Oriental plane pollen allergy: Identification of allergens and cross-reactivity between relevant species

Abstract

Pollen from different tree and grass species represent the greatest inducers of type I allergy worldwide. Oriental plane trees, as Platanus orientalis, are an important source of airborne allergens in cities of the southwest Asia and southeast Europe. This study was aimed to identify relevant allergens of P. orientalis pollen and to ascertain whether P. orientalis allergens have cross-reactivity with related plane trees, such as Platanus acerifolia and Platanus occidentalis pollen components. Nineteen patients with a clinical history of reaction to P. orientalis pollen and a positive skin-prick test (SPT) to P. orientalis pollen extract were included in this study. Identification of IgE-binding proteins in Platanus pollen extracts was elucidated by immunoblotting using sera from P. orientalis pollen-sensitive patients. Cross-reactivity studies among P. orientalis allergens and relevant species was evaluated by immunoblot-inhibition and ELISA inhibition assays. All the patients were polysensitive and exhibited positive SPT to grass and tree pollen allergens. The IgE-binding pattern of P. orientalis pollen extract was well defined. The inhibition experiments showed that the capacity of P. occidentalis was greater than P. acerifolia pollen extract in preventing the reactivity of immobilized P. orientalis pollen extract with the IgE antibodies of patients. The 28-kDa molecule was the most frequent allergen among nine IgE-binding proteins of P. orientalis pollen. The IgE-reactive components of P. orientalis pollen showed a higher level of cross-reactivity with P. occidentalis pollen in comparison with P. acerifolia pollen.

Tree pollen allergens—an update from a molecular perspective

“…In a study including 19 Iranian Platanus orientalis ‐allergic patients, the 18‐kDa plant invertase/pectin methylesterase inhibitor Pla or 1, the 42‐kDa polygalacturonase Pla or 2, and the 12‐kDa nsLTP Pla or 3 with IgE‐binding prevalences of 21%, 27%, and 27%, respectively, were identified. The allergens of Platanus orientalis show great similarities to the three main allergens of Platanus acerifolia .…”

Pollen Allergens for Molecular Diagnosis

“…With 3.3 % in the allergic population, clinically relevant sensitization throughout Europe is rather low but can reach almost 12 % in the UK [ 38 ••]. More than 80 % of plane-sensitized patients react to the major allergens Pla a 1 (plant invertase inhibitor) and Pla a 2 (polygalacturonase) [ 45 , 47 , 48 ]. The minor allergen Pla a 3 is a member of the nsLTP family and shows high cross-reactivity with Pru p 3, the major allergen from peach [ 49 ].…”

Urban allergy review: Allergic rhinitis and asthma with plane tree sensitization (Review)

“…Three major allergens have been identified in P. orientalis: Pla or 1, a non-glycosylated protein, and a member of invertase/pectin methylesterase inhibitor family, with a molecular weight of 18 kDa; Pla or 2, a 43 kDa glycoprotein, and a polygalacturonase; and Pla or 3, belonging to non-specific lipid-transfer proteins (ns-LTPs), and a 9-10 kDa protein (12). The IgE-reactive components of P. orientalis pollen described earlier showed a higher level of cross-reactivity with P. occidentalis pollen in comparison with P. acerifolia pollen in an Iranian study (32,36).…”

“…P. orientalis is, among long-lived tree species, the one with the largest leaves in the Mediterranean region, which made it a valuable option for providing shade from ancient times (antique Greece and Rome) to Renaissance and modern times (31). Oriental plane tree is the dominant tree species in parks and streets in many cities of the Asian continent, in countries including Iran (32) and China (33,34). In Europe, it can be found in countries such as Italy (drier and warmer climate), Bulgaria (more humid and colder climate), Albania, Greece and Turkey (31).…”