Single-cell suspensions were counted, lysed with TRIzol (15596018CN, Thermofisher-Invitrogen), and total RNA was extracted. 800 ng RNA was used for template switch with Superscript II (18064014, Thermofisher-Invitrogen) with a template switch oligo (TSO). TCR amplification was performed using a universal forward primer and Trac or Trbc-specific reverse primers. PCR products (300–700 bp) were gel-purified. Libraries were prepared with the VAHTS Universal DNA Library Prep Kit for Illumina V3 (Vazyme, ND607-01) and sequenced (2×150 bp paired-end) on the Illumina Novaseq XPlus platform.