Ine [17], and early depletion of NK cells led to clear improvements

Ine [17], and early depletion of NK cells led to clear improvements in survival of sepsis-challenged mice [11?6]. Thus, one might expect NK cells to contribute to the amplification of the inflammatory response during the early steps of severe sepsis in humans too. The identification of over-activated NK cells during the early phase of severe sepsis and septic shock in critically-ill patients, mirroring what has been observed in animal models, could provide a unique opportunity to define NK cell-based immunotherapeutic interventions. However, available human data are scarce. Most studies are limited to quantitative assessment of NK cells [18?2] (Table S1). Studies have addressed NK-cell functionality in patients with septic shock, but have been limited to cytotoxic functions [23?5] and used samples obtained 7 days after ICU admission [25] or have included immunocompromised (i.e., cancer) patients [23]. Herein, we aimed to quantitatively and qualitatively characterize at ICU admission circulating NK cells of critically-ill septic patients.SIRS of non-infectious origin (referred to thereafter as “SIRS group”) (Methods S1). Immunological analyses were then performed for these patients (n = 42) on frozen samples. Range values defining NK cell subsets and functions in unmatched healthy controls (n = 21; age range 25?0 years) were used to define “normal” values. They were analyzed in the same technical as for ICU patients to avoid technical bias.Immunological AnalysesImmuno-phenotype of NK cells. NK 1662274 cells were defined as CD3 D56+ cells within the lymphocyte gate, and the various monoclonal antibodies (mAbs) were used to define human subsets of NK cells (Methods S1). NK-cell effector functions. NK-cell effector functions were tested in a single-cell assay using CD107 (LAMP) mobilization and IFN-c production, as previously described [27] (Methods S1). To directly assess NK-cell function, a flow cytometric cytotoxicity assay based on staining with carboxyfluorescein diacetate succinimidyl ester (CFSE) was used (Methods S1).Serum 23727046 CytokinesLevels of various cytokines in serum were determined. The immunoassays were performed following the manufacturer’s instructions (Methods S1).Statistical AnalysesComparisons between healthy, SIRS and Sepsis groups were carried out using the non-parametric Kruskal allis test for unpaired continuous data, and Pearson Chi-square test for categorical variables. Then, pairwise comparisons between 3 groups (healthy, SIRS, Sepsis) were carried out using the KruskalWallis post oc methods for multiple comparisons adjusted by step-up Simes method [28] (Methods S1). The Mann-Whitney U test was used when two groups were just compared. Correlations were assessed by the Spearman correlation test. Data were expressed as median [IQR] or as counts ( ), as required. A pvalue (two-tailed) threshold of 0.05 was considered statistically significant.Methods Study DesignThis prospective cohort study was conducted in the medical ICU of Assistance Publique – Hopitaux de Marseille University ^ ML 281 Hospital (France). The study was approved by the SudMediterranee V Ethics Committee and AZ 876 site written informed consent ??was obtained from all patients or, according to French law, from their proxies when patients were not able to understand. The study, which one goal was to evaluate NK cell status before cytomegalovirus reactivation during the ICU stay (Methods S1), included a factorial study that is presented herein. The principal aim was the quantit.Ine [17], and early depletion of NK cells led to clear improvements in survival of sepsis-challenged mice [11?6]. Thus, one might expect NK cells to contribute to the amplification of the inflammatory response during the early steps of severe sepsis in humans too. The identification of over-activated NK cells during the early phase of severe sepsis and septic shock in critically-ill patients, mirroring what has been observed in animal models, could provide a unique opportunity to define NK cell-based immunotherapeutic interventions. However, available human data are scarce. Most studies are limited to quantitative assessment of NK cells [18?2] (Table S1). Studies have addressed NK-cell functionality in patients with septic shock, but have been limited to cytotoxic functions [23?5] and used samples obtained 7 days after ICU admission [25] or have included immunocompromised (i.e., cancer) patients [23]. Herein, we aimed to quantitatively and qualitatively characterize at ICU admission circulating NK cells of critically-ill septic patients.SIRS of non-infectious origin (referred to thereafter as “SIRS group”) (Methods S1). Immunological analyses were then performed for these patients (n = 42) on frozen samples. Range values defining NK cell subsets and functions in unmatched healthy controls (n = 21; age range 25?0 years) were used to define “normal” values. They were analyzed in the same technical as for ICU patients to avoid technical bias.Immunological AnalysesImmuno-phenotype of NK cells. NK 1662274 cells were defined as CD3 D56+ cells within the lymphocyte gate, and the various monoclonal antibodies (mAbs) were used to define human subsets of NK cells (Methods S1). NK-cell effector functions. NK-cell effector functions were tested in a single-cell assay using CD107 (LAMP) mobilization and IFN-c production, as previously described [27] (Methods S1). To directly assess NK-cell function, a flow cytometric cytotoxicity assay based on staining with carboxyfluorescein diacetate succinimidyl ester (CFSE) was used (Methods S1).Serum 23727046 CytokinesLevels of various cytokines in serum were determined. The immunoassays were performed following the manufacturer’s instructions (Methods S1).Statistical AnalysesComparisons between healthy, SIRS and Sepsis groups were carried out using the non-parametric Kruskal allis test for unpaired continuous data, and Pearson Chi-square test for categorical variables. Then, pairwise comparisons between 3 groups (healthy, SIRS, Sepsis) were carried out using the KruskalWallis post oc methods for multiple comparisons adjusted by step-up Simes method [28] (Methods S1). The Mann-Whitney U test was used when two groups were just compared. Correlations were assessed by the Spearman correlation test. Data were expressed as median [IQR] or as counts ( ), as required. A pvalue (two-tailed) threshold of 0.05 was considered statistically significant.Methods Study DesignThis prospective cohort study was conducted in the medical ICU of Assistance Publique – Hopitaux de Marseille University ^ Hospital (France). The study was approved by the SudMediterranee V Ethics Committee and written informed consent ??was obtained from all patients or, according to French law, from their proxies when patients were not able to understand. The study, which one goal was to evaluate NK cell status before cytomegalovirus reactivation during the ICU stay (Methods S1), included a factorial study that is presented herein. The principal aim was the quantit.