High PD-1 and PD-L1 expression is conserved in lesion-infiltrating CD8⁺ T cells and Cd11b⁺ DCs in BRAFV600E^CD11cmultisystem LCH mice. (A) viSNE plot of live cells from representative lesion biopsy specimens from lungs of BRAFV600E^CD11c and Cre^−/− littermate control mice. (B) Relative T-cell subtypes in lesion biopsy specimens from lung of BRAFV600E^CD11c mice depicted by FlowSOM analysis. (C) Expression of different immune checkpoint receptors on lung lesion-infiltrating CD8⁺ T cells was performed with FlowSOM analysis and visualized as pie charts. (D) Quantification of relative expression of immune checkpoint receptors in lesion-infiltrating CD8⁺ T cells in BRAFV600E^CD11c mice and Cre⁻/⁻ littermate control mice (n = 8 each). *P < .05; **P < .01; ns, not significant (P > .05), by WMW test. (E-F) Same as panels C and D, respectively, but for CD4⁺ T cells (n = 8 each). *P < .05; **P < .01; ns, not significant (P > .05), by the WMW test. (G) FlowSOM grid plots of CyTOF data of PD-L1 and PD-L2 expression on CD11C-gated cells.