GlycoMabs · Chemoenzymatic glyco-engineering of therapeutic monoclonal antibodies
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2019-04-16 → 2021-04-15
- EU contribution
- €160,932
- Participants
- 1
- Scheme
- MSCA-IF-EF-RI
Lines connect the coordinator with its partners.
Results in brief
Chemoenzymatic glyco-engineering of therapeutic monoclonal antibodies
Monoclonal antibodies (mAbs) are a prominent and rapidly expanding class of drugs used to treat various diseases, e.g., cancer, autoimmunity, neurodegenerative and infectious diseases, among others. Most of the therapeutically available mAbs are based on immunoglobulin G (IgG). IgGs have two conserved N-glycosylation sites on each heavy chain of the fragment crystallizable (Fc) region. The effector functions (e.g., Antibody-dependent cell-mediated cytotoxicity, complement activation) mediated by the Fc region of the antibodies are determined not only by the presence of this N-glycan of the Fc region but also by its carbohydrate composition. N-glycosylation is a highly complex and heterogenous post-translational modification that generates enormous diversity of glycan structures attached to an asparagine (Asn) residue of a glycoprotein. Controlling the composition of the N-glycan to generate a homogenous glycosylation profile has become a major challenge in recent years to improve the pharmacokinetic and functional properties of these drugs. Chemoenzymatic synthesis, using endo--acetylglucosaminidases (ENGases) mutants and N-glycans oxazoline derivatives, is a successful in vitro approach to obtain defined and homogenous N-glycans chemistry in mAbs. ENGases are endoglycosidases that hydrolyze the (1-4) linkage between the first two GlcNAc residues of N-linked glycans on proteins. They are classified in two glycosyl hydrolase families (GH18 and GH20) according to the CAZy database. Although they share a common catalytic mechanism, the substrate specificity is distinct for each enzyme. ENGases in general do not show protein specificity, except for EndoS and EndoS2 from Streptococcus pyogenes which are the only enzymes with a known specific protein substrate, the Fc region of IgG antibodies. But they also show a selectivity for N-glycan that are capable of hydrolyzing. N-glycans in eukaryotes can be classified into three main groups: complex-type (CT), high-mannose (HM) type and hybrid (Hy) type. EndoS is highly restrictive, only capable of hydrolyzing biantennary CT N-glycans, while EndoS2 is able to hydrolyze the three major N-glycan in the Fc of IgGs. In contrast, EndoF1 from Elizabethkingia meningoseptica and EndoH from Streptococcus plicatus hydrolyze HM and Hy-type N-glycans but they cannot process CT N-glycans. Therefore, the objective of this project is to understand the glycan specificity of these glycosyl hydrolases that modify the N-glycan of mAbs in order to rationally design enzymes with new and/or improved glycan selectivity.
Data: CORDIS, © European Union
Project objective
Monoclonal Antibodies (mAbs) have gained an important place in the therapeutic arsenal of anticancer drugs. mAbs are glycoproteins containing a conserved N-linked glycosylation site at residue Asn297 of the fragment crystallisable (Fc). Most of the mAbs approved by the EMA are commercialized as a complex mixture of glycoforms at this site. It is well stablished that the precise chemical structure of the N-linked glycan modulates the effector functions mediated by the Fc domain. Specifically, for cancer treatment applications, the lack of fucose on the glycan structure contributes to enhance the effector functions of the antibodies, via increased affinity of IgG1 for FcgRIIIa on immune cells. New strategies to glycoengineering mAbs with homogenous glycoforms and lacking fucose core on their glycan structures have become a priority for the biopharmaceutical industry in order to obtain “biosuperior” anticancer drugs. Here, we will engineer a novel fucosidase enzyme that can act on fully glycosylated mAbs in order to simplify the chemoenzymatic synthesis of antibody drugs, based on the host laboratory expertise in Carbohydrate Active Enzymes. We will address three specific aims: (1) to define the structural basis of EndoS antibody specificity; (2) to elucidate the molecular mechanisms of IgG defucosylation by AlfC; and (3) to engineer an enzyme with fucosidase activity and specific for IgG. The GlycoMabs project will provide me an excellent and unique career opportunity by learning new skills in structural biology, protein engineering and project management which will grant me a leading independent position. Moreover, I will explore the industry interest in the application of our novel enzymes to generate homogeneous and afucosylated antibodies through an intersectoral secondment. Altogether, we will contribute to construct the next generation of therapeutic glycoengineered mAbs to tailor the immune reactions and increase their clinical potency.
Original text from CORDIS.
Participants
- ASOCIACION CENTRO DE INVESTIGACION COOPERATIVA EN BIOCIENCIAS · DERIO VIZCAYACoordinatorSpain
Links
Data: CORDIS, © European Union