Induction of interleukin 1 secretion by murine macrophages and human monocytes after stimulation by RU 41740, a bacterial immunomodulator.

RU 41740, a glycoprotein extract from K. pneumoniae K2O1 strain, is an immunomodulating compound which has been shown to reduce infectious episodes in patients prone to recurrent infections. Data from preliminary experiments suggest that RU 41740 may affect several target cells, including T cells, B cells or macrophages. In the present report we show that RU 41740 can trigger mouse macrophages and human adherent mononuclear cells to produce interleukin 1 activity. Indeed, supernatants from mouse peritoneal adherent cells and human monocytes incubated in presence of RU 41740, can stimulate blastogenesis in thymocytes from C3H/HeJ mice. The data suggest that the immunomodulating effect of RU 41740 could be related to its ability to induce interleukin 1 production.