Complementary roles for lipid and protein allergens in triggering innate and adaptive immune systems

Allergy. 2008 Nov;63(11):1428-37. doi: 10.1111/j.1398-9995.2008.01810.x.


Background: Recent advances in allergy research mostly focussed on two major headings: improving protein allergen purification, which is aimed towards a better characterization of IgE- and T-cell reactive epitopes, and the potential new role for unconventional innate and regulatory T cells in controlling airway inflammation. These advancements could appear to be in conflict each other, as innate T cells have a poorly-defined antigen specificity that is often directed toward nonprotein substances, such as lipids.

Method: To reconcile these contrasting findings, the model of cypress pollinosis as paradigmatic for studying allergic diseases in adults is suggested.

Results: The biochemical characterization of major native protein allergens from undenatured pollen grain demonstrated that the most relevant substance with IgE-binding activity is a glycohydrolase enzyme, which easily denaturizes in stored grains. Moreover, lipids from the pollen membrane are implicated in early pollen grain capture and recognition by CD1(+) dendritic cells (DC) and CD1-restricted T lymphocytes. These T cells display Th0/Th2 functional activity and are also able to produce regulatory cytokines, such as IL-10 and TGF-beta. CD1(+) immature DCs expand in the respiratory mucosa of allergic subjects and are able to process both proteins and lipids.

Conclusion: A final scenario may suggest that expansion and functional activation of CD1(+) DCs is a key step for mounting a Th0/Th2-deviated immune response, and that such innate response does not confer long-lasting protective immunity.

MeSH terms

  • Allergens / immunology*
  • Allergens / metabolism
  • Antigens, CD1 / chemistry
  • Antigens, CD1 / immunology
  • Antigens, CD1 / metabolism
  • Cupressus / immunology*
  • Dendritic Cells / immunology
  • Dendritic Cells / metabolism
  • Epitopes, T-Lymphocyte / immunology
  • Epitopes, T-Lymphocyte / metabolism
  • Humans
  • Immune System / immunology*
  • Immune System / metabolism
  • Immunity, Innate
  • Immunoglobulin E / blood
  • Lipids / immunology*
  • Pollen / chemistry
  • Pollen / immunology
  • Pollen / metabolism
  • Proteins / immunology*
  • Proteins / metabolism
  • Rhinitis, Allergic, Seasonal / immunology*
  • T-Lymphocyte Subsets / immunology
  • T-Lymphocyte Subsets / metabolism


  • Allergens
  • Antigens, CD1
  • Epitopes, T-Lymphocyte
  • Lipids
  • Proteins
  • Immunoglobulin E