Nature
PUBLISHED
A pair of genetically altered beagles that don’t trigger allergies in humans are approaching their second birthday, and so far they don’t appear to be suffering from any unintended health conditions.
This suggests that the protein responsible for dog allergies can be safely removed from the canine genome without affecting their development, paving the way for the breeding of hypoallergenic pets.
Dog allergies are primarily caused by a protein called canis familiaris allergen 1, or Can f 1. This is found in the animals’ saliva and dander, and triggers an inflammatory response in certain individuals by stimulating immunoglobulin E (IgE) antibodies.
Usually, IgE only reacts to parasitic infections, but sometimes mistakes harmless proteins like Can f 1 for a pathogen and triggers a full-blown immune response.
Dog allergies are thought to affect about 15 percent of people, and can sometimes lead to asthma attacks or other dangerous outcomes. At present, allergen immunotherapy remains the only available option for people with this kind of sensitivity to dogs, though its efficacy is limited.
Researchers therefore sought to eliminate the cause of dog allergies at its source by genetically engineering puppies that don’t produce Can f 1.
Using CRISPR-Cas9 gene editing methods, they successfully bred two female beagles on September 22, 2024, neither of which had traces of the protein in their saliva or dander.
Named Alfie and Bailey, the pair of pooches have developed just fine over the past two years, and currently weigh approximately 9 to 10 kilograms (20 to 22 lbs), which is consistent with female beagle growth trajectories.
“Both dogs have received regular veterinary examinations and exhibited no clinically apparent health abnormalities to date,” write the researchers in a new study. “The dogs also display normal mentation and age-appropriate activity, with no clinically apparent behavioral abnormalities.”
At the moment, this research remains a proof-of-concept study, and genetically edited puppies are not yet available as pets.
But the researchers have exposed people with dog allergies to the saliva and dander of the two dogs, and found that this did not trigger an inflammatory response. In contrast, samples from poodles and goldendoodles - two breeds often touted as being hypoallergenic - did produce allergic reactions.
While the role of Can f 1 in dogs remains unclear, Alfie and Bailey are living proof that the protein is not essential for normal development, and can therefore be removed without causing any major issues in growing dogs.
“As someone who lives with dog allergies, this work is deeply personal,” explained study author Matt Walker in a statement. “For most of my life, I assumed I'd never have a dog but have lived with Bailey for almost two years. She's a happy, healthy, and incredibly sweet dog who reminds me every day why this work matters.”
The study has been published in The CRISPR Journal.
