Arginine Supplementation Emerges as a Simple Strategy to Boost Immune Surveillance Against Cancer and Viruses
Key Insights
Rockefeller University researchers discovered that the amino acid arginine is critical for MHC-1 (search) protein production, a key immune system alarm signal.
Low arginine levels impair the immune system's ability to detect mutated cancer cells and virus-infected cells, allowing threats to escape detection.
In mouse models, arginine-rich diets reduced colon tumor development and led to milder symptoms from influenza (search) and SARS-CoV-2 (search) infections.
A team at Rockefeller University has uncovered a previously underappreciated link between the common amino acid L-arginine and the immune system's capacity to detect and eliminate cancerous and virus-infected cells. The research, published in Cell, demonstrates that arginine scarcity directly disrupts production of major histocompatibility complex class I (MHC-1 (search)) proteins — the molecular "identification badges" that alert killer T cells to internal threats.
"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 in the lab of Sohail Tavazoie, who leads the Elizabeth and Vincent Meyer Laboratory of Systems Cancer Biology at Rockefeller. "Perhaps that means it could be used in combination with other therapies to treat both cancer and viral infections."
The MHC-1 Connection: How Arginine Powers Immune Surveillance
MHC-1 (search) proteins sit on the surface of virtually every cell in the body, displaying fragments of internal proteins for inspection by cytotoxic T lymphocytes. When a cell becomes cancerous or infected, it presents abnormal protein fragments, prompting T cells to destroy it. The Rockefeller team found that MHC-1 contains numerous sites where arginine must be incorporated during assembly. When arginine levels drop, ribosomes — the cellular machinery that builds proteins — stall while attempting to produce MHC-1, leaving cells with fewer signals capable of alerting the immune system.
Wu identified this mechanism by systematically examining gene and protein expression changes under low-arginine conditions. She found that 414 proteins were present at unusually low levels. Among the most striking results involved three HLA genes responsible for MHC-1 (search) production. "One of the most dramatic patterns to emerge was that arginine was the most depleted amino acid in all of these diseases," Wu noted, referring to the colon cancer (search), influenza (search), and SARS-CoV-2 (search) models studied.
Compelling Evidence in Disease Models
The translational implications became clear in animal studies. Mice fed a diet low in arginine developed more colon cancer (search) tumors, while those receiving higher arginine levels developed significantly fewer. Working with Heinz-Heinrich Hoffman, a research assistant professor in Charles Rice's Laboratory of Virology and Infectious Disease, Wu extended the dietary studies to viral infection models.
The results followed a similar pattern — and yielded an unexpected finding. "Not only did mice with an arginine-rich diet have milder symptoms from viral infections, giving the mice arginine after influenza (search) infection improved their outcomes too," Wu said. "That was very surprising. From our genetic models, we knew manipulating arginine levels had a strong effect on gene expression, but we didn't expect the dietary manipulation to be equally impactful."
Broader Implications for Aging and Nutrition
The findings may help explain long-observed links between poor nutrition, aging, and vulnerability to disease. Arginine levels naturally decline with age, potentially weakening immune recognition of abnormal or infected cells over time.
"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 (search)," Tavazoie said. "Similarly, age-related arginine loss could partially contribute to the greater mortality caused by respiratory viruses."
Tavazoie also noted that the concept of selective translational tuning — where dietary manipulation of a specific amino acid directly regulates gene expression by increasing production of proteins enriched in that amino acid — likely extends beyond arginine. "We're also investigating whether making dietary changes in other amino acids has beneficial effects in a variety of disease contexts. There are no doubt more discoveries to come."
A Readily Testable Intervention
The researchers emphasized the practical appeal of their discovery. A moderate amount of arginine, roughly equivalent to the quantity found in a couple of over-the-counter tablets, could potentially restore expression of the genes involved in MHC-1 (search) production.
"Arginine supplementation could be readily tested in patients receiving immunotherapies or given to high-risk populations exposed to viral pathogens," Tavazoie suggested. "Considering that arginine is inexpensive and readily available, we hope that therapeutic and preventative studies could be undertaken soon."
The work was supported in part by the Stavros Niarchos Foundation (SNF) Institute for Global Infectious Disease Research at The Rockefeller University and the Weill Cancer East Hub. The research builds on Tavazoie's earlier findings: in 2023, his team reported that depriving colon cancer (search) cells of arginine caused them to accumulate more mutations, suggesting the amino acid's importance extends across multiple dimensions of cancer biology.