Fig. 3. CD4+ effector T cells and innate immune stimulation promote the recruitment and IFN-dependent activation of monocytes to eradicate established tumours.
a, Experimental protocol for scRNA-seq analyses of tumour-infiltrating CD11b+ Ly6G− cells. b, Visualization and dimensionality reduction of single-cell transcriptomes from CD4 ACT-treated and non-treated (NT) mice using UMAP. c,d, UMAP plots with cell types assigned using SingleR (c) and z-score for the hallmark IFN gamma response gene set (MSigDB) of each cell (d). e, RNA velocity projected on UMAP plots for monocytes and macrophages (Mono–macs) of CD4 ACT-treated tumours. Arrows point towards the predicted course of cell maturation dynamics. Arrow sizes indicate the strength of predicted directionality. f, Immune cell composition of HCmel12 tumours treated as indicated (mean ± s.e.m. from n = 6 biologically independent samples). g,j, Experimental treatment protocol to investigate the impact of innate stimuli (g) or IFNγ-blockade (j) on myeloid cell activation and tumour control. h,k, Percentage of intratumoural iNOS+ mono–macs and neutrophils (mean ± s.e.m. from n = 5–7 biologically independent samples). h, ****P < 0.0001, *P = 0.0111, ***P = 0.0005; k, ****P < 0.0001, ***P = 0.0002). i,l, Kaplan–Meier survival curves of mice bearing established HCmel12 CRISPR-ctrl tumours, treated as indicated (i, ****P < 0.0001; l, **P = 0.0053). Means between groups were statistically compared using a one-way ANOVA with Tukey post hoc. Survival was statistically compared using log-rank Mantel–Cox test. NT, non-treated; C, cyclophosphamide; V, Ad-PT; T, TCRtg TRP-1 CD4+ T cells; I, innate stimuli, polyI:C and CpG; CR, complete responders.