DEC 25, 2020 6:00 AM PST

A High-Fat Diet Starves Immune Cells, Tumor Growth Goes Unchecked

WRITTEN BY: Tara Fernandez

Sitting down to enjoy an indulgent Christmas feast? A recent study in mice by Harvard Medicine scientists found that a diet high in saturated fat can stunt immune cells, allowing cancer cells to run rampant. The fatty diet also triggers tumor cells to tweak their metabolisms, allowing them to be fueled by fat instead of sugar. This further supports their uncontrolled growth in the absence of immune push-back.

In the study, led by cell biologist Marcia Haigis and published in the journal Cell, the research team provided new insights on the impact of diet on cancer immunity. Specifically, they found a sharp decline in the presence of cytotoxic CD8+ T lymphocytes within tumors. These white blood cells play a key role in antitumor immunity via their capacity to recognize and kill malignant cells.  

However, a diet high in fat cripples the ability of these immune cells to fight back against tumors. The authors managed to unravel the mechanism behind this phenomenon: tumor cells rewire their metabolisms to take full advantage of the abundance of fat (an energy-rich fuel source), which allows them to flourish, leaving “starving” T cells in their tracks.

"Putting the same tumor in obese and nonobese settings reveals that cancer cells rewire their metabolism in response to a high-fat diet," explained Haigis

"This finding suggests that a therapy that would potentially work in one setting might not be as effective in another, which needs to be better understood given the obesity epidemic in our society."

Interestingly, while high-fat diets caused CD8+ cell numbers to dwindle inside tumors, this observation was not noted in other parts of the body. Inside the tumors, the team found that T cells were sluggish with extremely impaired functionality. However, once extracted and relocated to cell culture dishes, they bounced back, with immune activity normals returning to baseline. Clearly, an essential fuel source was not available to these immune cells within the context of the tumor microenvironment.

The good news is that there is a way to stop tumor cells from rewiring their metabolisms using pharmaceutical interventions.

"Cancer immunotherapies are making an enormous impact on patients' lives, but they do not benefit everyone," said a senior author of the study, Arlene Sharpe.

We now know there is a metabolic tug-of-war between T cells and tumor cells that changes with obesity, says Sharpe. 

"Our study provides a roadmap to explore this interplay, which can help us to start thinking about cancer immunotherapies and combination therapies in new ways."

"Our study provides a high-resolution metabolic atlas to mine for insights into obesity, tumor immunity, and the crosstalk and competition between immune and tumor cells. There are likely many other cell types involved and many more pathways to be explored," added Haigis.

 

Sources: Cell, Science Daily.

About the Author
  • Tara Fernandez has a PhD in Cell Biology and has spent over a decade uncovering the molecular basis of diseases ranging from skin cancer to obesity and diabetes. She currently works on developing and marketing disruptive new technologies in the biotechnology industry. Her areas of interest include innovation in molecular diagnostics, cell therapies, and immunology. She actively participates in various science communication and public engagement initiatives to promote STEM in the community.
You May Also Like
DEC 13, 2020
Cell & Molecular Biology
The Immune Response to Infection and Vaccination Depends on Previous Infections
DEC 13, 2020
The Immune Response to Infection and Vaccination Depends on Previous Infections
After we are exposed to a pathogen or in the case of vaccines, a portion of a pathogen, our body mounts an immune respon ...
DEC 23, 2020
Immunology
COVID Survivors Stay Immune for at Least a Year
DEC 23, 2020
COVID Survivors Stay Immune for at Least a Year
Once the coronavirus enters the body, the immune system springs into action, producing antibodies that bind to and neutr ...
JAN 19, 2021
Immunology
Food Allergies Be Gone: Nanoparticles Call for an Immune Ceasefire
JAN 19, 2021
Food Allergies Be Gone: Nanoparticles Call for an Immune Ceasefire
Milk, eggs, peanuts, tree nuts, wheat, soy, fish, and shellfish—these foods are among the most unwanted list for t ...
MAR 16, 2021
Immunology
What Happens When Your Immune System Forgets
MAR 16, 2021
What Happens When Your Immune System Forgets
One of the most remarkable features of the immune system is its ability to “remember” past encounters with p ...
MAR 22, 2021
Immunology
Gene Mutation Keeps Tumors "Cold"
MAR 22, 2021
Gene Mutation Keeps Tumors "Cold"
Immunologists have identified a mechanism through which an oncogene mutation shields pancreatic tumors from immune cells ...
APR 01, 2021
Immunology
The Curious Case of COVID Immunity...a Threat to Vaccination Efforts?
APR 01, 2021
The Curious Case of COVID Immunity...a Threat to Vaccination Efforts?
After COVID infection, there’s a spectrum of diversity in how long antibodies against the coronavirus hang around& ...
Loading Comments...