How to wean the immune system to destroy beta cells?
Type 1 diabetes mellitus is an autoimmune disease in which the immune system attacks and destroys insulin-producing beta cells of the pancreas. This leads to insufficient insulin production, the deficiency of which patients with this disease are forced to make up for throughout their lives with regular subcutaneous injections. The root cause of type 1 diabetes is currently unknown.
It is known that the cells of the immune system – macrophages, normally protecting the body from inflammation-associated tissue damage, take an active part in the destruction of beta cells in type 1 diabetes.
To communicate with each other, immune cells release various signaling molecules – cytokines, which are a kind of instructions that determine the work of other parts of the immune system.
Swedish researchers from the Karolinska Institute, working under the leadership of Robert Harris, identified a combination of cytokines that gives macrophages the ability to protect mice from the development of type 1 diabetes.
As the object of the study, the scientists used NOD mice genetically predisposed to spontaneous development of type 1 diabetes at the age of 12-30 weeks. First, they isolated hematopoietic progenitor cells from the bone marrow of animals and differentiated them into macrophages. The resulting mature macrophages were stimulated using a specially selected combination of cytokines. After that, cytokine-stimulated macrophages were injected into 16–week-old mice of the experimental group, and intact macrophages were injected into animals of one of the control groups. Another control group was not treated at all.
The condition of the mice was monitored for 12 weeks after the procedure. By the end of the follow-up period, type 1 diabetes had developed in only 25% of mice who received an injection of stimulated macrophages, whereas for control groups this indicator was 83%.
According to the researchers, the animals were treated shortly before the appearance of clinical symptoms of the disease. At this stage, there are few functional insulin-producing cells left in the pancreas. However, even such a late intervention prevented the development of the disease. This gives great hope for the clinical application of the developed approach, since at the time of determining the diagnosis of type 1 diabetes, patients usually have a small number of functional beta cells.
Article by Roham Parsa et al. The Adaptive Transfer of Immunomodulatory M2 Macrophages Prevents Type 1 Diabetes in NOD Mice is published in the journal Diabetes.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of Karolinska Institutet: Researchers prevent mice from developing diabetes.
29.06.2012