Characterisation of the effects of ultraviolet radiation on host-microbiota interactions in skin

At the interface between the body and the outside world, the skin forms an essential barrier to prevent water loss from within the body and also entry of toxins and pathogens from the outside world. The importance of this barrier is exemplified in conditions where the barrier is breached e.g. premature babies or victims of severe burns. Morbidity is high in these groups because of infection and water and electrolyte loss.. On a daily basis, skin is subject to a number of potential stressors but arguably the most important is ultraviolet radiation (UVR) from sunlight. To date, a large amount of research has been conducted in characterising the effects of UVR on skin. UVR is known to have both positive and negative effects on skin. For example, chronic exposure to UVR causes negative effects ranging from premature ageing to UVR-induced cancers. Conversely, UVR is often used as a treatment for inflammatory conditions of the skin such as psoriasis.

The second major interaction of skin is with the bacteria that live on it. Humans live in constant contact with bacteria that live both in and on our bodies. Many of these, so-called commensal bacteria have important roles in human physiology. For example, bacteria in the gut harvest energy from food and synthesise essential vitamins The commensal biota in most body sites including the gut and the skin provide protection from adventitious pathogens. We are interested in how bacteria modulate the physiology of skin cells and we have shown that certain bacteria can enhance the barrier function of the keratinocytes1,2.

When skin is exposed to UVR, the barrier is known to be compromised. However, the bacteria present on the skin surface also get irradiated. To date, despite the huge importance of commensal bacteria to skin health, there have been very few studies looking into the effects of UVR on commensal bacteria of the skin yet irradiation has the potential to alter bacterial physiology that has either positive or negative effects on skin.

This project will investigate how the physiology of commensal skin bacteria is affected by UVR, and how in turn, this may alter their interactions with skin cells. We hypothesise that irradiation alters the physiology of commensal bacteria to help protect/repair the skin barrier. The data form this project will lead to a greater understanding of how the skin interacts with its environment and may lead to novel bacteria-based treatments for skin in health and disease.

The successful candidate will work between a world-class microbiology group (McBain) and the Dermatology research group. These two groups between them can provide all the necessary training which will include:
- Growth and analysis of bacteria
- Growth of human skin cells in culture
- Ex vivo organ culture of human skin
- Use of sources of UVR
- Measurements of skin barrier function
- Biochemical analysis of skin in response to bacteria including luminex technology
- PCR
- Immunoblotting

Applicants should hold (or expect to obtain) a minimum upper-second honours degree (or equivalent) in biological sciences. A Masters qualification in a similar area would be a significant advantage. Experience of microbiology is not an absolute requirement as full training will be provided.