Regulatory Effect of Lymphokine-Activated Killer Cells on Epidermal Proliferation Induced by Cholera Toxin in Mice

We investigated the effects of lymphokine-activated killer (LAK) cells on epidermal hyperplasia induced by cholera toxin (CT). LAK cells showed cytotoxic activity against both tumor cell lines and proliferating normal cells including skin epidermal cells. When 1 x 10(7) LAK cells were injected intradermally together with 1.0 ng of CT, epidermal hyperplasia was markedly suppressed. The LAK effectors inhibiting epidermal hyperplasia showed surface phenotypes of asialo-GM1+, Thy-1+, Lyt-2- and L3T4-, that were different from those of LAK cells killing tumor cells in vitro. Epidermal hyperplasia induced by CT was not suppressed by topical administration of cytokines such as interleukin-2, interferon and tumor necrosis factor. Therefore, the antiproliferative effect of LAK cells might be attributed to their direct action on the epidermal cells.