Professor Sheldon is interested in the fundamental mechanisms of host-pathogen interactions. Professor Sheldon was in clinical practice for 14 years before moving to the Royal Veterinary College in London, where he developed his research interests and was awarded his PhD in 2002. In 2006 he won a BBSRC Research Development Fellowship to move to full-time research and study fundamental questions about the biology of infection and immunity. In 2008 he was appointed to a personal Chair at Swansea University Medical School to focus full-time on research.
Professor Sheldon is interested in the general mechanisms of host-pathogen interactions, and the impact of infection and innate immunity in the female genital tract. Professor Sheldon and his team explore the cellular mechanisms of innate immunity, inflammation and microbial infection that apply across species. Professor Sheldon discovered novel bacteria that cause disease of the uterus in cattle. In addition, he has uncovered mechanisms that explain how these microbes cause inflammation and tissue damage in the endometrium of the uterus, and how these process perturb the health of the ovary and the oocyte. One of the key discoveries by Professor Sheldon was that the epithelial and stromal cells of the endometrium, and granulosa cells of the ovary have roles in innate immunity. In particular they express receptors, such as Toll-like Receptors (TLRs), which detect pathogen-associated molecular patterns to induce inflammatory responses, including the production of cytokines, chemokines and prostaglandins. Furthermore, pathogen-associated molecules perturb oocyte health and development, linking bacterial infections to long-term impacts on fertility. Another area of discovery is how pore-forming toxins and other virulence factors from bacteria damage tissues, and mechanisms of tolerance to pore-forming toxins in tissues.
A clinical background coupled with exploring the basic science of host-pathogen interactions, has provided Professor Sheldon with a unique perspective. In 2013, Professor Sheldon's research was recognised by the award of FRCVS, and in 2015 he was awarded the Schofield Prize.