Glycoprotein Therapeutics Laboratory
Co-workers: Prof. David Harvey, Dr Kavitha Baruah, Iona Easthope, Dr Laura Pritchard, Snezana Vasiljevic, Anna-Janina Behrens, Lan Ngoc Le, Dr Weston Struwe
Aim of research
We exploit the glycan modifications of proteins in the design of vaccines candidates and glycoprotein-based therapeutics. We have a particular interest in vaccine design against the Human Immunodeficiency Virus (HIV) and in the development of novel antibody-based cancer therapeutics. This involves understanding how glycans impact on protein and viral function, how they are structured, and how we they can be manipulated for therapeutic applications.
HIV immunogen design
Our work towards an HIV vaccine is based on targeting the carbohydrate coat of HIV that shields the virus . We have shown that this shield is different from normal ?self? carbohydrates and is remarkably constant despite huge variation in the underlying protein [2, 3]. We have been investigating using microbial mimics of this shield to elicit antibodies that can protect against the virus .
Antibodies are incredibly versatile therapeutics and can exhibit both pro- and anti-inflammatory properties. For this reason they are being applied to the treatment of conditions ranging from cancers to autoimmune disorders. Anti-cancer antibodies often rely on the recruitment of the immune system to cancerous cells through a constant region of the antibody termed the Fc region. We have structurally characterised how different glycans can impact on Fc structure [5, 6] and how they can be manipulated to fine-tune antibody effector functions . In addition, we are developing a new approach for enhancing therapeutic antibodies against cancer that involves deactivating competing endogenous antibodies that can limit the potency of anti-cancer antibodies . Finally, we are also investigating the molecular mechanism of intravenous immunoglobulin therapy in order to design effective recombinant alternatives to the current serum-derived therapeutic agents [9, 10].
- Crispin, M. and T.A. Bowden, Antibodies expose multiple weaknesses in the glycan shield of HIV. Nat Struct Mol Biol, 2013. 20(7): 771-2
- Bonomelli, C., K.J. Doores, D.C. Dunlop, V. Thaney, R.A. Dwek, D.R. Burton, M. Crispin, and C.N. Scanlan, The glycan shield of HIV is predominantly oligomannose independently of production system or viral clade. PLoS One, 2011. 6(8): e23521
- Doores, K.J., C. Bonomelli, D.J. Harvey, S. Vasiljevic, R.A. Dwek, D.R. Burton, M. Crispin, and C.N. Scanlan, Envelope glycans of immunodeficiency virions are almost entirely oligomannose antigens. Proc Natl Acad Sci U S A, 2010. 107(31): 13800-5
- Dunlop, D.C., C. Bonomelli, F. Mansab, S. Vasiljevic, K.J. Doores, M.R. Wormald, A.S. Palma, T. Feizi, D.J. Harvey, R.A. Dwek, M. Crispin, and C.N. Scanlan, Polysaccharide mimicry of the epitope of the broadly neutralizing anti-HIV antibody, 2G12, induces enhanced antibody responses to self oligomannose glycans. Glycobiology, 2010. 20(7): 812-23
- Bowden, T.A., K. Baruah, C.H. Coles, D.J. Harvey, X. Yu, B.D. Song, D.I. Stuart, A.R. Aricescu, C.N. Scanlan, E.Y. Jones, and M. Crispin, Chemical and structural analysis of an antibody folding intermediate trapped during glycan biosynthesis. J Am Chem Soc, 2012. 134(42): 17554-63
- Crispin, M., T.A. Bowden, C.H. Coles, K. Harlos, A.R. Aricescu, D.J. Harvey, D.I. Stuart, and E.Y. Jones, Carbohydrate and domain architecture of an immature antibody glycoform exhibiting enhanced effector functions. J Mol Biol, 2009. 387(5): 1061-6.
- Yu, X., K. Baruah, D.J. Harvey, S. Vasiljevic, D.S. Alonzi, B.D. Song, M.K. Higgins, T.A. Bowden, C.N. Scanlan, and M. Crispin, Engineering hydrophobic protein-carbohydrate interactions to fine-tune monoclonal antibodies. J Am Chem Soc, 2013. 135(26): 9723-32.
- Baruah, K., T.A. Bowden, B.A. Krishna, R.A. Dwek, M. Crispin, and C.N. Scanlan, Selective deactivation of serum IgG: a general strategy for the enhancement of monoclonal antibody receptor interactions. J Mol Biol, 2012. 420(1-2): 1-7.
- Crispin, M., X. Yu, and T.A. Bowden, Crystal structure of sialylated IgG Fc: Implications for the mechanism of intravenous immunoglobulin therapy. Proc Natl Acad Sci U S A, 2013. 110(38): E3544-6.
- Yu, X., S. Vasiljevic, D.A. Mitchell, M. Crispin, and C.N. Scanlan, Dissecting the molecular mechanism of IVIg therapy: the interaction between serum IgG and DC-SIGN is independent of antibody glycoform or Fc domain. J Mol Biol, 2013. 425(8): 1253-8.
Figure 1. Crystal structure of sialylated IgG1 sFc showing the electron density around the glycans. The sialic acid group extends away from the protein surface and is accessible for recognition by immunosuppressive receptors.
Graduate Student and Postdoctoral Positions: Enquiries with CV welcome