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1.
Clin Microbiol Infect ; 25(6): 763.e1-763.e3, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30898724

RESUMO

OBJECTIVES: Q fever is a zoonotic disease caused by Coxiella burnetii which affects men more than women (sex ratio men/women: 2.2). Acute Q fever complications are associated with elevation of anticardiolipin (aCL) antibodies. Here, we investigate the sexual dimorphism of aCL antibodies during acute C. burnetii infection. METHODS: IgG aCL antibodies were evaluated at the time of Q fever serological diagnosis with enzyme-linked immunosorbent assay. Results were analysed according to sex. RESULTS: Among the 1323 patients with Q fever tested for aCL, 1013 had acute Q fever (692 men/321 women) and 310 had persistent focalized infection (226 men/84 women). In cases of acute Q fever, men presented a significantly higher proportion of positive aCL antibodies (351/692, 50.7%) than women (113/321, 35.2%) (p <0.05). In addition, men had significantly higher aCL antibodies levels than women (p <0.001). CONCLUSIONS: We highlight a relationship between sex and markers of autoimmunity during Q fever. Further investigations are necessary to better understand the mechanisms of this sexual dimorphism.


Assuntos
Autoanticorpos/sangue , Cardiolipinas/imunologia , Coxiella burnetii/imunologia , Febre Q/patologia , Fatores Sexuais , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoglobulina G/sangue , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Adulto Jovem
2.
New Microbes New Infect ; 26: S100-S103, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30402251

RESUMO

Most infectious diseases are unequally distributed between male and female subjects. This sex dimorphism is confirmed by epidemiologic studies which suggest an increased number of male septic patients, while, due to the class age of septic patients, an overrepresentation of female patients would be expected. Lifestyle, recreational activities, professional exposition and access to care are plausible reasons for this dimorphism. However, biological differences should be carefully considered, particularly the weight of X-linked variability and the role of sex hormones. Animal models clearly show that clinical response to infection is more exuberant in males than in females. This is partly explained by an attenuation of the inflammatory response by female sex hormones. However, the translation from experimental studies to the bedside remains challenging as a result of confounding factors like age, hormone changes and response to treatment.

3.
New Microbes New Infect ; 26: S109-S113, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30402253

RESUMO

Since its creation in 2011, the Institut Hospitalo-Universitaire Méditerranée Infection (IHU MI) has devoted a major part of its funding to support higher education programs. In 2017, on a recurrent budget of 5.8 million Euros per year, 2.9 (50%) were spent on infrastructure, mostly for maintenance and equipment of our new building. Among the remaining 2.9 million Euros, 2.3 (80%) have been dedicated to support higher education programs.

4.
Allergy ; 72(11): 1632-1642, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28513848

RESUMO

A wide spectrum of pathological conditions may result from the interaction of Aspergillus fumigatus and the immune system of its human host. Allergic bronchopulmonary aspergillosis is one of the most severe A. fumigatus-related diseases due to possible evolution toward pleuropulmonary fibrosis and respiratory failure. Allergic bronchopulmonary aspergillosis occurs almost exclusively in cystic fibrosis or asthmatic patients. An estimated 8%-10% of patients with cystic fibrosis experience this condition. The diagnosis of allergic bronchopulmonary aspergillosis relies on criteria first established in 1977. Progress in the understanding of host-pathogen interactions in A. fumigatus and patients with cystic fibrosis and the ongoing validation of novel laboratory tools concur to update and improve the diagnosis of allergic bronchopulmonary aspergillosis.


