Enrichment for CMV-specific CD4⁺ T cells following repetitive stimulation with CMV antigen.

CMV protein–specific CD4⁺ T cells generated by repetitive stimulation with CMV antigen were analyzed by intracellular IFN-γ staining by flow cytometry after stimulation with CMV antigen (representative example of a T-cell line analyzed after 2 stimulations) (A, day 0; B, day 14).