Pectin Oligosaccharides Glycosylation Modification Reduced the Sensitization of Shrimp Tropomyosin by Regulating Cytokines Expression and Th1/Th2 Immune Balance

Tropomyosin (TM) is the predominant allergenic protein in shrimp, which has induced IgE-mediated food allergy reactions. In this study, Lit v 1 was purified from Penaeus vannamei muscles, which were glycosylated by pectic oligosaccharides. The results showed that Di-Galacturonic acid (DGA) and galacturonic acid (GA) induced the unfolding of the primary protein structure of TM, and changed alpha-helical structure, and IgE binding capacity. In addition, compared with TM-sensitized BALB/c mice, galacturonic acid-modified TM (GA-TM) and Di-Galacturonic acid-modified TM (DGA-TM) were insufficient to stimulate sensitization, and significantly reduced the hypersecretion of IgE, IgG1, HIS, and IL-4, up-regulated IgG2a and IFN-γ levels to improve imbalanced Th1/Th2, Treg/Th17 immunity, and promoted mRNA expression of tight junction proteins. Together, this study confirmed that glycosylation modification alleviated sensitization by altering TM structure, reducing IgE binding allergic inflammatory response, and regulating cytokine immune balance. Overall, these results indicated that glycosylation modification was a promising method for decreasing the allergenic reactivity of allergic proteins.