Simultaneous production of IFN-gamma, IFN-alpha/beta and nitric oxide in peritoneal macrophages from TDM-treated mice

Peritoneal macrophages (PM) were isolated from mice treated with Dimycolate of Trehalose (TDM), a glycolipid extracted from the cell wall of Myobacter ium tuberculosis. PM from TDM-treated mice (TDM-PM) were shown to secrete c onsistent amount of IFN-gamma, which was not detectable in control Resident -PM (Res-PM), as revealed by ELISA. In addition, biologically active IFN wa s detected in the supernatants of TDM-PM, whereas no IFN production was fou nd in those of control Res-PM. The addition of specific antisera to PM cult ures revealed the simultaneous production of both type I and II IFNs in TDM -PM cultures. No reciprocal regulation in the production of IFN-gamma and I FN-alpha/beta was found in these cultures. In parallel, nitric oxide (NO) p roduction was measured in TDM-PM cultures by detecting nitrites (NO2-). TDM -PM cultures accumulated high amounts of NO2- which decreased to the level of Res-PM in the presence of NMMA, an inhibitor of NO-synthases. In vitro, neither type I nor type II IFNs were involved in the stimulation og NO prod uction. The capacity of macrophages to simultaneously secrete IFN-gamma, IF N-alpha/beta and NO upon in vivo TDM-treatment could be of particular relev ance for the defense process of innate immunity in which macrophages play a crucial role.