Nobel Prize Honors Immune System Discovery

Sydney Barber

Staff Writer 

The Nobel Prize in medicine was awarded to three scientists on Oct. 6 for their key discoveries on the immune system. 

Mary E. Brunkow, Fred Ramsdell, and Dr. Shimon Sakaguchi discovered a critical pathway in the body known as peripheral immune tolerance. This pathway is crucial in autoimmune diseases, such as Type 1 diabetes, Lupus, and Multiple Sclerosis. 

The immune system is the body’s primary line of defense against bacteria, viruses, and other foreign invaders. However, sometimes certain immune cells can mistake healthy cells for these intruders and attack a person’s own cells and tissues, causing autoimmune diseases. 

The Nobel Prize Winners wanted to uncover the reason why these immune cells confused human cells for intruders, and began their research in separate projects over several years. 

Brunkow and Ramsdell conducted their set of research in the U.S., while Sakaguchi resided in Japan. The three were working simultaneously toward the same goal; however, Brunkow and Ramsdell were focused on the genomic level of autoimmune diseases, while Sakaguchi researched the cellular level. 

T cells are a kind of “immune soldier” that are trained to spot intruders that go awry in a way that may trigger autoimmunity. The intruders are then eliminated in the thymus, the gland in the body that produces these immune system cells. 

Sakaguchi began his experiments on mice, which showed that the thymus pathway could not be the only explanation as to why the immune system attacks itself. 

In 1995, he discovered a previously unknown T cell subtype, now known as the regulatory T cell, that could also suppress overreactive immune cells like biological security guards. 

In 2001, Brunkow and Ramsdell were investigating mice with an autoimmune disease. They discovered a mutation in a gene called Foxp3 that was present in all of the mice. This led them to realize that Foxp3 must play a major role in the immune system. 

The three scientists published their work, and upon reading the other scientists’ research, they began to work together to further their findings. 

Years later, Sakaguchi linked the discoveries to show that the Foxp3 gene controls the development of those regulatory T cells and gives them the ability to shut down overreactive cells present in autoimmune diseases. Therefore, if there is a mutation in this Foxp3 gene, then the regulatory T cells will either not be produced or will not work properly. 

So what does all of this mean? Essentially, all humans have cells that fight back against diseases. These fighters are called T cells and the human body contains different types of them. 

When these cells do not work properly, they can attack healthy cells, mistaking them for bacteria or viruses, which makes people sick. This is what causes autoimmune diseases. 

The three scientists discovered that the reason T cells attack healthy cells is because of a mutation in a gene that regulates the production of T cells, causing them to not work properly. 

From this breakthrough research, scientists are now able to come up with ways to increase the number of regulatory T cells in individuals with autoimmune diseases to help fight those diseases.

 It also opens the door for research concerning how to limit mutations in the Foxp3 gene to allow for regular production of regulatory T cells.