NleC, a Type III Secretion Protease, Compromises NF-κB Activation by Targeting p65/RelA


The NF-κB signaling pathway is central to the innate and adaptive immune responses. Upon their detection of pathogen-associated molecular patterns, Toll-like receptors on the cell surface initiate signal transduction and activate the NF-κB pathway, leading to the production of a wide array of inflammatory cytokines, in attempt to eradicate the invaders. As a countermeasure, pathogens have evolved ways to subvert and manipulate this system to their advantage. Enteropathogenic and enterohemorrhagic Escherichia coli (EPEC and EHEC) are closely related bacteria responsible for major food-borne diseases worldwide. Via a needle-like protein complex called the type three secretion system (T3SS), these pathogens deliver virulence factors directly to host cells and modify cellular functions, including by suppressing the inflammatory response. Using gain- and loss-of-function screenings, we identified two bacterial effectors, NleC and NleE, that down-regulate the NF-κB signal upon being injected into a host cell via the T3SS. A recent report showed that NleE inhibits NF-κB activation, although an NleE-deficient pathogen was still immune-suppressive, indicating that other anti-inflammatory effectors are involved. In agreement, our present results showed that NleC was also required to inhibit inflammation. We found that NleC is a zinc protease that disrupts NF-κB activation by the direct cleavage of NF-κB's p65 subunit in the cytoplasm, thereby decreasing the available p65 and reducing the total nuclear entry of active p65. More importantly, we showed that a mutant EPEC/EHEC lacking both NleC and NleE (ΔnleC ΔnleE) caused greater inflammatory response than bacteria carrying ΔnleC or ΔnleE alone. This effect was similar to that of a T3SS-defective mutant. In conclusion, we found that NleC is an anti-inflammatory bacterial zinc protease, and that the cooperative function of NleE and NleC disrupts the NF-κB pathway and accounts for most of the immune suppression caused by EHEC/EPEC.


Vyšlo v časopise: NleC, a Type III Secretion Protease, Compromises NF-κB Activation by Targeting p65/RelA. PLoS Pathog 6(12): e32767. doi:10.1371/journal.ppat.1001231
Kategorie: Research Article
prolekare.web.journal.doi_sk: https://doi.org/10.1371/journal.ppat.1001231

Souhrn

The NF-κB signaling pathway is central to the innate and adaptive immune responses. Upon their detection of pathogen-associated molecular patterns, Toll-like receptors on the cell surface initiate signal transduction and activate the NF-κB pathway, leading to the production of a wide array of inflammatory cytokines, in attempt to eradicate the invaders. As a countermeasure, pathogens have evolved ways to subvert and manipulate this system to their advantage. Enteropathogenic and enterohemorrhagic Escherichia coli (EPEC and EHEC) are closely related bacteria responsible for major food-borne diseases worldwide. Via a needle-like protein complex called the type three secretion system (T3SS), these pathogens deliver virulence factors directly to host cells and modify cellular functions, including by suppressing the inflammatory response. Using gain- and loss-of-function screenings, we identified two bacterial effectors, NleC and NleE, that down-regulate the NF-κB signal upon being injected into a host cell via the T3SS. A recent report showed that NleE inhibits NF-κB activation, although an NleE-deficient pathogen was still immune-suppressive, indicating that other anti-inflammatory effectors are involved. In agreement, our present results showed that NleC was also required to inhibit inflammation. We found that NleC is a zinc protease that disrupts NF-κB activation by the direct cleavage of NF-κB's p65 subunit in the cytoplasm, thereby decreasing the available p65 and reducing the total nuclear entry of active p65. More importantly, we showed that a mutant EPEC/EHEC lacking both NleC and NleE (ΔnleC ΔnleE) caused greater inflammatory response than bacteria carrying ΔnleC or ΔnleE alone. This effect was similar to that of a T3SS-defective mutant. In conclusion, we found that NleC is an anti-inflammatory bacterial zinc protease, and that the cooperative function of NleE and NleC disrupts the NF-κB pathway and accounts for most of the immune suppression caused by EHEC/EPEC.


