,
HauserA. R.2001; Prevalence of type III secretion genes in clinical and environmental isolates of Pseudomonas aeruginosa. Microbiology 147:2659–2669
FiloponD.,
MerieauA.,
BernotG.,
CometJ. P.,
LeberreR.,
GueryB.,
PolackB.,
Guespin-MichelJ.2006; Epigenetic acquisition of inducibility of type III cytotoxicity in P. aeruginosa. BMC Bioinformatics 7:272
FletcherM. P.,
DiggleS. P.,
CámaraM.,
WilliamsP.2007; Biosensor-based assays for PQS, HHQ and related 2-alkyl-4-quinolone quorum sensing signal molecules. Nat Protoc 2:1254–1262
FrumentoG.,
RotondoR.,
TonettiM.,
DamonteG.,
BenattiU.,
FerraraG. B.2002; Tryptophan-derived catabolites are responsible for inhibition of T and natural killer cell proliferation induced by indoleamine 2,3-dioxygenase. J Exp Med 196:459–468
FuquaW. C.,
WinansS. C.,
GreenbergE. P.1994; Quorum sensing in bacteria: the LuxR–LuxI family of cell density-responsive transcriptional regulators. J Bacteriol 176:269–275
HaU. H.,
KimJ.,
BadraneH.,
JiaJ.,
BakerH. V.,
WuD.,
JinS.2004; An in vivo inducible gene of Pseudomonas aeruginosa encodes an anti-ExsA to suppress the type III secretion system. Mol Microbiol 54:307–320
HauserA. R.,
CobbE.,
BodiM.,
MariscalD.,
VallesJ.,
EngelJ. N.,
RelloJ.2002; Type III protein secretion is associated with poor clinical outcomes in patients with ventilator-associated pneumonia caused by Pseudomonas aeruginosa. Crit Care Med 30:521–528
HoangT. T.,
Karkhoff-SchweizerR. R.,
KutchmaA. J.,
SchweizerH. P.1998; A broad-host-range Flp– FRT recombination system for site-specific excision of chromosomally-located DNA sequences: application for isolation of unmarked Pseudomonas aeruginosa mutants. Gene 212:77–86
HogardtM.,
RoederM.,
SchreffA. M.,
EberlL.,
HeesemannJ.2004; Expression of Pseudomonas aeruginosa exoS is controlled by quorum sensing and RpoS. Microbiology 150:843–851
HoveyA. K.,
FrankD. W.1995; Analyses of the DNA-binding and transcriptional activation properties of ExsA, the transcriptional activator of the Pseudomonas aeruginosa exoenzyme S regulon. J Bacteriol 177:4427–4436
HwuP.,
DuM. X.,
LapointeR.,
DoM.,
TaylorM. W.,
YoungH. A.2000; Indoleamine 2,3-dioxygenase production by human dendritic cells results in the inhibition of T cell proliferation. J Immunol 164:3596–3599
JainM.,
RamirezD.,
SeshadriR.,
CullinaJ. F.,
PowersC. A.,
SchulertG. S.,
Bar-MeirM.,
SullivanC. L.,
McColleyS. A.,
HauserA. R.2004; Type III secretion phenotypes of Pseudomonas aeruginosa strains change during infection of individuals with cystic fibrosis. J Clin Microbiol 42:5229–5237
LaskowskiM. A.,
OsbornE.,
KazmierczakB. I.2004; A novel sensor kinase-response regulator hybrid regulates type III secretion and is required for virulence in Pseudomonas aeruginosa. Mol Microbiol 54:1090–1103
LeeV. T.,
SmithR. S.,
TummlerB.,
LoryS.2005; Activities of Pseudomonas aeruginosa effectors secreted by the type III secretion system in vitro and during infection. Infect Immun 73:1695–1705
LinaresJ. F.,
LopezJ. A.,
CamafeitaE.,
AlbarJ. P.,
RojoF.,
MartinezJ. L.2005; Overexpression of the multidrug efflux pumps MexCD-OprJ and MexEF-OprN is associated with a reduction of type III secretion in Pseudomonas aeruginosa. J Bacteriol 187:1384–1391
LiuP.,
NesterE. W.2006; Indoleacetic acid, a product of transferred DNA, inhibits vir gene expression and growth of Agrobacterium tumefaciens C58. Proc Natl Acad Sci U S A 103:4658–4662
LucchiniS.,
LiuH.,
JinQ.,
HintonJ. C.,
YuJ.2005; Transcriptional adaptation of Shigella flexneri during infection of macrophages and epithelial cells: insights into the strategies of a cytosolic bacterial pathogen. Infect Immun 73:88–102
McCawM. L.,
LykkenG. L.,
SinghP. K.,
YahrT. L.2002; ExsD is a negative regulator of the Pseudomonas aeruginosa type III secretion regulon. Mol Microbiol 46:1123–1133
MorinD.,
GraslandB.,
Vallee-RehelK.,
DufauC.,
HarasD.2003; On-line high-performance liquid chromatography-mass spectrometric detection and quantification of N-acylhomoserine lactones, quorum sensing signal molecules, in the presence of biological matrices. J Chromatogr A 1002:79–92
