Proliferation of splenic T cells from gene-corrected, WASP^— animals in response to T-cell–receptor stimulation. As described in the text, 2 separate experiments were performed with 2 WASP^— animals that received transplants of WASP^— cells transduced with the MWG vector along with appropriate controls. Splenic T cells were cultured for 48 hours in 96-well dishes coated with anti-CD3 antibody (5 ng/well, overnight, 4°C [panel A]; 50 ng/well, 6 hours, 4°C [panel B]) or in untreated wells (control). ³H-thymidine was added, and 24 hours later total incorporation was measured. Each result is the mean of 3 independent measurements. The cells transplanted into the irradiated WASP^— mice and vectors, if any, used for transduction are as follows: lane 1, WASP^—; lane 2, WASP^— and MG; lane 3, WT; lane 4, WT and mock (A) or WT and MG (B); lanes 5 and 6, 2 separate mice with WASP^— cells transduced with the bicistronic MWG vector. The percentage of GFP⁺ T cells was measured in peripheral blood prior to the proliferation assays. Error bar equals standard error.