Effect of individual and combination treatment with cytokines on expression of sialoadhesin by bone marrow macrophages.

We studied the effects of lipopolysaccharide, interferon-gamma, interleukin-1, or tumor necrosis factor-alpha and combination treatment with tumor necrosis factor-alpha and interleukin-1 or interferon-gamma on the expression of sialoadhesin receptors on the membrane of bone marrow macrophages, macrophage adherent ability, and production of nitric oxide by these cells. Sialoadhesin expression was evaluated by binding of macrophages to sheep erythrocytes labeled with radioactive (51)Cr. Treatment of bone marrow cells with interferon-gamma improved adhesive properties of macrophages, but did not modulate expression of sialoadhesin. Interleukin-1 and tumor necrosis factor-alpha had no effect on the test parameters. Combination treatment with these cytokines enhanced binding of sheep erythrocytes to macrophages. Administration of lipopolysaccharide or combination treatment with interferon-gamma and tumor necrosis factor-alpha increased the count of macrophages adhering to plastic and stimulated expression of sialoadhesin. Combination treatment with interferon-gamma and tumor necrosis factor-alpha stimulated production of nitric oxide by bone marrow macrophages. Blockade of nitric oxide synthesis had no effect on adhesive properties of macrophages and expression of sialoadhesin.