RELATIONSHIP BETWEEN RADICAL PRODUCTION AND NATURAL-KILLER CYTOTOXIC FACTOR (NKCF) IN CANINE NATURAL-KILLER (NK) CELL-MEDIATED CYTOTOXICITY

The relationship between radical production and natural killer cytotox ic factor (NKCF) release via canine natural killer (NK)-mediated cytot oxic mechanism was examined. Radical production and NKCF release was i nduced in NK cells stimulated with either dead target cells, or their cytoplasmic membranes, as well as live target cells. Canine NKCF evoke d target cell lysis but did not induce radical production. Radical pro duction was inhibited by the addition of Tiron or n-propyl gallate, wh ereas NK-mediated cytotoxicity and NKCF release were only inhibited by the addition of n-propyl gallate. These results suggested that radica l production and NKCF release may be induced by the contact and bindin g of NK cells to the target cell cytoplasmic membrane, Therefore, the release of NKCF from NK cells attached to the target cell cytoplasmic membrane may be associated with the production of radicals, especially hydroxyl radicals. (C) 1997 Elsevier Science B.V.