engleski

IMMUNOGLOBULIN G GLYCOSYLATION IN ATOPIC CHILDREN

Immunoglobulin G (IgG) is considered one of modulators of immune responses in atopic diseases. Affinity of IgG binding to Fcγ receptors can be influenced by differential N-glycosylation of IgG Fc regions. This study aimed at examining serum IgG glycoprofile in children suffering from atopic diseases (allergic asthma, allergic rhinitis, atopic dermatitis and food allergy). Peripheral blood was collected from 61 patients and 74 healthy controls of both sexes aged 5-18 years. Patients' atopic status was confirmed by positive skin prick tests and elevated total serum IgE level. Plasma was separated by centrifugation and IgG isolated by affinity chromatography on CIMProtein G Monolithic Plate. Total plasma N- glycans (TPNG) and IgG N-glycans were released and processed by in-gel-block method, which included protein denaturation and N-glycan release by N- glycosydase F. After labeling with 2 aminobenzamide TPNG were examined by hydrophilic interaction high performance liquid chromatography, and IgG N-glycans by hydrophilic interaction ultra performance liquid chromatography. TPNG differed between two groups in surface area of only three out of sixteen glycan peaks containing mixed glycan populations. In contrast, IgG N-glycans different markedly between the two groups, concerning both carbohydrate unit number and composition. The atopic population showed a tendency towards bigger glycan structures (containing more than 10 monomer sugar units), as well as an increase in percentage of fully galactosylated and terminally sialylated structures. Thus, there is a markedly different and protein specific IgG N-glycoprofile in atopic vs. healthy children. This feature may be developed into a predisposition, prognostic or diagnostic biomarker of atopic diseases.

IgG; atopic diseases; glycosylation

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