On the mode of action of intravesical bacillus Calmette-Guérin: in vitro characterization of BCG-activated killer cells.
Previously we had shown that, upon activation with viable bacillus Calmette-Guérin (BCG), peripheral blood mononuclear cells (PBMNC) could be rendered cytotoxic against otherwise insensitive natural killer (NK)-resistant bladder cancer cell lines. This phenomenon had been termed the BCG-activated killer (BAK) cell phenomenon. By means of depletion and enrichment procedures of mononuclear cell subpopulations derived from BCG-activated PBMNC we further characterized the cytolytic BAK effector cells functionally in an in vitro cytotoxicity assay against the bladder carcinoma cell line BT-A and phenotypically in their pathway of activation. Neither macrophages nor CD4+ T-helper/inducer cells exerted cytotoxic BAK activity. This cytotoxicity was restricted to the CD8+CD56+ subpopulation of T-cytotoxic/NK cells. Furthermore, activation of BAK cells via interferon gamma (IFN-gamma) was evidenced by the complete inhibition of BAK cell generation with an IFN-gamma antibody.
Böhle
A
A
Department of Urology, Medical University of Lübeck, Germany.
Thanhäuser
A
A
Ulmer
A J
AJ
Mattern
T
T
Ernst
M
M
Flad
H D
HD
Jocham
D
D
D000283:Administration, Intravesical; D015703:Antigens, CD / Q000032:analysis; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D018956:CD5 Antigens; D006801:Humans; D007167:Immunotherapy; D007371:Interferon-gamma / Q000502:physiology; D007694:Killer Cells, Natural / Q000276:immunology* / Q000502:physiology*; D009000:Monocytes / Q000276:immunology; D009163:Mycobacterium bovis / Q000276:immunology*; D010641:Phenotype; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology / Q000502:physiology; D014407:Tumor Cells, Cultured
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D018956:CD5 Antigens; C062279:CD6 antigen; D007371:Interferon-gamma