Assuntos
Aspergilose Broncopulmonar Alérgica/imunologia , Aspergillus fumigatus/patogenicidade , Fibrose Cística/etiologia , Aspergilose Broncopulmonar Alérgica/diagnóstico , Fibrose Cística/microbiologia , Interações Hospedeiro-Patógeno/imunologia , Humanos
5.
Clin Microbiol Infect ; 23(7): 487.e7-487.e13, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28179203

RESUMO

OBJECTIVES: Chronic Q fever is a persistent infection with the intracellular Gram-negative bacterium Coxiella burnetii, which can lead to complications of infected aneurysms. Matrix metalloproteinases (MMPs) cleave extracellular matrix and are involved in infections as well as aneurysms. We aimed to study the role of MMPs in the pathogenesis of chronic Q fever. METHODS: We investigated gene expression of MMPs through microarray analysis and MMP production with ELISA in C. burnetii-stimulated peripheral blood mononuclear cells (PBMCs) of patients with chronic Q fever and healthy controls. Twenty single nucleotide polymorphisms (SNPs) of MMP and tissue inhibitor of MMP genes were genotyped in 139 patients with chronic Q fever and 220 controls with similar cardiovascular co-morbidity. Additionally, circulating MMPs levels in patients with chronic Q fever were compared with those in cardiovascular controls with and without a history of past Q fever. RESULTS: In healthy controls, the MMP pathway involving four genes (MMP1, MMP7, MMP10, MMP19) was significantly up-regulated in C. burnetii-stimulated but not in Escherichia coli lipopolysaccharide -stimulated PBMCs. Coxiella burnetii induced MMP-1 and MMP-9 production in PBMCs of healthy individuals (both p<0.001), individuals with past Q fever (p<0.05, p<0.01, respectively) and of patients with chronic Q fever (both p<0.001). SNPs in MMP7 (rs11568810) (p<0.05) and MMP9 (rs17576) (p<0.05) were more common in patients with chronic Q fever. Circulating MMP-7 serum levels were higher in patients with chronic Q fever (median 33.5 ng/mL, interquartile range 22.3-45.7 ng/mL) than controls (20.6 ng/mL, 15.9-33.8 ng/mL). CONCLUSION: Coxiella burnetii-induced MMP production may contribute to the development of chronic Q fever.


Assuntos
Coxiella burnetii/fisiologia , Interações Hospedeiro-Patógeno , Metaloproteinases da Matriz/análise , Febre Q/patologia , Febre Q/fisiopatologia , Ensaio de Imunoadsorção Enzimática , Perfilação da Expressão Gênica , Genótipo , Humanos , Leucócitos Mononucleares/enzimologia , Metaloproteinases da Matriz/genética , Polimorfismo de Nucleotídeo Único
6.
Clin Microbiol Infect ; 23(3): 209.e9-209.e15, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27876593

RESUMO

OBJECTIVES: Q fever is caused by Coxiella burnetii, an intracellular bacterium that infects phagocytes. The aim of the present study was to investigate whether the C. burnetii-induced IFN-γ response is defective in chronic Q fever patients. METHODS: IFN-γ was measured in supernatants of C. burnetii-stimulated peripheral blood mononuclear cells (PBMCs) of 17 chronic Q fever patients and 17 healthy individuals. To assess IFN-γ responses, expression profiles of IFN-γ-induced genes in C. burnetii-stimulated PBMCs were studied in six patients and four healthy individuals. Neopterin was measured in PBMC supernatants (of eight patients and four healthy individuals) and in sera (of 21 patients and 11 healthy individuals). In a genetic association study, polymorphisms in genes involved in the Th1-cytokine response were analysed in a cohort of 139 chronic Q fever patients and a cohort of 220 control individuals with previous exposition to C. burnetii. RESULTS: IFN-γ production by C. burnetii-stimulated PBMCs from chronic Q fever patients was significantly higher than in healthy controls. Many IFN-γ response genes were strongly upregulated in PBMCs of patients. Neopterin levels were significantly higher in PBMC supernatants and sera of patients. The IL12B polymorphisms rs3212227 and rs2853694 were associated with chronic Q fever. CONCLUSIONS: IFN-γ production, as well as the response to IFN-γ, is intact in chronic Q fever patients, and even higher than in healthy individuals. Polymorphisms in the IL-12p40 gene are associated with chronic Q fever. Thus, a deficiency in IFN-γ responses does not explain the failure to clear the infection. The genetic data suggest, however, that the IL-12/IFN-γ pathway does play a role.


