Targeted Genetic Knockout of Can f 1, the Major Allergen in Dogs

Dog allergy is a prevalent IgE-mediated condition, with the salivary lipocalin Can f 1 accounting for the majority of dog-specific IgE reactivity in sensitized individuals. Existing strategies for managing dog allergy primarily rely on modulating host immune responses and do not address allergen production at its source. Here, we report the generation of genetically engineered dogs lacking Can f 1. Using CRISPR-Cas9 editing and somatic cell nuclear transfer, we produced two healthy beagle puppies carrying a frameshift mutation in exon 1 of the Can f 1 gene. Salivary and hair/dander analysis demonstrated the absence of Can f 1 protein in the edited dogs. Skin prick testing in a sensitized individual demonstrated robust IgE-mediated reactivity to control dog extracts but no detectable response to extracts from the edited dogs. Together, these findings demonstrate that targeted genetic knockout of the major dog allergen is compatible with canine development and can abolish the IgE-mediated allergic response, supporting the feasibility of a gene-based approach to reducing canine allergenicity.