How Do Pollen Allergens Sensitize?

Abstract

Plant pollen is one of the main sources of allergens causing allergic diseases such as allergic rhinitis and asthma. Several allergens in plant pollen are panallergens which are also present in other allergen sources. As a result, sensitized individuals may also experience food allergies. The mechanism of sensitization and development of allergic inflammation is a consequence of the interaction of allergens with a large number of molecular factors that often are acting in a complex with other compounds, for example low-molecular-mass ligands, which contribute to the induction a type 2-driven response of immune system. In this review, special attention is paid not only to properties of allergens but also to an important role of their interaction with lipids and other hydrophobic molecules in pollen sensitization. The reactions of epithelial cells lining the nasal and bronchial mucosa and of other immunocompetent cells will also be considered, in particular the mechanisms of the activation of B and T lymphocytes and the formation of allergen-specific antibody responses.

Structural and Immunologic Properties of the Major Soybean Allergen Gly m 4 Causing Anaphylaxis

“…Homologues of Bet v 1 are panallergens involved in the development of pollen–pollen and pollen–food allergic cross-reactions due to their structural similarity and an ubiquitous presence in plant tissues [ 3 ]. It is well-known that the birch pollen allergen Bet v 1 is the main sensitizer of this class of allergens, causing cross-reactions in most cases.…”

“…Bet v 1-like proteins are generally heat sensitive, denature in an acidic environment, and, consequently, are rapidly degraded by gastric enzymes [ 11 ]. Therefore, food allergens of this class cause mostly mild allergic reactions—for example, oral allergic syndrome (OAS) [ 3 , 12 ]. At the same time, life threatening systemic allergic reactions, like urticaria and anaphylaxis, have also been described for some food homologues of Bet v 1, primarily, for the soybean Gly m 4 [ 13 , 14 ].…”

Protease allergens as initiators–regulators of allergic inflammation

“…Interestingly, Der p 2, Bet v 1, or Fel d 1 belong to families of lipid‐binding proteins and Der p 2 mediates TLR4‐ but also TLR2‐dependent proinflammatory responses. The complexity of the allergen sensing serves as a reminder that our understanding of the innate immune programming of allergy and its interaction with genetic predispositions remains rudimentary 175–177 …”

“…The complexity of the allergen sensing serves as a reminder that our understanding of the innate immune programming of allergy and its interaction with genetic predispositions remains rudimentary. [175][176][177] Despite all we have learned, our mechanistic understandings of how protease allergens induce the allergic response remains unresolved. Moreover, most of the data on protease allergens were focused on Der p 1 or proteolytically active HDM extracts, and it is presently unclear as to what extent these principles can be simply applied to other protease allergens.…”

DNA methylation regulatory patterns and underlying pathways behind the co-pathogenesis of allergic rhinitis and chronic spontaneous urticaria

“…Although pollen was considered a key allergen in AR and CSU, the intrinsic pathogenesis of how it leads to immune responses was still unclear. Studies have shown that Bet v1, one of the most significant plant allergens in pollen, can be recognized by T cells in individuals with birch pollen allergy ( 19 , 20 ). It was also widely accepted that immune responses to airborne allergens likely involve two subsets of CD4+ T cells, namely Tfh cells and Th2 cells ( 21 ).…”