Induction of natural suppressor-like cells from human adult peripheral blood lymphocytes by a K562-derived factor.
K562-AC1, a subclone of the human myeloid leukemia cell line K562, secreted an inhibitor of PHA-stimulated human T cell growth into the culture supernatant (K562sup). Kinetics and absorption assays in vitro revealed that the factor acts on PBMC during the very early growth phase. PBMC gained potent suppressor activity against autologous T cell growth after preculture with K562sup for 3 days in a dose-related manner. HLA class II negative and nylon wool-nonadherent subsets possessed higher suppressor potential than unfractionated PBMC. Treatment of K562sup-precultured PBMC with mAb followed by complement-lysing showed that the responsible suppressors belong to null cells expressing CD3-, CD4-, CD19-, CD14-, CD11b-, but partially CD2+. Exogenous IL-2 exhibited a synergistic effect on the activity of the suppressors committed by K562sup. However, K562sup inhibited IL-2-activated lymphocytes from generating anti-K562 cytolytic activity. Macrophages inhibited the induction of the suppressors, which was restored by adding indomethacin and/or IL-2. In conclusion, K562sup has the ability to induce efficient suppressor cells from human adult PBL, which belong to null cells without NK/lymphocyte-activated killer activity and are similar to natural suppressor cells.
Second Department of Surgery, Hiroshima University School of Medicine, Japan.
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Hayamizu
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Yahata
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Fukuda
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Dohi
D006801:Humans; D007111:Immunity, Cellular; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000494:pharmacology; D015979:Killer Cells, Lymphokine-Activated / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology; D004915:Leukemia, Erythroblastic, Acute / Q000276:immunology*; D008213:Lymphocyte Activation; D008264:Macrophages / Q000276:immunology; D011994:Recombinant Proteins / Q000494:pharmacology; D013491:Suppressor Factors, Immunologic; D013601:T-Lymphocytes / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D013997:Time Factors; D014407:Tumor Cells, Cultured
D007376:Interleukin-2; D011994:Recombinant Proteins; D013491:Suppressor Factors, Immunologic