CARBOHYDRATE CHAINS OF HUMAN TRACHEOBRONCHIAL MUCINS AND ANTIMICROBIAL DEFENSE OF RESPIRATORY MUCOSA

Human respiratory mucins consist of a broad family of glycoproteins synthesized by the respiratory mucosa. The peptide diversity (apomucins) stems from the expression of several genes. However the mucin diversity is significantly increased by post-translational phenomenons, mostly O-glycosylation that is responsible for 80 % of the weight of the mucin molecule. This O-glycosylation leads to a remarkable diversity of carbohydrate chains and several hundreds of different chains exist on the mucins from a single individual. This carbohydrate mosaic allows the recognition of inhaled microorganisms which are then eliminated by the activity of the mucociliary system. Thus the carbohydrate chain diversity may play an essential role in the defense of the underlying respiratory mucosa.