Scientists have found that hematopoietic stem cells (HSCs), involved in the immune response, use body fat stores to fight infection. The study could help develop new treatments for diseases in people with weakened immune systems.
A team from the University of East Anglia (UEA) and the Quadram Institute conducted joint research to study the body’s immune response, namely, the response of blood stem cells to Salmonella, a bacterium that causes diarrhea, vomiting, dehydration, pain in the abdomen, fever, and sepsis.
Scientists have found that after receiving a signal of infection, adipocytes begin to release their fat stores into the bloodstream in the form of fatty acids, which are then absorbed by the hematopoietic stem cells in the bone marrow. Once energized, HSCs begin to actively create millions of leukocytes (white blood cells) that fight Salmonella or other infections.
The study, published in the journal Nature Communications, showed that adipocytes are associated with the immune system and can synchronize their work when needed.
The team studied in detail the mechanism of delivery of fatty acids into the mitochondria of hematopoietic stem cells. As the study showed, with a lack of fat, hematopoietic stem cells did not receive enough energy, the bodies of laboratory mice could not cope with Salmonella infection, and the animals died.
“Our results provide insight into how the blood and the immune system can respond to infection. Fighting infection takes a lot of energy, and fat stores are huge energy deposits, which provide the fuel for the blood stem cells to power up the immune response. Working out the mechanism through which this ‘fuel boost’ works gives us new ideas on how to strengthen the body’s fight against infection in the future”, – said Dr. Stuart Rushworth from UEA.
“Our results allow us to understand how our immune system uses fat to fuel the response to infection. Defining these mechanisms will enable us to develop new therapeutics to treat infections in the liver,” – says Dr. Naiara Beraza of the Quadram Institute.
“In the future, I hope our findings will help improve treatment for vulnerable and older people with infections by strengthening their immune response. With antibiotic resistance being such a present and widespread challenge for society, there is an urgent need to explore novel ways like this to help the body’s immune system to fight infection,” – said Dr. Rushworth.