Interferon effect on cytolytic T lymphocytes in a single cycle assay.

In this study we analyse cell-mediated cytotoxicity by the use of 51chromium release and the killer cell enumeration assay. The latter enabled us to estimate cell-mediated cytotoxicity in a single cycle, which confirms the protective effect of interferon (IFN) after target cell treatment. This anti-cytolytic resistance is detected best by microassociation when effector and target cells are separately treated with IFN and associated thereafter. We suggest that, in inflammatory areas, enhanced cytotoxic activity of the IFN-treated effector cells is only operative before the establishment of protection in the targets, which is somewhat slower and appears in about 18 hr. Resistance of the targets could be at least partly attributed to the incapacity of effector cells to bind to them.