Fig 2: NELFB overexpression promotes the tumor-killing capacity of CD8+ T cells.a Representative Western blots for NELFB and ACTIN in WT/Tg splenic CD8+ T cells. The experiments were independently repeated three times with similar results. b Scheme of competitive co-transfer assay. c Representative flow cytometry plot of TILs in the mice that received WT/KO CD8+ T cells. d Percentage of total TILs CD8+ cells in mice receiving WT/KO CD8+ T cells, n = 6/group. e Representative flow cytometry plot of TILs in mice receiving WT/Tg CD8+ T cells. f Percentage of total TILs CD8+ cells in mice receiving WT/Tg CD8+ T cells, n = 10/group. g–i E0771 tumor growth curve (g), weight (h), and image (i) in Rag1-/- mice receiving WT or Tg CD8+ T cells; WT (n = 6), Tg (n = 5). j–q TIL analysis for E0771 tumors in Rag1-/- mice receiving WT or Tg CD8+ T cells, n = 6/group. j CD45+ (% of total live cells), k CD8+ (% of CD45+), l effector memory CD44+CD62L- (% of CD8+), m Ki67+ (% of CD8+), n Median fluorescence intensity (MFI) of PD1, o IFNg+ (% of CD8+), p TNFa+ (% of CD8+), q polyfunctional IFN?+TNFa+ (% of CD8+). Data were presented as mean ± SEM; mean differences were compared using Student’s t-test. Tumor curves were compared using two-way ANOVA followed by multiple comparisons. Two-sided tests were used. Source data are provided as a Source Data file.

Fig 3: Nelfb is required for CD8+ T cell-intrinsic antitumor function.a, b Growth curves of E0771 (a) and AT-3 (b) tumors in Nelfbf/f and KO mice. c, d E0771 tumor weight (c) and image (d) upon harvest in Nelfbf/f and KO mice. e–h TIL analysis for E0771 tumors in Nelfbf/f and KO mice: e CD45+ (% of all live cells), f CD8+ (% of CD45+), g effector memory CD44+CD62L- (% of CD8+), h Ki67+ (% of CD8+), n = 5/group. i, j E0771 tumor growth curve (i) and weight (j) in Rag1-/- mice receiving Nelfbf/f or KO CD8+ T cells. k, l TIL analysis for E0771 tumors in Rag1-/- mice receiving Nelfbf/f or KO CD8+ T cells. k CD8+ (% of CD45+), l effector memory CD44+CD62L- (% of CD8+); n = 5/group. Data were presented as mean ± SEM; Student’s t-test (for two groups) or one-way-ANOVA (for three or more groups). Tumor curves were compared using two-way ANOVA followed by multiple comparisons. Two-sided tests were used. Source data are provided as a Source Data file.

Fig 4: Nelfb deletion in T cells impairs memory response to tumor antigen vaccination.a Scheme of vaccination procedure using OVA protein followed by E.G7-OVA tumor challenge. b Survival curve for E.G7-OVA tumor-bearing Nelfbf/f and KO mice with or without vaccination. c CD8+ percentages among E.G7-OVA tumor-infiltrating CD45+ cells; n = 4/group. d B16 tumor growth curve in Nelfbf/f and KO mice with or without vaccination; Nelfbf/f non-vac (n = 4), Nelfbf/f vac (n = 7), KO non-vac (n = 6), KO vac (n = 9); one-way-ANOVA for comparing mean differences. Tumor curves were compared using two-way ANOVA followed by multiple comparisons. Source data are provided as a Source Data file.

Fig 5: NELF-mediated Pol II pausing at cis-regulatory elements of TCF1 targets genes.a Enrichment analysis of NELFB ChIP-seq of WT CD8+ T cells. b NELFB binding signals at enhancer and TSS regions of TCF1 and non-TCF1 targets of WT CD8+ T cells. c Cumulative curve of a pausing index for TCF1 and non-TCF1 targets in Nelfbf/f and KO CD8+ T cells. Dashed vertical line denotes the maximum difference in vertical distance between two cumulative distributions. d Pol II signals at enhancer and TSS regions of TCF1 or non-TCF1 targets of Nelfbf/f and KO CD8+ T cells. The bounds of the box represent the 25th and 75th percentiles of the interquartile range. The black line in the box interior represents the median of the data. The whiskers represent the minimum and maximum values of the data and the black dot outside the box and the whiskers represent an outlier. Violin plots were assessed by a two-sided Wilcoxon rank-sum test with continuity correction. For Pol II ChIP-seq analyses, n = 2 biological replicates/group.