Activation of human T cells with NK cell markers by staphylococcal enterotoxin A via IL-12 but not via IL-18.
We have reported recently that mouse liver NK cells and NK1 x 1+ T cells were activated by bacterial superantigens via the IL-12 production from Kupffer cells. In the present study, we examined the effect of staphyloccoccal enterotoxin A (SEA) on human T cells with NK cell markers, CD56 or CD57 (NK-type T cells). After stimulating peripheral blood mononuclear cells (PBMC) with SEA, PBMC produced a large amount of IFN- and acquired a potent antitumour cytotoxicity. The in vitro depletion of either CD56+ TCR NK cells, CD56+ T cells or 57+ T cells from PBMC significantly inhibited the IFN- production from PBMC. When purified NK-type T cells, NK cells and regular T cells were cultured with monocytes and SEA they all produced IFN-, while the IFN- amounts produced by both NK-type T cells were greater than those produced by NK cells. NK cells as well as CD56+ T cells showed cytotoxicity against NK-sensitive K562 cells, whereas both NK-type T cells showed a more potent cytotoxicity against NK-resistant Raji cells than did NK cells. The IFN- production from each population as well as from whole PBMC was greatly inhibited by anti-IL-12 antibody but not by anti-IL-18 antibody. The antitumour cytotoxicity of whole PBMC was also significantly inhibited by anti-IL-12 antibody while the SEA-induced proliferation of PBMC was not affected by anti-IL-12 antibody. Furthermore, SEA-activated NK-type T cells as well as NK cells showed cytotoxicities against vascular endothelial cells. Our findings suggest that human NK-type T cells are thus involved in bacterial superantigen-induced immune response.
Division of Basic Traumatology, National Defense Medical College Research Institute, Namiki, Tokorozawa, Japan.
K
K
Ami
T
T
Ohkawa
Y
Y
Koike
K
K
Sato
Y
Y
Habu
T
T
Iwai
S
S
Seki
H
H
Hiraide
D015415:Biomarkers; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D019002:CD56 Antigen / Q000276:immunology*; D018959:CD57 Antigens / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D002455:Cell Division; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic; D004730:Endothelium, Vascular / Q000166:cytology / Q000276:immunology; D004768:Enterotoxins / Q000276:immunology* / Q000494:pharmacology; D006801:Humans; D007369:Interferon Inducers / Q000276:immunology* / Q000494:pharmacology; D007371:Interferon-gamma / Q000096:biosynthesis; D018664:Interleukin-12 / Q000276:immunology*; D020382:Interleukin-18 / Q000276:immunology*; D020014:K562 Cells; D007694:Killer Cells, Natural / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D013211:Staphylococcus aureus / Q000276:immunology*; D018089:Superantigens / Q000276:immunology* / Q000494:pharmacology; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology*
D015415:Biomarkers; D019002:CD56 Antigen; D018959:CD57 Antigens; D004768:Enterotoxins; D007369:Interferon Inducers; D020382:Interleukin-18; D018089:Superantigens; D018664:Interleukin-12; C026066:enterotoxin A, Staphylococcal; D007371:Interferon-gamma