Salsola kali pollen allergens (Sal k allergens)

Salsola kali, commonly known as Russian thistle or tumbleweed, is a major source of highly allergenic pollen in arid and semi-arid regions worldwide. The immune response to these allergens is a classic Type I hypersensitivity reaction mediated by allergen-specific IgE antibodies. The primary molecular targets within this response are the specific proteins found in the pollen, most notably Sal k 1 (a pectin methylesterase), which is recognized by the majority of sensitized individuals (Barderas et al., 2004, PMID: 15125714). Other significant allergens include Sal k 2 (a kinase-related protein) and Sal k 3 (cobalamin-independent methionine synthase) (WHO/IUIS Allergen Nomenclature). Upon inhalation, these allergens cross-link IgE on mast cells and basophils, triggering the release of inflammatory mediators that cause allergic rhinitis, conjunctivitis, and bronchial asthma. While symptomatic treatments like antihistamines and corticosteroids manage the downstream effects of the immune response, allergen-specific immunotherapy (AIT) using Salsola kali extracts remains the only disease-modifying approach aimed at inducing long-term immune tolerance (Assarehzadegan et al., 2009, PMID: 19364562).

Other names

Russian thistle pollen allergensSalsola tragus allergensSal k 1Sal k 2Sal k 3Sal k 4Sal k 5Pectin methylesterase Sal k 1

Allergen-specific immunotherapy (AIT) involves the administration of standardized Salsola kali extracts to induce immunological tolerance. This is achieved by shifting the T-cell response from a Th2-dominated allergic profile to a Th1 and regulatory T-cell (Treg) profile, alongside the production of IgG4 blocking antibodies that prevent IgE-mediated mast cell degranulation (Gadermaier et al., 2014, PMID: 24601633).