library_construction_protocol: DAPI⁻, TCRβ⁺, CD8α⁻, CD4⁺, CD62L⁻, CD44⁺ activated CD4⁺ T cells were sorted using a MoFlo Astrios (Beckman) at the Flow Cytometry Core in the UIC Research Resources Center (RRC). Sorted cells were pelleted and lysed in RLT buffer (QIAGEN, 79216) supplemented with 1% β-mercaptoethanol (VWR Chemicals, M131) and immediately stored at -80 oC. Total RNA was extracted using Dynabeads MyOne Silane (Thermo Fisher Scientific, 37002D) with on-bead DNase I treatment (Thermo Fisher Scientific, AM2239) at 37 °C for 20 min to remove genomic DNA. After sequential washes with 80% ethanol, RNA was eluted. RNA quality was confirmed using a Tapestation 4200 (Agilent Technologies). Reverse transcription, TCR amplification and library preparation were performed using the SMART-seq Mouse TCR kit w/ UMIs (Takara, 634815) according to the manufacturer's instructions.