The Allergens of <i>Parietaria</i>

Abstract

Parietaria is a genus of dicotyledonous weeds of the Urticaceae family including several species and its pollen grain is one of the most important allergenic sources in the Mediterranean area. Species belonging to this genus induce IgE responses in approximately 10 million people. Identification of allergens by means of independent strategies suggest that the allergens of the two more common species, Parietaria judaica and Parietaria officinalis, show molecular weights ranging between 10 and 14 kD and that the allergens of the two extracts are highly cross-reactive. Biochemical analysis and molecular cloning allowed the isolation and immunological characterization of the two major allergens of the P. judaica pollen, Par j 1 and Par j 2. Sequence comparison suggests that the P j major allergens of P. judaica belong to the nonspecific lipid transfer protein family, and three-dimensional modeling by homology has revealed that both proteins present a very conserved structural motif composed of four α-helices. Immunological analysis has shown that Par j 1 and Par j 2 are able to bind most of the P. judaica-specific IgE and some of their IgE determinants have been mapped. Recombinant Par j 1 and Par j 2 allergens have been shown to possess immunological properties equivalent to their natural counterpart and their availability represents a fundamental tool for the diagnosis and therapy of Parietaria pollen allergy.

Allergic Rhinitis and its Impact on Asthma (ARIA) 2008*

“…The grasses pollinate at the end of spring and beginning of summer, but, in some places such as Southern California or Florida, they are spread throughout the year. Bermuda grass (Cynodon dactylon) and Bahia grass (Paspalum notatum) do not usually cross-react with other grasses (363); • weeds such as the Compositeae plants: mugwort (Artemisia) and ragweed (Ambrosia; 364-366), Parietaria, not only in the Mediterranean area (367)(368)(369)(370)(371)(372)(373), Chenopodium and Salsola in some desert areas (374), weeds such as ragweed flower at the end of summer and beginning of autumn. Parietaria often pollinates over a long period of time (March-November) and is considered as a perennial pollen; • and trees: the birch (Betula), other Betulaceae (375)(376)(377)(378)(379)(380)(381), Oleaceae including the ash (Fraxinus) and olive tree (Olea europea; 382-384), the oak (Quercus), the plane tree (Platanus; 385,386) and Cupressaceae including the cypress tree (Cupressus; 387-392), junipers (Juniperus; 393), thuyas (394), the Japanese cedar (Cryptomeria japonica; 395) and the mountain cedar (Juniperus ashei; 396, 397).…”

An approach to the knowledge of pollen and allergen diversity through lipid transfer protein localisation in taxonomically distant pollen grains

“…Asteraceae, Taraxacum officinalis (26630 mm). Colombo et al, 2003) and are localised in the cytoplasm and walls of P. judaica pollen grains (Vega-Maray et al, 2004). Moreover, nsLTPs have been reported as important allergens in fruits from the Rosaceae family, such as peach, Pru p 3 (Pastorello et al, 1999a;Sánchez-Monge et al, 1999;Fernández-Rivas et al, 2003), cherry, Pru av 3 (Scheurer et al, 2001) and apple, Mal d 3 (Pastorello et al, 1999b), as well as from the Corylaceae family, such as hazelnut, Cor a 8 (Schocker et al, 2004).…”

Lipid nanoparticles as delivery vehicles for the Parietaria judaica major allergen Par j 2

“…Parietaria is a genus of dicotyledonous weeds belonging to the Urticaceae family which is composed of several cross-reactive allergenic species representing a common cause of pollinosis in the Mediterranean area. [3][4][5] Using DNA recombinant technology, the major allergens of P. judaica (Par j 1 and Par j 2) were isolated and characterized in the authors' labs. 3 So far, the Par j 2 allergen has been a well established marker for the diagnosis of Parietaria pollinosis and, for this reason, it represents the primary target to tackle for the development of new therapeutic strategies.…”