Researchers have found a previously unknown link between metabolism and immunity, discovering more about why chronic inflammation develops in people who have obesity.
In new research, Dr. Megan Levings and colleagues demonstrate that insulin can damage regulatory immune cells, causing more inflammation in fat tissue.
Cells in people who have obesity often respond poorly to insulin, causing poor regulation of blood sugar. The body attempts to compensate by making more insulin, but over time unregulated blood sugar puts people at risk for complications such as type 2 diabetes, hypertension, cardiovascular disease and even some types of cancer later in life. The condition is especially worrisome in children who have obesity, as they face increased life-time risk of these complications.
In this study, the researchers looked at mice that were obese and found that high levels of insulin prevent a type of immune cell called regulatory T cells – or Tregs – from doing their job to suppress inflammation.
This finding could lead to new treatments for obesity-related complications, such as therapies for repairing Tregs. As a next step, the researchers are studying blood and adipose fat tissue donated from adults undergoing bariatric surgery.
The research is published in the January 2014 print issue of The Journal of Immunology. The journal is featuring the findings in a special section called “In This Issue”, which highlights articles considered to be among the top 10 per cent of articles published in that issue.
“This work represents a new and exciting collaboration between me and my colleague Dr. Jan Ehses in the whole new area of immunometabolism,” says Dr. Megan Levings, study’s lead investigator. Dr. Levings is a scientist at the Child & Family Research Institute (CFR) at BC Children’s Hospital and a professor in the Department of Surgery at the University of British Columbia (UBC).
Jonathan Han is the study’s first author. He is a PhD candidate at UBC working with Dr. Megan Levings at CFRI.
This research was supported by the Canadian Institutes for Health Research, the Canada Research Chairs Program, the Crohn’s and Colitis Foundation of Canada, and the Canadian Association of Gastroenterology.