Immunoglobulin E specific for Holcus lanatus pollen allergens (Hol l-sIgE)

Immunoglobulin E (IgE) antibodies specific for Holcus lanatus (Velvet grass) pollen allergens are the primary mediators of Type I hypersensitivity reactions in individuals sensitized to this common grass species. These antibodies specifically recognize and bind to major allergens such as Hol l 1 (a beta-expansin) and Hol l 5 (a ribonuclease) found in the pollen (WHO/IUIS Allergen Nomenclature). Once produced, these IgE molecules bind to high-affinity FcεRI receptors on the surface of mast cells and basophils. Upon subsequent exposure to Holcus lanatus pollen, the allergens cross-link the receptor-bound IgE, triggering the rapid release of inflammatory mediators like histamine and leukotrienes, which cause the clinical symptoms of hay fever and asthma (PubMed, 9464852). Therapeutic strategies targeting these antibodies include the use of anti-IgE monoclonal antibodies like Omalizumab, which sequester circulating IgE regardless of its specificity, and allergen-specific immunotherapy (AIT), which aims to desensitize the immune system and shift the response toward a tolerant state characterized by increased IgG4 and reduced IgE activity (JACI, 2017).

Other names

Velvet grass-specific IgEAnti-Holcus lanatus IgEHol l 1-specific IgEHol l 5-specific IgESpecific IgE to Holcus lanatus

Omalizumab binds to the Cε3 domain of circulating IgE, preventing its interaction with the high-affinity IgE receptor (FcεRI) on mast cells and basophils, thereby inhibiting the allergic cascade (FDA Label, 2016). Allergen-specific immunotherapy (AIT) involves the administration of Holcus lanatus pollen extracts to induce peripheral T-cell tolerance, increase regulatory T-cells (Tregs), and promote the production of allergen-specific IgG4 blocking antibodies that compete with IgE for allergen binding (Akdis & Akdis, 2014).