Figure 1. WT Tregs are expanded in a WAS patient following reversion of a pathogenic mutation.

Peripheral blood mononuclear cells were analyzed by flow cytometry using antibodies to CD4, CD45RA, CD27, CD62L, WASp, and FOXP3. (A) Characterization of the CD4⁺FOXP3⁺ (Tregs) and CD4⁺FOXP3^– (effector T cell [T_EFF]) cell populations within the total lymphocyte gate. (B) WASp expression within the CD4⁺FOXP3⁺ Treg population demonstrating that approximately 25% of the patient’s Tregs are WASp⁺. (C) Identification of the naive CD4⁺CD27⁺CD45RA⁺ T cells within the CD4⁺FOXP3 T_EFF cell population. Naive cells account for approximately 7% of the T_EFF population in this patient. (D) Within the naive T cell compartment, only a small proportion of the cells (approximately 2%) are WASp⁺. (E) In comparison with the T_EFF population, very few (<1%) CD27⁺CD45RA⁺ naive cells are present within the CD4⁺FOXP3⁺ Treg population. (F and G) Within the CD4⁺FOXP3⁺ Treg population, WASp⁺ cells account for equal percentages of the CD62L⁺ (F) and CD62L^– (G) Treg subsets.