Igg1 pe

For the identification of CD4⁺ Th cell subsets and CD8⁺ Tc cells, we used cytoplasmic cytokine staining method. Briefly, whole blood were diluted to 1:1 with saline solution and incubated with phorbol-12-myristate 13-acetate (PMA) (25 ng/ml), ionomycin (1 μg/ml) and Golgi Stop brefeldin A (10 μg/ml) (all from Sigma Aldrich, St. Louis, Missouri, USA) for 5 h at 37°C in 5% CO₂ milieu. The following monoclonal antibodies were used for cell surface staining: CD4-PE-Cy5 or CD8-PE-Cy5 (both from Beckman Coulter). The cells were then fixed and permeabilized with Intraprep™ permeabilization reagent (Beckman Coulter) according to the manufacturer’s instructions, and intracellular cytokines were stained with the combination of interferon (IFN)-γ-FITC, interleukin (IL)-4-PE, IL-10-PE (all from BD Biosciences) and IL-17-PE (R&D Systems, Minneapolis, MN, USA) monoclonal antibodies. Measurements were performed and data were analyzed on Coulter FC500 flow cytometer (Beckman Coulter) equipped with Kaluza 1.2a software. IgG1-FITC (BD Biosciences) and IgG1-PE (R&D Systems) isotype-matched antibodies were used during the identification. Cells were quantified as their percentage in the CD4⁺ or CD8⁺ lymphocyte population.