The Immune Basis of Allergic Lung Disease

Abstract The clinical manifestations and pathophysiology of allergic airways diseases result from complex responses of the innate and acquired immune systems to environmental stimuli leading to structural and functional changes in the neural networks, smooth muscle, connective tissue, circulation, and epithelium in the airway wall. Allergic airways diseases are common, and the impacts on health range from minor discomfort to debilitating and life-threatening airway obstruction. Many of the cells, transmitters, cytokines, and receptors involved in the responses to inhaled allergens have been identified, but integration of these components is not fully understood, particularly outside of the laboratory and clinic where diverse intrinsic and extrinsic factors can affect the responses. The intent in this chapter is to review the information that has accrued up to this point in time and equip the reader to interpret future discoveries in the context of previous findings. The pathophysiology of allergic lung disease is described, complexities of the cellular and cytokine networks are explored, and intrinsic and extrinsic factors that impact these mechanisms are identified. Animal models, particularly murine models of asthma and genetically-modified mouse strains, have contributed significantly to understanding of allergic diseases and immune mechanisms, and strengths and weaknesses of these models that have contributed to knowledge in this area are discussed.