Characterisation of secretion of engineered monoclonal antibodies from CHO cells

The aim of this project is to investigate why some monoclonal antibodies (mAbs) fail to be properly secreted by CHO cells. This project will make use MedImmune's considerable experience in developing CHO cell lines engineered for the production of therapeutic proteins suitable for both clinic and market supply. It will involve characterisation of of mAbs across a spectrum of secretion properties, from those which are effectively delivered in growth media to those that are very poorly secreted, often with an increased unfolded protein response and with retention in the cell. The student will employ novel methodologies developed in the laboratory of Professor Kathryn Lilley in the Cambridge Centre for Proteomics (CCP) focussed on the development and application of spatial proteomics methods that aim to accurately locate proteins to subcellular structures on a proteome wide scale 1. Her group has developed other methodologies which determine the components of multi-protein complexes and the spatial context of membrane proteins 2. These methods are well suited to interrogate mechanisms involved in efficient and inefficient secretion of mAbs. The student will employ these methods and protein cross-linking approaches to determine changes in sub-cellular locations, interacting partners and protein structure of mAbs and secretion machinery between 'good' and 'bad' secretion.
The outcome from the project will be a better understanding of the mechanisms involved in the secretion of recombinant antibodies, especially in cases where secretion is impaired. Knowing the interacting partners and location of retarded recombinant proteins will assist in design of future therapeutic agents and cell engineering platforms to ensure their efficient secretion which is of vital importance in the generation of manufacturing cell lines for clinical supply of therapeutic proteins.
1 Christoforou, A. et al. A draft map of the mouse pluripotent stem cell spatial proteome. Nat Commun 7, doi:10.1038/ncomms9992 (2016).
2 Rees, J. S., Lilley, K. S. & Jackson, A. P. SILAC-iPAC: A quantitative method for distinguishing genuine from non-specific components of protein complexes by parallel affinity capture. Journal of Proteomics 115, 143-156, doi:http://dx.doi.org/10.1016/j.jprot.2014.12.006 (2015).