Inflammation in fatty tissue: New approaches for treating obesity

Illustration doctor and obese patient with three icons showing diseases
Image: Colourbox.de

What causes obesity?

Researchers at the Institute of Microbiology – Clinical Microbiology, Immunology and Hygiene at Universitätsklinikum Erlangen and Trinity College Dublin have discovered a factor that may be involved in triggering obesity.

What causes obesity?

The researchers investigated how immune cells work together in visceral fat to cause inflammation that leads to weight gain and obesity. Inflammatory processes were investigated in obese patients with and without type 2 diabetes and in animal models. The consortium’s work indicated how regulating inflammation in fatty tissue can help in the search for new approaches to tackling obesity.

The study that has just been published in the leading international biomedical journal Science Translational Medicine DOI: 10.1126/scitranslmed.abj6879 was led by Dr. Christian Schwartz, head of a working group at the Institute of Microbiology – Clinical Microbiology, Immunology and Hygiene at Universitätsklinikum Erlangen and a former fellow of the European Molecular Biology Organization at Trinity College in Dublin, in collaboration with Professor Padraic Fallon (School of Medicine at Trinity College Dublin).

Obesity increases risk of infection

There is a global epidemic in obesity in both adults and children. People who are overweight or obese have a greater risk of developing diabetes, cardiovascular disease and certain types of cancer. As the Covid-19 pandemic showed, obese people infected with SARS-CoV-2 tend to develop a more severe form of the disease that often requires intensive care in hospital, and entails an increased risk of mortality. New therapies are required to tackle obesity and the serious consequences of an increased susceptibility to infection.

Checkpoint proteins trigger inflammation

During their study, the researchers identified how certain ‘checkpoint’ proteins alter immune cells within fatty tissue to trigger inflammation and cause obesity. In people with obesity (Body Mass Index BMI> 30 kg/m²) these changes in the visceral fat were predictive of the person’s weight. The researchers then showed that when mice lacking one of the checkpoint proteins were placed on a Western ‘high fat’ diet inflammatory reactions were triggered and the mice gained weight more rapidly.

Which cells are involved in this abnormal immune response?

‘As researchers working in immunology and infectiology, we hoped in the first instance to discover which cells are involved in this abnormal immune response, leading to obesity. For this reason, our main focus was on decoding the underlying mechanism. It is fascinating to see that a small change in one of the many cell populations in the visceral fat can have such an impact on weight gain,’ says Dr. Schwartz. Future research will show to what extent these findings may contribute to new concepts for treating obesity.

Further information:

Institute of Microbiology – Clinical Microbiology, Immunology and Hygiene, Universitätsklinikum Erlangen

christian.schwartz@uk-erlangen.de