Engraftment and expansion of TK⁺ lymphocytes in NOD/Scid mice that received a transplant of allogeneic human skin. NOD/Scid mice received a transplant of human skin (day 0), and were conditioned with anti-NK antibodies (day 10) and sublethal irradiation (day 11) prior to the intravenous infusion of TK⁺ lymphocytes or PBLs (day 11). TK⁺ lymphocytes infused to mice were transduced with optimized Mut2-SFCMM3 vector, enabling a transduction efficiency higher than 30% in all conditions. (A) Kinetics of human chimerism calculated as [% of circulating human CD3⁺ lymphocytes]/[(% of circulating murine CD45⁺ cells) + (% of circulating human CD3⁺ lymphocytes)] are shown. baCD3/CD28⁺ IL-7/IL-15 (■), baCD3/CD28⁺ IL-7 (), baCD3/CD28⁺ IL-2 (), aCD3⁺ IL-2 (□), or PBLs (). Medians of 8 independent experiments with 13 different donor cells are shown. *P < .05; **P < .01. WBC indicates white blood cells. (B) At weeks 1 and 2 after lymphocyte infusion, CD4/CD8 ratio was analyzed on circulating human CD3 lymphocytes. baCD3/CD28⁺ IL-7/IL-15 (■), baCD3/CD28⁺ IL-7 (), baCD3/CD28⁺ IL-2 (), aCD3⁺ IL-2 (□), or PBLs (). Averages plus or minus SD of 6 independent experiments with 11 different donor cells are shown. *P < .05. (C) At weeks 1 and 2 after lymphocyte infusion, human CD3⁺ lymphocytes were analyzed by flow cytometry for CD45RA and CD62L expression. Percentages of circulating human T_CM (CD45RA⁻CD62L⁺) and T_EM (CD45RA⁻CD62L⁻) T lymphocytes were measured in mice that received a transplant of baCD3/CD28⁺ IL-7/IL-15 TK⁺ lymphocytes (♦), baCD3/CD28⁺ IL-7 TK⁺ lymphocytes (), baCD3/CD28⁺ IL-2 TK⁺ lymphocytes (light gray triangle), aCD3⁺ IL-2 TK⁺ lymphocytes (white square with broken line), or PBLs (X with dotted line). Medians of 8 independent experiments with 13 different donors are shown. *P < .05; **P < .01. Asterisks on aCD3⁺ IL-2 indicate significant differences versus all the other samples. (D) At weeks 1 and 2 after lymphocyte infusion, IL-7Rα expression was assessed on circulating human CD3⁺ lymphocytes. Percentages CD3⁺ IL-7Rα⁺ T lymphocytes on animals infused with baCD3/CD28⁺ IL-7/IL-15 TK⁺ lymphocytes (♦), baCD3/CD28⁺ IL-7 TK⁺ lymphocytes (), baCD3/CD28⁺ IL-2 TK⁺ lymphocytes (light gray triangle), aCD3⁺ IL-2 TK⁺ lymphocytes (white square with broken line), or PBLs (X with dotted line) were measured. Medians of 8 experiments with 13 independent donors are shown. *P < .05; **P < .01 versus aCD3⁺ IL-2.