Quantifying B Cell Subpopulations

All fresh samples were transported at 4°C. Peripheral blood samples were mixed with an equal volume of 0.9% NaCl and centrifuged at 800g for 20 min using a Lymphoprep separation solution (Axis-Shield, Norway) to obtain peripheral blood mononuclear cells. The next steps were performed using previously published protocols (25 (link)). Briefly, B cells were labeled with various antibodies [NR1-FITC, OriGene; anti-CD19-percp/Cy5.5, Biolegend; LGI1-green fluorescent protein (GFP), our lab] and 4′,6-diamidino-2-phenylindole for sorting and counting. FlowJo software (version 10.7) was used for quantitative analysis of the flow cytometry, and the numbers of NR1-positive and LGI-positive B cells were calculated in 100,000 peripheral blood mononuclear cells from each sample.