Deglycosylation of shrimp tropomyosin modulates allergic reactions via immuoregulation and intestinal microbiota.

As reported, the glycans of tropomyosin (TM) affected its allergenicity. This work elucidates the regulatory role of glycans in Penaeus chinensis tropomyosin (Pen c 1) allergenicity via deglycosylation treatment. As the results, Pen c 1 is a glycoprotein with 2.625 % carbohydrate content, containing N-glycans and O-glycans. Compared with the native Pen c 1, deglycosylation treatment significantly reduced the carbohydrate content of de-N-glycosylated Pen c 1 (Pen c 1-DNG), de-O-glycosylated Pen c 1 (Pen c 1-DOG) and de-N&O-glycosylated Pen c 1 (Pen c 1-DNOG), promoted the IgG/IgE-binding capacity of deglycosylated Pen c 1, increased mast cell degranulation and allergic mediator secreation via exposing the previous hidden epitopes by glycans. Additionally, deglycosylated Pen c 1 exhibited elevated anaphylactic scores and serum allergic biomarkers in BALB/c mice, aggravated pulmonary inflammation in lung tissues, increased spleen index and Th2 cytokine secretion with unaffected Th1 responses. Moreover, deglycosylation of Pen c 1 increased the Firmicutes/Bacteroidota ratio and reduced Muribaculaceae abundance in intestinal microbiota. These findings demonstrated that removal of glycan from Pen c 1 could strengthen allergic reactions via modulating immune response and intestinal microbiota. This investigation could provide novel insights into regulating the glycan-dependent allergenicity of shrimp tropomyosin allergens via immuoregulation and intestinal microbiota.