Effective induction of human NK cells with OK-432 and further augmentation of their cytolytic function by rIL-2.
Low concentrations of exogenously added recombinant interleukin 2 (rIL-2) were able to augment OK-432-induced natural killer (NK) cell activity. This kind of augmenting effect depended on the dose of rIL-2 and manifested itself only in PBMC stimulated with OK-432 (OK-MC) followed by rIL-2; augmentation did not happen in the reverse order. The existence of CD16+/CD25+ (IL-2 receptor positive; IL-2R+) and CD57+/CD25+ double positive cells which possess NK cell surface markers in OK-MC markedly increased in a long-term culture (12 days). A strong positive correlation was observed between the IL-2-dependent augmentation of NK activity and the quantitative changes in cell populations that possessed NK cell phenotypes. Treatment of the day-12-OK-MC with monoclonal anti-CD56 antibody plus complement could almost completely abrogate the augmented NK cytotoxicity. Furthermore, this augmenting effect was detectable within 4 hr after addition of rIL-2 at single cell level, suggesting that the effect did not require NK cell's DNA synthesis. Thus it was suggested that OK-432 could promote and upregulate the expression of IL-2 receptor (CD25) on CD56+ NK cell populations. Moreover, it was considered that the interaction of low concentration rIL-2 with IL-2 receptors on OK-432-activated NK cells could augment their lytic function.
Hu
Z L
ZL
Department of Oral and Maxillofacial Surgery, Saga Medical School, Japan.
Kubota
E
E
Imamura
H
H
Katano
M
M
Katsuki
T
T
D015703:Antigens, CD / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology; D019002:CD56 Antigen; D018959:CD57 Antigens; D003602:Cytotoxicity, Immunologic; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D007376:Interleukin-2 / Q000276:immunology*; D007694:Killer Cells, Natural / Q000276:immunology*; D008213:Lymphocyte Activation; D010844:Picibanil / Q000276:immunology*; D015375:Receptors, Interleukin-2 / Q000276:immunology; D011994:Recombinant Proteins / Q000276:immunology; D014407:Tumor Cells, Cultured
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D019002:CD56 Antigen; D018959:CD57 Antigens; D007376:Interleukin-2; D015375:Receptors, Interleukin-2; D011994:Recombinant Proteins; D010844:Picibanil