IFNY TRIGGERS APOPTOSIS IN VITRO M.T. ACTIVATED ALVEOLAR MACROPHAGES

The molecules regulating monocyte/macrophage production and activation have been intensively studied, but the mechanisms eliminating the activated cells during the inflammatory wanes have not been well characterized. The aim of the present study was to investigate the modulatory role of cytokines on the death rate of human alveolar macrophage (AM) from BAL of healthy subjected. AM treatment with different cytokines, such as IL-1 beta, IL-4, IL-6, IL-10, TFN- alpha, TGF-beta 2, and IFN-gamma, was not capable of increasing the spontaneous rate of cell apoptosis. When AM (106/well) were incubated with heat-killed M.T. (106bacteria well), apoptosis of macrophage increased 4-fold in comparison with control culture (7.6 to 31.9%). Moreover, M.T.-induced apoptosis was significantly enhanced by the presence in the culture medium of the macrophage-activating cytokine IFN-gamma (59%) and decreased by the macrophage-deactivating cytokines IL-4, IL-10, and TGF-beta (17%). The observation may have relevance to understanding mechanisms regulating homeostasis of AM in case of M.T. infection.