title: Effects of Coxiella burnetii on MAPKinases phosphorylation.
abstract: Q fever is a disease caused by Coxiella burnetii, an obligate intracellular bacterium. Acute Q fever is characterized by efficient immune response, whereas chronic Q fever is characterized by dysregulated immune response as demonstrated by the lack of granulomas, the failure of C. burnetii to induce lymphoproliferation, and interferon-γ production. The mitogen-activated protein kinase (MAPK) signaling pathway plays crucial roles in innate immune responses and control of bacterial infections. However, its role in Q fever has not been addressed. First, we investigated the activation of MAPKs p38, c-jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) 1/2 in murine macrophages stimulated with C. burnetii. Coxiella burnetii NM phase I (virulent) and NM phase II (avirulent) induced the activation of JNK and ERK1/2. Avirulent C. burnetii activate p38, whereas C. burnetii did not induce the phosphorylation of p38. Second, the level of p38 activation was studied in Q fever patients. We found that p38 was activated in monocyte-derived macrophages from healthy donors and patients with acute Q fever in response to a potent agonist such as lipopolysaccharide. Interestingly, p38 was not activated in patients with active chronic Q fever and was activated in patients with cured chronic Q fever. These results suggest that the determination of p38 activation may serve as a tool for measuring Q fever activity.
authors.affiliation: URMITE, CNRS UMR 6236-IRD 198, Université de la Méditerranée, Marseille, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Boucherit
authors.forename: Abdoulaye Oury
authors.initials: AO
authors.lastname: Barry
authors.forename: Giovanna
authors.initials: G
authors.lastname: Mottola
authors.forename: Virginie
authors.initials: V
authors.lastname: Trouplin
authors.forename: Christian
authors.initials: C
authors.lastname: Capo
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Mege
authors.forename: Eric
authors.initials: E
authors.lastname: Ghigo
mesh_terms: D015415:Biomarkers; D016997:Coxiella burnetii / Q000472:pathogenicity*; D020869:Gene Expression Profiling; D006801:Humans; D008264:Macrophages / Q000276:immunology; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D010766:Phosphorylation
chemical_list: D015415:Biomarkers; D020928:Mitogen-Activated Protein Kinases