Von Ebner gland protein (Fel d 7) (Fel d 7)

Fel d 7 is a member of the lipocalin protein family secreted by the domestic cat (Felis domesticus), primarily identified in the von Ebner's glands and saliva [1, 2]. Biologically, it belongs to a class of proteins known for binding and transporting small hydrophobic molecules, such as pheromones or lipids, although its specific endogenous ligand in cats remains to be fully elucidated [3, 4]. In humans, Fel d 7 is a significant allergen that induces Type I hypersensitivity reactions, leading to clinical symptoms of allergic rhinitis, conjunctivitis, and asthma [2, 5]. It is particularly notable for its high sequence identity (approximately 63%) with the major dog allergen Can f 1, which serves as a molecular basis for cross-reactivity between cat and dog allergies in sensitized patients [2, 6]. While not a target for conventional small-molecule pharmacology, Fel d 7 is a central target for component-resolved diagnostics and allergen-specific immunotherapy (AIT) [7, 8]. In AIT, the protein is used to reprogram the immune system toward tolerance by stimulating the production of regulatory T cells and protective IgG4 antibodies, thereby reducing the severity of the allergic response upon subsequent environmental exposure [8, 9]. Sources: [1] WHO/IUIS Allergen Nomenclature Sub-Committee (allergen.org). [2] Smith, W., et al. (2011). 'Fel d 7, a new cat allergen...'. Journal of Allergy and Clinical Immunology. [3] UniProtKB, Accession P0C1U8 (VEGP_FELCA). [4] Flower, D.R. (1996). 'The lipocalin protein family: structure and function'. Biochemical Journal. [5] Jakobi, S., et al. (2014). 'Characterization of the cat lipocalin Fel d 7'. Molecular Immunology. [6] Nilsson, O.B., et al. (2014). 'Characterization of the dog lipocalin allergen Can f 1'. Allergy. [7] Kleine-Tebbe, J., et al. (2017). 'Allergen Components: Molecular Diagnosis'. Allergo Journal International. [8] Alvaro-Lozano, M., et al. (2020). 'EAACI Guidelines on Allergen Immunotherapy'. Pediatric Allergy and Immunology. [9] Moingeon, P. (2013). 'Strategies for designing next-generation vaccines for allergy'. Clinical and Developmental Immunology.

Other names

Felis domesticus allergen 7Felis domesticus lipocalinVEGPLipocalin-1-like protein

Induction of immune tolerance through controlled exposure to the allergen, which shifts the immune response from a Th2-mediated (allergic) profile to a regulatory T cell (Treg) and Th1 profile, characterized by the production of allergen-specific IgG4 antibodies that block IgE binding.