Percp cy5.5 anti mouse cd4

BV650 rat anti-mouse CD45 #563410 (BD Horizon), APC rat anti-mouse CD8a #553035, PE anti-mouse CD152 (CTLA-4) # 553720 (BD Pharmingen), Alexa Fluor 700 anti-mouse NK1.1 #56-5941-82, eFluor450 anti-mouse CD279 (PD-1) #48-9985-82, PerCP-Cy5.5 anti-mouse CD4 #45-0042-80 (Invitrogen).

Intracellular cytokine staining was performed on splenocytes harvested from BALB/c and C57BL/6 mice stimulated with the overlapping peptides spanning the SARS-CoV-2 S protein for 6 h at 37 °C, 5% CO₂. Cells were stained with the following antibodies from BD Biosciences, unless stated, with the dilutions stated in parentheses: FITC anti-mouse CD107a (1:100), PerCP-Cy5.5 anti-mouse CD4 (1:100), APC anti-mouse CD8a (1:100), ViViD Dye (1–40) (LIVE/DEAD® Fixable Violet Dead Cell Stain kit; Invitrogen, L34955), APC-Cy7 anti-mouse CD3e (1:100), and BV605 anti-mouse IFN-γ (1:75) (eBiosciences). Phorbol Myristate Acetate (PMA) were used as a positive control, and complete medium only as the negative control. Cells were washed, fixed and, cell events were acquired using an FACS CANTO (BD Biosciences), followed by FlowJo software (FlowJo LLC, Ashland, OR) analysis.