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Clermont-Ferrand, France

Demaret J.,Laboratoire dImmunologie
Cytometry. Part B, Clinical cytometry | Year: 2013

Diminished expression of human leukocyte antigen DR on circulating monocytes (mHLA-DR) is a reliable indicator of immunosuppression in critically ill patients, predictive of both adverse outcome and septic complications. The objective of the present work was to test, in an inter-laboratory clinical study, a standardized protocol for mHLA-DR measurement by flow cytometry. mHLA-DR was assessed in fresh whole blood according to a standardized staining protocol. Cells were analyzed on different flow cytometers (FC500, Navios, FACS Canto II) in different laboratories (Lyon and Grenoble). Results were expressed as numbers of antibodies bound per cell (AB/C). Correlations between results were excellent (Pearson and interclass correlation coefficients > 0.98). Coefficients of variations for intra-assay precision ranged from 1.9 to 3.2%. The present report highlights the robustness of this standardized flow cytometric protocol for mHLA-DR measurement in multicentric clinical studies. Copyright © 2012 International Clinical Cytometry Society. Source


Vernin C.,University of Lyon | Thenoz M.,University of Lyon | Gessain A.,Institute Pasteur Paris | Gout O.,Rothschild | And 5 more authors.
Cancer Research | Year: 2014

Viruses disrupt the host cell microRNA (miRNA) network to facilitate their replication. Human T-cell leukemia virus type I (HTLV-1) replication relies on the clonal expansion of its host CD4+ and CD8+ T cells, yet this virus causes adult T-cell leukemia/lymphoma (ATLL) that typically has a CD4+ phenotype. The viral oncoprotein Tax, which is rarely expressed in ATLL cells, has long been recognized for its involvement in tumor initiation by promoting cell proliferation, genetic instability, and miRNA dysregulation. Meanwhile, HBZ is expressed in both untransformed infected cells and ATLL cells and is involved in sustaining cell proliferation and silencing virus expression. Here, we show that an HBZ-miRNA axis promotes cell proliferation and genetic instability, as indicated by comet assays that showed increased numbers of DNA-strand breaks. Expression profiling of miRNA revealed that infected CD4+ cells, but not CD8+ T cells, overexpressed oncogenic miRNAs, including miR17 and miR21. HBZ activated these miRNAs via a posttranscriptional mechanism. These effects were alleviated by knocking down miR21 or miR17 and by ectopic expression of OBFC2A, a DNA-damage factor that is downregulated by miR17 and miR21 in HTLV-1-infected CD4+ T cells. These findings extend the oncogenic potential of HBZ and suggest that viral expression might be involved in the remarkable genetic instability of ATLL cells. ©2014 AACR. Source


Perl M.,University of Ulm | Lomas-Neira J.,University of Rhode Island | Venet F.,Laboratoire dImmunologie | Chung C.-S.,University of Rhode Island | Ayala A.,University of Rhode Island
Expert Review of Respiratory Medicine | Year: 2011

At present, therapeutic interventions to treat acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) remain largely limited to lung-protective strategies, as no real molecular-pathophysiologic-driven therapeutic intervention has yet become available. This is in part the result of the heterogeneous nature of the etiological processes that contribute to the state of ALI/ARDS. This article sets out to understand the development of ALI resulting from indirect pulmonary insults, such as extrapulmonary sepsis and trauma, shock, burn injury or mass transfusion, as opposed to direct pulmonary challenges, such as pneumonia, aspiration or lung contusion. Here, we consider not only the experimental and clinical data concerning the roles of various immune (neutrophil, macrophage, lymphocyte and dendritic) as well as nonimmune (epithelial and endothelial) cells in orchestrating the development of ALI resulting from indirect pulmonary stimuli, but also how these cell populations might be targeted therapeutically. © 2011 Expert Reviews Ltd. Source


Sanmarco M.,Laboratoire dImmunologie
Journal of Immunological Methods | Year: 2010

The aim of this study was to evaluate the influence on the results of the main variables of ELISA used for the detection of antiphosphatidylethanolamine antibodies (aPE). Forty sera from patients with either autoimmune disorders including antiphospholipid syndrome (APS) or the clinical features of APS only were assayed by ELISA performed under different conditions. Variables were sources of PE (egg yolk, soybean, bovine brain or Escherichia coli), microtiter plates (plain or gamma irradiated) and buffer components-fetal calf serum (FCS), adult bovine plasma (ABP), adult bovine serum (ABS) or bovine serum albumin (BSA). aPE binding was decreased with PE from E. coli while the other tested PE gave comparable results. The influence of the type of plates was restricted to IgM isotype with slightly, but significantly higher optical densities with plain than with irradiated plates. Most importantly, the component buffer had the highest impact on the results as shown by a strong decrease of the signal by ABP or ABS. This inhibitory effect was confirmed by using mixtures of FCS or BSA with increasing concentrations of ABS. Partial delipidation of ABS resulted in a recovery of OD levels close to those obtained with FCS. This study is the first to demonstrate that aPE reactivity is dependent on the lipid concentration of the buffer component. These results highlight the need for standardization of aPE-ELISA for a better understanding of their clinical significance. © 2010 Elsevier B.V. Source


Landelle C.,University of Lyon | Lepape A.,Center Hospitalier Of Lyon Sud | Voirin N.,University of Lyon | Tognet E.,Center Hospitalier Of Lyon Sud | And 4 more authors.
Intensive Care Medicine | Year: 2010

Purpose: Sepsisinduced immunosuppression is postulated to contribute to a heightened risk of nosocomial infection (NI). This prospective, single-center, observational study was conducted to assess whether low monocyte human leukocyte antigen-DR expression (mHLA-DR), proposed as a global biomarker of sepsis immunosuppression, was associated with an increased incidence of NI after septic shock. Methods: The study included 209 septic shock patients. mHLA-DR was measured by flow cytometry at days (D) 3-4 and 6-9 after the onset of shock. After septic shock, patients were screened daily for NI at four sites (microbiologically documented pulmonary, urinary tract, bloodstream, and catheter-related infections). A competing risk approach was used to evaluate the impact of low mHLA-DR on the incidence of NI. Results: At D3-4, we obtained measurements in 153 patients. Non-survivors (n = 51) exhibited lower mHLA-DR values expressed as means of fluorescence intensities than survivors (n = 102) (33 vs. 67; p<0.001). The patients who developed NI (n = 37) exhibited lower mHLA-DR values than those without NI (n = 116) (39 vs. 65; p = 0.008). mHLA-DR ≤ 54 remained independently associated with NI occurrence after adjustment for clinical parameters (gender, simplified acute physiology score II, sepsis-related organ failure assessment, intubation, and central venous catheterization) with an adjusted hazards ratio (aHR) of 2.52 (95% CI 1.20-5.30); p = 0.02. Similarly, at D6-9, low mHLA-DR (≤ 57) remained independently associated with NI with an aHR of 2.18 (95% CI 1.04-4.59); p = 0.04. Conclusions: In septic shock patients, after adjustment with usual clinical confounders (including ventilation and central venous catheterization), persistent low mHLA-DR expression remained independently associated with the development of secondary NI. © The Author(s) 2010. Source

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