Assuntos
Coxiella burnetii/imunologia , Imunidade Inata , Interferon gama/metabolismo , Leucócitos Mononucleares/imunologia , Febre Q/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Células Cultivadas , Feminino , Perfilação da Expressão Gênica , Estudos de Associação Genética , Humanos , Subunidade p40 da Interleucina-12/genética , Masculino , Pessoa de Meia-Idade , Neopterina/análise , Neopterina/sangue , Polimorfismo de Nucleotídeo Único
7.
Clin Microbiol Infect ; 23(1): 38-45, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27720865

RESUMO

OBJECTIVES: Cytomegalovirus (CMV) reactivation in intensive care unit patients may increase mortality and favour bacterial pneumonia. We developed a murine model to compare the severity of staphylococcal pneumonia after CMV reactivation and in CMV-negative mice. METHODS: Balb/c mice were primo-infected with murine cytomegalovirus (MCMV n=90) or received saline (control n=90). After latency, all mice underwent caecal ligation and puncture to trigger MCMV reactivation in MCMV primary-infected mice. Surviving animals received an intra-nasal inoculation with methicillin-susceptible Staphylococcus aureus (MSSA) to induce pneumonia. Mortality, lung bacterial count, histology and interferon-alpha and gamma serum levels were compared in MCMV reactivated and control mice 2, 5 and 15 days after pneumonia. RESULTS: After MSSA pneumonia, MCMV mice showed a trend towards a higher mortality (9.4% versus 0%; p 0.09) and a higher weight loss (2.2 (0.6-4.1 g) versus 0.7 (-0.3 to 1.3 g); p 0.005). The lung bacterial count was higher in MCMV mice 2 days (5×103 (103 to 3×105) versus 102 (0 to 4×102) CFU/lung; p 0.007) and 5 days (2.5×104 (1.6×104 to 6.5×105) versus 15 (10-40) CFU/lung; p 0.005) after MSSA pneumonia. 8/40 (20%) MCMV mice developed lung abscesses compared to 0% in control (p 0.011). Interferon-alpha serum levels 2 days after staphylococcal pneumonia were higher in MCMV mice. CONCLUSIONS: MCMV reactivation decreased lung bacterial clearance and favoured the development of staphylococcal abscessing pneumonia. CMV reactivation may be responsible for a higher susceptibility to bacterial sepsis.


Assuntos
Infecções por Citomegalovirus/complicações , Pneumonia Bacteriana/microbiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/patogenicidade , Ativação Viral , Animais , Coinfecção , Camundongos , Pneumonia Bacteriana/complicações , Virulência
8.
Allergy ; 71(11): 1640-1643, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27542151

RESUMO

Aspergillus fumigatus is the causative agent of allergic broncho-pulmonary aspergillosis. Prompt and accurate diagnosis may be difficult to achieve with current clinical and laboratory scores, which do not include immune responses to recombinant A. fumigatus allergens. We measured specific immunoglobulin E and G4 directed to recombinant A. fumigatus allergens in 55 cystic fibrosis patients without allergic broncho-pulmonary aspergillosis but sensitized to A. fumigatus and in nine patients with allergic broncho-pulmonary aspergillosis (two with cystic fibrosis and seven with asthma). IgG4 responses to recombinant A. fumigatus allergens were detected in all patients, but neither prevalence nor levels were different between the two patient groups. On the other hand, both prevalence and levels of IgE responses to Asp f 3, Asp f 4, and Asp f 6 helped distinguish allergic broncho-pulmonary aspergillosis from A. fumigatus sensitization with good negative and positive predictive values.


