After discovering how immune cells work in the body, Cornell researchers say that one day, the cells may be harnessed as a better treatment for stubborn allergies as well as viral and bacterial infections.
More allergies than ever before
Allergic reactions are widespread. Worldwide sensitivity to allergens among children is soaring. Statistics from the American Academy of Allergies, Asthma, and Immunology suggest that between 40 and 50 percent of children are sensitive to one or more allergens. At the same time, millions of Americans suffer from viral and bacterial infections.
The Cornell researchers, who studied both mice and humans, took a close look at type 1 regulatory (Tr1) cells. These are immune cells that suppress immune response, like inflammation and tissue damage. They described in a June Nature Communications report how an enzyme known as ITK plays a vital role in the development of Tr1 cells during an immune response. They indicated that the enzyme offers an entry point for manipulation of the development of Tr1 cells to enhance them to treat allergies or block them to treat viral and bacterial infections.
Allergies are caused by an overactive immune response to an allergen. Tr1 cells can help to suppress the immune system and lower inflammation. When it comes to treating infections, such as the flu, doctors may want to block the pathway and lower the number of Tr1 cells. Experiments conducted with mice show that Tr1 cells increase when the mouse is infected with a virus or bacteria and when fighting tumors. It is believed by adjusting the development of Tr1 cells, people may have the ability to recover faster from certain diseases.
The study
During the study, the Cornell team bred genetically altered mice to have glowing green Tr1 cells. This made it easier to track them. They also bred another type of mouse that had fluorescent Tr1 cells, which allowed them to block the enzyme activity of ITK. Using a similar approach, the researchers created a third type of mouse that didn’t have ITK. In both the mice with relaxed ITK and mice that lacked ITK, Tr1 cells did not develop. They got the same results using blood cells from anonymous human volunteers.
In another experiment, the researchers identified a second important enzyme in the development of Tr1 cells. The other enzyme, called IRF4, regulates the expression of a number of genes and turned out to be key for controlling whether Tr1 cells developed. The team says that the same pathway exists in people.
While the discovery is of interest to immunology experts around the globe, the Cornell team admits that working with their model is a balancing act. For instance, in the case of the flu, other types of immune cell system T cells, focused on killing infected cells, start to destroy tissue. In these cases, an overactive immune response can lead to death. The experts have stated that they would have to do further research to determine whether they can tune the function of Tr1 cells so that they can balance the beneficial aspects of the immune response with the damaging aspects.
Right now, lifestyle changes, avoiding triggers, and prescription medications are often the go-to treatment for allergy suffers. Many complain that despite attempts to fight allergies, they still have symptoms. Meanwhile, the misuse and overuse of antibiotics to fight infection can lead to resistance to the medication. All of this makes a great case for finding better treatments.
Related: Immune cells differ in men and women