Fig. 6: CMV-reactive CD4⁺ T cells are enriched in patients with CD4⁺ T_EM cell expansion.

CMV-reactive CD4⁺ T cells in patients with unresectable metastatic melanoma were assayed by in vitro stimulation with CMV lysates (blue boxes). Neutralising antibodies (red hatching) were used to detect T cells unable to respond to CMV antigens owing to expression of PD-1 or CTLA-4. T cell responses were quantified by flow cytometry analysis of cytokine expression. a Example data from a CMV IgG⁺ CD4⁺ T_EM^≥16% patient who developed hepatitis. Gating of live, singlet, IFN-γ-producing CD4⁺ T cells is illustrated in Supplementary Fig. 11. b Frequencies of IFN-γ-producing CD4⁺ T cells in patients categorised according to CMV IgG serostatus and baseline CD4⁺ T_EM frequency (n = 42; two-way ANOVA with Tukey correction for multiple comparisons; n.s. = not significant). Boxplots represent the median, 25th and 75th percentiles, and Tukey whiskers. c Absolute numbers of circulating IFN-γ-producing CD4⁺ T cells patients categorised according to CMV IgG serostatus and baseline CD4⁺ T_EM frequency (n = 42; two-way ANOVA with Tukey correction for multiple comparisons; n.s. = not significant). Boxplots represent the median, 25th and 75th percentiles, and Tukey whiskers.