Posted by: Hourglass PJ20 FEB 2013
Zinc is an essential trace element of interest, among other things, for its role in the immune system and preventing infection. Zinc supplementation has been shown in some studies to reduce the severity of the common cold and possibly shorten its duration. Zinc has also been associated with improved wound healing.
How zinc might reduce infection is not fully understood, but new research from Ohio University, published in the journal Cell Reports, suggests that zinc’s reported ability to help fight off infection may lie in its ability to kick start and shut off immune pathways. This new study suggests that the mineral plays a key role in controlling infection by “tapping the brakes” on immune system pathways in a way that stops them causing a spiral of out of control inflammation.
The study also found that if there is not enough zinc available at the time of infection, the consequences include excessive inflammation.
The research team studied the activity of zinc in sepsis using cell culture models to examine what happens when the immune response is launched. They found that when a pathogen is recognised a series of molecules wakes up to create a process that activates the immune response. As part of this process, the activation of a transcription factor called NF-kB results in the expression of a gene that produces a zinc transporter, SLC39A8 (ZIP8).
ZIP8 then rapidly moves to the cell’s wall, where it can shuttle zinc from the bloodstream into the cell. After entering the cell, zinc is directed to and binds to a different protein, which then halts any further activity in that process. The effect of this negative feedback loop is to prevent the excessive inflammation as part of the immune response which could cause damage to cells.
Consistent with this finding, mice that were provided with a zinc-deficient diet in a linked study developed excessive inflammation to sepsis. Although a robust inflammatory response to infection is required, too much inflammation causes wider damage to cells involving more than the pathogen.
This finding improves understanding of zinc’s role in regulating immune function and preventing excessive inflammation. And if research is able to build further on this finding, it may be possible to identify more therapeutic indications for zinc.