Profiling of pp65 peptide-stimulated CD4 T cells. (A) Twelve patient PBMC samples were treated with pp65 peptide or control (no peptide). Representative sample shows results of pp65-stimulated samples compared with control with respect to TNF and IFN-γ staining as well as Granzyme B and CD107a staining. (B) The fraction of CD57⁺/CD27^– cells out of the TNF⁺/IFN-γ⁺ CD4⁺ subset as well as out of the GranB⁺/CD107a⁺ CD4⁺ subset is shown in a representative sample treated with pp65. (C) The fraction of CD57⁺/CD27^– cells out of bulk CD4⁺ subsets, TNF⁺/IFNγ⁺ CD4⁺ subsets, and GranB⁺/CD107a⁺ CD4⁺ subsets show a higher percentage of CD57⁺/CD27^– cells in the latter groups compared with the former (P < .0001, both groups). (D) Profiling of CD4⁺ T cells in a patient carrying class II allele HLA-DRB1*0701 with respect to CMV-specific peptide. CD4⁺ T cells in a patient carrying the class II HLA-DRB1*0701 allele profiled with tetramer HLA-DRB1*0701 loaded with the DYS peptide. (E) The same patient in panel D profiled with tetramer HLA-DRB1*0701 loaded with the irrelevant CLIP peptide. Statistical significance is denoted by ****P < .0001.