Λεξικό .. Bermuda grass-pollen allergens

Studies have shown that Bermuda grass-pollen contains at least 12 IgE -binding proteins which could be analyzed by immunoblot technique. Cyn d 1 is the major allergen of Bermuda grass pollen. Bermuda grass pollen (BGP) contains a very complex mixture of allergens, but only a few have been characterized. One of the allergens, with an apparent molecular mass of 21 kDa, has been shown to bind serum IgE from 29% of patients with BGP allergy. The purified 21 kDa allergen was designated Cyn d 24 according to the protocol of International Union of Immunological Societies (IUIS). It has a molecular mass of 18,411 Da by MALDI-TOF analysis and a pI of 5.9. The cDNA encoding Cyn d 24 was predicted to produce a 153 amino acid mature protein containing tow conserved sequences seen in the pathogen-related protein family. Carbohydrate analysis showed that the most abundant N-linked glycan is a alpha(3)-fucosylated pauci-mannose (Man3GlcNAc2) structure, without a Xyl beta-(1,2)-linked to the branching beta-Man. Thus, Cyn d 24 is a glycoprotein and the results of the sequence alignment indicate that this novel allergen is a pathogenesis-related protein 1. To the best of our knowledge, this is the first study to identify any grass pollen allergen as a pathogenesis-related protein 1 [1].

According Rossi RE,et al (2009) showed that all Bermuda grass pollen (BGP)-allergic patients simultaneously exhibit higher IgE antibody levels to recombinant and natural Phleum pratense allergens as well as to crude timothy grass pollen (TGP) extract. This suggests that when choosing an immunotherapeutic regimen for BGP-sensitised patients (after establishing their IgE profile via purified TGP-allergens), subcutaneous or sublingual TGP-extract vaccines in appropriate doses, in order to influence T epitope specificity, might be beneficial. Though extremely uncommon, in cases where a patient is exclusively BGP allergen-sensitised, BGP-extract therapy is the appropriate therapeutic response [2]. See Cyn d 1.

References

1. Chow LP, Chiu LL, Khoo KH, Peng HJ, Yang SY, Huang SW, Su SN. Purification and structural analysis of the novel glycoprotein allergen Cyn d 24, a pathogenesis-related protein PR-1, from Bermuda grass pollen. FEBS J. 2005 Dec;272(24):6218-27

2. Rossi RE, Monasterolo G, Prina P, Coco G, Operti D, Rossi L. IgE profiles of Bermuda grass pollen sensitised patients evaluated by Phleum pratense allergens Phl P 1, 2, 4, 5, 6 , 7, 11, 12. Allergol Int. 2008 Jun;57(2):157-64