New research in The Journal of Immunology suggests that a lack of dietary iron can negatively affect the ability of immune cells to respond to viral infection in the lungs. In mice with dietary iron deficiency and influenza, immune cells struggled to produce a key signal needed to fight viruses and did not regain this ability even when iron levels returned to normal.

The results suggest that iron deficiency during infection may leave lasting effects on lung immune cells, making people more susceptible to viral infections. It may also help explain why iron deficiency is linked to conditions like asthma. Iron deficiency is a very common problem disproportionately affecting women and young children.

Dr. Thomas J. Connors, Assistant Professor of Pediatrics at Columbia University Vagelos College of Physicians and Surgeons, who led the study, said: “We hope this study deepens the understanding of how iron influences immune system development and raises awareness of iron deficiency as an important global health issue. This research could lead to new dietary interventions to support healthy T cell function, strengthen protection against infections, and prevent harmful immune responses by promoting healthy iron levels.”

Memory T cells are a type of immune cell that stay in tissues such as the lungs, where they can act quickly if the same infection returns. In this study, Dr. Connors and his team investigated how iron deficiency affects these memory T cells and their ability to respond to influenza infection.

The researchers fed two different groups of mice a diet that was either iron-rich or iron-deficient. All mice were infected with influenza, and the ability of their T cells to respond to infection was compared between the two diets.

When iron was very low, the researchers found that T cells could still form memory cells that looked normal at first glance. However, when tested for their function, the lung T cells had trouble making a protein called interferon gamma — a key immune signal needed to fight viruses. This problem was specific to the lungs and could not be corrected, even when the cells were later exposed to iron-rich conditions. 

Dr. Connors shared that one of the key findings from their study was that impaired immune function due to iron deficiency was specific to immune cells in the lungs. To build on this, the researchers plan to focus on understanding immune responses in the lungs and how iron deficiency affects the lungs. They also plan to partner with a local pediatric clinic to study immune responses in children with iron deficiency, helping to translate their laboratory findings into insights that could improve child health. 

The research article is available on The Journal of Immunology website, or you can read more on AAI News & Views.

Requests for interviews with authors, The Journal of Immunology or the American Association of Immunologists can be made to kpalmer@aai.org.

About The American Association of Immunologists

The American Association of Immunologists (AAI) is one of the world’s largest organizations of immunologists and scientists in related disciplines. Our mission is to improve global health and well-being by advancing immunology and elevating public understanding of the immune system. AAI members are responsible for some of the most significant biomedical discoveries of the past century, including the development of life-saving cancer immunotherapies, antibody therapies, transplant technologies, and vaccines. We support scientists across the field of immunology through knowledge dissemination, community building, advocacy, and public outreach.

About The Journal of Immunology

The Journal of Immunology (The JI) publishes peer-reviewed manuscripts describing novel findings in all areas of experimental immunology, including both basic and clinical studies. The JI is owned by the American Association of Immunologists and published in partnership with Oxford University Press.