Two gene-edited beagles, named Alfie and Bailey, were bred without the major dog allergen Can f 1 in their saliva and dander. Using CRISPR-Cas9 technology, researchers disrupted the gene responsible for producing Can f 1, and genetic testing revealed no unintended edits in the evaluated sites. While the dogs have developed normally, their genetic modification remains investigational and has not received approval from the FDA.
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Born on September 22, 2024, these two beagles carry a genetic change aimed at eliminating Can f 1, a protein that triggers allergic reactions in approximately 15% of the population, potentially leading to allergic rhinitis and asthma. Kindred Companion Sciences, the organization behind this research, published their findings in The CRISPR Journal. This study serves as a proof of concept for the possibility of reducing dog allergens at their source rather than treating allergic reactions after exposure.
The Can f 1 protein, prevalent among dog-specific IgE binding in sensitized individuals, has largely been targeted by conventional methods that focus on avoiding allergens or modifying immune responses. Current strategies, including allergen immunotherapy, offer limited effectiveness for dog allergies.
To create the gene-edited beagles, researchers began with fibroblast cells from female beagle fetal tissue and introduced a one-base-pair insertion in the Can f 1 gene to disrupt its protein production. Following genetic screening, a successful edited clone was selected for somatic cell nuclear transfer (SCNT). This method involved replacing the nucleus of canine eggs with that of the edited cells. From 25 embryos created, two developed to term.
Genetic testing confirmed the intended modification in both dogs, and extensive analysis ruled out major unintended genetic changes. Veterinary assessments showed Alfie and Bailey developed without significant health issues, showing normal behavior, growth, and responses to routine vaccinations.
In terms of allergen levels, researchers conducted tests that indicated Can f 1 was present in unedited beagles and some other breeds but not in Alfie and Bailey. Skin prick tests with a sensitized individual showed no allergic reactions to samples from the edited dogs, contrasting sharply with allergic responses to unedited dogs’ saliva and dander.
Though this research demonstrates a novel method for reducing allergens, it is not a definitive solution for all dog allergy sufferers, as human reactions to allergens vary greatly. The results also highlight that the gene modification approach remains experimental, and no commercially available Kindred dogs are currently offered for adoption.
The findings raise questions about the long-term implications for dog allergens and whether similar genetic modifications could benefit other animal species without adverse effects.