Immune Netw.  2017 Jun;17(3):133-143. 10.4110/in.2017.17.3.133.

The Role of Lipids in Development of Allergic Responses

• del Moral
• Martínez-Naves E

• KMID: 2383351
• DOI: http://doi.org/10.4110/in.2017.17.3.133

Abstract

Most allergic diseases are caused by activation of Th2 type immune responses resulting in the production of specific IgE against proteins found in normally harmless substances such as pollen, mites, epithelia or food. Allergenic substances are composed, in addition to proteins, of other compounds such as carbohydrates and lipids. Those lipids are able to promote the development of Th2-type responses associated with allergy. There are lipids found in pollen, milk or insect venom that are specifically recognized by CD1 restricted unconventional T lymphocytes, which can promote allergic reactions. Furthermore, a large number of allergens are proteins containing hydrophobic parts that specifically bind lipids that are capable to favor allergenic immune responses. Also, lipids associated to substances like pollen, dander, epithelia or the bacteria can act on cells of the innate system, including dendritic cells, which in turn lead to the differentiation of Th2-type clones. Finally, lipids may also influence the ability of allergens to be exposed to the immune system within the oral, respiratory or intestinal mucosa where allergic response occurs with great frequency.

Keyword

Allergy; Lipids; Adaptive immunity; T-cells; Innate immunity; Allergens

MeSH Terms

Adaptive Immunity
Allergens
Bacteria
Carbohydrates
Clone Cells
Dander
Dendritic Cells
Hypersensitivity
Immune System
Immunity, Innate
Immunoglobulin E
Insects
Intestinal Mucosa
Milk
Mites
Pollen
T-Lymphocytes
Venoms
Allergens
Carbohydrates
Immunoglobulin E
Venoms

Figure

• 

  Figure 1 A model of how lipids can influence the allergic response. Particles (1) (pollen, animal hair, food, etc.) containing peptidic (red squares) allergens and lipids (yellow triangles) can be internalized by DCs (2). These cells present lipids (3) to NKT cells or other CD1 restricted T lymphocytes, which release cytokines (4) such as IL4, which in turn promote the differentiation of Th0 lymphocytes into Th2 cells (4) which recognize peptidic antigens through HLA class II molecules. Subsequently, Th2 cells promote the activation of B-cells (5) to develop into IgE producing plasma cells (6). On the other hand, lipids in different forms, for example attached to lipid-carrying proteins (7), PALMS (pollen associated lipids mediators), etc. can influence the relationship between peptidic allergens and a variety of cell types, including respiratory or intestinal epithelial cells (8) or antigen-presenting cells (9), which, by mechanism still undefined (10) , may facilitate the development of Th2-type responses.

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