Anti cd8 phycoerythrin

Samples of EDTA anticoagulated peripheral blood (2 mL) were collected from patients with the Delta variant on admission. All the samples were tested within 6 h. Briefly, CD3+/CD4+/CD8 + T-cell, CD19 + B-cell, and CD16 + CD56 + NK-cell counts (cells/µL) were measured by multiple-color flow cytometry with human monoclonal anti-CD3-fluorescein isothiocyanate (FITC), anti-CD8-phycoerythrin (PE), anti-CD45-PerCP, anti-CD4-allophycocyanin (APC), anti-CD16-PE, anti-CD56-PE, and anti-CD19-APC antibodies (BD Multitest) according to the manufacturer’s instructions. The cells were analyzed on a BriCyte E6 flow cytometry system (Mindray).

PBMCs were stimulated with phorbol myristate acetate (50 ng/mL) and ionomycin (1 µg/mL) in the presence of brefeldin A (10 µg/mL) for 6 h. Cells were stained with anti-CD3-fluorescein isothiocyanate (BD Pharmingen, San Jose, CA, USA; Clone UCHT1), anti-CD4–peridinin–chlorophyll–protein complex (BD Pharmingen, San Jose, CA, USA; Clone SK3), anti-CD8–phycoerythrin (BD Pharmingen, San Jose, CA, USA; Clone HIT8α) for 30 min in the dark at 4 ^∘C. Cells were then fixed and permeabilized using BD Cytofix/Cytoperm Fixation/Permeabilization (BD Biosciences, San Jose, CA, USA) and stained with anti-IL-9–allophycocyanin (R&D Systems, Minneapolis, MN, USA; Clone #623153). Flow cytometric analysis was performed using a BD LSR II System (BD Biosciences, San Jose, CA, USA).