Direct evidence for the presence of allergens in Rosaceae fruit tree pollen

Abstract

The allergen content of insect-carried fruit tree pollen is poorly investigated. A recent report on orange allergy indicates a possible cosensitisation to fruits by digestion and inhalation, suggesting an alternative mechanism for allergy development. Allergy to Rosaceae fruits like apple, pear, peach and cherry has been described as cross-reactivity to the birch pollen allergen Bet v 1. The expression of two major apple allergens Mal d 1 and Mal d 3 and their homologues in Rosaceae pollen was investigated. Transcript expression of five Mal d 1 isoforms and of Mal d 3 was examined by RT-PCR. A Mal d 1 specific ELISA was used to quantify the content of Mal d 1 homologues in Pomoideae pollen. Polyclonal antibodies against Mal d 1 and Mal d 3 were used for allergen detection in pollen extracts in Western blots. The cross-reactivity of pollen allergens with patient sera was confirmed by IgE-Western blotting. Pollen counts were carried out by using Hirst-type volumetric samplers, revealing an intermittent Rosaceae fruit tree pollen load, without remarkable peaks across large parts of Europe. The expression of Mal d 1 was confirmed in pollen of all tested Rosaceae fruit tree species by ELISA, Western blot and RT-PCR. IgE-Western blots showed a strong cross-reactivity, particularly with Mal d 1 and Mal d 3 homologues in different Rosaceae pollen. Although the pollen load of Rosaceae is rather low as a rule, there is certified evidence for temporary peaks, indicating that allergen exposure for sensitized individuals is likely.

Occupational respiratory allergy in peach crop workers

“…The presence of allergens in Rosaceae fruit tree pollen has been documented by Berrens et al . (a Bet v 1 homologous protein in apple tree pollen) and Marzban et al . (Mal d 1, Mal d 3 and their homologues in different Rosaceae fruit tree pollen).…”

Differential transcript abundance and genotypic variation of four putative allergen-encoding gene families in melting peach

“…There is also evidence for the presence of Pru p 1 and Pru p 3 in pollen (Marzban et al 2006) andleaf (GarcÌa et al 2004). A correlation of expressed isoforms between transcript and protein level has been shown in apple (Mal d 1) (Beuning et al 2004;Marzban et al 2006) and Birch (Bet v 1) (Schenk et al 2009) pollen.…”

“…A correlation of expressed isoforms between transcript and protein level has been shown in apple (Mal d 1) (Beuning et al 2004;Marzban et al 2006) and Birch (Bet v 1) (Schenk et al 2009) pollen. The transcript expression profile of the four allergens in the anther (Fig.…”

“…Northern blotting (Botton et al 2002(Botton et al , 2006 and MALDI-mass spectrometry imaging (Cavatorta et al 2009) have, in fact, confirmed that peach LTP (Pru p 3) essentially concentrates in peel, with less in pulp. Pru p 3 has also been detected in fruit surface fuzz (Asero et al 2006), leaves (Garcia et al 2004) and pollen (Marzban et al 2006). Less Pru p 1 and Pru p 4 have been found in the fruit compared with Pru p 3 (Gaier et al 2008;RodriguezPerez et al 2003).…”

Awareness and knowledge of allergens: A need and a challenge to assure a safe and healthy consumption of small fruits

“…As is the case with most of the other PR-protein families, PR-10-type proteins are also expressed in a tissue-specific manner during development. The presence of allergens in Rosaceae pollen was originally reported for a Bet v 1 homologous protein in apple tree pollen [6] and, the expression of Mal d 1, Mal d 3 and their homologues was confirmed by three independent methods ELISA, Western blot and RT-PCR [37].…”