PBMCs were quickly thawed at 37°C and resuspended in DMEM + 10% heat-inactivated FBS. 1 million cells were resuspended in 200 μl of 1x PBS, 2% FBS, and 1mM CaCl2, then the suspension was flowed through a 40 μm Flowmi cell strainer (Millipore Sigma BAH136800040), and dead cells were removed with the EasySep Dead Cell Removal Kit (Stemcell Technologies 17899). The samples were loaded onto a 10X Genomics Chromium chip. Reverse transcription and library preparation were performed with Chromium Single Cell 3ʹ Reagent Kits (v3.1). Library quality was assessed with a Bioanalyzer DNA chip, and the libraries were sequenced on one lane (S4 flowcell) of an Illumina NovaSeq 6000 sequencer.