Antibodies that bind to CD3 or the clonotypic TCR cause rapid apoptosis of CTCL cells.

CTCL cells were CD2–bead purified from 2-month cultures and incubated for 1 hour with an isotype control (A; IgG₁), CD3 (B), or an antibody to the variable region of the β chain of the clonotypic TCR (C; Vβ5c). Apoptosis was assessed by the binding of annexin V–FITC, a marker of early apoptotic cells. Tx indicates treatment.