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IgA and Intestinal Homeostasis

  • Per Brandtzaeg
  • Finn-Eirik Johansen

The body is under constant threat of attack by viruses, bacteria, and parasites, and most pathogens use the mucosae as portals of entry. Evolution has therefore provided mammalians with several complex and potent layers of defense. Microorganisms have inhabited Earth for at least 2.5 billion years, and the power of immunity is a result of coevolution in which particularly the commensal bacteria have shaped the body’s defense functions in a state of mutualism (Bäckhed et al., 2005; Hooper and Gordon, 2001). In humans, the critical role of the immune system becomes clinically apparent when it is defective. Thus, inherited and acquired immunodeficiency states, or more subtle immunoregulatory defects, are characterized by increased susceptibility to infectious diseases—sometimes caused by the commensal microbiota that is normally considered to be nonpathogenic (Haller and Jobin, 2004; Sansonetti, 2004; Yan and Polk, 2004).

Keywords

Celiac Disease Lamina Propria Oral Tolerance Commensal Bacterium Intestinal Homeostasis 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  • Per Brandtzaeg
    • 1
  • Finn-Eirik Johansen
    • 1
  1. 1.Department and Institute of PathologyRikshospitalet University HospitalNorway

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