University of Virginia researchers believe they are one step closer to understanding why some people bitten by the Lone Star tick develop an allergy to red meat — and hope they are one step closer to identifying potential treatments for the allergy.
According to an article published Aug. 15 in the Journal of Immunology, a team has identified key characteristics about the development of the red meat allergy. The allergy is triggered by eating meat from mammals or using products such as coated pills or lotions and can cause rashes, nausea and anaphylaxis. The allergic reaction and the link to ticks, as well as various complications of the allergy, have been fairly well-documented thanks to pioneering work by UVa’s Dr. Thomas Platts-Mills, but the reason cells turn and attack is still not well understood.
“But now that we have a model, we can work our way backwards to the tick bite and find out what causes the response,” said Loren Erickson, an associate professor of microbiology and immunology who is an author of the article.
Erickson studies a type of white blood cell called B cells, which help protect the body from all types of disease, such as the flu and bacterial infections. Some diseases, however, cause the B cells to send out antibodies that attack otherwise healthy parts of the body.
Erickson’s team went through the laborious process of creating a mouse model so they can track how the red meat allergy presents in mice and how the mice respond in real time.
They discovered that mice with the meat allergy have a high number of B cells that create a specific antibody when the cells detect the presence of alpha-gal, a sugar, after red meat is eaten.
“We are likely dealing with a disease that involves B cells that are different than what was classically thought,” he said. “And, by better understanding how B cells work, that gives us hopefully a clue of how to go after, therapeutically, to interrupt B cells and their production of [an antibody to] alpha-gal.”
Moving forward, Erickson’s team hopes to use their mouse model to continue testing various aspects of the allergy, if they can predict how severe a person’s allergic reaction might be and how to understand how other immune cells interact with B cells.
Finally, Erickson said the model might help researchers understand an outstanding question about the allergy: whether it is caused by the tick bite itself, a bacterium or virus harbored in the tick and transmitted by the bite, or some combination of the two.
Immune cells harbor a family of molecules that are triggered by different viruses, bacteria, fungi or other invaders, and by back-tracking through the pathway of the presentation of the allergy to a tick bite, researchers might be able to determine whether the tick is transmitting a bacterium or virus.
“We hit the low-hanging fruit with this study and hit the hammer on the head of the presence of B cells,” Erickson said. “Now we can go after this in more refined tests to see which member of this family [of molecules] causes the response, which might lead to therapeutic treatment.”