Development of workflows for O-glycan profiling and structural characterisation of biopharmaceuticals

In 2016, more than half of the top ten drugs by revenue were biologics, the majority of which are glycoproteins. The value of glycoprotein therapeutics for the pharmaceutical industry is thus clear, but this comes with a catch. The biological production of these drugs can generate batch-to-batch variability, in particular due to the non-templated biosynthesis of glycans. The glycans have important modulating effects on drug function, and they are fundamental for determining serum half-life. In order to maintain drug safety and efficacy, robust quality control methods for glycan analysis are required. In addition, cell line engineering to limit glycan heterogeneity and steer biosynthesis towards beneficial structures is needed. Glycan analysis is now routine for N-glycan profiling but methods for analysis of the second main class of protein-linked glycans, O-glycans, lag well behind, and are generally considered inadequate for industrial adoption. Routine characterisation and/or quantification of O-glycans is required to further explore the functional link with changes in O-glycan structures.

In the Thomas-Oates (mass spectrometry) and Ungar (cell biology) groups, previous shared PhD students have developed a robust combined N- and O-glycan profiling method for cultured cells (Abdul Rahman et al, J. Proteome Res., 2014, 13: 1167-1176; Skeene et al., Anal Chem 2017, 89: 5840-5849). In this BBSRC/IBioIC PhD project the student will join these groups, where they will build on the previous work to generate such an integrated method for glycoprotein-based biologics, which can be routinely used by CROs like industrial partner Covance, in support of future drug development projects. At the same time, cell lines with altered O-glycosylation will be generated to challenge the new method, while also producing cells with beneficial glycosylation properties. The location of Covance's R&D laboratories close to York facilitates frequent face-to-face visits. The student will spend approximately one month every year at Covance, and Covance will provide expertise to help shape the proposed analytical workflows to meet industry and regulatory requirements and offer appropriate biopharmaceutical materials from the outset of the project. Through the programme, the student will gain experience in analytical carbohydrate chemistry, state of the art mass spectrometry, glycobiology, cell biology and industrial biotechnology approaches, enhancing their employability.