Effect of macrophage migration inhibition factor on the content of stromal precursor cells in mouse bone marrow and efficiency of bone marrow precursor cell cloning in vitro.

The content of stromal precursor cells in the bone marrow of mice decreased 2-5.7 times 24 h after injection of macrophage migration inhibition factor in doses of 0.1-50 ng/kg, this reduction depending on the dose of inhibition factor. The content of precursor cells in the bone marrow of mice increased 2-fold 24 h after injection of S. typhimurium bacterial mass. One day after injection of S. typhimurium bacterial mass, the count of precursor cells in mouse spleen was 7-fold higher than 24 h after injection of macrophage migration inhibition factor. The efficiency of cloning of mouse bone marrow stromal precursor cells in vitro was suppressed 1.7-2.8 times in the presence of macrophage migration inhibition factor in doses of 0.1 to 50 ng/ml culture medium. The effect of cloning inhibition was preserved, if macrophage migration inhibition factor was added to the culture medium after 2 days of bone marrow cell culturing. In general, macrophage migration inhibition factor inhibits stromal precursor cells in vivo and in vitro. The data also indicate that macrophage migration inhibition factor is not responsible for rapid and sharp increase in the count of stromal precursor cells after immunization of animals.