Assuntos
Antígenos de Fungos/imunologia , Aspergilose Broncopulmonar Alérgica/imunologia , Aspergillus fumigatus/imunologia , Imunoglobulina E/imunologia , Imunoglobulina G/imunologia , Adolescente , Adulto , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/imunologia , Aspergilose Broncopulmonar Alérgica/epidemiologia , Aspergilose Broncopulmonar Alérgica/microbiologia , Criança , Fibrose Cística/complicações , Humanos , Imunização , Masculino , Pessoa de Meia-Idade , Curva ROC , Estudos Soroepidemiológicos , Adulto Jovem
9.
Prog Urol ; 25(16): 1140-5, 2015 Dec.
Artigo em Francês | MEDLINE | ID: mdl-26431745

RESUMO

UNLABELLED: The diagnostic for prostate cancer is changing. To improve the detection of this cancer, urologists expect a lot from the contribution of magnetic resonance imaging (MRI). What is the role of this imaging in prostate cancer detection? This is a retrospective study, from 2011 to 2013, mono-centric and single-operator. Of the 464 needle biopsy of the prostate (BP), we excluded those with PSA>20 ng/mL or digital rectal examination (DRE)>T3. The remaining 430 BP were submitted or not to a 1.5 tesla MRI with pelvic antenna. The primary aim is the overall detection of prostate cancer. Secondary aim was the detection rate during the first series of BP and repeat BP, between the two groups in the MRI group. MRI and MRI without populations are comparable for age (63.3 vs 64.6), PSA (6.10 vs 6.13), DRE>T1c, prostate volume (55.4 cm(3) vs 51.7 cm(3)). There is no significant difference in overall detection between the two groups (P=0.12). There is no significant difference in cancer detection between the first BP (P=0.13) and the repeat BP (P=0.07). There is a significant difference in the early detection of BP MRI group (P=0.03) but not for the BP repeat MRI group (P=0.07). For 108 BP iterative MRI group, there were 67 BP targeted "mentally" with MRI: 18 cancers were detected, making a 25% detection rate. This study helps to highlight the value of MRI in the early rounds of BP but we can ask the value of this imaging during repeat biopsies. Targeted biopsies "mentally" do not have the expected detection sensitivity and seems to require a three-dimensional reconstruction to be more effective. LEVEL OF EVIDENCE: 5.


Assuntos
Imageamento por Ressonância Magnética , Neoplasias da Próstata/patologia , Idoso , Idoso de 80 Anos ou mais , Biópsia por Agulha , Humanos , Masculino , Pessoa de Meia-Idade , Cuidados Pré-Operatórios , Estudos Retrospectivos
10.
Acta Anaesthesiol Scand ; 54(5): 643-8, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20148771

RESUMO

BACKGROUND: Major cancer surgery is a high-risk situation for sepsis in the post-operative period. The aim of this study was to assess the relation between the monocyte production of IL-12 and the development of post-operative sepsis in patients undergoing major cancer surgery. METHODS: In 19 patients undergoing major cancer surgery, the production of cytokines by basal and lipolysaccharide (LPS)-stimulated monocytes was measured before and after (from day 1 to day 3 and day 7) surgery. Seven of them developed a post-operative sepsis. Ten healthy volunteers were used as controls for the assessment of pre-operative values. RESULTS: Before surgery, the production of interleukin (IL)-12 p40 by LPS-stimulated monocytes was similar in the patients and the healthy volunteers. The production of IL-12 p40 by unstimulated monocytes was higher in the patients than in the healthy volunteers. IL-12 production did not differ between the septic and the non-septic patients. After surgery, the production of IL-12 p40 was dramatically reduced in the LPS-stimulated monocytes of the septic patients from day 1 to day 3, as compared with that of the non-septic patients. Before surgery, the production of IL-6, IL-10, and IL-1 receptor antagonist (IL-1ra) in the patients was significantly higher than that of the healthy volunteers for both stimulated and unstimulated monocytes. After surgery, the production of these cytokines by both stimulated and unstimulated monocytes of the septic patients was similar to that of the non-septic patients. Intragroup analysis showed significant changes for IL-6, IL-10, and IL-1ra under all conditions, with the exception of changes in unstimulated monocytes of septic patients that were not significant for IL-10 release. CONCLUSION: After surgery, the septic patients showed drastic failure to up-regulate monocyte LPS-stimulated production of IL-12 p40.


