Energy metabolism and T-cell-mediated cytolysis. I. Synergism between inhibitors of respiration and glycolysis

The energy requirements for T-cell-mediated cytolysis have been investigated. Cytolytic thymus-derived lymphocytes (CTL) were generated in vitro in mixed leukocyte cultures and assayed for cytotoxicity on 51Cr-labeled mastocytoma target cells. Cytolysis was only slightly reduced in the absence of exogenous glucose (less than 5 micrometer) or under conditions of extreme hypoxia (less than 0.2 micrometer oxygen). Furthermore, neither the glucose analogues 2-deoxy-D-glucose and 5-thio-D-glucose nor the respiratory antagonists sodium azide and 2,4-dinitrophenol were very effective inhibitors of cytolysis when used individually. However, these glucose analogues were highly effective in inhibiting cytolysis in the absence of oxygen, and the respiratory antagonists inhibited cytolysis to a much greater extent in the absence of glucose. In addition, synergistic effects were observed when the glycolytic and respiratory inhibitors were combined. Taken together, these results indicate that T-cell-mediated cytolysis is an energy-dependent process which can be supported by either oxidative or glycolytic energy pathways.