Approximately 30,000 CD44low naïve CD8+ T cells per replicate from LNs were sorted by FACS into PBS containing 10% FBS in DNA loBind Eppendorf tubes. Pelleted cells were lysed in 50 μl of reaction mix (25 μl of 2 x TD, 2.5 μl of Tn5 enzyme, 0.25 μl of 2% digitonin, 22.25 μl of nuclease-free water). The mix was incubated at 37°C for 30 minutes with agitation at 300 rpm. DNA was purified using a QIAgen MinElute Reaction Cleanup kit and Nextera sequencing primers ligated using PCR amplification. Agencourt AMPure XP bead cleanup (Beckman Coulter/Agencourt) was used post-PCR and library quality was verified using a Tapestation machine.