Immune cells help fat deal with environmental challenges

September 8, 2017, Helmholtz Association of German Research Centres
T cells after a short-term cold treatment (left) and under control conditions (right). Immunofluorescent staining of the T cell marker CD3 (green), the Treg marker Foxp3 (red) and the nucleus (blue). The cold treatment results in a significant increase of Foxp3 expression in T cells. Credit: Helmholtz Zentrum München

Immunosuppressive regulatory T-cells play an important role in the functioning of adipose tissue. This is the discovery of scientists from the Helmholtz Diabetes Center (HDC) at Helmholtz Zentrum München and the Technical University of Munich (TUM). Their findings are published in the journal Cell Metabolism.

The number of obese people as well as those suffering from type 2 diabetes is increasing worldwide. Both disorders are associated with metabolic changes including amplified inflammatory responses in . "Previous studies have indicated that immunosuppressive regulatory T-cells – or Tregs for short – play an important role in these processes", explains the leader of the study Dr. Carolin Daniel, group leader at the Institute for Diabetes Research (IDF) of the Helmholtz Zentrum München and a scientist in the German Center for Diabetes Research (DZD). "We now wanted to examine how these immune cells might support adipose function in more detail."

In an experimental model, Daniel, together with co-first authors Dr. Stefanie Kälin and Maike Becker and colleagues, determined that the number of Tregs in adipose tissue increases in response to different environmental stimuli. These stimuli included a short-term cold treatment, stimulation of the sympathetic nervous system (β3-adrenoreceptors) or short-term high-caloric exposure. "All these stimuli supported those immunosuppressive cells directly in the adipose tissue", says Becker.

Fat burning activated

The magnitude of the increase in Tregs differed depending on the type of adipose tissue: it was particularly pronounced in , somewhat weaker in subcutaneous fat and weakest in visceral fat. To investigate the specific function of Tregs, the researchers determined how gene expression changes in adipose tissue. Especially in brown fat, genes were activated that promote heat production (thermogenesis) as well as those that are used for the breakdown (lipolysis) and burning (oxidation) of fatty acids. Subsequent experiments revealed that the signalling molecules Stat6 und Pten play a vital role in this process.

"A better understanding of the immunological mechanisms involved in the target tissue will be critical for the development of personalized interventions in order to improve adipose function during obesity and diabetes", says the leader of the study Carolin Daniel. "Our experiments show for the first time that Tregs can support fat depots in dealing with environmental challenges."

"Our findings highlight the complex interactions between our body and the environment. We have known for a while that hormones play a key role here – but now have to accept that may be just as important for a balanced metabolism", comments Prof. Dr. Matthias Tschöp. He is the scientific director of the HDC at Helmholtz Zentrum München and holds the chair for metabolic diseases at the TUM. "These insights therefore help us tremendously with designing more efficient ways to therapeutically optimize when and how to store calories."

Explore further: Fatty liver can cause damage to other organs via crosstalk

More information: Stefanie Kälin et al. A Stat6/Pten Axis Links Regulatory T Cells with Adipose Tissue Function, Cell Metabolism (2017). DOI: 10.1016/j.cmet.2017.08.008

Related Stories

Fatty liver can cause damage to other organs via crosstalk

August 21, 2017
Nonalcoholic fatty liver disease is increasingly common. Approximately every third adult in industrialized countries has a morbidly fatty liver. This not only increases the risk of chronic liver diseases such as liver cirrhosis ...

Omega-3 fatty acids stimulate brown adipose tissue metabolism

November 22, 2016
Omega-3 fatty acids are able to stimulate the activation of brown and beige adipose tissues, a discovery that would promote the development of new therapies for obesity and other metabolism diseases, according to a research ...

Making metabolically active brown fat from white fat-derived stem cells

March 3, 2017
Researchers have demonstrated the potential to engineer brown adipose tissue, which has therapeutic promise to treat metabolic diseases such as obesity and type 2 diabetes, from white adipose-derived stem cells (ASCs). The ...

Bariatric surgery improves adipose tissue function

June 20, 2016
(HealthDay)—Bariatric surgery is associated with improvements in adipose tissue function, some of which are independent of weight loss, according to research published online June 8 in Obesity Reviews.

To eat or not to eat (before exercising)—that is the question

April 7, 2017
Exercise enthusiasts often wonder whether it's better to eat or fast before a workout. A new study is the first of its kind to show the effects of eating versus fasting on gene expression in adipose (fat) tissue in response ...

IL-32 has inflammatory properties in human obesity

September 20, 2016
(HealthDay)—Interleukin (IL)-32 has inflammatory and remodeling properties in human obesity, according to a study published online Sept. 14 in Diabetes.

Recommended for you

Genomics reveals key macrophages' involvement in systemic sclerosis

January 18, 2018
A new international study has made an important discovery about the key role of macrophages, a type of immune cell, in systemic sclerosis (SSc), a chronic autoimmune disease which currently has no cure.

First vaccine developed against grass pollen allergy

January 18, 2018
Around 400 million people worldwide suffer in some form or other from a grass pollen allergy (rhinitis), with the usual symptoms of runny nose, cough and severe breathing problems. In collaboration with the Viennese firm ...

Researchers discover key driver of atopic dermatitis

January 17, 2018
Severe eczema, also known as atopic dermatitis, is a chronic inflammatory skin condition that is driven by an allergic reaction. In their latest study, researchers at La Jolla Institute reveal an important player that promotes ...

Who might benefit from immunotherapy? New study suggests possible marker

January 16, 2018
While immunotherapy has made a big impact on cancer treatment, the fact remains that only about a quarter of patients respond to these treatments.

Researchers identify new way to unmask melanoma cells to the immune system

January 16, 2018
system, which enables these deadly skin cancers to grow and spread.

How the immune system's key organ regenerates itself

January 15, 2018
With advances in cancer immunotherapy splashing across headlines, the immune system's powerful cancer assassins—T cells—have become dinner-table conversation. But hiding in plain sight behind that "T" is the organ from ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.