BACKGROUND: The identity of allergenic almond proteins is incomplete. OBJECTIVE: Our objective was to characterize patient IgE reactivity to a recombinant and corresponding native almond allergen. METHODS: An almond cDNA library was screened with sera from patients with allergy for IgE binding proteins. Two reactive clones were sequenced, and 1 was expressed. The expressed recombinant allergen and its native counterpart (purified from unprocessed almond flour) were assayed by 1-dimensional and 2-dimensional gel electrophoresis, dot blot, and ELISA, and screened for cross-reactivity with grass profilin. RESULTS: The 2 selected clones encoded profilin (designated Pru du 4) sequences that differed by 2 silent mutations. By dot-blot analyses, 6 of 18 patient sera (33%) reacted with the recombinant Pru du 4 protein, and 8 of 18 (44%) reacted with the native form. ELISA results were similar. Almond and ryegrass profilins were mutually inhibitable. Two-dimensional immunoblotting revealed the presence of more than 1 native almond profilin isoform. The strength of reactivity of some patients' serum IgE differed markedly between assays and between native and recombinant profilins. CONCLUSION: Almond nut profilin is an IgE-binding food protein that is cross-reactive with grass pollen profilin and is susceptible to denaturation, resulting in variable reactivity between assay types and between patients. CLINICAL IMPLICATIONS: Serum IgE of nearly half of the tested patients with almond allergy reacts with almond nut profilin. Because most patients also had pollinosis, the well-known cross-reactivity between pollen and food profilins could account for this pattern of reactivity.
BACKGROUND: The identity of allergenic almond proteins is incomplete. OBJECTIVE: Our objective was to characterize patient IgE reactivity to a recombinant and corresponding native almond allergen. METHODS: An almond cDNA library was screened with sera from patients with allergy for IgE binding proteins. Two reactive clones were sequenced, and 1 was expressed. The expressed recombinant allergen and its native counterpart (purified from unprocessed almond flour) were assayed by 1-dimensional and 2-dimensional gel electrophoresis, dot blot, and ELISA, and screened for cross-reactivity with grass profilin. RESULTS: The 2 selected clones encoded profilin (designated Pru du 4) sequences that differed by 2 silent mutations. By dot-blot analyses, 6 of 18 patient sera (33%) reacted with the recombinant Pru du 4 protein, and 8 of 18 (44%) reacted with the native form. ELISA results were similar. Almond and ryegrass profilins were mutually inhibitable. Two-dimensional immunoblotting revealed the presence of more than 1 native almond profilin isoform. The strength of reactivity of some patients' serum IgE differed markedly between assays and between native and recombinant profilins. CONCLUSION:Almond nut profilin is an IgE-binding food protein that is cross-reactive with grass pollen profilin and is susceptible to denaturation, resulting in variable reactivity between assay types and between patients. CLINICAL IMPLICATIONS: Serum IgE of nearly half of the tested patients with almondallergy reacts with almond nut profilin. Because most patients also had pollinosis, the well-known cross-reactivity between pollen and food profilins could account for this pattern of reactivity.
Authors: Lesa R Offermann; Caleb R Schlachter; Makenzie L Perdue; Karolina A Majorek; John Z He; William T Booth; Jessica Garrett; Krzysztof Kowal; Maksymilian Chruszcz Journal: J Biol Chem Date: 2016-05-26 Impact factor: 5.157
Authors: Christian Lupinek; Eva Wollmann; Alexandra Baar; Srinita Banerjee; Heimo Breiteneder; Barbara M Broecker; Merima Bublin; Mirela Curin; Sabine Flicker; Tetiana Garmatiuk; Heidrun Hochwallner; Irene Mittermann; Sandra Pahr; Yvonne Resch; Kenneth H Roux; Bharani Srinivasan; Sebastian Stentzel; Susanne Vrtala; Leanna N Willison; Magnus Wickman; Karin C Lødrup-Carlsen; Josep Maria Antó; Jean Bousquet; Claus Bachert; Daniel Ebner; Thomas Schlederer; Christian Harwanegg; Rudolf Valenta Journal: Methods Date: 2013-10-22 Impact factor: 3.608