Cell surface lectins of human granulocytes: their expression is modulated by mononuclear cells and granulocyte/macrophage colony-stimulating factor

摘要

This paper presents the characterization of a sugar-specific receptor on the surface of human circulating poly-morphonuclear cells. With the help of fluorescent neo-glycoproteins and flow cytometry, a receptor was identified as being specific forα-L-rhamnosyl residues. The number of receptors was 55 000/cell and their affinity reached 2×108I mol−1. This number changed as a function of the biological state of the cells. Indeed, receptor expression was modulated by the presence of other cells. T cells and B cells increased the number of receptors on the granulocyte surface. Expression of theα-L-rhamnose-specific lectin was dependent on lymphocyte derived soluble factor(s), which induce(s) growth and differentiation of polymorphonuclear phagocytes. Granulocyte/macrophage colony-stimulating factor (GM-CSF) specifically produced a significant increase in the number of receptors forα-L-rhamnose (2–10-fold/cell). This modulation was independent of protein kinase C activators such as phorbol ester, which produced no effect onα-L-rhamnose receptor expression. These findings demonstrate that GM-CSF may stimulate post differentiation functions and properties of mature gran