Study Certain killer cells cause the increased diabetes risk in overweight

Special killer cells increase the risk of diabetes if you are overweight
Overweight has a negative impact on human health in many ways. With regard to the risk of diabetes, scientists from the University of Cologne and the Max Planck Institute for Metabolism Research have now discovered that a special subgroup of immune cells in obese patients leads to a significantly increased risk of type 2 diabetes.

More than half of Germans, according to the scientists, are overweight and this leads, among other things, "that the immune system is chronically activated and thus stressed." Jens C. Brüning from the University of Cologne has investigated in his current study how the immune system reacts to obesity and how sequelae arise. They discovered a subgroup of natural killer (NK) cells of the immune system in obese patients, which increases the risk of type 2 diabetes. The researchers published their study results in the renowned science journal "Cell Metabolism".

In case of obesity, the immune system is permanently activated, which leads to increased insulin residual and eventually to diabetes. (Image: andriano_cz / fotolia.com)

Obesity permanently activates the immune system
Due to the increasing number of overweight people, there are more and more diabetes and stroke patients, the researchers report. Added to this is the fact that the risk of cancer is also growing, as obesity, among other things, permanently activates the immune system. This is shown by the increased expression of a specific subset of NK cells in overweight people. Normally, NK cells are responsible for fighting virus-infected or malignant cells.

Certain killer cells lead to increased insulin resistance
In the mouse model, the scientists found that in overweight mice in a small subset of NK cells, other genes are active than in animals with normal weight, according to the Communication of the University of Cologne. According to the researchers, this adiposity-associated NK cell subgroup is involved in the regulation of the immune system and apparently enhances its chronic activity. This in turn leads to increased insulin resistance - the precursor of type 2 diabetes. Using human blood samples, the researchers were able to show that the composition of NK cells is also different in lean and obese people.

Radical diets reduce the risk
The scientists report that in blood samples from obese patients, the killer cells have a similar gene expression profile as in obese mice. In addition, the number of altered killer cells and the risk of diabetes have decreased when the obesity patients have undergone a radical diet, in which they decreased markedly, reports Priv.-Doz. Dr. Sebastian Theurich, scientist at the Max Planck Institute for Metabolism Research and Haemato-oncologist at the Clinic I for Internal Medicine of the University of Cologne. "Meaning, the number of this particular NK cell subset is related to obesity and chronic inflammation," Theurich continued.

Approach to new treatments
According to the researchers, the discovered subgroup of NK cells could also "be a target for new therapeutic options if it succeeds to turn off these cells targeted." In the mouse model, the risk of diabetes had significantly reduced, if the animals were genetically manipulated that the subgroup of altered killer cells could no longer develop in high-fat diets. "Without these special killer cells, the mice did not gain weight despite high-fat foods and did not develop insulin resistance," reports the University of Cologne. (Fp)