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The role of N-glycosylation in kiwi allergy.

Garrido-Arandia M, Murua-García A, Palacin A, Tordesillas L, Gómez-Casado C, Blanca-Lopez N, Ramos T, Canto G, Blanco C, Cuesta-Herranz J, Sánchez-Monge R, Pacios LF, Díaz Perales A - Food Sci Nutr (2014)

Bottom Line: The physical, biochemical, and immunological characteristics of plant allergens have been widely studied, but no definite conclusion has been reached about what actually makes a protein an allergen.With this aim, we evaluated and compared the allergenic activity of the protein fraction and the N-glycan fraction of the thaumatin-like protein and the main kiwi allergen, Act d 2.Related to this, the production of cytokines such as IL6 and IL10 was increased by the incubation of dendritic cells with sugar moiety.

View Article: PubMed Central - PubMed

Affiliation: Centre for Plant Biotechnology and Genomics U.P.M. - I.N.I.A., Campus de Montegancedo Pozuelo de Alarcón, Madrid, Spain.

ABSTRACT
The physical, biochemical, and immunological characteristics of plant allergens have been widely studied, but no definite conclusion has been reached about what actually makes a protein an allergen. In this sense, N-glycosylation is an exclusive characteristic of plant allergens not present in mammals and it could be implied in allergenic sensitization. With this aim, we evaluated and compared the allergenic activity of the protein fraction and the N-glycan fraction of the thaumatin-like protein and the main kiwi allergen, Act d 2. The natural allergen, Act d 2, was deglycosylated by trifluoromethanesulfonic acid treatment; the N-glycan fraction was obtained by extended treatment with proteinase K. N-glycan- and protein- fractions were recognized by specific IgE of kiwi-allergic patients. By contrast, the sugar moiety showed a reduced capacity to activate basophils and T cells, but not dendritic cells derived from patients' monocytes. Related to this, the production of cytokines such as IL6 and IL10 was increased by the incubation of dendritic cells with sugar moiety. Thus, the sugar moiety plays a significant role in sensitization, inducing the activation of antigen-presenting cells, but it is the protein fraction that is responsible for the allergic reactions.

No MeSH data available.


Related in: MedlinePlus

(A) N-glycan structures detected by mass spectrometry. Circles correspond to mannose, squares to N-acetylglucosamine, triangles to fucose, and stars to xylose. (B) Ribbon diagrams of Act d 2 showing the main sugar moiety as stick-like structures.
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fig02: (A) N-glycan structures detected by mass spectrometry. Circles correspond to mannose, squares to N-acetylglucosamine, triangles to fucose, and stars to xylose. (B) Ribbon diagrams of Act d 2 showing the main sugar moiety as stick-like structures.

Mentions: To study the contribution of N-glycan to IgE recognition of Act d 2, this fraction was isolated by extensive treatment of the natural allergen with proteinase K. The purity of the sugar fraction was confirmed by thin layer chromatography (data not shown) and mass spectrometry (Fig. 2A), in which no protein contamination was detected. The monomer composition of the N-glycan was analyzed by extensive acidic treatment and mass spectrometry. The sugar motif of Ac t d 2 consisted of monomers of mannose, N-acetyl glucosamine, xylose, and fucose, suggesting the presence of a typical N-plant glycosylation.


The role of N-glycosylation in kiwi allergy.

Garrido-Arandia M, Murua-García A, Palacin A, Tordesillas L, Gómez-Casado C, Blanca-Lopez N, Ramos T, Canto G, Blanco C, Cuesta-Herranz J, Sánchez-Monge R, Pacios LF, Díaz Perales A - Food Sci Nutr (2014)

(A) N-glycan structures detected by mass spectrometry. Circles correspond to mannose, squares to N-acetylglucosamine, triangles to fucose, and stars to xylose. (B) Ribbon diagrams of Act d 2 showing the main sugar moiety as stick-like structures.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4048612&req=5

fig02: (A) N-glycan structures detected by mass spectrometry. Circles correspond to mannose, squares to N-acetylglucosamine, triangles to fucose, and stars to xylose. (B) Ribbon diagrams of Act d 2 showing the main sugar moiety as stick-like structures.
Mentions: To study the contribution of N-glycan to IgE recognition of Act d 2, this fraction was isolated by extensive treatment of the natural allergen with proteinase K. The purity of the sugar fraction was confirmed by thin layer chromatography (data not shown) and mass spectrometry (Fig. 2A), in which no protein contamination was detected. The monomer composition of the N-glycan was analyzed by extensive acidic treatment and mass spectrometry. The sugar motif of Ac t d 2 consisted of monomers of mannose, N-acetyl glucosamine, xylose, and fucose, suggesting the presence of a typical N-plant glycosylation.

Bottom Line: The physical, biochemical, and immunological characteristics of plant allergens have been widely studied, but no definite conclusion has been reached about what actually makes a protein an allergen.With this aim, we evaluated and compared the allergenic activity of the protein fraction and the N-glycan fraction of the thaumatin-like protein and the main kiwi allergen, Act d 2.Related to this, the production of cytokines such as IL6 and IL10 was increased by the incubation of dendritic cells with sugar moiety.

View Article: PubMed Central - PubMed

Affiliation: Centre for Plant Biotechnology and Genomics U.P.M. - I.N.I.A., Campus de Montegancedo Pozuelo de Alarcón, Madrid, Spain.

ABSTRACT
The physical, biochemical, and immunological characteristics of plant allergens have been widely studied, but no definite conclusion has been reached about what actually makes a protein an allergen. In this sense, N-glycosylation is an exclusive characteristic of plant allergens not present in mammals and it could be implied in allergenic sensitization. With this aim, we evaluated and compared the allergenic activity of the protein fraction and the N-glycan fraction of the thaumatin-like protein and the main kiwi allergen, Act d 2. The natural allergen, Act d 2, was deglycosylated by trifluoromethanesulfonic acid treatment; the N-glycan fraction was obtained by extended treatment with proteinase K. N-glycan- and protein- fractions were recognized by specific IgE of kiwi-allergic patients. By contrast, the sugar moiety showed a reduced capacity to activate basophils and T cells, but not dendritic cells derived from patients' monocytes. Related to this, the production of cytokines such as IL6 and IL10 was increased by the incubation of dendritic cells with sugar moiety. Thus, the sugar moiety plays a significant role in sensitization, inducing the activation of antigen-presenting cells, but it is the protein fraction that is responsible for the allergic reactions.

No MeSH data available.


Related in: MedlinePlus