Hakata Antigen, a New Member of the Ficolin/Opsonin p35 Family, Is a Novel Human Lectin Secreted into Bronchus/Alveolus and Bile

• Published in: The journal of histochemistry and cytochemistry Vol. 47; no. 6; pp. 777 - 785
• Main Authors: Akaiwa, Mina, Yae, Yoshiaki, Sugimoto, Rie, Suzuki, Satoshi O, Iwaki, Toru, Izuhara, Kenji, Hamasaki, Naotaka
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA Histochemical Soc 01.06.1999; SAGE Publications
• Subjects: Antibodies, Monoclonal; Bile Ducts - metabolism; Bronchi - metabolism; Glycoproteins - biosynthesis; Glycoproteins - genetics; Glycoproteins - immunology; Glycoproteins - metabolism; Humans; Immunohistochemistry; Lectins; Liver - metabolism; Lung - metabolism; Pulmonary Alveoli - metabolism; RNA, Messenger - biosynthesis; Tissue Distribution; bronchus; Hakata antigen; lectin; alveolus; opsonin p35; ficolin; bile
• ISSN: 0022-1554; 1551-5044
• DOI: 10.1177/002215549904700607

Hakata antigen was first reported as a serum protein that reacted with an autoantibody from patients with systemic lupus erythematosus. Recently, it has been found that Hakata antigen is a new member of the ficolin/opsonin p35 family, which is a distinct lectin family, on the basis of homology of structures and the common characteristic of possessing lectin activity. In this study we analyzed the tissue distribution of Hakata antigen. Hakata antigen mRNA and protein were generated in the lung and liver. In the lung, Hakata antigen was produced by both ciliated bronchial epithelial cells and Type II alveolar epithelial cells and was secreted into the bronchus and alveolus. In the liver, Hakata antigen was produced by bile duct epithelial cells and hepatocytes and was also secreted into the bile duct. These results demonstrate that Hakata antigen is a unique lectin protein that exists not only in serum but also in bronchus/alveolus and bile, and indicate that Hakata antigen plays a role in bronchus/alveolus and bile under physiological conditions.