Protein tyrosine kinase p56-Lck regulates lymphocyte function-associated 1 adhesion molecule expression, granule exocytosis, and cytolytic effector function in a cloned T cell

J Exp Med. 1994 Sep 1;180(3):1115-27. doi: 10.1084/jem.180.3.1115.

Abstract

Elevated levels of p56-Lck kinase activity were achieved in an interleukin 2 (IL-2)-dependent cloned cytolytic T cell CTLL-2 through gene transfer approaches. CTLL-2-Lck cells remained dependent on IL-2 for growth and survival in culture but exhibited markedly elevated, IL-2-independent cytolytic activity against a variety of tumor targets. This immune cell effector function was similar to the non-major histocompatibility complex-restricted cytolytic activity previously described for lymphokine activated killer (LAK) cells, and involved a cytolytic mechanism that was independent of protein synthesis in either the T cells or the tumor targets. Characterization of CTLL-2-Lck cells revealed markedly elevated levels of both the alpha (CD11a) and beta (CD18) chains of the cell adhesion molecule lymphocyte function-associated 1 (LFA-1) and increased binding of these T cells to a recombinant protein representing the extracellular domain of the LFA-ligand, intercellular adhesion molecule 1 (ICAM-1). Antibodies to CD11a partially abrogated cytolytic killing of tumor target cells by CTLL-2-Lck cells, suggesting that the upregulation in LFA protein levels potentially accounts at least in part for the phenotype of these T cells. Gene transfer-mediated elevations in p56-Lck kinase activity in an IL-3-dependent myeloid cell clone 32D.3 also resulted in increased LFA-1 expression, demonstrating that the findings are not unique to CTLL-2 cells. In addition to upregulation of LFA-1 expression, CTLL-Lck cells also exhibited more efficient exocytosis of cytotoxic granules upon activation with Ca(2+)-ionophore and phorbol ester, relative to control transfected and untransfected CTLL-2 cells. The findings functionally link the Lck kinase to a T cell effector pathway involved in cell-mediated cytotoxicity.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cell Adhesion
  • Cell Adhesion Molecules / physiology
  • Cells, Cultured
  • Clone Cells
  • Cytoplasmic Granules / metabolism*
  • Cytotoxicity, Immunologic*
  • Exocytosis*
  • Glucuronidase / metabolism
  • Humans
  • Intercellular Adhesion Molecule-1
  • Lymphocyte Function-Associated Antigen-1 / biosynthesis*
  • Lymphocyte Specific Protein Tyrosine Kinase p56(lck)
  • Protein-Tyrosine Kinases / physiology*
  • T-Lymphocytes / physiology*
  • Transfection

Substances

  • Cell Adhesion Molecules
  • Lymphocyte Function-Associated Antigen-1
  • Intercellular Adhesion Molecule-1
  • Protein-Tyrosine Kinases
  • Lymphocyte Specific Protein Tyrosine Kinase p56(lck)
  • Glucuronidase