title: Characterization of a series of vacuolar type H(+)-ATPase inhibitors on CTL-mediated cytotoxicity.
abstract: Four vacuolar type H(+)-ATPase (V-ATPase) inhibitors, i.e. concanamycin A (CMA), bafilomycin A1 (BMA), destruxin E (DRE) and prodigiosin 25-C (PRG) profoundly blocked the perforin-dependent cytotoxicity mediated by CD8+ CTL clone. Cytoplasmic acidic compartments were not detected under fluorescent microscopy after treatment of the cells with these V-ATPase inhibitors. In the lytic granule fractions, BMA, CMA, DRE and PRG completely abrogated the perforin activity, although these drugs slightly decreased the granzyme A activity. Under the same conditions, BMA and CMA markedly reduced the perforin content, while DRE and PRG had no significant effects as assayed by immunoblotting using anti-perforin antibody. These data suggest that perforin is predominantly inactivated even without proteolysis in DRE- or PRG-treated cells. We propose that acidic pH is essential to maintain not only quantity but also quality of perform in the lytic granules.
authors.affiliation: Department of Bioengineering, Tokyo Institute of Technology, Yokohama, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Togashi
authors.forename: T
authors.initials: T
authors.lastname: Kataoka
authors.forename: K
authors.initials: K
authors.lastname: Nagai
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D002999:Clone Cells; D003594:Cytoplasmic Granules / Q000187:drug effects / Q000378:metabolism; D003602:Cytotoxicity, Immunologic / Q000187:drug effects / Q000502:physiology*; D047630:Depsipeptides; D004791:Enzyme Inhibitors / Q000737:chemistry; D005656:Fungal Proteins; D006863:Hydrogen-Ion Concentration; D007111:Immunity, Cellular / Q000276:immunology*; D007166:Immunosuppressive Agents / Q000737:chemistry; D018942:Macrolides; D008562:Membrane Glycoproteins / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D015394:Molecular Structure; D010456:Peptides, Cyclic / Q000737:chemistry; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D011353:Prodigiosin / Q000031:analogs & derivatives / Q000737:chemistry; D006180:Proton-Translocating ATPases / Q000037:antagonists & inhibitors* / Q000502:physiology; D051381:Rats; D013602:T-Lymphocytes, Cytotoxic / Q000502:physiology*; D025262:Vacuolar Proton-Translocating ATPases
chemical_list: D000900:Anti-Bacterial Agents; D047630:Depsipeptides; D004791:Enzyme Inhibitors; D005656:Fungal Proteins; D007166:Immunosuppressive Agents; D018942:Macrolides; D008562:Membrane Glycoproteins; D010456:Peptides, Cyclic; D052899:Pore Forming Cytotoxic Proteins; D054353:Perforin; C077331:prodigiosin 25C; C036978:concanamycin A; C040929:bafilomycin A1; D025262:Vacuolar Proton-Translocating ATPases; D006180:Proton-Translocating ATPases; D011353:Prodigiosin; C040425:destruxin E