Elisa B. Sodemann, Sabrina Dähling, Robert Klopfleisch, Ekaterina Boiarina, Didier Cataldo, Moumen M. Alhasan, Ali Ö. Yildirim, Martin Witzenrath, Christoph Tabeling, Melanie L. Conrad

• Background Maternal asthma during pregnancy is considered an environmental risk factor for asthma development in children. Immunoglobulin G (IgG) antibodies that are transferred from the mother to the fetus are known to act in a pro‐ or anti‐inflammatory manner depending on their glycosylation status. Objective Using a mouse model, we examined how maternal allergic airway inflammation during pregnancy influenced offspring experimental asthma severity, as well as maternal and offspring serum IgG antibody glycosylation patterns.Background Maternal asthma during pregnancy is considered an environmental risk factor for asthma development in children. Immunoglobulin G (IgG) antibodies that are transferred from the mother to the fetus are known to act in a pro‐ or anti‐inflammatory manner depending on their glycosylation status. Objective Using a mouse model, we examined how maternal allergic airway inflammation during pregnancy influenced offspring experimental asthma severity, as well as maternal and offspring serum IgG antibody glycosylation patterns. Additionally, the effects of maternal and offspring exposure to the same or different allergens were investigated. Methods Female mice were either sham sensitized or sensitized to casein (CAS) or ovalbumin (OVA) before mating. Subsequently, allergic lung inflammation was induced in pregnant dams via aerosol allergen challenge (sham, CAS or OVA). After weaning, pups were subjected to an experimental asthma protocol using OVA. Asn‐297 IgG glycosylation was analysed in maternal and offspring serum. Results When mothers and offspring were sensitized to the same allergen (OVA‐OVA), offspring had more severe experimental asthma. This was evidenced by altered antibody concentrations, increased bronchoalveolar lavage inflammatory cell influx and decreased lung tissue and lung draining lymph node regulatory T cell percentages. When mothers and offspring were sensitized to different allergens (CAS‐OVA), this phenotype was no longer observed. Additionally, maternal serum from allergic mothers had significantly higher levels of pro‐inflammatory IgG1, shown by decreased galactosylation and sialylation at the Asn‐297 glycosylation site. Similar glycosylation patterns were observed in the serum of adult allergic offspring from allergic mothers. Conclusions and Clinical Relevance We observed a strong association between maternal experimental asthma during pregnancy, increased offspring airway inflammation and pro‐inflammatory IgG glycosylation patterns in mothers and offspring. IgG glycosylation is not a standard measurement in the clinical setting, and we argue that it may be an important parameter to include in future clinical studies.…