TY - JOUR
T1 - Calcium-dependent immunoglobulin E recognition of the apo- and calcium- bound form of a cross-reactive two EF-hand timothy grass pollen allergen, Phl p 7
AU - Niederberger, Verena
AU - Hayek, Brigitte
AU - Vrtala, Susanne
AU - Laffer, Sylvia
AU - Twardosz, Anna
AU - Vangelista, Luca
AU - Sperr, Wolfgang R.
AU - Valent, Peter
AU - Rumpold, Helmut
AU - Kraft, Dietrich
AU - Ehrenberger, Klaus
AU - Valenta, Rudolf
AU - Spitzauer, Susanne
PY - 1999/1/1
Y1 - 1999/1/1
N2 - Type I allergy, an immunodisorder that affects almost 20% of the population worldwide, is based on the immunoglobulin E (IgE) recognition of per se innocuous antigens (allergens). Pollen from wind-pollinated plants belong to the most potent allergen sources. We report the isolation of a cDNA coding for a 8.6 kDa two EF-hand calcium binding allergen, Phl p 7, from a timothy grass (Phleum pratense) pollen expression cDNA library, using serum IgE from a grass pollen allergic patient. Sequence analysis identified Phl p 7 as a member of a recently discovered subfamily of pollen-specific calcium binding proteins. Recombinant Phl p 7 was expressed in Escherichia coli and purified to homogeneity as determined by mass spectroscopy. Approximately 10% of pollen allergic patients displayed IgE reactivity to rPhl p 7 and Phl p 7- homologous allergens present in pollens of monocotyledonic and dicotyledonic plants. Circular dichroism analysis of the calcium-bound and apo-rPhl p 7 indicated that differences in IgE recognition may be due to calcium-induced changes in the protein conformation. The fact that patients mount IgE antibodies against different protein conformations is interpreted as a footprint of a preferential sensitization against either form. The biological activity of rPhl p 7 was demonstrated by its ability to induce basophil histamine release and immediate type skin reactions in sensitized individuals. In conclusion, IgE binding to Phl p 7 represents an example for the conformation-dependent IgE recognition of an allergen. Recombinant Phl p 7 may be used for diagnosis and perhaps treatment of a group of patients who suffer from allergy to pollens of many unrelated plant species.
AB - Type I allergy, an immunodisorder that affects almost 20% of the population worldwide, is based on the immunoglobulin E (IgE) recognition of per se innocuous antigens (allergens). Pollen from wind-pollinated plants belong to the most potent allergen sources. We report the isolation of a cDNA coding for a 8.6 kDa two EF-hand calcium binding allergen, Phl p 7, from a timothy grass (Phleum pratense) pollen expression cDNA library, using serum IgE from a grass pollen allergic patient. Sequence analysis identified Phl p 7 as a member of a recently discovered subfamily of pollen-specific calcium binding proteins. Recombinant Phl p 7 was expressed in Escherichia coli and purified to homogeneity as determined by mass spectroscopy. Approximately 10% of pollen allergic patients displayed IgE reactivity to rPhl p 7 and Phl p 7- homologous allergens present in pollens of monocotyledonic and dicotyledonic plants. Circular dichroism analysis of the calcium-bound and apo-rPhl p 7 indicated that differences in IgE recognition may be due to calcium-induced changes in the protein conformation. The fact that patients mount IgE antibodies against different protein conformations is interpreted as a footprint of a preferential sensitization against either form. The biological activity of rPhl p 7 was demonstrated by its ability to induce basophil histamine release and immediate type skin reactions in sensitized individuals. In conclusion, IgE binding to Phl p 7 represents an example for the conformation-dependent IgE recognition of an allergen. Recombinant Phl p 7 may be used for diagnosis and perhaps treatment of a group of patients who suffer from allergy to pollens of many unrelated plant species.
KW - Allergen
KW - Circular dichroism spectroscopy
KW - Conformational epitopes
KW - Cross-reactivity
KW - EF-hand protein
KW - Pollen-specific expression
KW - Type I allergy
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UR - http://www.scopus.com/inward/citedby.url?scp=0032895187&partnerID=8YFLogxK
U2 - 10.1096/fasebj.13.8.843
DO - 10.1096/fasebj.13.8.843
M3 - Article
C2 - 10224228
AN - SCOPUS:0032895187
VL - 13
SP - 843
EP - 856
JO - FASEB Journal
JF - FASEB Journal
SN - 0892-6638
IS - 8
ER -