1988 Fiscal Year Final Research Report Summary

The absorption of inhaled antigens and pulmonary immune responses

Research Project

Project/Area Number	61570365
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	Respiratory organ internal medicine
Research Institution	University of Tsukuba
Principal Investigator	YASHIZAWA Yasuyuki University of Tsukuba, 臨床医学系内科, 助教授 (20174914)
Co-Investigator(Kenkyū-buntansha)	OHTSUKA Morio University of Tsukuba, 臨床医学系内科, 講師 (00143173) HASEGAWA Shizuo University of Tsukuba, 臨床医学系内科, 教授 (90009481)
Project Period (FY)	1986 – 1988
Keywords	Isolated perfused Lung System / Antigen Absorption / Antigen presentation / 過敏性肺炎の消褪
Research Abstract	The present study was designed to learn the absorption process of inhaled antigens, the capability of antigen presentation by alveolar macrophage and the immunological observations in a patient with hypersensitivity pneumonitis who has been asymptomatio in spite of continuous exposure to the antigen. The results indicated that, 1) isolated perfused lung system in which the only route for antigen absorption is the alveolo-capillary membrane maintained the lungs intact for 6 h, 2) the absorption rate of antigens was different depending upon the molecular size, 3) alveolar macrophage were capable of presenting PPD to T lvmphocytes in PPD-induced T lymphocyte proliferation, 4) most alveolar macrophages expressed HLA-DR antigen on their surface membrane. 5) intact HAL-DR antigen was required for antigen presentation. 6) continuous exposure to the antigen resulted in the disappearance of hypersensitivity pneumonitis. 7) antibodies to antigen were found in sera and bronchoalveolar (BAL) fluids even at the asymptomatic, 8) BAL revealed lymphocytosis, predominantly suppressor/cytotoxic T lymphocvtes avan at the asymptomatic stage. 9) The ensuing disappearance of disease was closely associated with the reduction of antigen-induced lymphocyte proliferation. We coneluded that the complicated mechanisms are involved in the pulmonary immunolors.