Semin Respir Crit Care Med 2004; 25(1): 21-31
DOI: 10.1055/s-2004-822302
Copyright © 2004 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA.

Macrophages in Innate and Acquired Immunity

Homer L. Twigg1  III 
  • 1Division of Pulmonary and Critical Care, Indiana University Medical Center, Indianapolis, Indiana
Further Information

Publication History

Publication Date:
12 March 2004 (online)

Preview

Alveolar macrophages play a central role in pulmonary host defense. When foreign particles or pathogens enter the respiratory tract, constitutively present innate host defenses attempt to clear the challenge. Alveolar macrophage phagocytosis of foreign material is a critical component of this response, as is secretion of inflammatory mediators designed to combat invading pathogens. If the pathogenic burden is too large and overwhelms innate immunity, then acquired immune responses are initiated resulting in the generation of antigen-specific cellular and humoral immunity. In response to evolutionary pressures to minimize unnecessary inflammation in the lower respiratory tract, alveolar macrophages are generally poor accessory cells in the initiation of specific immunity. However, in many circumstances, especially those associated with cellular activation, alveolar macrophages can play an important role in the generation and expansion of pulmonary immune responses. This review discusses the role of alveolar macrophages in innate and acquired pulmonary host defense.

REFERENCES

Homer L Twigg IIIM.D. 

Indiana University Medical Center

1481 West 10th St., 111P-IU

Indianapolis, IN 46202

Email: htwig@iupui.edu