IL-1 induces ornithine decarboxylase in normal T lymphocytes.

IL-1 alpha regulation of ornithine decarboxylase (ODC) was examined in T cells because IL-1 is a costimulus for T cell proliferation and ODC is a critical enzyme in the metabolic events associated with cellular proliferation. In the present study, we demonstrate that IL-1 alpha induces ODC mRNA and ODC enzyme activity in T cells. Unlike many IL-1 actions on T cells, this did not require a costimulus from the TCR, IL-1 alone being sufficient to induce ODC. The mechanism of IL-1 induction of ODC probably operates at several levels, including transcription, mRNA stability, and translation. Previous studies have shown that IL-1 prepares T cells for replication by increasing the production of c-jun, c-fos, c-myc, growth factors, growth factor receptors, and the response to growth factors. From the present study, ODC induction can be added to the list of IL-1-induced replicative machinery in T cells.