title: Antigen-specific directional target cell lysis by perforin-negative T lymphocyte clones.
abstract: Despite a number of reports indicating that perforin, a pore-forming protein, is the primary effector molecule mediating specific target cell lysis by cytotoxic T lymphocytes (CTL), several lines of evidence suggest the existence of perforin-independent mechanisms. We established class II-restricted, soluble protein-specific CD4+ T cell clones with killing function which do not express a detectable amount of perforin and perforin mRNA. Nevertheless, these clones induced cytolysis and DNA fragmentation of target cells in a specific and highly directional manner which was not inhibitable by antibody against TNF/lymphotoxin. These data not only indicate the existence of cytotoxic T cell subsets which do not utilize perforin, but also suggest that perforin is not mandatory for specific target lysis by T cells.
authors.affiliation: Laboratory of Cellular Immunology, Mitsubishi Kasei Institute of Life Sciences, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Takayama
authors.forename: N
authors.initials: N
authors.lastname: Shinohara
authors.forename: A
authors.initials: A
authors.lastname: Kawasaki
authors.forename: Y
authors.initials: Y
authors.lastname: Someya
authors.forename: S
authors.initials: S
authors.lastname: Hanaoka
authors.forename: H
authors.initials: H
authors.lastname: Kojima
authors.forename: H
authors.initials: H
authors.lastname: Yagita
authors.forename: K
authors.initials: K
authors.lastname: Okumura
authors.forename: Y
authors.initials: Y
authors.lastname: Shinkai
mesh_terms: D000818:Animals; D000941:Antigens; D015704:CD4 Antigens; D002999:Clone Cells / Q000276:immunology / Q000378:metabolism; D003602:Cytotoxicity, Immunologic; D004247:DNA / Q000378:metabolism; D006433:Hemocyanins / Q000276:immunology; D008233:Lymphotoxin-alpha / Q000276:immunology; D008562:Membrane Glycoproteins; D008565:Membrane Proteins / Q000276:immunology* / Q000378:metabolism; D010047:Ovalbumin / Q000276:immunology; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
chemical_list: D000941:Antigens; D015704:CD4 Antigens; D008233:Lymphotoxin-alpha; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D052899:Pore Forming Cytotoxic Proteins; D014409:Tumor Necrosis Factor-alpha; D054353:Perforin; D010047:Ovalbumin; D004247:DNA; D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin