t216 rBet v 2 Profilin, Birch

Allergens within Tree Pollens

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  • Latin name: Betula verrucosa
  • Common names: Profilin
  • Source material: Recombinant non-glycosylated protein produced in an E. coli strain carrying a cloned cDNA encoding Betula verrucosa allergen Bet v 2
Recombinant allergen
Betula verrucosar allergen Bet v 2. 
 
Biological function  
Profilin (actin-binding protein).
 
Mw
14 kDa.
 
Allergen description
Bet v 2 (1, 2, 3, 4-11), a well-described minor allergen from birch pollen, belongs to the family of profilins, a group of common actin-binding proteins (10, 12). Profilins can be found as cross-reactive allergens not only in pollen from unrelated plants (trees, grasses, weeds) but also in other plant tissues (of fruits, vegetables, nuts, spices, and latex) (13).
 
Bet v 2 and Bet v 3 are recognised by IgE from about 10% of Birch-allergic patients, Bet v 6 by approximately 32%, and Bet v 1 by 95% (14). The sensitisation patterns to Bet v 1 and Bet v 2, differ geographically; among Swedish and Finish patients, for example, approximately 5-7% were shown to be sensitised to Birch-profilin, compared to 20-38% of patients in Central and Southern Europe. Also, differences in IgE reactivity to rBet v 1 and rBet v 2 were demonstrated among allergic patients from six countries. The complexity of reactivity tended to be greater in individuals from the central and southern parts of Europe, as compared to Sweden and Finland (13, 15).
 
The profilin Bet v 2, has also been shown to be involved in cross-reactivity to certain foods in tree pollen-sensitive patients.
 
It has been suggested that Bet v 1 can be a diagnostic marker allergen for identifying patients with genuine sensitisation to Birch-pollen (16), as opposed to patients reacting to highly cross-reactive allergens, such as Bet v 2 and Bet v 4; these may be considered marker allergens for syndromes involving cross-reactivity with numerous unrelated plants and plant products (16-17). In other words, patients who exhibit positive skin tests to Birch pollen extracts, but have not been exposed to Birch, might have IgE to highly cross-reactive allergens such as Bet v 2 (17).
 
One study gives an example of the diagnostic application of recombinant Birch pollen allergens. Specific serum IgE antibodies to recombinant allergens Bet v 1, Bet v 2 and Bet v 4 were examined in Birch-sensitive patients from the province of Cuneo, in northwest Italy. The study concluded that the 3 recombinant Birch pollen allergens alone could identify 90% of Birch pollen-sensitive patients (2).

References:

    1. De Amici M, Mosca M, Vignini M, Quaglini S, Moratti R. Recombinant birch allergens (Bet v 1 and Bet v 2) and the oral allergy syndrome in patients allergic to birch pollen. Ann Allergy Asthma Immunol 2003 Nov;91(5):490-2.
    2. Rossi RE, Monasterolo G, Monasterolo S. Detection of specific IgE antibodies in the sera of patients allergic to birch pollen using recombinant allergens Bet v 1, Bet v 2, Bet v 4: evaluation of different IgE reactivity profiles. Allergy 2003 ;58(9):929-32.
    3. Niederberger V, Pauli G, Gronlund H, Froschl R, Rumpold H, et al. Recombinant birch pollen allergens (rBet v 1 and rBet v 2) contain most of the IgE epitopes present in birch, alder, hornbeam, hazel, and oak pollen: a quantitative IgE inhibition study with sera from different populations. J Allergy Clin Immunol 1998;102(4 Pt 1):579-91.
    4. Diez-Gomez ML, Quirce S, Cuevas M, Sanchez-Fernandez C, et al. Fruit-pollen-latex cross-reactivity: implication of profilin (Bet v 2). Allergy 1999;54(9):951-61.
    5. Niederberger V, Laffer S, Froschl R, Kraft D, Rumpold H, et al. IgE antibodies to recombinant pollen allergens (Phl p 1, Phl p 2, Phl p 5, and Bet v 2) account for a high percentage of grass pollen-specific IgE. J Allergy Clin Immunol 1998;101(2 Pt 1):258-64.
    6. Domke T, Federau T, Schluter K, Giehl K, Valenta R, Schomburg D, Jockusch BM. Birch pollen profilin: structural organization and interaction with poly-(L-proline) peptides as revealed by NMR. FEBS Lett 1997;411(2-3):291-5.
    7. Fedorov AA, Ball T, Valenta R, Almo SC. X-ray crystal structures of birch pollen profilin and Phl p 2. Int Arch Allergy Immunol 1997;113(1-3):109-13.
    8. Wiedemann P, Giehl K, Almo SC, Fedorov AA, Girvin M, Steinberger P, Rudiger M, Ortner M, Sippl M, Dolecek C, Kraft D, Jockusch B, Valenta R. Molecular and structural analysis of a continuous birch profilin epitope defined by a monoclonal antibody. J Biol Chem 1996;271(47):29915-21.
    9. Susani M, Jertschin P, Dolecek C, Sperr WR, Valent P, Ebner C, Kraft D, Valenta R, Scheiner O. High level expression of birch pollen profilin (Bet v 2) in Escherichia coli: purification and characterization of the recombinant allergen. Biochem Biophys Res Commun 1995;215(1):250-63.
    10. Valenta R, Ferreira F, Grote M, Swoboda I, Vrtala S, Duchene M, Deviller P, Meagher RB, McKinney E, Heberle-Bors E, et al. Identification of profilin as an actin-binding protein in higher plants. J Biol Chem 1993;268(30):22777-81.
    11. Valenta R, Duchene M, Breitenbach M, Pettenburger K, Koller L, Rumpold H, Scheiner O, Kraft D. A low molecular weight allergen of white birch (Betula verrucosa) is highly homologous to human profilin. Int Arch Allergy Appl Immunol 1991;94(1-4):368-70
    12. Valenta R, Duchene M, Pettenburger K, Sillaber S, Valent P. Identification of profilin as a novel pollen allergen; IgE autoreactivity in sensitized individuals. Science 1991;253:557-60.
    13. Martinez A, Asturias JA, Monteseirin J, Moreno V, Garcia-Cubillana A, Hernandez M, de la Calle A, Sanchez-Hernandez C, Perez-Formoso JL, Conde J. The allergenic relevance of profilin (Ole e 2) from Olea europaea pollen. Allergy 2002;57 Suppl 71:17-23.
    14. Karamloo F, Schmitz, N, Scheurer S, et al. Molecular cloning and characterization of a birch pollen minor allergen, Bet v 5, belonging to a family of isoflavone reductase-related proteins. J Allergy Clin Immunol 1999;104:991-999.
    15. Elfman L, Svensson M, Lidholm J, Pauli G, Valenta R. Different profiles in specific IgE to rBet v 1 and rBet v 2 in patients allergic to birch pollen from six countries. Int Arch Allergy Immunol 1997;113(1-3):249-51.
    16. Kazemi-Shirazi L, Niederberger V, Linhart B, Lidholm J, Kraft D, Valenta R. Recombinant marker allergens: diagnostic gatekeepers for the treatment of allergy. Int Arch Allergy Immunol 2002;127(4):259-68.
    17. Mothes N, Valenta R. Biology of tree pollen allergens. Curr Allergy Asthma Rep 2004;4(5):384-90.

2006



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