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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

Phenotype of monocyte-derived dendritic cells (DCs). (A, B) Maturation index (MI, average) of monocyte-derived DCs from healthy donors (Control) and kiwi-allergic patients (Patient), after stimulation with natural protein (Act d 2; 20 μg/mL), protein fraction (dActd2; 20 μg/mL), and N-glycan fraction (N-gly; 20 μg/mL). The means of five experiments are shown. Comparison between Controls and Patients (A). Comparison among different fractions (B). Data were analyzed by the Wilcoxon test or Mann–Whitney U test, respectively. (C) Cytokine profile. Changes in the production of Il-6, IL-10, TNFα, and IL-1β were measured by quantitative PCR. Amplifications were performed in triplicate and four independent assays. Means and SD (bars) are shown. Data were analyzed by Wilcoxon (with values of P < 0.05 considered significant).
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fig04: Phenotype of monocyte-derived dendritic cells (DCs). (A, B) Maturation index (MI, average) of monocyte-derived DCs from healthy donors (Control) and kiwi-allergic patients (Patient), after stimulation with natural protein (Act d 2; 20 μg/mL), protein fraction (dActd2; 20 μg/mL), and N-glycan fraction (N-gly; 20 μg/mL). The means of five experiments are shown. Comparison between Controls and Patients (A). Comparison among different fractions (B). Data were analyzed by the Wilcoxon test or Mann–Whitney U test, respectively. (C) Cytokine profile. Changes in the production of Il-6, IL-10, TNFα, and IL-1β were measured by quantitative PCR. Amplifications were performed in triplicate and four independent assays. Means and SD (bars) are shown. Data were analyzed by Wilcoxon (with values of P < 0.05 considered significant).

Mentions: Peripheral blood mononuclear cells from six kiwi-allergic patients were cultured either in the presence of the natural protein (Act d 2) or together with one of the isolated fractions, that is, the protein (dAct d 2*) or the N-glycan (N-gly) (Fig. 4). The protein fractions were able to activate lymphocytes in the same way as the natural protein did. Nevertheless, the capacity of N-glycan fraction was considerably reduced. Curiously, only PBMCs from one out of the six patients were capable of activating T-cell proliferation in the presence of sugar.


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)

Phenotype of monocyte-derived dendritic cells (DCs). (A, B) Maturation index (MI, average) of monocyte-derived DCs from healthy donors (Control) and kiwi-allergic patients (Patient), after stimulation with natural protein (Act d 2; 20 μg/mL), protein fraction (dActd2; 20 μg/mL), and N-glycan fraction (N-gly; 20 μg/mL). The means of five experiments are shown. Comparison between Controls and Patients (A). Comparison among different fractions (B). Data were analyzed by the Wilcoxon test or Mann–Whitney U test, respectively. (C) Cytokine profile. Changes in the production of Il-6, IL-10, TNFα, and IL-1β were measured by quantitative PCR. Amplifications were performed in triplicate and four independent assays. Means and SD (bars) are shown. Data were analyzed by Wilcoxon (with values of P < 0.05 considered significant).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig04: Phenotype of monocyte-derived dendritic cells (DCs). (A, B) Maturation index (MI, average) of monocyte-derived DCs from healthy donors (Control) and kiwi-allergic patients (Patient), after stimulation with natural protein (Act d 2; 20 μg/mL), protein fraction (dActd2; 20 μg/mL), and N-glycan fraction (N-gly; 20 μg/mL). The means of five experiments are shown. Comparison between Controls and Patients (A). Comparison among different fractions (B). Data were analyzed by the Wilcoxon test or Mann–Whitney U test, respectively. (C) Cytokine profile. Changes in the production of Il-6, IL-10, TNFα, and IL-1β were measured by quantitative PCR. Amplifications were performed in triplicate and four independent assays. Means and SD (bars) are shown. Data were analyzed by Wilcoxon (with values of P < 0.05 considered significant).
Mentions: Peripheral blood mononuclear cells from six kiwi-allergic patients were cultured either in the presence of the natural protein (Act d 2) or together with one of the isolated fractions, that is, the protein (dAct d 2*) or the N-glycan (N-gly) (Fig. 4). The protein fractions were able to activate lymphocytes in the same way as the natural protein did. Nevertheless, the capacity of N-glycan fraction was considerably reduced. Curiously, only PBMCs from one out of the six patients were capable of activating T-cell proliferation in the presence of sugar.

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