2.11. Splenocyte proliferation assay
Spleen cells (2×106 cells) from the immunized mice
were seeded in the tissue culture plates (Corning, USA) and stimulated
with ORF8 (10 μg/mL) at 37 °C with 5% (v/v) CO2 for 60
h. Cells were stimulated with 1 μg ConA/mL, which served as a positive
control. Cells were stimulated with medium alone, which acted as a
negative control. Proliferation was determined by CCK-8 vital stain
(Dojindo Laboratories, USA). The proliferation index (PI) was calculated
as the ratio of the average OD450 value of the
ORF8-stimulated cells to the one of the medium-stimulated cells.