Lymphoma-derived IL-10 prevents the burnout of CD8⁺ TILs and predicts responses to immune-checkpoint blockade. (A) Overall percentage of CD8 (from total CD3 lymphocytes), DCs, NK, and NKT (from total splenocytes) cells by flow cytometry in pBIC and pBIC^Δ10 tumors (t test). (B) Heat map (z scores) of chemokines involved in the attraction of CD8/NK/DCs cells (left) and MHC-I and -II antigen-presenting genes (right), derived from RNA-seq analysis of FACS-sorted lymphoma cells (B220⁺GFP⁺) from pBIC and pBIC^Δ10 tumors. (C) Dot plot based on scRNA-seq data showing scaled expression levels of pDC or cDC2 marker genes in the dendritic cell population infiltrating pBIC and pBIC^Δ10 tumors. (D) t-SNE distribution (left) and proportion of each DC subtype (from total DCs, right) detected by scRNA-seq in pBIC and pBIC^Δ10 tumors. (E) Bubble plot of CD8 TCR repertoire identified by scTCR-seq in the same pBIC and pBIC^Δ10 tumors submitted to scRNA-seq (supplemental Figure 4A). Each bubble represents a unique TCR clonotype, sized and colored according to cell count abundance (hits). Shannon index for evaluation of relative TCR diversity and Gini index for evaluation of TCR diversity are shown. (F) Scatterplot of cytotoxic and exhaustion programs within each CD8 clonotype from scTCR-seq showing a trend toward an exhaustion state in pBIC^Δ10 TCRα/β-CDR3 clonotypes. (G) Overall percentage of double-positive PD-1⁺LAG3⁺ CD8 T cells by flow cytometry (t test). (H) Proportion of CD8 cells with the highest expression of LAG3 or PD-1; and overall percentage of IFN-γ⁺ secretor cells by flow cytometry of pBIC and pBIC^Δ10 tumors (t test). (I) Proportion of Tcf1/Pd1 populations detected by scRNA-seq within the CD8⁺ T-cell compartment. (J) Overall percentage of TCF-1⁺ (int, intermediate, or high) by flow cytometry within pBIC and pBIC^Δ10 tumor-infiltrating CD8⁺ cells (ANOVA). (K) In vivo regime for αCD20 either in monotherapy or in combination with αPD-1; and associated survival curves from the time of treatment in pBIC and pBIC^Δ10 mice (log-rank test). ∗∗P < .01; ∗∗∗P < .001; d, days; hi, high; i.p., intraperitoneal; int, intermediate; ns, nonsignificant; wk, week.