Alloreactive T Cell Photodepletion.

Stimulator mononuclear/T cells are collected from the patient by leukopheresis. They are expanded in culture (with IL-2 and OKT3), and before use they are inactivated by irradiation. The cells are co-cultured in a 1:1 ratio with donor T cells collected by leukopheresis. The cells are then incubated with the photosensitizer TH9402. Alloactivated T cells incorporate the photosensitizer. Activation of TH9402 by light exposure causes their lysis and allodepletion of the alloreactive lymphocytes. Only non-alloreactive donor T cells remain in the product.