This is the first identified function for this molecule, says co-senior author Susan Gilfillan, Ph.D., research instructor in pathology and immunology at the School of Medicine. Our findings suggest that this molecule may play a fundamental role in gut immunology.
When a virus enters the body, proteins called antigens appear on the surface of cells and alert the immune system to infection. A molecule called MR1, which was discovered eight years ago, appears to be very similar to the main category of molecules that deliver antigens to the cell surface, called major histocompatibility complex class I (MHC Class I). However, its function is not yet understood.
To learn more about MR1, Gilfillan and colleagues developed a strain of mice lacking the molecule. The mice failed to develop a small population of immune cells known as mucosal-associated invariant t cells (MAIT cells). MAIT cells were just recently discovered by the studys other co-senior author, Olivier Lantz, Ph.D., at the Institut Curie in Paris. The current study presents the first extensive characterization of these cells.
These results help us begin to understand the function of MR1 and the role of MAIT cells in immunology, Gilfillan says. Both are found not only in mice but also in humans and other animals, such as cows, which implies that they probably are very important.
The team also discovered that MAIT cells appear to be primarily located in the mucous membrane of the intestine, or gut. Moreover, mice lacking bacteria normally found in the gut do not have MAIT cells.
From these results, Gilfillan and colleagues conclude that MAIT
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Contact: Gila Z. Reckess
reckessg@msnotes.wustl.edu
314-286-0109
Washington University School of Medicine
13-Mar-2003