**Background of GAL Antibodies**
GAL antibodies target the galactose-α-1.3-galactose (α-Gal) epitope, a carbohydrate structure expressed on cell surfaces of most non-primate mammals but absent in humans due to evolutionary inactivation of the *GGTA1* gene. Humans naturally produce anti-GAL antibodies (IgG, IgM, and IgE) as part of immune responses to environmental exposures, such as gut microbiota or consumption of red meat containing α-Gal.
These antibodies gained prominence due to their role in **xenotransplantation rejection**, where α-Gal on donor organs (e.g., from pigs) triggers hyperacute immune rejection in humans. Research into gene-edited *GGTA1*-knockout animals aims to mitigate this barrier.
Additionally, anti-GAL IgE antibodies are linked to **α-Gal syndrome**, a delayed allergic reaction to red meat, often initiated by tick bites (e.g., lone star tick). This syndrome highlights the interplay between environmental triggers and immune sensitization.
Beyond clinical implications, anti-GAL antibodies are explored in cancer immunotherapy and infectious disease research, as some pathogens exploit α-Gal mimicry for host invasion. Their dual role—as protective agents and mediators of pathology—underscores their significance in immunology and translational medicine.