Differential expression of Lewis x and sialyl‐Lewis x antigens in fetal human neural cells in culture

Lewis x is a cell‐surface carbohydrate antigen defined by the trisaccharide structure, Galβ 1→4 (Fucα 1→3) GlcNAc. Expression of Lewis x and sialyl‐Lewis x antigens in primary cell cultures isolated from fetal human brains of 12‐15 weeks gestation was investigated by double immunolabelling with antibodies against monomeric Lewis x (4C9), oligomeric Lewis x (FH4), and sialylated oligomeric Lewis x (FH6) antigens and cell type‐specific markers. The monomeric Lewis x antigen was expressed in more than 15% of astrocytes and 100% of oligodendrocytes, whereas it was not identified in neurons or in microglia. The oligomeric Lewis x antigen was undetectable in any cell types, while the sialylated oligomeric Lewis x antigen was expressed in more than 95% of microglia but not in any other cell types. The cell type‐specific expression of Lewis x and sialyl‐Lewis x antigens in fetal human glial cells suggests that these fucose‐containing carbohydrate molecules play roles in intercellular recognition between distinct cell types during the development of the human central nervous system. © 1994 Wiley‐Liss, Inc.