Our immune system’s job is to protect our body and work as a self-defense tool against viruses and other harmful substances. Our immune system works as a cohesive unit spread across our body in different organs, cells and even the blood. Without it, our bodies would be more prone to infection and we would get sicker than usual. The immune system acts as a strong barrier to harmful bacteria that try to enter our body and cause infections. However, despite having a well-functioning immune system, sometimes we still get sick and develop infections. Researchers have suggested there’s a strong crosstalk between the immune cells and other cells of the body in diseases such as asthma. They have proven that immune cells communicate with the structural cells in the lungs to cause asthma attacks.

My lab recently published a review article that discusses the influence of the three major sex steroids—estrogen, progesterone and testosterone—on the independent immune cells in our body. Interestingly, we found that cells of the immune system are influenced by circulating sex hormones (also called sex steroids) in the body. From the immune system’s point of view, there are two main classes of asthma—called Th1 and Th2—that are categorized by the type of immune cells each class activates. Asthma has long been considered a Th2-driven disease, but newer research suggests there may be more subtypes of asthma.

Sex steroids are an integral part of human development. Women appear to have stronger immune systems than men, but at the same time women suffer more severely from asthma. This observation prompted researchers to look deeper into the sex differences involved in immune system regulation in asthma. Immunotherapy—the practice of manipulating the immune system to help treat diseases—was recognized as a priority topic in the latest edition of asthma management guidelines. Immune system crosstalk with sex steroids has also been reported in other lung diseases.

Looking ahead, newer research suggests scientists need to learn more about the immune system to be able to develop new treatments for disease. More research that makes the best use of our immune system will help us all breathe better.