STRUCTURE, SECRETION, AND BACTERIAL SPECIFICITY OF AN ENDOGENOUS LECTIN FROM CYSTIC-FIBROSIS LUNG

Endogenous heparin-binding lectin purified from postmortem lung samples of two cystic fibrosis (CF) patients was compared to lectin derived from normal tissue with respect to structure, carbohydrate specificity, interaction with alginate derived from CF isolates of Pseudomonas aeruginosa, and secretion within the lung. Lectin was purified from extracts of lung tissue by gel filtration on Sepharose CL-2B followed by affinity chromatography on heparin-Sepharose. Lectin purified from either CF lung or control tissue ran as two peptides of approximately 16,000 and 13,000 molecular weight on electrophoresis in sodium dodecyl sulfate. The lectins displayed similar carbohydrate specificity and interacted in much the same way with bacterial alginate. An increase in lectin secretion was seen in CF lungs affecting the bronchial epithelial cells and the mucosal glands. The data suggest that the major changes seen in endogenous heparin-binding lectin in CF are related to the quantity and distribution of lectin secretion.