library_construction_protocol: Mice were culled using 100 Î¼l intraperitoneal pentobarbitone (20 mg dose, Pentoject, Animalcare Ltd. UK) and lymph node tissues were collected as previously described RNA was extracted by the Trizol method after tissue disruption using a TissueLyzer (Qiagen). RNA concentrations were determined using a Nanodrop (ThermoFisher) before sending for sequencing to Imperial BRC Genomics Facility sequencing facility. RNA quality check and library preparation was performed by Imperial College London using the Illumina PE150 at a target depth of 50 million 100-150 base pair (bp)  end reads per sample.