title: Distinct role of lymphocyte function-associated antigen-1 in mediating effective cytolytic activity by cytotoxic T lymphocytes.
abstract: Lymphocyte function-associated antigen-1 (LFA-1) interaction with intercellular adhesion molecules (ICAMs) facilitates T cell antigen receptor (TCR)-mediated killing. To dissect TCR and LFA-1 contributions, we evaluated cytolytic activity and granule release by cytotoxic T lymphocytes (CTL) as well as intracellular granule redistribution and morphology of CTL stimulated with natural TCR ligand in the presence or absence of LFA-1 engagement. Although other adhesion mechanisms, e.g., CD2-CD58 interaction, could substitute for LFA-1 to trigger CTL degranulation, productive LFA-1 ligation was indispensable for effective target cell lysis by the released granules. LFA-1-mediated adhesion to glass-supported bilayers containing intercellular adhesion molecule-1 was characterized by a much larger junction area, marked by LFA-1 segregation, and a more compact cell shape compared with those observed for CD2-mediated adhesion to bilayers containing CD58. A larger contact induced by intercellular adhesion molecule 1 determined a unique positioning of granules near the interface. These data provide evidence that LFA-1 delivers a distinct signal essential for directing released cytolytic granules to the surface of antigen-bearing target cells to mediate the effective destruction of these cells by CTL.
authors.affiliation: Department of Microbiology and Immunology and Kimmel Cancer Institute, Thomas Jefferson University, Philadelphia, PA 19107, USA.
authors.forename: Nadia
authors.initials: N
authors.lastname: Anikeeva
authors.forename: Kristina
authors.initials: K
authors.lastname: Somersalo
authors.forename: Tasha N
authors.initials: TN
authors.lastname: Sims
authors.forename: V Kaye
authors.initials: VK
authors.lastname: Thomas
authors.forename: Michael L
authors.initials: ML
authors.lastname: Dustin
authors.forename: Yuri
authors.initials: Y
authors.lastname: Sykulev
mesh_terms: D002448:Cell Adhesion / Q000276:immunology*; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002460:Cell Line; D003601:Cytotoxicity Tests, Immunologic; D003602:Cytotoxicity, Immunologic / Q000276:immunology*; D005455:Fluorescent Antibody Technique; D015789:HLA-A2 Antigen / Q000378:metabolism; D006801:Humans; D006825:Hybridomas / Q000276:immunology; D016169:Lymphocyte Function-Associated Antigen-1 / Q000276:immunology* / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000276:immunology* / Q000378:metabolism; D022142:Secretory Vesicles / Q000276:immunology; D015398:Signal Transduction / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology / Q000276:immunology* / Q000378:metabolism
chemical_list: D015815:Cell Adhesion Molecules; D015789:HLA-A2 Antigen; D016169:Lymphocyte Function-Associated Antigen-1; D011948:Receptors, Antigen, T-Cell