Assuntos
Neoplasias do Sistema Digestório/cirurgia , Neoplasias dos Genitais Femininos/cirurgia , Interleucina-12/sangue , Monócitos/metabolismo , Complicações Pós-Operatórias/sangue , Sepse/sangue , Estudos de Casos e Controles , Procedimentos Cirúrgicos Eletivos , Feminino , Humanos , Proteína Antagonista do Receptor de Interleucina 1/sangue , Interleucina-10/sangue , Interleucina-6/sangue , Lipopolissacarídeos/sangue , Estudos Prospectivos
11.
Cell Death Dis ; 1: e34, 2010 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-21364641

RESUMO

Tropheryma whipplei, the etiological agent of Whipple's disease, is an intracellular bacterium that infects macrophages. We previously showed that infection of macrophages results in M2 polarization associated with induction of apoptosis and interleukin (IL)-16 secretion. In patients with Whipple's disease, circulating levels of apoptotic markers and IL-16 are increased and correlate with the activity of the disease. To gain insight into the understanding of the pathophysiology of this rare disease, we examined the molecular pathways involved in T. whipplei-induced apoptosis of human macrophages. Our data showed that apoptosis induction depended on bacterial viability and inhibition of bacterial protein synthesis reduced the apoptotic program elicited by T. whipplei. Induction of apoptosis was also associated with a massive degradation of both pro- and anti-apoptotic mediators. Caspase-specific inhibition experiments revealed that initiator caspases 8 and 10 were required for apoptosis, in contrast to caspases 2 and 9, in spite of cytochrome-c release from mitochondria. Finally, the effector caspases 3 and 6 were mandatory for apoptosis induction. Collectively, these data suggest that T. whipplei induces apoptosis through the extrinsic pathway and that, beside M2 polarization of macrophages, apoptosis induction contributes to bacterial replication and represents a virulence trait of this intracellular pathogen.


Assuntos
Apoptose , Macrófagos/citologia , Macrófagos/microbiologia , Transdução de Sinais , Tropheryma/fisiologia , Doença de Whipple/microbiologia , Proteínas Reguladoras de Apoptose/metabolismo , Caspases/metabolismo , Ativação Enzimática , Humanos , Macrófagos/enzimologia , Macrófagos/ultraestrutura , Potencial da Membrana Mitocondrial , Monócitos/citologia , Processamento de Proteína Pós-Traducional , Tropheryma/ultraestrutura
16.
Prog Urol ; 18(5): 311-7, 2008 May.
Artigo em Francês | MEDLINE | ID: mdl-18538277

RESUMO

OBJECTIVE: Prospective evaluation of the short-, medium- and long-term efficacy of the "ABDO-MG concept" technique in the rehabilitation of urinary incontinence following radical prostatectomy (abdominal or laparoscopic approach). METHODOLOGY: Fifty-three patients suffering from clinical urinary stress or triple incontinence (pure stress incontinence, incontinence due to bladder instability or sphincteric insufficiency) took part in the study. Rehabilitation treatment, begun six weeks before the operation, continued during the immediate postoperative period, at home and at the physiotherapist's office for three to 12 months until the urinary incontinence had disappeared or was considered to be minimal and acceptable, therefore tolerated. The exercises were performed according to a strict protocol defined by the inventor of the concept, involving expiration into a specific end-piece (called "sound end-piece") and connection with an abdominal neurostimulator for which the current is triggered and maintained by the sound of the patient's breathing into the sound end-piece. The efficacy of this concept was confirmed by a comparative trial before and during rehabilitation and then at the end of treatment. There was triple monitoring: evaluation by LFT noting, for each breath, the flowrate/volume curve and FEV1/s, clinical abdominal testing with monitoring of abdominal movement both vertically and horizontally during coughing and a "pad test" at home, assessing the quantity of nocturnal and diurnal urinary leakage relative to each patient's activity. RESULTS: The results were meaningful and significant. The improvement of the flowrate/volume curve and FEV1/s varied between 1.4436 and 1.1209 L. Abdominal testing showed constant positive evolution in the correction of abdominal incompetence under stress (test improved by one point on a negative graduation of -1 to -3). The home "pad test" confirmed a highly significant result with leakage virtually disappearing, sometimes falling from nearly 800 cc to just a few drops at the end of treatment. The subjective results were marked by the improvement in various dysfunctions within the context of abdominal incompetence increased by the abdominal surgery. CONCLUSION: This prospective study was the first to provide an evaluation of the abdominal motor score and the relationship between expiration thrust and pelviperitoneal protection.


Assuntos
Modalidades de Fisioterapia , Prostatectomia/efeitos adversos , Incontinência Urinária/reabilitação , Idoso , Idoso de 80 Anos ou mais , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Incontinência Urinária/etiologia
17.
Br J Surg ; 89(11): 1450-6, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12390391

RESUMO

BACKGROUND: Patients who undergo major surgery for cancer are at high risk of postoperative infection. Postoperative immunosuppression may be due to dysregulation of cytokine production. The aim of this study was to investigate the association between changes in serum proinflammatory and anti-inflammatory cytokine concentrations and postoperative septic complications after major surgery. METHODS: Serial blood samples were collected from 30 consecutive patients for determination of serum cytokine levels. Healthy volunteers were used as the control group. RESULTS: Eleven patients developed no complications (group 1), 14 developed sepsis or severe sepsis (group 2), and five developed septic shock (group 3). On day 1 the patients in groups 2 and 3 had significantly higher levels of interleukin (IL) 6 than those in group 1. IL-6 levels remained high until day 5. Tumour necrosis factor (TNF), IL-1, interferon (IFN) gamma and IL-12 levels were not affected by surgical trauma or by the occurrence of septic complications. After operation the circulating IL-1 receptor antagonist (IL-1ra) concentration was increased in all groups, but patients in group 3 had significantly higher levels of IL-1ra than those in group 1. IL-1ra levels correlated with IL-6 levels. The pattern of IL-10 levels was similar to that of IL-1ra levels. CONCLUSION: Serum concentrations of proinflammatory cytokines (TNF, IL-1, IFN-gamma and IL-12) were not affected by operation or the occurrence of septic complications. The postoperative increase in IL-6 concentration was associated with septic morbidity, while raised IL-1ra concentration was associated with postoperative septic shock.


Assuntos
Citocinas/metabolismo , Neoplasias/cirurgia , Síndrome de Resposta Inflamatória Sistêmica/metabolismo , Feminino , Humanos , Interleucina-10/metabolismo , Interleucina-6/metabolismo , Masculino , Pessoa de Meia-Idade , Neoplasias/metabolismo , Período Pós-Operatório , Estudos Prospectivos , Receptores de Interleucina-1/antagonistas & inibidores , Fator de Necrose Tumoral alfa/metabolismo
18.
Ann Urol (Paris) ; 36(3): 196-203, 2002 May.
Artigo em Francês | MEDLINE | ID: mdl-12056093

RESUMO

The surgical repair of anterior hypospadias depends on the surgeon's custom and the anatomical variations of this anomaly. However, most publications agree nowadays on the one-stage surgery. We report on 585 hypospadias operated in our department. Our procedure is based on the Duplay technique, in addition to personal modifications in order to correct the frequently associated penis anomalies. The procedure is described herein. Aesthetic and functional results are reported and seem to be very satisfactory in comparison with the literature and permit the homologation of our technique.


