The surface of human skin is colonized by millions of microorganisms, forming a complex microbial community. The skin, together with its microbiota, is continuously exposed to environmental factors, including solar radiation, which exerts both short-term and long-term effects on skin cells. Although numerous studies have investigated the impact of ultraviolet radiation (UVR) on cutaneous tissues, there remains limited data regarding the influence of UVR on the skin microbiome and its subsequent effects on skin physiology.
Previous work in the O’Neill laboratory has identified that model polymicrobial community (PMC) modifies the secretion of cytokines from keratinocyte monolayers following a single dose of solar simulated radiation (SSR) (Serrage et al., (2026) Appl Environ Microbio, in press), with specific strains that elicit particular responses. In a separate study, the laboratory has also showed that irradiated bacteria have altered metabolite profile that resulted in improved keratinocyte barrier function (Mercer et al., (2026), Appl. Environ. Microbiol In press).
These data have led to the following hypotheses:
- The skin microbiome influences how skin responds to ultraviolet radiation.
- Certain strains within the microbiome may confer protective benefits and support more effective recovery pathways in skin following UVR exposure.
Thus far, the work in O’Neill lab has been confined to human keratinocyte cultures for such studies. This project will utilize explant human skin acquired from elective plastic surgery procedures, which the lab has experience working with (El Chami et al. (2021) Br J Dermatol, 184 (3): 482).
The objectives of this project are:
- To quantify the impact of a single dose of SSR on a model polymicrobial community artificially inoculated on ex vivo human skin.
- To compare the transcriptome and secretome of ex vivo human skin to irradiation with and without the PMC.
- To examine whether the microbiome influences potential pathway(s) for enhanced recovery in irradiated skin.
Methodologies
- Establishing Single strain and Polymicrobial community on ex vivo skin, solar simulator radiation exposure, and quantify microbial recovery post-incubation.
- Pre- and post-irradiation transcriptome and secretome profile of microbial community and skin using advanced measurement and bioinformatic tools
- Validation of identified markers using tools such as QPCR, Immunostaining, ELISA, etc.
- Further investigate identified recovery pathways and role of single species and/or community using colonization models.
References:
Serrage et al., (2026) Appl Environ Microbio, in press
Mercer et al., (2026), Appl. Environ. Microbiol In press