Cells and cell culture

Peripheral blood (10 mL) samples were collected from lung cancer patients. Peripheral blood mononuclear cells (PBMCs) were separated from the samples using PBMC isolation solution (Shanghai Solarbio Bioscience and Technology Co., Ltd., Shanghai, China). PBMCs were counted, separated by centrifugal precipitation, suspended in PBS buffer containing 0.5% bull serum albumin (BSA) (Solarbio), and incubated with CD14-conjugated magnetic beads (Miltenyi Biotec, Auburn, CA, USA) at 2–8 °C for 15 minutes, followed by resuspension and centrifugation. After being washed 3 times, the peritoneal cell-derived mast cells (PCMCs) were eluted, collected, and then incubated in Iscove’s Modified Dulbecco’s Medium (IMDM, pH 7.2–7.4; GIBCO-BRL, Grand Island, NY, USA) supplemented with 10% fetal bovine serum (FBS) and 100 U/mL penicillin-streptomycin at 37 °C with 5% CO₂. Human embryonic kidney (HEK) 293 cells harboring the adenovirus E1A region, human lung epithelial cells (BEAS-2B), and human lung carcinoma cell lines A549 and NCI-H1650 were obtained from American Type Culture Collection (ATCC; Rockville, MD, USA) and maintained in Dulbecco’s modified Eagle’s medium (DMEM; GIBCO-BRL) or Roswell Park Memorial Institute (RPMI) 1640 medium (GIBCO-BRL) containing 5% FBS at 37 °C with 5% CO₂.