Fig. 1: PSR is triggered in T_ex cells with a dynamic expression of chaperone proteins.

a, Schematic of the experiment to isolate mouse splenic LCMV antigen-specific CD8⁺ T cell subpopulations in LCMV acute (Armstrong (Arm)) and chronic (clone 13 (Cl13)) infection models. b, Heatmap of expression levels of proteins belonging to 11 T cell signatures across 9 groups (n = 3–4, representing pooled 5–15 mice per replicate). D, day. c, Heatmap of the expression profiles of 5,284 proteins quantified in naive T cells, acutely activated T cells (T_eff) and chronically activated T cells (T_ex) at 2, 4, 6 and 8 days after initial activation, as described in Extended Data Fig. 1a, with k-means clustering identifying 8 distinct expression patterns (n = 4, each replicate was pooled from 3 mice). d, Enrichment analysis of proteins from cluster 6 defined in c (one-sided Fisher’s exact test with Benjamini–Hochberg correction). e, Heatmap of expression levels of proteins belonging to 12 gene ontology terms. f, Schematic of MS-based proteomic analysis of CD8⁺ T cells in different exhaustion states from the MC38 colon cancer mouse model and the MB49 bladder tumour mouse model. s.c., subcutaneous. g, Principal component analysis plots of proteomes of T_prog, T_int and T_tex cells (n = 3, each biological replicate was pooled from 12–13 mice). h, Heatmap of protein expression across eight gene ontologies in three CD8⁺ T cell subpopulations from MC38 and MB49 tumour models. i, Bubble plot of the expression levels of protein-folding chaperones in naive, T_eff and T_ex CD8⁺ T cells generated in vitro as described in Extended Data Fig. 1a. The bubble colour intensity is proportional to the protein expression level. The bubble size is proportional to the absolute z score value. j, Heatmap of the expression levels of chaperone proteins (defined in i) in three CD8⁺ T cell subpopulations from MC38 and MB49 tumours. The diagrams in a and f were created using BioRender (https://www.biorender.com).