title: Direct evidence for release of pore-forming protein during NK cellular lysis.
abstract: In the present study, we have examined the exocytosis model for cellular lysis. Using monoclonal antibodies reactive with human pore-forming protein (PFP), we examined the localization of PFP at the interaction site of natural killer (NK) cells and the NK tumor targets K562 and Molt-4 as well as during antibody-dependent cellular cytotoxicity. Following the interaction of effector-target cell contact, an increased frequency of PFP was detected on the effector surface, in the micro-environment, and on the target surface of the interaction site. This temporal deposition of PFP was paralleled by loss of target cell integrity and release of chromium. In addition, selective deposition of PFP was seen at the interaction site of the target cell compared to other target cell regions. Collectively, these results are consistent with the exocytosis model and further support the hypothesis that PFP is one of the secreted moieties involved in NK cellular cytotoxicity.
authors.affiliation: Laboratory of Experimental Immunology, Division of Cancer Treatment, National Cancer Institute, Frederick Cancer Research Facility, Maryland 21702-1201.
authors.forename: J R
authors.initials: JR
authors.lastname: Ortaldo
authors.forename: R T
authors.initials: RT
authors.lastname: Winkler-Pickett
authors.forename: K
authors.initials: K
authors.lastname: Nagashima
authors.forename: H
authors.initials: H
authors.lastname: Yagita
authors.forename: K
authors.initials: K
authors.lastname: Okumura
mesh_terms: D000911:Antibodies, Monoclonal; D000920:Antibody-Dependent Cell Cytotoxicity; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic; D005089:Exocytosis; D006801:Humans; D007111:Immunity, Cellular; D066298:In Vitro Techniques; D007694:Killer Cells, Natural / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000378:metabolism*; D008854:Microscopy, Electron; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D013997:Time Factors
chemical_list: D000911:Antibodies, Monoclonal; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D054353:Perforin