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Semin Liver Dis 1997; 17(4): 311-318
DOI: 10.1055/s-2007-1007207
ORIGINAL ARTICLE

© 1997 by Thieme Medical Publishers, Inc.

The Role of Collectins in Host Defense

Michiko Sumiya, John A. Summerfield
  • Liver Unit, Imperial College School of Medicine at St. Mary's, London, England
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Publication History

Publication Date:
17 March 2008 (online)

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ABSTRACT

Mannose-binding protein (MBP) belongs to a group of Ca2+-dependent lectins called collectins that play a role in first-line host defense. It recognizes specific carbohydrate residues (mannose and N-acetylglu-cosamine) on the surface of microorganisms and promotes the killing of microbes either by acting directly as an opsonin or by activating the lectin complement pathway. The collagenlike domain of MBP is important for the binding of MBP to the collectin receptors expressed on different phagocytes, and for activation of complement. The binding of MBP to bacteria, viruses, and parasites has been demonstrated in vitro. Three major mutations have been found in exon 1 of the MBP gene, which encodes the collagenous domain of the protein. These mutations cause low levels of serum MBP and have been linked with lifelong risk of infection. The homozygotes for these mutations are especially susceptible to severe infections.

KEY WORDS

mannose-binding protein - collectin - opsonin - lectin complement pathway - innate immunity

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