THE PHOTODYNAMIC EFFECT OF VICTORIA BLUE BO ON PERIPHERAL-BLOOD MONONUCLEAR AND LEUKEMIC-CELLS

The photodynamic effect of Victoria blue BO (VB-BO) and photoirradiati on on peripheral blood mononuclear cells was studied. The cells were p reincubated with VB-BO followed by photoirradiation and overnight cult ure. The highest percentage of dead cells (propidium iodide assay in f low cytometry) was seen in the monocyte population. The lymphocytes sh owed a lower sensitivity to VB-BO photodynamic action than the monocyt es (12% vs 80% of PI-positive cells). The effect of VP-PO and phototre atment on lymphocyte function was studied using a mitogen-induced prol iferation assay. A decrease of mitogen response was observed. The VB-B O and photoirradiation were also used on leukemic cells. The leukemic cells from acute myeloid leukemia and B precursors leukemia were sensi tive to VB-BO photodynamic action. The high VB-BO sensitivity of monoc ytes and leukemic cells (myeloid and lymphoid B derived) suggests poss ible application of VP-PO for selective depletion of monocytes or sens itive leukemic cells.