Distribution of WASP^bright and WASP^dim cells of the patient examined by flow cytometry.

(A) Isolated PBMCs were surface stained with marker antibodies to CD3 and CD45RA or CD19 prior to intracellular staining with 5A5 mAb. Note that the CD3⁺ cells consist of both WASP^brightand WASP^dim cells. All WASP^dim cells are within the CD3⁺CD45RA⁺ (naive) populations, whereas CD3⁺CD45RA⁻ cells are only WASP^bright. B cells (CD19⁺) are largely WASP^dim. Open histograms indicate isotype control; closed histograms, WASP staining. (B) PBMCs were activated with OKT3 mAb, anti-CD28 mAb, and rIL-2 for 3 days, expanded with rIL-2 for 9 days, and stained as in panel A. Note that only WASP^brightCD3⁺CD45RA⁻ were present after activation. (C) X chromosome inactivation of freshly isolated PBMCs (left) and T cells after activation in vitro (right). Note that in vitro activated T cells have paternal (wild-type) X chromosome as active. H indicatesHpaII + RsaI digest; R, RsaI digest.