During degranulation, vesicles located in a cell combine with its cell membrane to release increased secretions. This process is used by the immune system, among others, to fight pathogens with these secretions. Disturbances in degranulation can therefore also affect the immune system.
What is degranulation?
Medicine refers to degranulation as a biological process at the cellular level that is important for the functioning of the immune system, among other things. Degranulation is the medical term for a biological process at the cellular level that is important for the functioning of the immune system, among other things. During degranulation, a cell releases substances into the environment; this process is also known as exocytosis and can occur in numerous functional systems and anatomical structures. Accordingly, the substances that the cell releases through degranulation represent secretions. Which secretion is involved depends on the role of the cell in the organism. Inside cells capable of this process there are small bubbles; medicine calls them vesicles. They are surrounded by a membrane and contain the secretion. When the cell receives the signal to degranulate, the vesicles move toward the cell’s membrane and fuse with it, allowing the secretion to pass out of the cell. Degranulation involves not only individual vesicles, but a very large number. As a result, the secretion output (secretion) of the cell is higher than usual.
Function and task
Among other things, degranulation is significant for the proper functioning of the immune system, especially for actively fighting pathogens after the human body has already recognized them. Such pathogens include viruses and bacteria. However, the defensive reaction of the immune system can also be directed against human cells, for example, if they are no longer functional or even represent a potential danger to the organism. One substance that the body can release in this way is perforin, which is directed against human cells. Perforin is thus part of the “suicide program” (apoptosis) that, for example, curbs the development of tumors through uncontrolled cell division. Another secretion involved in degranulation is histamine. This is a tissue hormone that the organism can also secrete as part of the inflammatory response to initiate various other reactions. In this case, therefore, histamine is part of a chain reaction. Other substances that play a role as secretions in degranulation include the enzyme peroxidase, as well as other enzymes from the group of protein-cleaving proteinases and several others. The cells that can degranulate are not of a uniform type. For example, the secretions may originate from lymphocytes. These immune cells move in the blood and develop in the bone marrow. Granulocytes, which are more involved in defense against bacteria, are also included. So do mast cells, which are relevant to allergic reactions and wound healing, for example.
Diseases and disorders
Because degranulation plays an important role in the proper functioning of the immune system, it is indirectly linked to an innumerable number of diseases. One example is the natural prevention of cancer in the human body. As long as a person is alive, cells divide almost continuously. In addition, the organism is constantly exposed to environmental stresses: sunlight, pollutants from the air and other influences can damage the genetic material contained in every cell. Errors in the genetic material can also occur during cell division itself. These changes (mutations) do not lead to serious consequences in every case, thanks in part to the immune system. In many cases, it is able to detect cancer cells, for example, before a tumor even forms. A tumor arises from uninhibited cell growth and, depending on its location, size and malignancy, can have a variety of health consequences that often manifest themselves non-specifically. Cancers can be fatal. Therefore, if the body discovers such a risky cell, it initiates an immune response. Depending on the localization, the organism mobilizes appropriate immune cells – including those carrying vesicles with secretions.By degranulation, they release their secretion, which is directed against the potential cancer cell and destroys it. If this reaction is successful, the risk is eliminated and no tumor develops. In cancer, however, this system usually fails. Some researchers therefore see improved treatment options and the opportunity for cancer prevention in improving this immune response and promoting the recognition of cancer cells even before they can cause damage. Currently, however, this research is in its infancy and requires much further basic research. Other examples of the link between degranulation and disease (which are only a selection) include bronchoconstriction by histamine release in bronchial asthma, various allergic reactions (including the immediate reaction), inflammatory reactions, and an increase in gastric acid secretion.
