What can a primate tell us about cat allergies?

The toxin from the world’s only venomous primate appears to have given researchers an unexpected insight into the origins of cat allergies.

An international team led by the University of Queensland, Australia, made the link after studying the venom of the slow loris (genus Nycticebus) from Indonesia, which induces an allergy-like reaction in humans.

“We analysed the DNA sequence of the protein in slow loris venom, discovering that it’s virtually identical to the allergenic protein on cats,” says lead researcher Bryan Fry. 

“Cats secrete and coat themselves with this protein, and that’s what you react to if you’re allergic to them.”

Generally, slow lorises only use their venom to fight other slow lorises. When humans are bitten, Fry says, they display similar symptoms to that of an allergic shock.

That led him and his colleagues to suggest that when people are “allergic” to cats they are in fact responding to a defence mechanism.

“Our theory is that since this protein is being used as a defensive weapon in slow lorises, it makes sense that cats may be using the allergen as a defensive weapon too,” he says.

“Your pet cat wouldn’t know it, but it may have evolved a toxic defence to keep predators as far away from it as possible.”

That raises more questions, however.

“Similarly, this line of research opens up other fascinating research areas, such as the allergies to ants and bees also being something that has been selected for by evolution – where the victim’s immune system is being hijacked,” says Fry.

“This study is a great example of what makes science so wonderful, where every answer spawns several new and interesting questions”.

The research is published in the journal Toxins.