These laboratories are concerned with the elucidation of the pathogenesis of immunologic mechanisms involved in chronic pulmonary diseases. This is done through the study of immune reactions in existing disease or by the construction of suitable experimental models. Some of the individual projects covered by this grant include (1) understanding the role of immune complexes in experimental hypersensitivity pneumonitis; (2) studying the role of homologously produced lung antibody in tuberculosis and experimental coalworkers' pneumoconiosis; (3) establishing the delayed hypersensitivity aspects of immune injury in berylliosis; (4) investigating delayed hypersensitivity to self-contained lung connective tissue antigens; (5) utilizing better serologic techniques for the study of fungus induced hypersensitivity pneumonitides.