Scientists at Northwestern Medicine recently made an exciting discovery regarding why there is a higher prevalence rate for women than men in multiple sclerosis (MS) and other autoimmune diseases. They found that the innate lymphoid cell, which is a type of white blood cell, works differently in males versus females.
Most labs that study MS use female mice because they are much more likely than male mice to get the disease. Typically, two groups of female mice are used: one group of normal mice used as a control group and one group of mice with a genetic mutation in a growth factor receptor, which blocks the development of a subset of immune cells. However, a graduate student in the lab made an honest mistake and used two sets of male mice instead of female mice. At the end of the experiment, the male mice who had the mutation were extremely sick, which led to the realization that the mutation was acting differently in females and males.
The mice with the mutation were found to lack type 2 innate lymphoid cells, which are normally present in bone marrow, lymph nodes, and the thymus of both females and males. These cells are not found in the males with the mutation, which leads to a drastic change in the immune response of the mice and means that they are not protected against MS. In the normal male mice, these lymphoid cells were activated and protected the mice from the disease.
While female mice have the same lymphoid cells that male mice do, they do not become activated and therefore do no protect them from developing MS. This discovery in the lab has led to the current investigation into why these cells are activated more so in males than females and subsequently if it is possible to activate them in females in order to reduce their vulnerability to contracting MS.
Background on MS
Multiple sclerosis is a disease in which your immune system attacks your central nervous system, which is made up of your brain, optic nerves, and spinal cord. More specifically, the protective layer (myelin) that covers your nerves is attacked and subsequently damaged, disrupting the crucial communication between your brain and the rest of your body. The distortion and disturbance of nerve impulses traveling to and from the brain generate a wide variety of symptoms, depending on which nerves are affected and how damaged they become.