Sunlight Produces Faster T Cells to Boost Immunity

Researchers have found that in addition to providing the body with vitamin D, sunlight’s rays also speed up helper and killer T cells in the skin, enhancing their ability to travel to infection sites and orchestrate an immune response. The new findings at Georgetown University show that the sun-enhanced immune response is independent of the production of vitamin D. “We found a completely separate role of sunlight on immunity,” said Gerard Ahern, PhD, an associate professor in Georgetown University’s Department of Pharmacology and Physiology. “Some of the roles attributed to vitamin D on immunity may be due to this new mechanism.” And, importantly, while vitamin D production requires UV light, which can promote skin cancer, enhanced T-cell mobility only requires blue light that can be provided by the sun or special lamps, which is safer.

According to Dr. Ahern, sunlight drives the motility response by synthesizing hydrogen peroxide, which activates a signaling pathway that increases T-cell movement. Hydrogen peroxide is a compound that white blood cells release when they sense an infection in order to kill bacteria and activate T cells and other immune cells to mount an immune response. While the impact of these findings is not yet known, the researchers suggest that it’s possible that offering patients blue light therapy can boost their immunity.