Single-cell transcriptomic sequencing of BCMA CAR-T cells during CAR-T therapy in refractory primary plasma cell leukemia

Chimeric antigen receptor T-cell (CAR-T) therapy has revolutionized the clinical treatment of hematological malignancies due to the prominent anti-tumor effects. B-cell maturation antigen (BCMA) CAR-T cells have demonstrated promising effects in patients with relapsed/refractory multiple myeloma. However, the dynamics of CAR-T cell proliferation and cytotoxicity in a patient remains largely unexplored. Single-cell RNA sequencing samples were collected at three phases: CAR-T products before infusion, CAR-T on day 8 after infusion, and CAR-T on day 15 after infusion. After obtaining the PBMCs for each phase, CAR-T and endogenous T cells were collected by fluorescence-activated cell sorting with anti-Mouse IgG Biotin, FITC Streptavidin, and anti-human CD3 APC. Overall design: ScRNA-seq libraries were generated from the 10X Chromium Single Cell 3 Reagent Kits v2 (PN-120237) according to the manufacturer's protocol (10x Genomics). Libraries were sequenced on the Illumina Hiseq X10 platform according to the manufacturer's instructions (Illumina). Read 1 and Read 2 (paired end) were 150 bp, and the index primer was 8 bp.