Flame Thrower

Adipose Tissue and Inflammation in Obesity

The immune activity and inflammation linked to adipose tissue in obesity is getting a lot of attention. Part of this is due to the interaction of inflammation, obesity, and the risks of COVID-19. But even more interesting is the insight into obesity itself. The insight comes from new study in Science Translational Medicine. In short, that study raises the possibility that controlling a very specific inflammation pathway in adipose tissue might help to control obesity.

That pathway involves a protein called PD-L1 that regulates immune function of T cells.

Insights from Cancer Research

Much of the research on PD-L1 comes from cancer research. Too much PD-L1 allows cancers to evade the immune system. So immunotherapy to suppress this protein has promise for treating cancer.

The gist of this new research in obesity is relatively straightforward. Christian Schwartz and colleagues demonstrated in mice that PD-L1 was important in mice for preventing obesity. Because without this protein, mice developed more obesity and more symptoms of metabolic syndrome. They also found a correlation in humans between BMI and PD-L1 in the visceral fat of humans.

Implications for Obesity Treatment

Regarding this pathway, senior author Padraic Fallon said:

“This new process of checkpoint regulation of cells in visceral fat of obese individuals advances our understanding of how the immune system controls diet-induced weight gain that can lead to conditions such as obesity and type 2 diabetes.”

Schwartz points to PD-L1 as a “checkpoint” that can be a therapeutic target:

“It will be interesting to investigate now how we can manipulate this checkpoint on specific cell populations of interest to help people with obesity.”

By now, it’s pretty apparent. As important as nutrition is, it’s not the whole story in obesity. If we want to control the harm it causes to health, then we had better understand the inflammation that drives it. Because by regulating the inflammation, we might be able to regulate obesity.

Click here for the study by Schwartz et al, here, here, and here for further perspective.

Flame Thrower, photograph by Scouse Smurf, licensed under CC BY-ND 2.0

Subscribe by email to follow the accumulating evidence and observations that shape our view of health, obesity, and policy.


April 6, 2022