Pathogenesis of summer-type hypersensitivity pneumonitis : Analysis with serotype-related polysaccharide of Trichosporon cutaneum and its nonoclonal antibodies

Research Project

Project/Area Number	03670405
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	Respiratory organ internal medicine
Research Institution	Kumamoto University
Principal Investigator	ANDO Masayuki Kumamoto University, First Department of Internal Medicine, Professor, 医学部, 教授 (00040204)
Project Period (FY)	1991 – 1992
Project Status	Completed (Fiscal Year 1992)
Budget Amount *help	¥2,000,000 (Direct Cost: ¥2,000,000) Fiscal Year 1992: ¥300,000 (Direct Cost: ¥300,000) Fiscal Year 1991: ¥1,700,000 (Direct Cost: ¥1,700,000)
Keywords	Summer-type hypersensitivity pneumonitis / Trichosporon cutaneum / monoclonal antibody / enzyme-linked immunosorbent assay / glucuronoxylomannan / serotype-specific polysaccharide antigen / 診断用ELISAキット / モノクロ-ナル抗体 / 菌血清型関連抗原 / 発症機序 / 気管支肺胞洗浄液
Research Abstract	Summer-type hypersensitivity pneumonitis (SHP) is a unique type of hypersensitivity pneumonitis and the most prevalent in Japan. Our previous study clarified that the causative agent of the disease is Trichosporon cutaneum, and that the patients with SHP have high titer of antibodies against the serotype-specific antigen of polysaccharide nature which exist in the high molecular weight fraction of the culture supernatant of the yeast. In this study, we purified the serotype-specific antigen of serotype II T.cutaneum by gel filtration and affinity chromatography using a monoclonal antibody, D-8, specific for serotype II T.cutaneum, and elucidated the structure of the antigen. The affinity-purified antigen was shown to be essentially acidic polysaccharide comprising mannose, xylose, and glucuronic acid. Chemical analysis showed that this polysaccharide antigen contains a (1-3)-linked mannan backbone attached with short chains of (1-4)-linked mannose and a small portion of (1-2) linked xylose residues by substituting the 2-or4- positions of the (1-3)-linked mannose residues of the main chain. The antigenic epitope was shown to involve the terminal glucuronic acid residues as revealed by immunodiffusion test and sandwich enzyme-linked immunosorbent assay using monoclonal antibody D-8.