Systematic characterization of human CD8+ T cells with natural killer cell markers in comparison with natural killer cells and normal CD8+ T cells

• Published in: Immunology 2001-07, Vol.103 (3), p.281-290
• Main Authors: Ohkawa, Takashi, Seki, Shuhji, Dobashi, Hiroshi, Koike, Yuji, Habu, Yoshiko, Ami, Katsunori, Hiraide, Hoshio, Sekine, Isao
• Format: Article
• Language: English
• Subjects: Adult; Apoptosis - immunology; CD3 Complex - immunology; CD56 Antigen - analysis; CD57 Antigens - analysis; CD8-Positive T-Lymphocytes - immunology; Cell Culture Techniques; Cell Division - immunology; Child; Cytotoxicity, Immunologic; Granzymes; Humans; Immunophenotyping; Interferon-gamma - biosynthesis; K562 Cells - immunology; Killer Cells, Natural - immunology; Lymphocyte Activation - immunology; Membrane Glycoproteins - metabolism; Original; Perforin; Pore Forming Cytotoxic Proteins; Receptors, Antigen, T-Cell, alpha-beta - analysis; Serine Endopeptidases - metabolism; T-Lymphocyte Subsets - immunology; Tumor Cells, Cultured
• ISSN: 0019-2805; 1365-2567
• DOI: 10.1046/j.1365-2567.2001.01248.x

Summary We investigated the function of CD56+ CD8+ T cells (CD56+ T cells) and CD56− CD57+ CD8+ T cells (CD57+ T cells; natural killer (NK)‐type T cells) and compared them with those of normal CD56− CD57− CD8+ T cells (CD8+ T cells) and CD56+ NK cells from healthy volunteers. After the stimulation with immobilized anti‐CD3 antibodies, both NK‐type T cells produced much larger amounts of interferon‐γ (IFN‐γ) than CD8+ T cells. Both NK‐type T cells also acquired a more potent cytotoxicity against NK‐sensitive K562 cells than CD8+ T cells while only CD56+ T cells showed a potent cytotoxicity against NK‐resistant Raji cells. After the stimulation with a combination of interleukin (IL)‐2, IL‐12 and IL‐15, the IFN‐γ amounts produced were NK cells ≥ CD56+ T cells ≥ CD57+ T cells > CD8+ T cells. The cytotoxicities against K562 cells were NK cells > CD56+ T cells ≥ CD57+ T cells > CD8+ T cells while cytotoxicities against Raji cells were CD56+ T cells > CD57+ T cells ≥ CD8+ T cells ≥ NK cells. However, the CD3‐stimulated proliferation of both NK‐type T cells was smaller than that of CD8+ T cells partly because NK‐type T cells were susceptible to apoptosis. In addition to NK cells, NK‐type T cells but not CD8+ T cells stimulated with cytokines, expressed cytoplasmic perforin and granzyme B. Furthermore, CD3‐stimulated IFN‐γ production from peripheral blood mononuclear cells (PBMC) correlated with the proportions of CD57+ T cells in PBMC from donors. Our findings suggest that NK‐type T cells play an important role in the T helper 1 responses and the immunological changes associated with ageing.