[Cellular regulation of human interleukin-2 production]

The mechanism of IL2 production by T lymphocytes has been clearly established in Mice. Previous studies have also suggested that control of IL2 production is similar in the Human. We have observed that a complete depletion of adherent monocytes abrogates IL2 production by T lymphocytes. On the other hands in humane inhibition of IL2 production was also mediated by an excess of monocytes. This inhibition was mediated by soluble products and could be blocked by treatment with indomethacin. PGE2 was identified as one of this, inhibitory monokine. A possible mechanism of this inhibition by PGE2 is suggested. Such inhibition was not observed if the T lymphocyte suspension was irradiated (1000 rad) before addition of PGE2 or excess monocytes. These results suggest that activation of a radiosensitive T cell by monokines is required for the inhibition of IL2 production. A model for the cellular control of human IL2 production is proposed.