Cytokines and pulmonary host defenses

The generation of a vigorous inflammatory response is essential for rapid clearance of microbes from the alveolar space. The magnitude of the inflammatory response is tightly controlled by host-derived cytokines, which mediate lung inflammation by serving as leukocyte chemoattractants, leukocyte activating factors, or afferent signals in the induction or regulation of other effector molecules. In this chapter, the role of specific cytokines in lung innate and adaptive immunity against bacterial, mycobacterial, fungal, and parasitic pathogens is reviewed. Future directions regarding the use of specific forms of immunotherapy, including compartmentalized cytokine delivery using gene therapy, as adjuvant therapy in the treatment of pneumonia are explored.