A vaccine against dog allergies

The article was written by Shepard Price. Article saw on www.thetelegraph.com

Well, it could be possible to have a vaccine against dog allergies.

<< Researchers at Osaka Prefecture University of Japan have for the first time identified candidates to try and cure people of dog allergies by artificially inducing immune tolerance to those parts of the molecules that make up dog allergens, creating a potential “dog allergy vaccine.”

Being allergic to dogs is a common malady across the globe and one that is growing, researchers said. Scientists have been able to identify seven different dog allergens, or molecules or molecular structures that bind to an antibody and produce an unusually strong

immune response that is normally harmless, over the years. These seven are named Canis familiaris allergens 1 to 7. Of the seven, just one, Can f 1, is responsible for the majority (50-75%) of reactions in people allergic to dogs. That allergen is found in dogs’ tongue tissue, salivary glands and their skin.

The findings were published in the Federation of European Biochemical Societies journal on Oct. 26.

Researchers have yet to identify the specific parts of the antigens that are recognized by the immune system and stimulate or determine an immune response (epitopes or antigen determinants) which bind to a specific antigen receptor on the surface of immune system antibodies like a jigsaw puzzle piece fits the specific shape of another puzzle piece, researchers said.

Antibodies, also known as immunoglobulin, come in five different categories and the IgE isotope, which is only found in mammals, plays a key role in allergies and allergic diseases.

Recently, there has been an extensive effort aimed at developing epitope-focused vaccines — in this case, a vaccine against dog allergies, researchers said.

“We want to be able to present small doses of these epitopes to the immune system to train it to deal with them, similar to the principle behind any vaccine,” said Takashi Inui, a specialist in allergy research, said in a statement. “But we can’t do this without first identifying the Can f 1’s IgE epitope.”

So the researchers used X-ray crystallography (in which the diffraction of x-rays through a material is analyzed to identify its ‘crystal’ structure) to determine the structure of the Can f 1 protein as a whole — the first time this had ever been done.

They found that the protein’s folding pattern is at first glance extremely similar to three other Can f allergens. However, the locations of surface electrical charges were quite different, which in turn suggest a series of “residues” that are good candidates for the IgE epitope.

Using this basic data, further experimental work needs to be performed to narrow the candidates down, but the findings suggest the development of a hypoallergenic vaccine against Can f 1 — a dog-allergy vaccine — is within grasp, researchers said.

The production of a “hypoallergenic vaccine” by use of such epitopes would not just be a world-first with respect to dog allergies but is rare with respect to any allergic reaction. If the researchers’ work is indeed used to develop a dog allergy vaccine, the principles behind it could be used much more widely against various allergies. The Philadelphia Inquirer reported earlier this year that Purina was developing a cat food that could help with cat allergies, reducing the protein that most allergic people react to by 47% after three weeks. Healthline reported that in 2019, a Swiss company was developing a vaccine focused on cat allergies that was administered to the animal. >>

Source: www.thetelegraph.com