BioTechniques News
Tristan Free
For those whose canine companions give them the sniffles, CRISPR may have just offered a ray of light, helping create a pair of genetically modified beagles that don’t produce the main cause of dog allergies.
Taking a step toward the creation of hypoallergenic dogs, biotech company Kindred Companion Sciences (NY, USA) has used CRISPR-Cas9 editing and somatic cell nuclear transfer to produce two healthy beagle pups, named Alfie and Bailey, with a mutation in the Can f 1 gene, which encodes a major dog allergen. Analyses of the pooches’ saliva and dander revealed the absence of the targeted protein, while skin prick tests in an allergic individual resulted in no immune reactivity, raising hopes for a gene-based approach to reducing allergenicity in man’s best friend.
As well as a pain for pet owners, dog allergies can pose a danger to human health, featuring as a risk factor for allergic rhinitis and asthma. The major canine allergen Can f 1, found in the animals’ saliva and dander, is responsible for the majority of IgE-mediated reactivity in dog allergy sufferers. As things stand, allergen immunotherapy is the only disease-modifying treatment option; however, this does not address allergen production at its source and its success has been limited and inconsistent, underscoring the need for alternatives.
Advances in CRISPR-Cas9 genome editing have enabled specific genomic modifications in a wide range of mammalian species and represent a promising strategy to target animal allergens. To date, the technology has not been applied to allergens in dogs – but this latest development from Kindred changes that.
Using CRISPR-Cas9, the team engineered canine primary fibroblasts to introduce a 1-bp insertion and frameshift mutation in exon 1 of the Can f 1 gene. These cells were then used for somatic cell nuclear transfer and embryo transfer into female beagles, resulting in the births of two female puppies in September 2024. Genotyping of DNA from saliva samples using PCR amplification and Sanger sequencing confirmed the successful insertion in the Can f 1 gene, while whole-genome sequencing revealed no detectable off-target edits.
To evaluate the loss of Can f 1 protein, saliva samples were collected from the edited dogs as well as a wild-type beagle and a standard poodle and goldendoodle, both of which are commonly perceived as hypoallergenic. SDS-PAGE and Western blot analysis demonstrated the complete absence of the protein in the edited beagles, while it was detectable in all of the control dogs.
As exposure to Can f 1 can also occur through a dog’s hair and dander, the researchers also analyzed extracts of these from the same animals, again finding no signal in the edited dog samples.
These findings confirm the loss of Can f 1 production across multiple sources of exposure and demonstrate that so-called ‘hypoallergenic’ breeds still express the major allergen.
What does this mean for allergenicity in humans? The team performed skin prick tests on a sensitized human volunteer to find out. They compared salivary and dander samples from all the aforementioned dogs with saline and histamine, which acted as negative and positive controls. Extracts from the CRISPR-edited dogs did not trigger an inflammatory response, although robust reactivity was seen in response to control dog samples.
In addition, both dogs (Left) received regular veterinary examinations and exhibited no clinically apparent health or behavioral abnormalities.
“In summary, these findings demonstrate the feasibility of eliminating the major dog allergen through targeted genome editing without overt adverse effects,” the study’s authors conclude.
There is still much more research to be done before hypoallergenic hounds become commercially available; however, the research nudges us a little closer to this becoming a reality.
“We’re hopeful that Alfie and Bailey will be the first of many Kindred dogs as we build carefully and responsibly toward the next generation of companion animals,” commented Matt Walker, CEO of Kindred. “As someone who lives with dog allergies, this work is deeply personal. For most of my life, I assumed I’d never have a dog but have lived with Bailey for almost 2 years. She’s a happy, healthy and incredibly sweet dog who reminds me every day why this work matters.”
The post Meet the world’s first CRISPR-edited hypoallergenic hounds appeared first on BioTechniques.
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