Fig. 4: MCT-induced CXCL16 mediates intratumoral immune dynamics and ICB efficacy.

a Volcano plot shows genes expressed differentially between Cluster 0 and DC clusters. b Violin plots show the expression of CXCL16, IFN-γr1, and IFN-γr2 by the DC clusters. c Schematic shows the intratumoral IgG or CXCL16 neutralizing antibody (NAb) injection into CD45.1⁺ cell adoptive transfer recipients treated with either PBS or MCT. d, e Box plots show the infiltration of CXCL16⁺ CD45.1⁺ cells, CD11b^highPD-L1^high, c-KIT⁺LIN⁻, and CD11c^highI-A-I-E^high cells in PBS and MCT-treated tumors upon CXCL16 NAb injection. f Box plots show changes in CD4⁺, PD-1^high CD4⁺, CD8a⁺, and PD-1^high CD8a⁺ T cells in PBS and MCT-treated tumors upon CXCL16 NAb injection. Box plots quantify PD-1⁺CD8a⁺ cells among the CD3⁺ CD45.1⁺ cells in MCT + IgG treated blood, lymph node, and tumor (g), in MCT + CXCL16 NAb treated blood, lymph node, and tumor (h). i Schematic shows combinatorial treatment with anti-PD-1 antibody and CXCL16 NAb in C3-1-TAg mice. j Histograms (left) show CXCL16⁺ CD45⁺ cell frequency and box plot (right) quantify CXCL16⁺ CD45⁺ cells in different treatment conditions. Box plots quantify (k) the tumor burden on Day 28 relative to Day 14, l CD4 and CD8a T cells associated with tumors, and m CD11c^high I-A-I-E^high, CD11b^high PD-L1^high, and Cluster 0 cells in different treatment conditions. In (b) violin plot, error bar = Mean ± SEM, center = Means (Diamonds) (A-B, n = 3 biological replicates). d–m In box plots, n = 3 to 5 biological replicates, error bar = Mean ± SEM, center = Means (Diamonds) and Medians (Line), bottom and top boundaries of the box = 25 and 75th percentiles of the data, (whiskers) minima and maxima =  lowest and highest data points, and two-sided T-test p-values. Also see associated Fig. S4.