In vitro expression of IL-1α, GM-CSF, and TNF-α by multinucleated macrophages from BCG-infected mice.

Peritoneal cells from intact and BCG-infected mice were explanted in vitro. In these cultures, multinucleated macrophages in different number of nuclei were formed. The intensity of multinucleated cell formation was higher in cultures from BCG-infected mice. Increasing role of amitosis in the formation of multinucleated macrophages with relatively high number of nuclei was noted with presumable domination of cell fusion mechanism. Relatively high level of IL-1α expression was noted only in the population of binucleated macrophages of BCG-infected mice in comparison with mononuclear cells. It was found macrophages from BCG-infected mice demonstrate a kind of "lineage commitment" towards multinucleated cells, which manifested in culture in initially high and increasing (with increasing the number of nuclei in cells) expression of granulocyte-macrophage CSF and TNF-α as well as initially high amitotic activity of macrophages.