Expression of perforin and serine esterases by human gamma/delta T cells.

• DOI: 10.1084/jem.173.2.499
• Publication Date: 2004-06-24T07:56:10Z
• Authors: H Koizumi; C C Liu; L M Zheng; S V Joag; N K Bayne; J Holoshitz; J D Young
• Keywords: Cytotoxicity, Immunologic; Pore Forming Cytotoxic Proteins; Membrane Glycoproteins; Perforin; Blotting, Western; Esterases; Receptors, Antigen, T-Cell; Fluorescent Antibody Technique; Membrane Proteins; Receptors, Antigen, T-Cell, gamma-delta; Blotting, Northern; Immunophenotyping; 3. Good health; Killer Cells, Natural; T-Lymphocyte Subsets; Humans; RNA; DNA Probes

gamma/delta T cells have recently been described in association with a number of disorders, including autoimmune diseases. gamma/delta T cells are thought to play a cytotoxic role, but their mechanism of action is not known. Several granule mediators of cytotoxicity, including a pore-forming protein (perforin), and a family of serine esterases, have been isolated from cytotoxic T lymphocytes (CTL), lymphokine-activated killer (LAK) cells, and natural killer (NK) cells. We demonstrate here that gamma/delta T cells also express these mediators. Northern blots show that gamma/delta T cells express perforin, serine esterase 1 (SE 1), and SE 2. Three polyclonal antisera - raised against murine perforin, a peptide composed of amino acids 1-34 of human perforin, and human peforin expressed in bacteria - all reacted with a 70-kD protein in gamma/delta T cells on Western blots. Immunostaining with antiperforin antisera shows that primary gamma/delta T cells also contain perforin. Electron microscopy reveals that the granules of gamma/delta T cells resemble those of CTL, LAK, and NK cells. Gamma/delta T cells also resemble LAK cells in possessing inclusion bodies in their nuclei. These results imply that gamma/delta T cells resemble other cytolytic lymphocytes in their mechanism of action.