Sialo-oligosaccharide receptors for Mycoplasma pneumoniae and related oligosaccharides of poly-N-acetyllactosamine series are polarized at the cilia and apical-microvillar domains of the ciliated cells in human bronchial epithelium.
The occurrence and distribution of the sialo-oligosaccharide receptors (sialosyl-I and sialosyl-i) for Mycoplasma pneumoniae as well as other related oligosaccharide structures of poly-N-acetyllactosamine type, and their short-chain analogs based on galactose linked beta 1-4 or beta 1-3 to N-acetylglucosamine (Gal beta 1-4GlcNAc or Gal beta 1-3GlcNAc, respectively) were investigated in the human bronchial epithelium by histochemistry by using sequence-specific monoclonal antibodies and lectins. Among the mature epithelial cells, only ciliated cells were found to express the long-chain antigens, whereas mucus-secreting cells contained the short-chain antigens associated with mucus globules. The long-chain oligosaccharides were found to be highly polarized at the luminal aspects of the ciliated cells where the branched structures (I and sialosyl-I antigens) were detected both at the apical-microvillar border and on the cilia, but the linear structures (i, sialosyl-i, and VIM-2 antigens) were detected exclusively at the apical-microvillar border. These observations provide the first in situ visualization of the receptor structures for M. pneumoniae at the primary site of infection. The lack of sialo-oligosaccharide receptors in secretory cells and the mucus they produce provides a biochemical basis for evasion by this microorganism of the secreted mucus barrier.
Loveless
R W
RW
Section of Glycoconjugate Research, MRC Clinical Research Centre, Harrow, United Kingdom.
Feizi
T
T
D000606:Amino Sugars / Q000302:isolation & purification / Q000378:metabolism*; D000942:Antigens, Bacterial / Q000032:analysis; D001980:Bronchi / Q000378:metabolism / Q000382:microbiology*; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002923:Cilia / Q000378:metabolism*; D003208:Concanavalin A; D004848:Epithelium / Q000378:metabolism / Q000382:microbiology; D006801:Humans; D008358:Mannose / Q000502:physiology; D008871:Microvilli / Q000378:metabolism / Q000382:microbiology*; D008969:Molecular Sequence Data; D009093:Mucus / Q000378:metabolism; D009177:Mycoplasma pneumoniae / Q000378:metabolism*; D019158:N-Acetylneuraminic Acid; D009844:Oligosaccharides / Q000302:isolation & purification / Q000378:metabolism*; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic / Q000302:isolation & purification*; D012794:Sialic Acids / Q000302:isolation & purification / Q000378:metabolism*
D000606:Amino Sugars; D000942:Antigens, Bacterial; D009844:Oligosaccharides; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; D012794:Sialic Acids; C028583:sialyloligosaccharide receptor; D003208:Concanavalin A; C000458:N-acetyllactosamine; D019158:N-Acetylneuraminic Acid; D008358:Mannose