Target cell lysis by cytotoxic T lymphocytes that lack detectable hemolytic perforin activity |
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Authors: | N L Allbritton C Nagler-Anderson T J Elliott C R Verret H N Eisen |
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Affiliation: | Department of Biology, Massachusetts Institute of Technology, Cambridge 02139. |
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Abstract: | When mouse target cells are subjected to cytolytic attack by mouse CTL cell lines that have been cultured for many months in high levels of IL-2, and have abundant perforin-rich secretory granules, they exhibit two prominent changes: 1) rapid and massive increase (greater than 10-fold) in intracellular Ca2+ concentration and 2) fragmentation of DNA into nucleosome-sized fragments. We show here that when the same target cells are subjected to cytolytic attack by perforin-deficient CTL, either human CTL or primary mouse CTL from peritoneal exudates, the same changes are observed, suggesting that perforin-rich and perforin-deficient CTL kill their target cells by similar (if not identical) mechanisms. It is possible that perforin-deficient CTL produce enough perforin to destroy target cells but not enough to be detected by currently available methods. |
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