The role of commensal bacteria in the skins response to ultraviolet radiation

Our skin is populated by an assortment of bacteria and other microorganisms that contribute to our physiological health. This is known as the skin microbiome. Among the numerous environmental factors that impact upon skin on a daily basis, ultraviolet radiation (UVR) from sunlight is arguably the most important. In contrast to other human microbiomes, the commensal bacteria of the skin are unique in that they are regularly exposed to UVR. That bacteria are responsive to UVR is well established given numerous studies looking at the use of UVR as a method of sterilisation. However, the response of the skin microbiota to UVR has not been studied in any detail. In particular, whether the bacteria on skin can alter the response of skin cells (keratinocytes) to UVR is unknown.
We have preliminary evidence that members of the skin microbiome can modify the response of keratinocytes to UVR. We have shown that particular bacteria can promote apoptosis of UVR exposed keratinocytes. Other bacteria can promote the survival of keratinocytes following UVR exposure. In this project, we will study these responses in more detail. We will aim to:
1) Identify the factors in bacteria that promote apoptosis or survival of keratinocytes following exposure to UVR
2) Using microarray, begin to identify the signalling pathways modified by bacterial components