Cancer ResearchDietary Arginine Boosts Immune Surveillance Against Cancer and Viral Infection
Researchers at Rockefeller University discovered that the amino acid arginine regulates a key immune mechanism called MHC class I, which allows immune cells to detect and destroy cancer cells and virus-infected cells. When arginine levels are low — as commonly occurs in tumors and infections — specific arginine-carrying RNA molecules are suppressed, slowing production of MHC class I proteins and blinding the immune system. In mouse models, restricting dietary arginine worsened colon cancer and impaired defense against influenza and SARS-CoV-2. Conversely, supplementing arginine or genetically blocking an enzyme that depletes it enhanced immune surveillance and improved outcomes. The effects depended entirely on intact MHC class I function, confirming the mechanism. This reveals a direct, diet-modifiable link between a single amino acid and immune competence against two major age-related threats.
