Abstract
The authors recently demonstrated that pollen are far more than only allergen carriers as they release also bioactive lipid mediators (pollen-associated lipid mediators, PALMs) upon contact with an aqueous phase. These mediators released by pollen (birch and grass) activate and recruit granulocytes in vitro. Pollen-derived granulocytic chemotactic activity may be attributable to one or more lipids that are functionally and structurally closely related to leukotrienes. Pollen extracts contained substantial amounts of linolenic acid-derived hydroxy fatty acid derivatives, namely 13-HODE and 13-HOTE which also lead to activation and migration of granulocytes. Apart from these pro-inflammatory substances also immunmodulatory lipid mediators were identified. This immunomodulatoiy activity was shown by a block of the LPS-/CD40-induced IL-12 production in human monocyte-derived dendritic cells, leading also to an enhanced ensuing TH2 response. The chemical analysis revealed substantial amounts of the recently described phytoprostanes of which the phytoprostanes E1 could be identified as one of the IL-12-reducing factors in aqueous pollen extracts. These results suggest that pollen-derived lipid mediators play an important role in the modulation of dendritic cell function, and consequently influence the nature of the corresponding T-cell response.
Translated title of the contribution | Pollen-associated lipid mediators (PALMs): Pro-inflammatory and immunomodulatory activity on cells of the allergic inflammation |
---|---|
Original language | German |
Pages (from-to) | 396-401 |
Number of pages | 6 |
Journal | Allergo Journal |
Volume | 14 |
Issue number | 5 II |
DOIs | |
State | Published - Jul 2005 |