Immunotherapy promising for type 1 diabetes
11th August 2017 – Immunotherapy is similar to a desensitisation technique already in use for allergies, and now researchers say it is showing promise for delaying the progression of type 1 diabetes.
According to the results of a clinical trial, it may be possible to "retrain" the immune system to slow the progression of type 1 diabetes. Researchers leading the MonoPepT1DE trial at King's College London and Cardiff University observed noticeable changes in the behaviour of the immune system in type 1 diabetes patients who had been injected with specific peptides, small fragments of the protein molecules found in the beta cells of the pancreas.
Type 1 diabetes
Type 1 diabetes is a type of autoimmune disease. It develops when a person's immune system mistakenly attacks the beta cells in the pancreas that produce insulin. Without treatment, the number of beta cells slowly decreases and the body can no longer maintain normal blood sugar (blood glucose) levels.
There is currently no cure for type 1 diabetes, and it can affect major organs in the body, including the heart, blood vessels, nerves, eyes and kidneys. With 400,000 people currently living in the UK with the condition, this country has one of the highest rates of type 1 diabetes in the world. Levels of type 1 diabetes have been increasing in recent decades at a rate of about 4% a year, most notably in children and adolescents.
The idea behind proinsulin peptide immunotherapy is to suppress underlying autoimmunity by awakening or restoring regulatory T cells – these are "defender" cells that make up part of the immune system to fight off infections. One method scientists are researching is the introduction of short peptides that form part of the epitopes (the part of the antigen to which an antibody attaches itself) of major autoantigens that stimulate an immune system response. This approach is known as peptide immunotherapy (PIT), and it is also being tested to treat allergies and autoimmune inflammatory conditions, such as multiple sclerosis and coeliac disease.
There has been interest in this area of research on diabetes. The study was given support by the National Institute for Health Research (NIHR) Biomedical Research Centre (BRC) at Guy's and St Thomas' NHS Foundation Trust, King's College London and Diabetes UK, and it was funded by JDRF, the type 1 diabetes charity.
Building on previous research
In a previous 2009 study led by Mark Peakman, professor of clinical immunology at King's College London, he and his colleagues administered peptide to people with long-standing type 1 diabetes. The goal was to modify the activity of cells known as autoreactive CD4 T cells and to detect insulin production from circulating C-peptide, a surrogate marker for insulin secretion. However, the study found that beta-cell destruction in this group was too advanced to detect C-peptide, so the researchers could not measure the results of the trial.