The human body is equipped with a line of warriors to combat all types of harmful molecules and substances that the body could encounter. One of the fiercest warriors the body has to offer are T cells.

T cells are white blood cells that develop from bone marrow. They play a central role in protecting our body from infection. When the body is infected with a virus, T cells find and destroy infected cells that have turned into virus-making factories. T cells are able to find which cells have been infected with the antigens, identification tags, present on the cell surface. If a cell has been infected, it will display a virus antigen which tells T cells immediately that said cell needs to be destroyed. T cells will also remember this antigen for the next time the body faces a similar viral attack. So, not only do T cells help the body combat infections, they also maintain an immunological memory, making them critical to maintaining a person’s health.

However, in a recent study conducted by scientists at Washington University, researchers looked at T cells and whether they could play a role in Alzheirmer’s development. Researchers have known for a while that the brain’s immune cells, known as microglia, cause brain damage that can trigger Alzheimer’s. These cells tend to be stimulated when plaque builds up in the brain. As plaque builds up, microglia become more active and cause the brain to shrink and nerve cells to die.

Recently though, scientists found that microglia activated by plaque buildup release molecular compounds that bring more blood to the brain. The blood brings T cells with it that are activated by microglia. Once activated, the T cells release compounds that push microglia to inflame the surrounding tissue and attack nearby neurons. The study shows that the T cells trigger microglia to create an inflammatory response in the brain which then causes neurological damage and ultimately Alzhiemers.

Given this knowledge, the second part of the study focused on what would happen if the T cells never reached the brain. Scientists found that when the mice were given an antibody to deplete the T cells they had fewer activated microglia and less inflammation. The mice also had an improved ability to carry out normal behavior like building nests. The next steps will be to investigate whether depleting T cells in humans will show a similar effect as well as developing therapies to deplete T cells while also finding a way to keep a patient from becoming immunocompromised.

Although there’s a lot of unanswered questions regarding possible therapies and whether they will work in humans, researchers are hopeful that clinical trials will be approved and will start as soon as possible. If successful, targeting T cells could be key to combating Alzheimer’s.