Experimental Model to Study Microbiota Perturbation Role in Alpha-Gal Syndrome

This chapter describes a standardized experimental protocol to induce and analyze galactose-α-1,3-galactose (α-Gal)-specific IgE responses in α-Gal-deficient (α1,3-galactosyltransferase knockout) mice. The absence of endogenous α-Gal in this model enables controlled sensitization to exogenous α-Gal-containing antigens from microbial, arthropod, and mammalian sources. The protocol integrates sequential oral exposure to α-Gal-expressing Escherichia coli O86:B7, capsule-based infestation with Ixodes ricinus nymphs, oral administration of porcine tissue homogenate, and subcutaneous injection of tick-derived protein extracts. Step-by-step procedures are provided for antigen preparation, animal handling, tick infestation, blood sampling, and indirect ELISA-based quantification of α-Gal-specific IgE. The protocol is designed for repeated sampling over time following defined antigen exposures and can be applied as an in vivo experimental framework for studies of α-Gal-associated IgE responses.