Circulating γδ T cells in patients experiencing CMV reactivation. (A) Vδ1 and Vδ2 subsets (percentages are indicated) were identified in gated CD45⁺CD3⁺γδ⁺ cells by flow cytometry using PBMCs from 2 representative cases, evaluating both donors and patients 1, 3, and 6 months post-HSCT. Patient 7 did experience CMV reactivation, whereas patient 2 did not. (B) Comparative analysis of Vδ1 (left panel) and Vδ2 (right panel) T cells was performed in patients who did experience CMV reactivation (white plots) and in those who did not (gray plots). Vδ1 and Vδ2 cells were identified in gated CD45⁺CD3⁺γδ⁺ cells. (C) Intranuclear expression of Ki-67 (filled profiles) shows proliferating status in CD45⁺CD3⁺γδ⁺, CD45⁺CD3⁺γδ⁺Vδ1⁺, and CD45⁺CD3⁺γδ⁺Vδ2⁺ cells. Empty profiles represent staining with isotype control. (D) Percentage of naïve, CM, EM, and TD was evaluated by flow cytometry in gated CD45⁺CD3⁺γδ⁺Vδ1⁺ T cells collected from patients who did experience CMV reactivation (white plots) and in those who did not (gray plots) 3 months after HSCT. Pooled results are shown. Whisker lines represent the highest and lowest values; horizontal lines represent median values.