Examinando por Autor "Fernández, Javier"

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A Hypoallergenic Polygalacturonase Isoform from Olive Pollen Is Implicated in Pollen-Pollen Cross-Reactivity
(KARGER, 2018) Oeo-Santos, Carmen; Mas, Salvador; Quiralte, Joaquín; Colás, Carlos; Blanca, Miguel; Fernández, Javier; Feo Brito, Francisco; Villalba, Mayte; Barderas, Rodrigo
Cross-reactivity reactions between allergenic polygalacturonases (PGs) from different biological sources, especially foods and pollens from the Oleaceae family, have been described using Salsola kali PG (Sal k 6). No PG from olive pollen has been characterized to date, hampering further knowledge about cross-reactions through PGs. The aim of this work was to determine the potential allergenicity of the PG from olive pollen and clarify its role in crossreactivity. A cDNA-encoding olive pollen PG sequence was subcloned into the pET41b vector and used to transform BL21(DE3) Escherichia coli cells to produce a Histag fusion recombinant protein. The allergenic properties of olive pollen PG were determined by immunoblotting and ELISA in comparison to Sal k 6. The cross-reactivity potential of the protein with other pollen sources was analyzed by inhibition immunoassays. Results: The existence of other isoforms of Ole e 14 with different allergenicity was confirmed by proteomics and a meta-analysis of the recently reported olive genome. Sal k 6 showed a higher IgE recognition than Ole e 14 regardless of patient sensitization, suggesting the existence of more allergenic Ole e 14 isoforms in olive pollen. IgG and IgE inhibition assays supported the existence of cross-reactions between them and with other PGs from Oleaceae and Poaceae plant families. A new allergen from olive pollen, Ole e 14, has been identified, produced as a recombinant isoform, and structurally and immunologically characterized. Its role in cross-reactivity has been confirmed and, due to its smaller IgE binding capacity, it could have an important role for therapeutic purposes.
A relevant IgE-reactive 28 kDa protein identified from Salsola kali pollen extract by proteomics is a natural degradation product of an integral 47 kDa polygalaturonase
(ELSEVIER, 2017) Mas, Salvador; Oeo-Santos, Carmen; Cuesta-Herranz, Javier; Díaz-Perales, Araceli; Colás, Carlos; Fernández, Javier; Barber, Domingo; Rodríguez, Rosalía; de Los Ríos, Vivian; Barderas, Rodrigo; Villalba, Mayte
A highly prevalent IgE-binding protein band of 28 kDa is observed when Salsola kali pollen extract is incubated with individual sera from Amaranthaceae pollen sensitized patients. By an immunoproteomic analysis of S. kali pollen extract, we identified this protein band as an allergenic polygalacturonase enzyme. The allergen, named Sal k 6, exhibits a pI of 7.14 and a molecular mass of 39,554.2 Da. It presents similarities to Platanaceae, Poaceae, and Cupressaceae allergenic polygalacturonases. cDNA-encoding sequence was subcloned into the pET41b vector and produced in bacteria as a His-tag fusion recombinant protein. The far-UV CD spectrum determined that rSal k 6 was folded. Immunostaining of the S. kali pollen protein extract with a rSal k 6-specific pAb and LC-MS/MS proteomic analyses confirmed the co-existence of the 28 kDa band together with an allergenic band of about 47 kDa in the pollen extract. Therefore, the 28 kDa was assigned as a natural degradation product of the 47 kDa integral polygalacturonase. The IgE-binding inhibition to S. kali pollen extract using rSal k 6 as inhibitor showed that signals directed to both protein bands of 28 and 47 kDa were completely abrogated. The average prevalence of rSal k 6 among the three populations analyzed was 30%, with values correlating well with the levels of grains/m3 of Amaranthaceae pollen. Sal k 6 shares IgE epitopes with Oleaceae members (Fraxinus excelsior, Olea europaea and Syringa vulgaris), with IgE-inhibition values ranging from 20% to 60%, respectively. No IgE-inhibition was observed with plant-derived food extracts.