Zdroje

1. ClarkeSC

2001 Diarrhoeagenic Escherichia coli—an emerging problem? Diagn Microbiol Infect Dis 41 93 98

2. KaperJB

NataroJP

MobleyHL

2004 Pathogenic Escherichia coli. Nat Rev Microbiol 2 123 140

3. MoonHW

WhippSC

ArgenzioRA

LevineMM

GiannellaRA

1983 Attaching and effacing activities of rabbit and human enteropathogenic Escherichia coli in pig and rabbit intestines. Infect Immun 41 1340 1351

4. JerseAE

YuJ

TallBD

KaperJB

1990 A genetic locus of enteropathogenic Escherichia coli necessary for the production of attaching and effacing lesions on tissue culture cells. Proc Natl Acad Sci USA 87 7839 7843

5. KnuttonS

BaldwinT

WilliamsPH

McNeishAS

1989 Actin accumulation at sites of bacterial adhesion to tissue culture cells: basis of a new diagnostic test for enteropathogenic and enterohemorrhagic Escherichia coli. Infect Immun 57 1290 1298

6. GarmendiaJ

FrankelG

CrepinVF

2005 Enteropathogenic and enterohemorrhagic Escherichia coli infections: translocation, translocation, translocation. Infect Immun 73 2573 2585

7. McDanielTK

KaperJB

1997 A cloned pathogenicity island from enteropathogenic Escherichia coli confers the attaching and effacing phenotype on E. coli K-12. Mol Microbiol 23 399 407

8. JarvisKG

GironJA

JerseAE

McDanielTK

DonnenbergMS

1995 Enteropathogenic Escherichia coli contains a putative type III secretion system necessary for the export of proteins involved in attaching and effacing lesion formation. Proc Natl Acad Sci U S A 92 7996 8000

9. TobeT

BeatsonSA

TaniguchiH

AbeH

BaileyCM

2006 An extensive repertoire of type III secretion effectors in Escherichia coli O157 and the role of lambdoid phages in their dissemination. Proc Natl Acad Sci U S A 103 14941 14946

10. OguraY

AbeH

KatsuraK

KurokawaK

AsadulghaniM

2008 Systematic Identification and Sequence Analysis of the Genomic Islands of the Enteropathogenic Escherichia coli Strain B171-8 by the Combined Use of Whole-Genome PCR Scanning and Fosmid Mapping. J Bacteriol 190 6948 6960

11. IguchiA

ThomsonNR

OguraY

SaundersD

OokaT

2009 Complete genome sequence and comparative genome analysis of enteropathogenic Escherichia coli O127:H6 strain E2348/69. J Bacteriol 191 347 354

12. DeanP

KennyB

2009 The effector repertoire of enteropathogenic E. coli: ganging up on the host cell. Curr Opin Microbiol 12 101 109

13. FiocchiC

1997 Intestinal inflammation: a complex interplay of immune and nonimmune cell interactions. Am J Physiol 273 G769 775

14. SansonettiPJ

2004 War and peace at mucosal surfaces. Nat Rev Immunol 4 953 964

15. RothwarfDM

1999 The NF-kappaB Activation Pathway: A Paradigm in Information Transfer from Membrane to Nucleus. Science's STKE 1999 1re-1

16. SenR

BaltimoreD

1986 Inducibility of kappa immunoglobulin enhancer-binding protein Nf-kappa B by a posttranslational mechanism. Cell 47 921 928

17. O'NeillLAJ

BowieAG

2007 The family of five: TIR-domain-containing adaptors in Toll-like receptor signalling. Nat Rev Immunol 7 353 364

18. AkiraS

TakedaK

2004 Toll-like receptor signalling. Nat Rev Immunol 4 499 511

19. HäckerH

KarinM

2006 Regulation and function of IKK and IKK-related kinases. Sci STKE 2006 re13

20. BonizziG

KarinM

2004 The two NF-kappaB activation pathways and their role in innate and adaptive immunity. Trends Immunol 25 280 288

21. SavkovicSD

KoutsourisA

HechtG

1996 Attachment of a noninvasive enteric pathogen, enteropathogenic Escherichia coli, to cultured human intestinal epithelial monolayers induces transmigration of neutrophils. Infect Immun 64 4480 4487

22. HaufN

ChakrabortyT

2003 Suppression of NF-kappa B activation and proinflammatory cytokine expression by Shiga toxin-producing Escherichia coli. J Immunol 170 2074 2082

23. Ruchaud-SparaganoM-H

MarescaM

KennyB

2007 Enteropathogenic Escherichia coli (EPEC) inactivate innate immune responses prior to compromising epithelial barrier function. Cell Microbiol 9 1909 1921

24. GaoX

WanF

MateoK

CallegariE

WangD

2009 Bacterial effector binding to ribosomal protein s3 subverts NF-kappaB function. PLoS Pathog 5 e1000708

25. NadlerC

BaruchK

KobiS

MillsE

HavivG

2010 The Type III Secretion Effector NleE Inhibits NF-kappaB Activation. PLoS Pathog 6 e1000743

26. NewtonHJ

PearsonJS

BadeaL

KellyM

LucasM

2010 The Type III Effectors NleE and NleB from Enteropathogenic E. coli and OspZ from Shigella Block Nuclear Translocation of NF-kappaB p65. PLoS Pathog 6 e1000898

