Thechapter describes the cells and structures of the lung that participate in pulmonary immunity and how the lung responds to challenges fromforeign antigens, with particular emphasis on animal models that have been developed to explore these issues. Some ligands-receptor interactions are specific while others are not, and it is the particular pattern of surface molecules and secreted factors expressed by interacting immune cells that determines the type of immune response that develops during central processing. The cells that are the major initiators and regulators of immunity in the lung include macrophages, dendritic cells (DCs), and lymphocytes, each expressing surface molecules and secretory products that depend on perturbations in the environments. Immune cells and structures of the lung and lung immunity to noninfectious particulate and soluble antigens are discussed. Several models for regulation of pulmonary immunity such as models for immunity in lung infections, models for hypersensitivity lung disease, models for lung transplantation, and graft versus host are also presented. Demonstration that lung cells regulate both nonspecific inflammation and immunity through the expression of adhesion molecules and the secretion of cytokines offers hope for ways to design more effective vaccines, enhance microbial clearance in immune-suppressed hosts, and to suppress manifestations of immunologically mediated lung disease.
The Regulation of Pulmonary Immunity