Phenotypic and functional characterization of T-cell clones. (A) Relative mRNA expression of ADA in T-cell clones. Expression was measured with the microfluidic card in UT clones from patient 2 (gray dots), clones from healthy donors (black dots), clones carrying up-regulating (red dots) or down-regulating (green dots) RIS, clones with 2 vector copy/cell (white dots) and 1 vector copy/cell (box and whiskers). (B) ADA protein expression. Expression was determined by intracytoplasmic staining as described in “Analysis of T-cell phenotype and function.” M.F.I. indicates mean fluorescence intensity. (C) Proliferative responses and cytokine production. T-cell clones generated from patients and age-matched controls were stimulated with immobilized anti-CD3 monoclonal antibody (OKT3, 1 μg/mL), and 3H-thymidine incorporation was assessed after 48 hours. In parallel, cytokine secretion was evaluated in the culture supernatants collected at different time points (18 hours for IL-2 and 48 hours for the other cytokines; D). *P < .05 vs transduced clones. **P < .01 versus transduced clones.