Assuntos
Hipospadia/cirurgia , Procedimentos Cirúrgicos Urológicos Masculinos/métodos , Pré-Escolar , Humanos , Lactente , Masculino , Uretra/cirurgia
19.
Infect Immun ; 69(4): 2345-52, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11254592

RESUMO

Coxiella burnetii, an obligate intracellular bacterium, is the agent of Q fever. The chronic form of the disease is associated with the overproduction of interleukin-10 and deficient C. burnetii killing by monocytes. We hypothesized that the replication of C. burnetii inside monocytes requires a macrophage-deactivating cytokine such as interleukin-10. In the absence of interleukin-10, C. burnetii survived but did not replicate in monocytes. C. burnetii replication (measured 15 days) was induced in interleukin-10-treated monocytes. This effect of interleukin-10 is specific since transforming growth factor beta1 had no effect on bacterial replication. C. burnetii replication involves the down-modulation of tumor necrosis factor (TNF) release. First, interleukin-10 suppressed C. burnetii-stimulated production of TNF. Second, the addition of recombinant TNF to interleukin-10-treated monocytes inhibited bacterial replication. Third, the incubation of infected monocytes with neutralizing anti-TNF antibodies favored C. burnetii replication. On the other hand, deficient C. burnetii killing by monocytes from patients with chronic Q fever involves interleukin-10. Indeed, C. burnetii replication was observed in monocytes from patients with Q fever endocarditis, but not in those from patients with acute Q fever. Bacterial replication was inhibited by neutralizing anti-interleukin-10 antibodies. As monocytes from patients with endocarditis overproduced interleukin-10, the defective bacterial killing is likely related to endogenous interleukin-10. These results suggest that interleukin-10 enables monocytes to support C. burnetii replication and to favor the development of chronic Q fever.


Assuntos
Atividade Bactericida do Sangue , Coxiella burnetii/fisiologia , Interleucina-10/farmacologia , Monócitos/imunologia , Monócitos/microbiologia , Febre Q/imunologia , Fator de Necrose Tumoral alfa/biossíntese , Antígenos CD/metabolismo , Regulação para Baixo , Endocardite Bacteriana/imunologia , Humanos , Receptores do Fator de Necrose Tumoral/metabolismo , Receptores Tipo II do Fator de Necrose Tumoral , Fator de Crescimento Transformador beta/farmacologia
20.
Infect Immun ; 69(4): 2520-6, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11254615

RESUMO

Coxiella burnetii, the agent of Q fever, is an obligate intracellular microorganism that grows in monocytes/macrophages. The internalization of virulent organisms by monocytes is lower than that of avirulent variants and is associated with actin cytoskeleton reorganization. We studied the activation of protein tyrosine kinases (PTKs) by C. burnetii in THP-1 monocytes. Virulent organisms induced early PTK activation and the tyrosine phosphorylation of several endogenous substrates, including Hck and Lyn, two Src-related kinases. PTK activation reflects C. burnetii virulence since avirulent variants were unable to stimulate PTK. We also investigated the role of PTK activation in C. burnetii-stimulated F-actin reorganization. Tyrosine-phosphorylated proteins were colocalized with F-actin inside cell protrusions induced by C. burnetii, and PTK activity was increased in Triton X-100-insoluble fractions. In addition, lavendustin A, a PTK inhibitor, and PP1, a Src kinase inhibitor, prevented C. burnetii-induced cell protrusions and F-actin reorganization. We finally assessed the role of PTK activation in bacterial phagocytosis. Pretreatment of THP-1 cells with lavendustin A and PP1 upregulated the uptake of virulent C. burnetii but had no effect on the phagocytosis of avirulent organisms. Thus, it is likely that PTK activation by C. burnetii negatively regulates bacterial uptake by interfering with cytoskeleton organization.


Assuntos
Actinas/fisiologia , Coxiella burnetii/fisiologia , Citoesqueleto/fisiologia , Fagocitose , Proteínas Tirosina Quinases/fisiologia , Ativação Enzimática , Humanos , Antígeno de Macrófago 1/fisiologia , Fenóis/farmacologia , Fosforilação , Tirosina/metabolismo , Quinases da Família src/metabolismo
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