title: Photodynamic effect on the specific antitumor immune activity.
abstract: Photofrin is a potent sensitizer which localizes, among other sites in membranes of malignant cells. To evaluate the effect of photodymanic therapy (PDT) on specific antitumoral immunological response, we used a chromium release assay to compare the specific cytolytic activity (CLA) of primed mouse spleen T lymphocytes sensitized against syngeneic mastocytoma P511 cells. P511 cells or lymphocytes or both were treated or not with Photofrin and/or light (514 nm). Photofrin alone (1 microg/ml, 2 h) reduced CLA by 59% when P511 cells were treated although this decrease was not drug dose dependent. Photofrin (1 microg/ml, 2 h) followed by light (25 J/cm2) reduced CLA by 35% in a drug dose dependent manner. Longer incubation times led to reduced CLA inhibition (10% for 3 h incubation) after Photofrin followed by light. The light dose (25, 37, 50 J/cm2) did not influence CLA for a given Photofrin concentration. Photofrin alone (0.5 microg/ml, followed by light (25 J/cm2 for 2 h) reduced CLA respectively by 8 and 45% only when lymphocytes were treated. When lymphocytes and P511 cells were treated with Photofrin alone or followed by light (25 J/cm2), CLA was also reduced (by 19 and 41% respectively). This type of damage can be evaluated in terms of antigen expression on the target cells, on the lymphocyte T receptor, on H-2 (histocompatibility major complex), or on lymphocyte activity after PDT.
authors.affiliation: Département Laser, Hopital Nord Laënnec, Nantes, France.
authors.forename: V
authors.initials: V
authors.lastname: Vonarx
authors.forename: M T
authors.initials: MT
authors.lastname: Foultier
authors.forename: L
authors.initials: L
authors.lastname: Anasagasti
authors.forename: L
authors.initials: L
authors.lastname: Morlet
authors.forename: Y
authors.initials: Y
authors.lastname: Lajat
authors.forename: T
authors.initials: T
authors.lastname: Patrice
mesh_terms: D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000187:drug effects; D000951:Antigens, Neoplasm / Q000187:drug effects; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D017324:Hematoporphyrin Derivative / Q000627:therapeutic use; D066298:In Vitro Techniques; D012515:Mast-Cell Sarcoma / Q000188:drug therapy* / Q000276:immunology*; D051379:Mice; D008811:Mice, Inbred DBA; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000627:therapeutic use; D013154:Spleen / Q000187:drug effects / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000187:drug effects / Q000276:immunology; D014407:Tumor Cells, Cultured
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D000951:Antigens, Neoplasm; D017319:Photosensitizing Agents; D017324:Hematoporphyrin Derivative