Immunobiology of lymphocytes in the lung

Lymphocytes in the lung offer unique opportunities for studying lymphocyte function that cannot be studied as easily in other regions of the body. Single lobes can be immunized and challenged as required for the evaluation of lymphocytes within the sensitized and unsensitized lung lobes. Results address questions of basic immunology and can specifically evaluate the phenomena of memory and traffic. Lymphocytes from a single grafted lung lobe can be compared to the lymphocytes washed from the intact lobes for insights into cells that invade the grafted organs. Similarly, lymphocytes washed from lungs that harbor malignancy or infection offer information pertaining to those diseases. Although rarely considered by lung biologists and physiologists as more than transitory warriors, evidence in this review support the concept that lymphocytes participate in cell-cell interactions in both health and disease. Although studies to define the interaction of the lymphocyte with other lung cells to regulate growth and development in the lung are in their infancy, the abundant information about the lymphokines that are growth factors for nonlymphoid cells and the cell surface molecules that recognize other cells carry with it the prediction that the lymphocyte is primarily important to lung biology. Well accepted is the fact that lymphocytes in the lung are important to nonspecific and specific defenses in that organ. Contemporary studies purposely evaluate cells recovered from the lung for insight into pulmonary immune responses because studies dissecting immune responses in peripheral blood or spleen (experimental animals) may bear little or no relationship to the immune events that conspire toward healing or disease in the lung.(ABSTRACT TRUNCATED AT 250 WORDS)