Glycoprofile of the different cell types present in the mucosa of the horse guttural pouches

Histochemical characterization of the equine guttural pouches was performed using lectins combined with sialidase digestion and deglycosylation pre-treatments.The goblet cells contained O- and N-linked oligosaccharides with α-Fuc, GlcNAc moieties whereas β-GalNAc, β-Gal-(1–3)-GalNAc, β-Gal-(1–4)-GlcNAc and α-Gal residues belonged only to O-linked glycoproteins. The acinar and ductal cells expressed α-Man/α-Glc in N-linked oligosaccharides, GlcNAc in both O- and N-glycoproteins and β-GalNAc, β-Gal-(1–3)-GalNAc, β-Gal-(1–4)-GlcNAc and α-Gal residues included in O-linked glycoproteins. The Golgi area of the epithelial lining expressed α-Fuc in O-linked glycoproteins, internal GlcNAc in N-linked glycoproteins and large amounts of sialic acid residues linked to subterminal β-GalNAc, Galβ1,4GlcNAc and Galβ1,3GalNAc. High amounts of sulpho-carbohydrates and of sialic acids (α2,3–6), linked to-α/β-Gal and sialic acids (α2–6) linked to β-GalNAc, were also demonstrated.Such diversity of the mucin saccharide residues may be implicated in the binding of macromolecules such as those of bacterial or viral etiology, thus playing a role in the organism's host-defense mechanism in the guttural pouches.