Scientists have recognized a collection of molecular candidates for these elements of canine allergens that trigger immune reactions in folks—step one in creating a vaccine towards most causes of canine allergy symptoms.
There have been many analysis efforts describing the character and development of canine allergy symptoms, however there have been only a few utilized research that use this info to attempt to treatment folks of canine allergy symptoms totally by artificially inducing immune tolerance. However researchers have now for the primary time recognized candidates for these elements of the molecules that make up canine allergens that would give us exactly that: a ”canine allergy vaccine.”
Their findings had been revealed just lately within the Federation of European Biochemical Societies journal.
Being allergic to canine is a typical illness and one that’s rising worldwide. Through the years, scientists have been capable of establish seven completely different canine allergens—molecules or molecular constructions that bind to an antibody and produce an unusually sturdy immune response that may usually be innocent.
These seven are named Canis familiaris allergens 1 to 7 (Can f 1-7). However whereas there are seven, only one, Can f 1, is accountable for almost all (50-75 p.c) of reactions in folks allergic to canine. It’s present in canine’ tongue tissue, salivary glands, and their pores and skin.
Researchers have but to establish Can f 1’s IgE epitopes—these particular elements of the antigens which might be acknowledged by the immune system and stimulate or ‘decide’ an immune response (which is why epitopes are additionally known as antigen determinants). Extra particularly, epitopes are brief amino acid sequences making up part of a protein that induces the immune response.
Researchers for the first time identified candidates for those parts of molecules that make up dog allergens that could give us precisely that: a “dog allergy vaccine.” Credit: T. Inui, Osaka Prefecture University
Epitopes bind to a specific antigen receptor on the surface of immune system antibodies, B cells, or T Cells, much like how the shape of a jigsaw puzzle piece fits the specific shape of another puzzle piece. (The part of the receptor that binds to the epitope is in turn called a paratope). Antibodies, also known as immunoglobulin, come in five different classes or isotypes: IgA (for immunoglobulin A), IgD, IgE, IgG, or IgM. The IgE isotype (only found in mammals) plays a key role in allergies and allergic diseases. There is also an IgE epitope that is the puzzle piece that fits the IgE isotype’s paratope.
In recent years, there has been extensive effort at developing epitope-focused vaccines—in this case, a vaccine against dog allergies.
“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, professor at Osaka Prefecture University and a lead author of the study. “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 our grasp.
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.
Reference: “Structure-based prediction of the IgE epitopes of the major dog allergen Can f 1” by Masatoshi Nakatsuji, Keisuke Sugiura, Keisuke Suda, Michiko Sakurai, Miki Ubatani, Haruka Muroya, Rina Okubo, Ryo Noguchi, Yoichi Kamata, Yuma Fukutomi, Osamu Ishibashi, Shigenori Nishimura and Takashi Inui, 26 October 2021 , Federation of European Biochemical Societies.
DOI: 10.1111/febs.16252
