GAINESVILLE, Fla. — Just in time for what federal authorities warn could be an extremely severe flu season, University of Florida research has revealed a fundamental mechanism behind zinc’s immune-boosting power-it ramps up one of the body’s primary lines of defense, white blood cells known as T-cells.

“We’ve known for a long time that zinc can give your system a helping hand when you’re fighting illness,” said Tolunay Aydemir, a researcher with UF’s Institute of Food and Agricultural Sciences and lead author of the study. “This gives us an important bit of understanding as to why it confers that benefit.”

Found in most multivitamins and many mineral supplements, zinc has been shown to reduce the duration and severity of digestive and respiratory tract infections as well as blood infections such as malaria.

“One of the most important things that this study shows is that a modest increase in the amount of zinc via supplement form can lead to a notable increase in certain immune functions,” said Daren Knoell, a pharmacology researcher at The Ohio State University. “A lot of people are zinc deficient, and this shows that a small supplementation could probably go a long way.”

As they report in the August issue of the Journal of Leukocyte Biology, the researchers gave a group of healthy volunteers 15 milligrams of zinc as oral supplements for four days, a dosage at the upper boundary of the recommended daily allowance. Volunteers in a control group got a placebo.

They then drew blood from the patients to examine their T-cells, an essential part of the body’s immune function. Some T-cells identify and destroy bacterial and viral pathogens, as well as human cells infected by those pathogens.

Others “remember” pathogens, reacting quickly to summon the body’s defenses if exposed to those pathogens again. Still other T-cells moderate the activity of all the others.

The researchers found that, when exposed to chemicals known to invoke an immune response, the T-cells from the group taking the supplements showed much greater biochemical activity than T-cells from the placebo group.

In particular, they observed a stimulation of the T-cell protein ZIP8. This protein ferries zinc into a specific region inside the T-cells, where it triggers a chain of events that prime the cell for action.

The work not only helps illuminate the mechanisms behind zinc’s ability to improve immune

function, but it could also be a first step toward developing medicines based on those mechanisms, said professor Robert Cousins, a co-author of the paper and director of the UF/IFAS Center for Nutritional Sciences.

“We’re still just scratching the surface of the role zinc plays in the body,” said Cousins, a National Academy of Sciences member. “But it’s not just about tracking this one element. It’s discovering all of the associated processes-that’s the ultimate payoff.”

Along that line of thought, Aydemir, Cousins and colleagues will soon embark on a much more ambitious research project. In 2010, they hope to study how zinc interplays with the entirety of the human genome.

Contacts

Writer: Stu Hutson, 352-273-3569, stu@ufl.edu

Source: Robert Cousins, 352-392-2133, cousins@ufl.edu

Source: Tolunay Aydemir, tbeker@ufl.edu

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