TGF-β–dependent resident program in exhausted CD8 ⁺ T cells during chronic viral infection. (A) Experimental setup for B. Briefly, naive P14 isolated from WT and Tgfbr2^−/− mice were co-transferred into B6 recipients followed by LCMV Cl13 infection. Daily injection of FTY720 was started 10 d later. (B) The percentage of Tcf-1⁺ cells was determined on day 22 after infection by flow cytometry. Each pair of symbols in B represents the results from an individual recipient. Pooled results from three independent experiments are shown (n = 15). *, P < 0.05; **, P < 0.01; and ****, P < 0.0001 by Student’s t test. (C and D) Similar experimental setup as in Fig. 1 A. Day 15 after infection, different subsets of control and Tgfbr2^−/− P14 T cells were FACS sorted from pooled spleen and lymph nodes and subjected to bulk RNA-seq analysis. Gene set enrich analysis for core circulating memory T cells gene signature (C) and core resident memory T cell gene signature (D) are shown. For C and D, each group contain biological independent duplicates.