27. HayashiT

MakinoK

OhnishiM

KurokawaK

IshiiK

2001 Complete genome sequence of enterohemorrhagic Escherichia coli O157:H7 and genomic comparison with a laboratory strain K-12. DNA Res 8 11 22

28. OguraY

OokaT

IguchiA

TohH

AsadulghaniM

2009 Comparative genomics reveal the mechanism of the parallel evolution of O157 and non-O157 enterohemorrhagic Escherichia coli. Proceedings of the National Academy of Sciences 106 17939 17944

29. NakagawaR

NakaT

TsutsuiH

FujimotoM

KimuraA

2002 SOCS-1 participates in negative regulation of LPS responses. Immunity 17 677 687

30. MansellA

SmithR

DoyleSL

GrayP

FennerJE

2006 Suppressor of cytokine signaling 1 negatively regulates Toll-like receptor signaling by mediating Mal degradation. Nat Immunol 7 148 155

31. RyoA

SuizuF

YoshidaY

PerremK

LiouY-C

2003 Regulation of NF-kappaB signaling by Pin1-dependent prolyl isomerization and ubiquitin-mediated proteolysis of p65/RelA. Mol Cell 12 1413 1426

32. GengH

WittwerT

Dittrich-BreiholzO

KrachtM

SchmitzML

2009 Phosphorylation of NF-kappaB p65 at Ser468 controls its COMMD1-dependent ubiquitination and target gene-specific proteasomal elimination. EMBO Rep 10 381 386

33. CoirasM

López-HuertasMR

MateosE

AlcamíJ

2008 Caspase-3-mediated cleavage of p65/RelA results in a carboxy-terminal fragment that inhibits IkappaBalpha and enhances HIV-1 replication in human T lymphocytes. Retrovirology 5 109

34. HooperNM

1994 Families of zinc metalloproteases. FEBS J 354 1 6

35. ArbibeL

KimDW

BatscheE

PedronT

MateescuB

2007 An injected bacterial effector targets chromatin access for transcription factor NF-kappaB to alter transcription of host genes involved in immune responses. Nat Immunol 8 47 56

36. KimDW

LenzenG

PageAL

LegrainP

SansonettiPJ

2005 The Shigella flexneri effector OspG interferes with innate immune responses by targeting ubiquitin-conjugating enzymes. Proc Natl Acad Sci U S A 102 14046 14051

37. LadSP

YangG

ScottDA

WangG

NairP

2007 Chlamydial CT441 is a PDZ domain-containing tail-specific protease that interferes with the NF-kappaB pathway of immune response. J Bacteriol 189 6619 6625

38. MarchesO

WilesS

DzivaF

La RagioneRM

SchullerS

2005 Characterization of two non-locus of enterocyte effacement-encoded type III-translocated effectors, NleC and NleD, in attaching and effacing pathogens. Infect Immun 73 8411 8417

39. KellyM

HartE

MundyR

MarchesO

WilesS

2006 Essential role of the type III secretion system effector NleB in colonization of mice by Citrobacter rodentium. Infect Immun 74 2328 2337

40. SekiyaK

OhishiM

OginoT

TamanoK

SasakawaC

2001 Supermolecular structure of the enteropathogenic Escherichia coli type III secretion system and its direct interaction with the EspA-sheath-like structure. Proc Natl Acad Sci U S A 98 11638 11643

41. YuJ-H

HamariZ

HanK-H

SeoJ-A

Reyes-DomÌnguezY

2004 Double-joint PCR: a PCR-based molecular tool for gene manipulations in filamentous fungi. Fungal Genetics and Biology 41 973 981

42. WangRF

KushnerSR

1991 Construction of versatile low-copy-number vectors for cloning, sequencing and gene expression in Escherichia coli. Gene 100 195 199

Štítky
Hygiena a epidemiológia Infekčné lekárstvo Laboratórium

Článok vyšiel v časopise

PLOS Pathogens


2010 Číslo 12
Najčítanejšie tento týždeň
Najčítanejšie v tomto čísle
Kurzy

Zvýšte si kvalifikáciu online z pohodlia domova

Získaná hemofilie - Povědomí o nemoci a její diagnostika
nový kurz

Eozinofilní granulomatóza s polyangiitidou
Autori: doc. MUDr. Martina Doubková, Ph.D.

Všetky kurzy
Prihlásenie
Zabudnuté heslo

Zadajte e-mailovú adresu, s ktorou ste vytvárali účet. Budú Vám na ňu zasielané informácie k nastaveniu nového hesla.

Prihlásenie

Nemáte účet?  Registrujte sa