Downmodulation of CD62L on CD4^+/–CD25^+/– T cells during treatment with hOKT3γ1(Ala-Ala). PBMCs were isolated from patients before and after treatment with hOKT3γ1(Ala-Ala). The cells were stained with mAb’s to CD4, CD25, and CD62L, or isotype controls. Electronic gates were placed around CD4⁺ lymphocytes, and the percentage of the CD4⁺ cells staining with CD25 (left panels) or CD62L (right panels) are shown. These data are from a single patient, representative of four of five patients in whom this analysis was performed. The expression of CD62L was reduced on the CD4⁺CD25⁺ population of cells.