Immunologic reconstitution after Treg-based transplantation. (A) Reconstitution of pathogen-specific T-cell responses. Right panels: posttransplantation frequencies of CD4⁺ and CD8⁺ pathogen-specific T-cell clones in Treg-haploidentical transplantation versus standard haploidentical transplantation (left panels). Sample numbers were at least 3 for each time point. CD4⁺ pathogen-specific T-cell clones in the Treg haploidentical transplantation group at month +1 (ASP = 2.6 ± 1.2; CAND = 5.3 ± 2.1; CMV = 115 ± 61; ADV = 156 ± 78; HSV = 32 ± 4; TOXO = 65 ± 26; VZV = 48 ± 34); at months +3 (ASP = 37.5 ± 34; CAND = 69.5 ± 42; CMV = 68 ± 48; ADV = 422 ± 333; HSV = 79 ± 16; TOXO = 170 ± 57; VZV = 48 ± 34); at months +6 (ASP = 91.6 ± 29; CAND = 133 ± 91; CMV = 259 ± 245; ADV = 303 ± 216; HSV = 137 ± 90; TOXO = 263 ± 156; VZV = 337 ± 280); at months +12 (ASP = 210.5 ± 190.2; CAND = 139 ± 104; CMV = 359 ± 288; ADV = 160 ± 103; HSV = 222 ± 173; TOXO = 277 ± 218; VZV = 155 ± 111) (P < .0001 compared with standard haploidentical transplantations at each time point). CD8⁺ pathogen-specific T-cell clones in the Treg-haploidentical transplantation group at month +1 (CMV = 1.2 ± 3; ADV = 0; HSV = 1.5 ± 1; TOXO = 3 ± 0.4; VZV = 2 ± 2); at month +3 (CMV = 4.4 ± 3.5; ADV = 0; HSV = 1.6 ± 1.5; TOXO = 1.5 ± 1.2; VZV = 4.2 ± 4); at month +6 (CMV = 4.3 ± 2.3; ADV = 4 ± 3.4; HSV = 4.8 ± 4.5; TOXO = 3.6 ± 2; VZV = 4.2 ± 4.1); at month +12 (CMV = 11 ± 1; ADV = 11 ± 1; HSV = 9 ± 2; TOXO = 10.3 ± 1.5; VZV = 11 ± 1) (P < .0001 compared with standard haploidentical transplantations at each time point). (B) Episodes of CMV reactivation are significantly lower (P < .05) after “haplo with Tregs” (right panel) compared with “standard haplo” (left panel) transplantations.