Type 1 diabetes is triggered by a common virus, Coxsackie B, which confuses the immune system and causes it to destroy pancreatic cells, according to a study.
- Type 1 diabetes is an autoimmune disease characterized by a dysfunction of the pancreas which does not secrete enough insulin. According to a new study, this dysfunction could be caused by a virus, Coxsackie B.
- The virus can specifically kill pancreatic cells. An attack which generates inflammation of the tissues, which the immune system, “scrambled”, will consider as a threat. As a result, the body will produce antibodies to destroy the cells of the pancreas, hence the onset of diabetes.
- Thanks to this discovery, researchers hope to create a vaccine to prevent Coxsackie B infections and thus type 1 diabetes in children.
Type 1 diabetes, which represents 10% of cases of diabetes and affects around 300,000 people in France, is an autoimmune disease which most often occurs before the age of 20. It is characterized by a dysfunction of the pancreas which does not secrete enough insulin, the hormone essential to regulate blood sugar (the level of glucose in the blood).
If the origin of this dysfunction remained mysterious until now, a team of doctors from the Cochin hospital in Paris has just discovered that it could be caused by a virus, in this case Coxsackie B. Their work was published in the journal Science Advances.
Virus kills cells in the pancreas that are supposed to produce insulin
Well known to scientists, Coxsackie B is a type of virus belonging to the enterovirus family, which also includes viruses such as poliovirus and enterovirus D68. It is transmitted mainly by the fecal-oral route (contact with contaminated stools, often through unwashed hands or contaminated surfaces), but also by the respiratory route.
The Coxsackie B virus causes common infections, particularly in children, manifested by flu-like symptoms or gastroenteritis which often disappear spontaneously. Among children who contract this virus, some develop type 1 diabetes, others do not. How to explain such a disparity?
By examining in the laboratory (in vitro) the way Coxsackie B behaved in the bodies of diabetic children, they found that the virus was capable of specifically killing the pancreatic cells responsible for producing insulin (the ß cells of the islets of Langerhans). “Increased β-cell death was apparent after 8 hours”, underline the researchers. An attack which generates inflammation of the tissues… which the “scrambled” T lymphocytes (cells of the immune system), will consider as a threat. As a result, the body begins to produce antibodies in order to destroy the β cells of the pancreas, hence the onset of diabetes.
Towards a future vaccine to prevent type 1 diabetes?
This discovery allowed doctors to conduct clinical trials to try to boost the immune systems of children infected with the Coxsackie B virus. They have succeeded, for the moment, in delaying the onset of diabetes by 2 to 3 years thanks to a drug, according to information from RTL. Ultimately, researchers hope to create a vaccine to prevent Coxsackie B infections and thus type 1 diabetes in children.
