Preparation of PBMCs
BLOOD
Blood samples were collected at 0, 1, and 2 years after SLIT. Lymphoprep (Fresenius Kabi Norge AS, Oslo, Norway) was used for the preparation of PBMCs. The standard operation was performed according to the manufacturer’s instructions. The sorted cells were divided into two parts: one part (PBMCs from all samples at 0, 1, and 2 years after SLIT) was prepared for flow cytometry directly; the other part (PBMC from all samples at 2 years after SLIT) was used for the intervention trial.