Source: National Institutes of Health
Summary: Researchers have found that a type of immune cell – called a memory T-cell – seems to be stored in the body fat of mice. These cells learn to fight infection.
White adipose tissue (WAT) is one of the 2 types of adipose tissue found in mammals. The other being the brown adipose tissue. White adipose tissue provides insulation, serves as an energy store for times of starvation or great exertion, bridges body organs and plays a fundamental role in host metabolism. The extent to which adipose tissue contributes to immune surveillance and long-term protective defense remains largely unknown. Researchers from the National Institutes of Health have found that a type of immune cell called a memory T-cell seems to be stored in the white adipose tissue of mice. WAT represents a memory T cell reservoir that provides potent and rapid effector memory responses and contributes to immunological memory. The research findings were published in the journal Immunity.
When the research team infected mice with bacteria, they found that memory T-cells are clustered densely in the animals’ body fat. Tests showed that these cells seemed to be more effective than those stored in other organs, being better at replicating and at releasing infection-fighting chemicals. In a further experiment, the team took body fat from mice that had been exposed to a pathogen and implanted it in mice that had never been infected with it. When these mice were then exposed to the bacteria, the memory cells in the donated fat kicked into gear, giving them as much protection as if they had encountered the pathogen before. They hope that the study could lead to new ways to boost our body’s immune response to infections, cancer and vaccinations.
Senior Investigator, Yasmine Belkaid said, “These memory T-cells are particularly powerful because they may be feeding on the energy-rich fat tissue they are stored in and has an enormous amount of nutrients.
Dr. Anthony Ferrante at Columbia University said, “The findings should change the way we think about fat”, “If you picked up a textbook, it would list the immune organs as the lymph nodes, thymus, but this study and others are changing that, fat should be considered an immune organ, too.”
More Information: Seong-Ji Han et al, “White Adipose Tissue Is a Reservoir for Memory T Cells and Promotes Protective Memory Responses to Infection”, Immunity (2017). DOI: 10.1016/j.immuni.2017.11.009