We studied the enhancement of cytolytic activity of T3- natural killer cell-derived clones, of T3+ T cell activated killer (AK) clones, and of fresh peripheral blood lymphocytes (PBL) by various crude and recombinant interferon (r-IFN) as well as IL 2 preparations. It was found that IFN-β had the highest cytotoxicity inducing potency as compared to crude or r-IFN-α or -γ preparations. This enhancement was blocked by anti-IFN-β antibodies but not by anti-IFN-γ antibodies. IL 2 also strongly enhances cytolytic activity in cloned T3- killer cells that express the IL 2 receptors as determined with the anti-Tac monoclonal antibody (MAb) at concentrations of IL 2 (25 U/ml) which induced one-half of the maximal proliferation capacity in human T cells and murine CTLL cells. For enhancement of cytolytic activity in fresh NK cells, a much higher concentration of IL 2 is required. In addition, the enhancement of cytolytic activity by r-IL 2 but not that by IFN-β can be reduced by anti-Tac MAb, suggesting that the IL 2 receptor is involved in the enhancement by IL 2, but not by IFN. Both IFN-β and IL 2 were able to enhance (over threefold) the cytolytic activity of T3- cloned killer cells against a variety of tumor target cell types. Another remarkable observation was that K562 cells, the most commonly used target cell for determining NK cell cytolytic activity, are not the most suitable targets to assess enhancement of non-specific lytic activity as compared to Daudi or lung tumor-derived cell lines. No enhancement of antibody-dependent cellular cytotoxicity was observed. Finally, the effects of these biological response modifiers were much more pronounced on 'fresh' and cloned T3- natural killer cell-derived than on T3+- activated killer mature T cell-derived clones.
|Original language||English (US)|
|Number of pages||8|
|Journal||Journal of Immunology|
|State||Published - 1986|
ASJC Scopus subject areas
- Immunology and Allergy