As the skin is the largest organ of the human body. Almost all of the microbes, bacteria, viruses and other infectious micro-organisms get an entry in the human body through the skin. Human skin is composed of multi-components, forming three layers. Basically, there are three main layers found in skin, hypodermis; the innermost, dermis; the middle layer and epidermis; the outermost skin layer. Epidermis makes our body water resistant and keeps our skin in the proper tone. When our body skin is exposed to sunlight, a natural mechanism happens which results in vitamin D production, provides energy to the human body. In recently conducted research, it has been revealed that how this energy intensifies human immune system. The new research suggests how the skin, stays active in the nesting of various microbes in the skin. Sunlight activates the vitamin D production, resulting with healthier living, but recent research makes us surprised by breaking another powerful benefit of getting some sunbath. Georgetown University Medical Center researchers have discovered that when the human body is exposed to sunlight, Vitamin D production is activated and this produced vitamin D energizes T cells that play a key role in human immunity. In their scientific report, they said that we know sunlight provides vitamin D, which has an impact on immunity. But what they found is a completely separate role of sunlight on immunity, said Gerard Ahern, Ph.D., associate professor in the Georgetown’s Department of Pharmacology and Physiology. They focused on low blue light intensity in the sunlight that improves the T cells movement. T cells, whether they are helper or killer, they need to move for their specific functioning, which is to reach the site of an infection. This study shows that sunlight directly activates immune cells by increasing their movement. Ahern also said that while vitamin D production requires UV light, which may cause skin cancer or melanoma. But blue light from the sun is safer for human skin. The skin has a large share of T cells in humans; these are about twice the number circulating in the blood. T cells are some sort of white blood cells which identify and destroy foreign invaders. The researchers isolated T cells from mouse and human blood then exposed them to sun’s rays. They identified the molecular pathway activated by light. The researchers found that when these T cells exposed to low levels of blue light (<300 mJ cm−2). T cells became faster. This activity was due to the synthesis of hydrogen peroxide which is released by white blood cells. T cells release hydrogen peroxide when they sense an infection to kill invaded microbes and to call T and other immune cells to build an immune response. Ahern said there is much more research is to do, for understanding the impact of this research. He suggested that if cell activation by blue light has only beneficial responses, it gives the sense to treat patients by blue light therapy for boosting up their immunity.

Author: Asad Riaz-Center of Agricultural Biochemistry and Biotechnology University of Agriculture, Faisalabad