New study points to what makes an allergen, an allergen

Differences in the structure of proteins from outside the body from the structure of proteins made within the body may be what makes those foreign proteins allergenic, according to a new study.

Allergic reactions occur when a foreign protein from an allergen, such as peanuts or pet dander, enters the body and triggers an immune response. These responses can range from mild symptoms, such as a runny nose, to severe reactions such as anaphylactic shock and even death.

The new findings are the result of a “data mining” study where researchers combed a database of 499 allergens and compared their genetic similarities with the genes of parasitic bacteria, fungi, worms and protozoans, according to a statement from the National Institute of Allergy and Infectious Diseases (NIAID), the organization that conducted the study.

Their findings? Of the 499 allergens, 312 had genes “significantly similar” to genes in protozoa, fungi or worms and 180 had genes similar across three groups of microbes.

They also found that allergens that have a differing structure to microbes caused more immunoglobulin E (an antibody in the blood) to be released than those allergens with a structure more similar to the microbes. After also comparing the allergenic genes to the human genome, researchers found major allergens that caused a larger immunoglobulin E response had a “low structural similarity to human proteins,” according to the statement.

The results suggest that these structural differences between foreign proteins (i.e., those from outside of the body) and human-produced proteins are what make allergens allergenic.

Food allergies affect approximately 5 percent of kids and 4 percent of adults in the U.S., a number that’s increasing, according to NIAID.

The full study is set to be published in the July 18 edition of PLoS ONE. It can be found online in advance of publication at PLoS ONE here.

To read the full statement from NIAID, click here.

For a list of allergen-related posts from Neogen blog, click here.

Comments are closed.