Cell culture
PBMCs were obtained from human peripheral blood using Ficoll-Paque PLUS
(GE Healthcare, Sweden) density gradient centrifugation. Briefly, whole
blood was diluted with equal volume of phosphate-buffered saline (PBS)
and layered on top of Ficoll-Paque PLUS. After centrifugation, the PBMC
layer was collected and washed twice with PBS. The cells were then
resuspended in RPMI Medium Modified (Thermo Fisher Scientific, USA)
supplemented with 10% heat-inactivated fetal bovine serum (FBS) (Thermo
Fisher Scientific, USA) and 1% penicillin/streptomycin (Thermo Fisher
Scientific, USA). PBMCs were cultured in a humidified incubator at 37°C
with 5% CO2.