POTENTIATION OF NATURAL-KILLER ACTIVITY OF HUMAN-LYMPHOCYTES BY STAPHYLOCOCCUS-AUREUS BACTERIA AND ITS PROTEIN-A

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  • 1 January 1981
    • journal article
    • research article
    • Vol. 42  (2) , 175-183
Abstract
Cytotoxic activity of human lymphocytes against the myeloid cell line K-562 was augmented greatly by 24 h incubation with S. aureus Cowan I bacteria (SpA CoI) and its protein A. This effect was not observed when these stimulants were added after preincubation, suggesting that this activity was different from so-called lectin-induced cellular cytotoxicity. Potentiation required at least 12-18 h lymphocyte incubation with these stimulants. Macrophage depletion did not affect the potentiation by protein A or SpA CoI, although the potentiation by poly I:C or OK-432, an immunopotentiator of Streptococcus pyogenes was completely reduced. Further cell separation procedures revealed that neither T cells nor FcR- cells, which showed little natural killer (NK) activity, were enhanced by protein A or SpA CoI. Null cells which were obtained from nylon column (NC)-passed fraction by depleting T cells and surface membrane Ig-positive cells, and FcR+ E- [non erythrocyte-rosette forming] cells which were obtained from NC-passed fraction by depleting FcR- cells and T cells, showed marked NK activity by themselves and were further augmented by these stimulants. FcR+ E+ cells failed to show NK activity even if they were stimulated by these stimulants. Thus, protein A and SpA CoI, as well as human interferon, can stimulate NC-non-adherent, FcR+ E- NK cells and potentiate markedly their NK activity.