title: Decreased sialylation of the acute phase protein alpha1-acid glycoprotein in feline infectious peritonitis (FIP).
abstract: Feline infectious peritonitis (FIP) is an immune-mediated disease of domestic and exotic felides infected with feline coronavirus. FIP is characterized by the overexpression of an acute phase protein, the alpha1-acid glycoprotein (AGP). In humans, AGP is a heavily glycosylated protein that undergoes several modifications of its glycan moiety during acute and chronic inflammatory pathologies. We studied the changes in AGP glycosylation in the course of FIP. Specifically, we focussed our attention on the degree of sialylation, fucosylation and branching. This study presents a purification method for feline AGP (fAGP) from serum, using an ion exchange chromatography strategy. The glycosylation pattern was analyzed in detail by means of interaction of purified fAGP with specific lectins. In particular, Sambucus nigra agglutinin I and Maackia amurensis agglutinin lectins were used to detect sialic acid residues, Aleuria aurantia lectin was used to detect L-fucose residues and Concanavalin A was used to evaluate the branching degree. By this method we showed that fAGP did not present any L-fucose residues on its surface, and that its branching degree was very low, both in normal and in pathological conditions. In contrast, during FIP disease, fAGP underwent several modifications in the sialic acid content, including decreased expression of both alpha(2-6)-linked and alpha(2-3)-linked sialic acid (76 and 44%, respectively when compared to non-pathological feline AGP).
authors.affiliation: Dipartimento di Patologia Animale Igiene e Sanità Pubblica Veterinaria, University of Milano, Via Celoria 10, 20133 Milan, Italy. fabrizio.ceciliani@unimi.it
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Ceciliani
authors.forename: Claudia
authors.initials: C
authors.lastname: Grossi
authors.forename: Alessia
authors.initials: A
authors.lastname: Giordano
authors.forename: Vanessa
authors.initials: V
authors.lastname: Pocacqua
authors.forename: Saverio
authors.initials: S
authors.lastname: Paltrinieri
mesh_terms: D000818:Animals; D015153:Blotting, Western / Q000662:veterinary; D002236:Carbohydrate Conformation; D002415:Cats; D002852:Chromatography, Ion Exchange / Q000662:veterinary; D016765:Coronavirus, Feline / Q000276:immunology*; D016766:Feline Infectious Peritonitis / Q000276:immunology / Q000378:metabolism*; D005260:Female; D006031:Glycosylation; D008297:Male; D009961:Orosomucoid / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D037121:Plant Lectins / Q000378:metabolism; D012794:Sialic Acids / Q000276:immunology / Q000378:metabolism*
chemical_list: D009961:Orosomucoid; D037121:Plant Lectins; D012794:Sialic Acids