5-Hydroxymethylcytidine (5hmC) has recently emerged as a transformative nucleobase modification for self-amplifying RNA (saRNA) vaccines, delivering 14-fold higher transfection efficiency than other modifications (e.g. pseudouridine-mRNA) while reducing innate immune responses. However, the use of 5hmC for RNA therapeutic applications is limited by metabolic instability as it is susceptible to enzymatic oxidation. 

This studentship proposes to overcome these limitations through the development of synthetic routes to replace the 5hmC hydroxyl group with metabolically stable analogues. With these synthetic routes established, phosphoramidites and triphosphates of these cytidine analogues will be prepared for incorporation into RNA by solid phase and enzymatic synthesis, respectively. Finally, the biophysical and biological properties of these cytidine analogues when incorporated into oligonucleotides and longer RNA molecules will be explored in vitro and in live cell assays. A successful outcome of this studentship would be access to a new generation of nucleotide modifications suitable for further therapeutic development in RNA vaccines or as a key building block in oligonucleotide therapeutics.

Training

The student undertaking this project will receive unparalleled training in medicinal chemistry and nucleic acid chemical biology. The Burley group has extensive experience in small molecule and nucleoside synthesis, solid phase peptide/nucleic acid synthesis, biophysical analysis and structural biology. The group has state-of-the-art automated synthesizers, HPLC equipment for purification and analysis, and mass spectrometry facilities. Biological evaluation will be done in collaboration with Haiyan Zhou (UCL) and Yvonne Perrie (Strathclyde).

Further information

The successful applicant will be expected to spend at least 3 months working alongside chemical biology groups at GSK's Stevenage site.