The amino acid arginine, produced by the body and found in high-protein foods, may play a key role in supporting immune defenses against cancer and viral infections, according to research published on Jul. 31 by scientists at Rockefeller University.
Sohail Tavazoie, head of the Elizabeth and Vincent Meyer Laboratory of Systems Cancer Biology at Rockefeller University, has led studies investigating how arginine levels affect disease. In previous work from 2023, Tavazoie's team found that depriving colon cancer cells of arginine increased their mutation rates. The latest study expands on this by showing that an arginine-deficient diet also impairs the immune system's ability to produce MHC-1 protein—a molecule that alerts immune cells to dangers such as mutating cells or invading viruses.
The researchers reported that providing a moderate dose of arginine—comparable to what is found in over-the-counter supplements—could restore gene expression responsible for MHC-1 production. "Our work reveals how a lack of arginine interferes with the immune system, and suggests that upping arginine intake could prove beneficial," said first author Qiushuang Wu, a postdoctoral researcher at Rockefeller University. "Perhaps that means it could be used in combination with other therapies to treat both cancer and viral infections."
Tavazoie said, "Arginine supplementation could be readily tested in patients receiving immunotherapies or given to high-risk populations exposed to viral pathogens. Considering that arginine is inexpensive and readily available, we hope that therapeutic and preventative studies could be undertaken soon." The study also noted that among several diseases examined—including colon cancer, influenza, and SARS-CoV-2—arginine was consistently the most depleted amino acid.
Wu’s experiments showed mice fed low-arginine diets developed more colon tumors than those given higher amounts; similar patterns were observed when testing responses to influenza and SARS-CoV-2 infections. Wu said, "Not only did mice with an arginine-rich diet have milder symptoms from viral infections, giving the mice arginine after influenza infection improved their outcomes too." Additional findings indicated ribosomes stalled during protein production when deprived of sufficient arginine.
Tavazoie concluded, "Qiushuang's findings illuminate how poor diet and aging—during which arginine levels naturally decline—could create the perfect storm for the initiation of colon cancer. Similarly, age-related arginine loss could partially contribute to the greater mortality caused by respiratory viruses... There are no doubt more discoveries to come."
