Home Applications Glycobiology & Proteomics Glycans in Immunity
glyco application

Glycans in Immunity

Return to Glycobiology & Proteomics

The immune response is intimately associated with glycan recognition. Protein glycosylation is critical for the differentiation and maturation of immune cells. Glycan-binding proteins (lectins), on the other hand, are critical for activation and function.
 
Examples of the roles of glycans in the immune system include:

  • Many CDs (clusters of differentiation) are glycoproteins or lectins (glycan-binding proteins).
  • The cell surface of mammalian cells is rich in glycoconjugates (glycocalyx) displaying self-identity determinants and other antigens, such as the A-B-O blood groups.
  • Many pathogen-associated molecular patterns (PAMPs) are glycans, and their immune receptors are carbohydrate-binding proteins (lectins).
  • Cell-surface glycans determine lymphocyte migration to injury sites.
  • While the Fab (variable) region of antibodies determines their specificity, the glycosylation at the Fc (constant) region modulates their effector functions.
  • Galectins (galactose-binding lectins) are intimately associated with pathogen recognition, inflammation, effector functions and cancer progression.
  • The mannose receptor binds terminal sugars found on some microorganisms. It has an important role in the innate and adaptive immune responses, as well in glycoprotein clearance from the bloodstream.

During inflammation, circulating leukocytes are recruited via their glycans, which are recognized by specific receptors (selectins) in the endothelial wall. The leukocytes stop and firmly adhere to the endothelium before moving out towards the injured tissue. This process is a critical component of the innate immune response: patients affected with glycosylation disorders often present with recurrent infections, due to leukocyte adhesion deficiency.

References:

  1. Maverakis, E. et al. (2015) J. Autoimmun., 57:1-13. PMID 25578468.
  2. Kumar. S. et al. (2012) Bioinformatics. 28(19):2553-5. PMID 22847935.
  3. Johnson, J.L. et al. (2013) Trends Immunol. 34(6):290-8. PMID 23485517.
  4. Cerliani, J.P. et al. (2011) J. Clin. Immunol. 31(1):10-21. PMID 21184154.

Learn about Glycobiology & Proteomics