ABSTRACT
This chapter discusses immune recruitment of neural mediators and lymphocyte recognition and responses to neuropeptides and describes new findings of neuromodulation of pulmonary immune responses in a mouse model. Peptidergic nerves in lung tissues end on or in close proximity to lymphocytes and other immune cells, as well as smooth muscle, epithelial, secretory, and vascular elements. A role for neuropeptides, especially Substance P and Vasoactive Intestinal Peptide, in the mediation and regulation of pulmonary compartmental immune responses is suggested by their capacity to increase lymphocyte adherence to other lymphocytes and endothelial cells. Immediate hypersensitivity reactions are characterized by the IgE-dependent release from mast cells of the phospholipid platelet-activating factor (PAF), which enhances neural proliferation, and histamine, which facilitates neural transmission. Intrapulmonary antigenic challenge of sensitized subjects results in a temporally-ordered influx of lymphocytes and other immunocompetent mononuclear leukocytes, with distinct phenotypic and functional characteristics.
