Immunomodulation for the prevention and treatment of lung infections

The clearance of microbes from the respiratory tract requires the generation of a vigorous and compartmentalized host immune response. When pulmonary infection occurs in the setting of impaired innate and acquired immune responses, antimicrobial agents alone often cannot cure the host. This article reviews both conventional and experimental approaches to stimulate innate and acquired immune responses. These strategies include immunotherapy to directly enhance effector cell function of phagocytic cells (e.g., cytokine immunotherapy) or skew immune responses toward protective type 1 immunity (e.g., CD40 ligand, CpG dinucleotides, cytokines). Additionally, the role of immunization (either active or passive) in the prevention and treatment of respiratory tract infection is addressed. Although the clinical context in which these immunomodulatory approaches may be of benefit in the treatment of respiratory tract infection remains uncertain, potential applications of immunotherapy are explored.