Yersinia enterocolitica promotes deactivation of macrophage mitogen-activated protein kinases extracellular signal-regulated kinase-1/2, p38, and c-Jun NH2-terminal kinase. Correlation with its inhibitory effect on tumor necrosis factor-alpha production.

Klaus Ruckdeschel,Jean-Pierre Liautard,Robert Zumbihl,Jürgen Heesemann,Andreas Roggenkamp,Jan Machold,Bruno Rouot,Sören Schubert,Josiane Pierre

doi:10.1074/jbc.272.25.15920

Abstract

The enteropathogenic bacterium Yersinia enterocolitica counteracts host defense mechanisms by interfering with eukaryotic signal transduction pathways. In this study, we investigated the mechanism by which Y. enterocolitica prevents macrophage tumor necrosis factor-alpha (TNFalpha) production. Murine J774A.1 macrophages responded to Y. enterocolitica infection by rapid activation of mitogen-activated protein kinases (MAPK) extracellular signal-regulated kinase (ERK), p38, and c-Jun NH2-terminal kinase (JNK). However, after initial activation, the virulent Y. enterocolitica strain harboring the Y. enterocolitica virulence plasmid caused a substantial decrease in ERK1/2 and p38 tyrosine phosphorylation. Simultaneously, the virulent Y. enterocolitica strain gradually suppressed phosphorylation of the transcription factors Elk-1, activating transcription factor 2 (ATF2), and c-Jun, indicating time-dependent inhibition of ERK1/2, p38, and JNK kinase activities, respectively. Analysis of different Y. enterocolitica mutants revealed that (i) MAPK inactivation parallels the inhibition of TNFalpha release, (ii) the suppressor effect on TNFalpha production, which originates from the lack of TNFalpha mRNA, is distinct from the ability of Y. enterocolitica to resist phagocytosis and to prevent the oxidative burst, (iii) the tyrosine phosphatase YopH, encoded by the Y. enterocolitica virulence plasmid, is not involved in the decrease of ERK1/2 and p38 tyrosine phosphorylation or in the cytokine suppressive effect. Altogether, these results indicate that Y. enterocolitica possesses one or more virulence proteins that suppress TNFalpha production by inhibiting ERK1/2, p38, and JNK kinase activities.

Highlights

The enteropathogenic bacterium Yersinia enterocolitica counteracts host defense mechanisms by interfering with eukaryotic signal transduction pathways
Analysis of different Y. enterocolitica mutants revealed that (i) mitogen-activated protein kinases (MAPK) inactivation parallels the inhibition of TNF␣ release, (ii) the suppressor effect on TNF␣ production, which originates from the lack of TNF␣ mRNA, is distinct from the ability of Y. enterocolitica to resist phagocytosis and to prevent the oxidative burst, (iii) the tyrosine phosphatase YopH, encoded by the Y. enterocolitica virulence plasmid, is not involved in the decrease of ERK1/2 and p38 tyrosine phosphorylation or in the cytokine suppressive effect
Y. enterocolitica Reduces p38 and ERK1/2 Tyrosine Phosphorylation and MAPK Activities—To determine possible differences between the virulent and nonvirulent Y. enterocolitica strain during infection, we compared the patterns of tyrosinephosphorylated proteins in cells stimulated with LPS from E. coli or with the two Y. enterocolitica strains

Summary

The abbreviations used are

Yersinia outer protein; TNF␣, tumor necrosis factor; GST, glutathione S-transferase; MAPK, mitogenactivated protein kinase (MAPK is used here in a general sense and includes ERK, JNK, and p38 kinases); ERK, extracellular signal-regulated kinase; JNK, c-Jun NH2-terminal kinase ( termed SAPK); SAPK, stress-activated protein kinase; p38, murine homologue of the Saccharomyces cerevisiae high osmolarity glycerol protein kinase HOG1; LPS, lipopolysaccharide of Gram-negative bacteria; PAGE, polyacrylamide gel electrophoresis; PCR, polymerase chain reaction; PVDF, polyvinyldifluoride; ␤2m, ␤2-microglobuline; PMSF, phenylmethylsulfonyl fluoride; MEK, MAPK/ERK kinase; ATF2, activating transcription factor 2. Seems to play an important role [37], since LPS was shown to activate a ceramide-dependent kinase [38] and ceramide itself stimulates the JNK/SAPK pathway [39]. Irrespective of the mechanism of LPSinduced MAPK stimulation, it is well established that among MAPKs, p38 plays an important role in LPS-induced TNF␣ production in macrophages [41,42]. We report that virulent Y. enterocolitica strongly interferes with macrophage signal transduction, resulting in blockade of ERK, JNK, and p38 MAPK activities. This MAPK inhibition correlates with the suppression of TNF␣ production but is not required for the inhibition of macrophage phagocytosis and oxidative burst

EXPERIMENTAL PROCEDURES

RESULTS

65 Ϯ 2 5Ϯ4

DISCUSSION