Uded from the analysis.23?3 years) were run as an independent cohort following the same experimental steps described for the principal study cohort.Results Flow Cytometry antibody cocktail and lyoplate designOur goal was to assess the performance of a lyoplate-based flow cytometry platform (LFP) versus a conventional (liquid) flow cytometry platform (CFP) using a panel of 12 parameters (nine markers + one viability dye + FSC-A and SSC-A), including surface markers (CD3, CD4, CD8, CD45RO, and CD25) and intracellular markers (IFN-c, IL-10, IL-17A, and Foxp3) focussing on the investigation of T cell subsets [T helper (Th) 1, Th17, T regulatory cells (T regs) and CD8+ T cells]. For induction of cytokine production, experiments were performed in the presence and absence of a polyclonal stimulation. Antibody panel (Fig. S1A) was chosen after testing different antibody-fluorochrome combinations, maximizing antigen detection and minimizing major spectral overlaps between fluorochromes using FMO controls (data not shown). Lyoplate layout (Fig. S1B) was designed leaving empty wells between different samples and stimulation conditions to avoid cross contamination.Data analysis and statisticsManual flow cytometry data analysis was done with FlowJo (TreeStar) or FACSDiva (BD Biosciences). Specific cell frequencies obtained from each donor were averaged by experimental triplicates and the agreement between the frequencies obtained with the two experimental methods was assessed using the BlandAltman 95 limits of agreement. Systematic differences between the frequencies from the two methods were analysed using the paired two-tailed t test, or the Wilcoxon signed rank test if indicated by a normality test (D’Agostino Pearson ominibus normality test). Analysis were performed using GraphPad Prism version 5. As many statistical tests were carried out, the p,0.05 threshold was corrected for multiple testing: we referred to a Bonferroni-corrected p-value significance threshold of 0.05/ 24 = 0.002. P-values that are smaller than 0.05 but larger than 0.002 may be due to chance and do not infer the same strength of evidence as they would if a single test was carried out. The stain index (SI) was calculated according to the formula SI = D/W, where D = difference between the medians of the positive and negative populations and W = spread (26rSD) of the negative population [20].Lyoplate based flow cytometry has higher sensitivity for IFN-c and IL-10 detection than conventional 23727046 flow cytometryTo quantitatively compare conventional and lyoplate-based flow cytometry platform (CFP and LFP respectively), peripheral blood mononuclear cells (PBMC) from healthy donors were Title Loaded From File stimulated and stained in parallel using liquid and lyophilized reagents (Fig. S1C). CFP and LFP 4EGI-1 biological activity derived bi-dimensional dot plots were similar (Fig. S2). Cell frequencies of the main T cell subsets and cytokine producing cells obtained by CFP and LFP were compared (Fig. 1). Both techniques showed comparable results for the detection of CD4+ T cells, CD8+ T cells, memory CD4+ T cells (identified as live CD3+CD4+CD45RO+ cells), memory CD8+ T cells (identified as live CD3+CD8+CD45RO+ cells), and Tregs (identified as live CD3+CD4+CD25highFoxp3+ cells), as shown by the small bias and relatively narrow 95 limits of agreement in the Bland-Altman plot (Fig. 1A). PBMC were stimulated with Phorbol 12-myristate 13acetate (PMA)/Ionomycin and cytokine (IFN-c, IL-10 and IL-17A) production assessed in memory CD4+ a.Uded from the analysis.23?3 years) were run as an independent cohort following the same experimental steps described for the principal study cohort.Results Flow Cytometry antibody cocktail and lyoplate designOur goal was to assess the performance of a lyoplate-based flow cytometry platform (LFP) versus a conventional (liquid) flow cytometry platform (CFP) using a panel of 12 parameters (nine markers + one viability dye + FSC-A and SSC-A), including surface markers (CD3, CD4, CD8, CD45RO, and CD25) and intracellular markers (IFN-c, IL-10, IL-17A, and Foxp3) focussing on the investigation of T cell subsets [T helper (Th) 1, Th17, T regulatory cells (T regs) and CD8+ T cells]. For induction of cytokine production, experiments were performed in the presence and absence of a polyclonal stimulation. Antibody panel (Fig. S1A) was chosen after testing different antibody-fluorochrome combinations, maximizing antigen detection and minimizing major spectral overlaps between fluorochromes using FMO controls (data not shown). Lyoplate layout (Fig. S1B) was designed leaving empty wells between different samples and stimulation conditions to avoid cross contamination.Data analysis and statisticsManual flow cytometry data analysis was done with FlowJo (TreeStar) or FACSDiva (BD Biosciences). Specific cell frequencies obtained from each donor were averaged by experimental triplicates and the agreement between the frequencies obtained with the two experimental methods was assessed using the BlandAltman 95 limits of agreement. Systematic differences between the frequencies from the two methods were analysed using the paired two-tailed t test, or the Wilcoxon signed rank test if indicated by a normality test (D’Agostino Pearson ominibus normality test). Analysis were performed using GraphPad Prism version 5. As many statistical tests were carried out, the p,0.05 threshold was corrected for multiple testing: we referred to a Bonferroni-corrected p-value significance threshold of 0.05/ 24 = 0.002. P-values that are smaller than 0.05 but larger than 0.002 may be due to chance and do not infer the same strength of evidence as they would if a single test was carried out. The stain index (SI) was calculated according to the formula SI = D/W, where D = difference between the medians of the positive and negative populations and W = spread (26rSD) of the negative population [20].Lyoplate based flow cytometry has higher sensitivity for IFN-c and IL-10 detection than conventional 23727046 flow cytometryTo quantitatively compare conventional and lyoplate-based flow cytometry platform (CFP and LFP respectively), peripheral blood mononuclear cells (PBMC) from healthy donors were stimulated and stained in parallel using liquid and lyophilized reagents (Fig. S1C). CFP and LFP derived bi-dimensional dot plots were similar (Fig. S2). Cell frequencies of the main T cell subsets and cytokine producing cells obtained by CFP and LFP were compared (Fig. 1). Both techniques showed comparable results for the detection of CD4+ T cells, CD8+ T cells, memory CD4+ T cells (identified as live CD3+CD4+CD45RO+ cells), memory CD8+ T cells (identified as live CD3+CD8+CD45RO+ cells), and Tregs (identified as live CD3+CD4+CD25highFoxp3+ cells), as shown by the small bias and relatively narrow 95 limits of agreement in the Bland-Altman plot (Fig. 1A). PBMC were stimulated with Phorbol 12-myristate 13acetate (PMA)/Ionomycin and cytokine (IFN-c, IL-10 and IL-17A) production assessed in memory CD4+ a.
