People may be genetically programmed to produce antibodies against peanuts, according to research that could lead to population-level treatments for this and other dietary allergies.
The study indicated that different individuals create converging antibodies from a variety of antibody gene arrangements, which all bind to peanut protein in a similar way.
This discovery, in Science Translational Medicine, could be considered surprising given the importance of randomness in the ability of the immune system to recognize and respond to diverse pathogens.
The research findings indicate that people have an intrinsic inclination to produce antibodies against the dominant allergen in peanuts, even if they have different genetic backgrounds.
Specifically, it suggests that a germline-encoded antibody repertoire exists to specific epitopes—the part of a protein that the immune system recognizes—and that this underlies serum IgG recognition to the Ara h 2 peanut allergen.
“Our discovery that humans are intrinsically predisposed by our antibody genes to make antibodies to peanut suggest that multiple pathways to antibody development may result in similar antibodies on a population basis,” researcher Sarita Patil, MD, co-director of the food allergy center at Massachusetts General Hospital, told Inside Precision Medicine.
“In individuals with peanut allergy, knowing this information helps us engineer therapeutic tools with atomic level precision, such as protective antibodies or specialized peanut proteins, that will allow us to treat a large proportion of the population.”
During childhood, people often develop IgG antibodies against allergens in the food they consume that are mostly harmless. However, in some people these can turn pathogenic and cause life-threatening reactions.
Patil and co-workers found that antibodies reacting to the Ara h 2 allergen were common in people, regardless of whether they were allergic to peanuts.
The team then examined the crystal structures and characteristics of isolated monoclonal antibodies that bind to Ara h 2 and found these remained similar after shuffling their corresponding genes.
Further investigation showed that these anti-Ara h 2 antibodies were convergent, despite coming from unrelated people and arising from diverse B cell receptor gene sequences.
The antibodies were widespread in serum samples from two groups of adults and older children allergic to peanuts, but also appeared in more than half (53%) of a sample of 45 infants and toddlers who were not allergic.
Speaking on the Science podcast, Patil said: “These are the first steps to really thinking about how we, as humans, on a population basis, have these antibody genes that might be predestined or preprogrammed to bind to certain proteins in the world in pathways that are eerily similar.”
