This project is designed to study local and systemic, humoral and cellular immunological responses in the lung of the rabbit following repeated inhalation of simple protein antigens. Immunogenic requirements for hypersensitivity lung disease will be studied, as will immunological accompaniments of disease and of defense mechanisms. Antigen-specific antibodies of individual immunoglobulin classes will be quantitated using a modified enzyme-linked immunosorbent assay (ELISA) and immunoglobulin localization in the lung will involve immunohistological techniques. Antigen-specific cell-mediated immunity will employ lymphocyte blastogenesis and cellular cytotoxicity assays, using cells obtained from peripheral blood, peripheral lymph nodes, broncho-alveolar lavage, bronchus-associated lymphoid tissue and hilar-mediastinal lymph nodes. Using these techniques we hope to better understand immunogenic requirements, pathogenesis and potential protective mechanisms in human inhalational lung diseases.