NordfelthR.,
KauppiA. M.,
NorbergH. A.,
Wolf-WatzH.,
ElofssonM.2005; Small-molecule inhibitors specifically targeting type III secretion. Infect Immun 73:3104–3114
PattenC. L.,
GlickB. R.2002; Role of Pseudomonas putida indoleacetic acid in development of the host plant root system. Appl Environ Microbiol 68:3795–3801
PesciE. C.,
MilbankJ. B.,
PearsonJ. P.,
McKnightS.,
KendeA. S.,
GreenbergE. P.,
IglewskiB. H.1999; Quinolone signaling in the cell-to-cell communication system of Pseudomonas aeruginosa. Proc Natl Acad Sci U S A 96:11229–11234
Pires de MeloM.,
CuriT. C.,
MiyasakaC. K.,
PalanchA. C.,
CuriR.1998; Effect of indole acetic acid on oxygen metabolism in cultured rat neutrophil. Gen Pharmacol 31:573–578
RietschA.,
WolfgangM. C.,
MekalanosJ. J.2004; Effect of metabolic imbalance on expression of type III secretion genes in Pseudomonas aeruginosa. Infect Immun 72:1383–1390
RietschA.,
Vallet-GelyI.,
DoveS. L.,
MekalanosJ. J.2005; ExsE, a secreted regulator of type III secretion genes in Pseudomonas aeruginosa. Proc Natl Acad Sci U S A 102:8006–8011
Roy-BurmanA.,
SavelR. H.,
RacineS.,
SwansonB. L.,
RevadigarN. S.,
FujimotoJ.,
SawaT.,
FrankD. W.,
Wiener-KronishJ. P.2001; Type III protein secretion is associated with death in lower respiratory and systemic Pseudomonas aeruginosa infections. J Infect Dis 183:1767–1774
SchaberJ. A.,
CartyN. L.,
McDonaldN. A.,
GrahamE. D.,
CheluvappaR.,
GriswoldJ. A.,
HamoodA. N.2004; Analysis of quorum sensing-deficient clinical isolates of Pseudomonas aeruginosa. J Med Microbiol 53:841–853
ShenD. K.,
FiloponD.,
KuhnL.,
PolackB.,
ToussaintB.2006; PsrA is a positive transcriptional regulator of the type III secretion system in Pseudomonas aeruginosa. Infect Immun 74:1121–1129
SimonR.,
PrieferU.,
PuhlerA.1983; A broad host range mobilization system for in vivo genetic engineering: transposon mutagenesis in Gram negative bacteria. Bio/Technology 1:784–791
SperandioV.,
MelliesJ. L.,
NguyenW.,
ShinS.,
KaperJ. B.1999; Quorum sensing controls expression of the type III secretion gene transcription and protein secretion in enterohemorrhagic and enteropathogenic Escherichia coli. Proc Natl Acad Sci U S A 96:15196–15201
TernessP.,
BauerT. M.,
RoseL.,
DufterC.,
WatzlikA.,
SimonH.,
OpelzG.2002; Inhibition of allogeneic T cell proliferation by indoleamine 2,3-dioxygenase-expressing dendritic cells: mediation of suppression by tryptophan metabolites. J Exp Med 196:447–457
ToussaintB.,
Delic-AttreeI.,
VignaisP. M.1993; Pseudomonas aeruginosa contains an IHF-like protein that binds to the algD promoter. Biochem Biophys Res Commun 196:416–421
UrbanowskiM. L.,
LykkenG. L.,
YahrT. L.2005; A secreted regulatory protein couples transcription to the secretory activity of the Pseudomonas aeruginosa type III secretion system. Proc Natl Acad Sci U S A 102:9930–9935
VallisA. J.,
YahrT. L.,
BarbieriJ. T.,
FrankD. W.1999; Regulation of ExoS production and secretion by Pseudomonas aeruginosa in response to tissue culture conditions. Infect Immun 67:914–920
WestS. E.,
SchweizerH. P.,
DallC.,
SampleA. K.,
Runyen-JaneckyL. J.1994; Construction of improved Escherichia- Pseudomonas shuttle vectors derived from pUC18/19 and sequence of the region required for their replication in Pseudomonas aeruginosa. Gene 148:81–86
WolfK.,
BettsH. J.,
Chellas-GeryB.,
HowerS.,
LintonC. N.,
FieldsK. A.2006; Treatment of Chlamydia trachomatis with a small molecule inhibitor of the Yersinia type III secretion system disrupts progression of the chlamydial developmental cycle. Mol Microbiol 61:1543–1555
WolfgangM. C.,
LeeV. T.,
GilmoreM. E.,
LoryS.2003; Coordinate regulation of bacterial virulence genes by a novel adenylate cyclase-dependent signaling pathway. Dev Cell 4:253–263
WongS. M.,
MekalanosJ. J.2000; Genetic footprinting with mariner-based transposition in Pseudomonas aeruginosa. Proc Natl Acad Sci U S A 97:10191–10196
YahrT. L.,
FrankD. W.1994; Transcriptional organization of the trans-regulatory locus which controls exoenzyme S synthesis in Pseudomonas aeruginosa. J Bacteriol 176:3832–3838