Obesity: Immune Cells That Fight Obesity, New Look Into Autoimmunity
The immune system has an obvious job of fighting foreign invaders, like bacteria and viruses. But, a team of researchers from the Weizmann Institute of Science in Israel identified a tiny subtype of immune cells that seem to also prevent metabolic syndrome - which includes conditions like obesity, high blood pressure, and high cholesterol and blood sugar.
The study, published in Immunity, took mice and fed them a regular diet, which showed that immunological mechanisms can play a role in obesity, among other parts of metabolic syndrome, without any connection to dietary fat. Previous studies have only linked the immune system to obesity when mice were deliberately fed high-fat diets.
Originally, the team focused on dendritic cells, which serve as guards for the the immune system - alerting other immune mechanisms and processes to danger. The team's examination looked at the function of dendritic cells that possessed a "killing" protein, known as perforin, that can eliminate other cells on demand. To do this, the team, headed by Yair Reisner, a professor in the Immunology Department, created mice that lacked perforin-rich dendritic cells.
Surprisingly, Reisner's team saw that these mice became overweight and developed symptoms of metabolic syndrome.
Upon further investigation, the researchers found that the mice's fat tissue had incredibly high levels of inflammation-causing immune T cells, according to a news release. When these cells were removed from the perforin-lacking mice's fat tissue, the mice did not grow obese. This suggested that the dendritic cells that are perforin-rich can regulate the levels of certain T cells, which in turn can actually prevent metabolic syndrome.
Additionally, the study also has the ability to provide further insights into autoimmunity, as the scientists noted that the mice who lacked perforin-rich dendritic cells became more prone than normal to develop the equivalent to multiple sclerosis (MS) in humans. This has motivated the team to look into whether or not patients with MS lack these regulatory cells. These findings could have an enormous impact on millions of people.
Currently, more than one-third of adults in the U.S. are obese, equating to some 78.6 million people, according to the CDC. MS affects more than 400,000 people in the United States, and 2.5 million people worldwide.
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