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Jegatheeswaran S, Asnani A, Forman A, Hendel JL, Moore CJ, Nejatie A, Wang A, Wang JW, Auzanneau FI. Recognition of Dimeric Lewis X by Anti-Dimeric Le x Antibody SH2. Vaccines (Basel) 2020; 8:vaccines8030538. [PMID: 32957489 PMCID: PMC7563222 DOI: 10.3390/vaccines8030538] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 09/11/2020] [Accepted: 09/14/2020] [Indexed: 11/16/2022] Open
Abstract
The carbohydrate antigen dimeric Lewis X (DimLex), which accumulates in colonic and liver adenocarcinomas, is a valuable target to develop anti-cancer therapeutics. Using the native DimLex antigen as a vaccine would elicit an autoimmune response against the Lex antigen found on normal, healthy cells. Thus, we aim to study the immunogenic potential of DimLex and search internal epitopes displayed by DimLex that remain to be recognized by anti-DimLex monoclonal antibodies (mAbs) but no longer possess epitopes recognized by anti-Lex mAbs. In this context, we attempted to map the epitope recognized by anti-DimLex mAb SH2 by titrations and competitive inhibition experiments using oligosaccharide fragments of DimLex as well as Lex analogues. We compare our results with that reported for anti-Lex mAb SH1 and anti-polymeric Lex mAbs 1G5F6 and 291-2G3-A. While SH1 recognizes an epitope localized to the non-reducing end Lex trisaccharide, SH2, 1G5F6, and 291-2G3-A have greater affinity for DimLex conjugates than for Lex conjugates. We show, however, that the Lex trisaccharide is still an important recognition element for SH2, which (like 1G5F6 and 291-2G3-A) makes contacts with all three sugar units of Lex. In contrast to mAb SH1, anti-polymeric Lex mAbs make contact with the GlcNAc acetamido group, suggesting that epitopes extend further from the non-reducing end Lex. Results with SH2 show that this epitope is only recognized when DimLex is presented by glycoconjugates. We have reported that DimLex adopts two conformations around the β-d-GlcNAc-(1→3)-d-Gal bond connecting the Lex trisaccharides. We propose that only one of these conformations is recognized by SH2 and that this conformation is favored when the hexasaccharide is presented as part of a glycoconjugate such as DimLex-bovine serum albumin (DimLex-BSA). Proper presentation of the oligosaccharide candidate via conjugation to a protein or lipid is essential for the design of an anti-cancer vaccine or immunotherapeutic based on DimLex.
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Affiliation(s)
- Sinthuja Jegatheeswaran
- Department of Chemistry, University of Guelph, Guelph, ON N1G 2W1, Canada; (S.J.); (A.A.); (A.F.); (J.L.H.); (C.J.M.); (A.N.); (A.W.); (J.-W.W.)
- Immunology Department, University of Toronto, 1 King’s College Circle, Toronto, ON M5S-1A8, Canada
| | - Ari Asnani
- Department of Chemistry, University of Guelph, Guelph, ON N1G 2W1, Canada; (S.J.); (A.A.); (A.F.); (J.L.H.); (C.J.M.); (A.N.); (A.W.); (J.-W.W.)
- Department of Chemistry, Universitas Jenderal Soedirman, Purwokerto, Jawa Tengah 53123, Indonesia
| | - Adam Forman
- Department of Chemistry, University of Guelph, Guelph, ON N1G 2W1, Canada; (S.J.); (A.A.); (A.F.); (J.L.H.); (C.J.M.); (A.N.); (A.W.); (J.-W.W.)
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON M5S-3H6, Canada
| | - Jenifer L. Hendel
- Department of Chemistry, University of Guelph, Guelph, ON N1G 2W1, Canada; (S.J.); (A.A.); (A.F.); (J.L.H.); (C.J.M.); (A.N.); (A.W.); (J.-W.W.)
- Research and Development, Ludger Ltd., Culham Science Centre, Abingdon, Oxfordshire OX14-3EB, UK
| | - Christopher J. Moore
- Department of Chemistry, University of Guelph, Guelph, ON N1G 2W1, Canada; (S.J.); (A.A.); (A.F.); (J.L.H.); (C.J.M.); (A.N.); (A.W.); (J.-W.W.)
- Quality Control, SteriMax Inc., 2770 Portland Dr, Oakville, ON L6H-6R4, Canada
| | - Ali Nejatie
- Department of Chemistry, University of Guelph, Guelph, ON N1G 2W1, Canada; (S.J.); (A.A.); (A.F.); (J.L.H.); (C.J.M.); (A.N.); (A.W.); (J.-W.W.)
- Department of Chemistry, Simon Fraser University, Burnaby, BC V5A1S6, Canada
| | - An Wang
- Department of Chemistry, University of Guelph, Guelph, ON N1G 2W1, Canada; (S.J.); (A.A.); (A.F.); (J.L.H.); (C.J.M.); (A.N.); (A.W.); (J.-W.W.)
- SGS-CSTC Standards Technical Services Co., Ltd. 4/F, 4th Building, 889 Yishan Road, Xuhui District, Shanghai 200233, China
| | - Jo-Wen Wang
- Department of Chemistry, University of Guelph, Guelph, ON N1G 2W1, Canada; (S.J.); (A.A.); (A.F.); (J.L.H.); (C.J.M.); (A.N.); (A.W.); (J.-W.W.)
- IQVIA, QuintilesIMS, Clinical Research, 10188 Telesis Ct #400, San Diego, CA 92121, USA
| | - France-Isabelle Auzanneau
- Department of Chemistry, University of Guelph, Guelph, ON N1G 2W1, Canada; (S.J.); (A.A.); (A.F.); (J.L.H.); (C.J.M.); (A.N.); (A.W.); (J.-W.W.)
- Correspondence:
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Dingjan T, Imberty A, Pérez S, Yuriev E, Ramsland PA. Molecular Simulations of Carbohydrates with a Fucose-Binding Burkholderia ambifaria Lectin Suggest Modulation by Surface Residues Outside the Fucose-Binding Pocket. Front Pharmacol 2017; 8:393. [PMID: 28680402 PMCID: PMC5478714 DOI: 10.3389/fphar.2017.00393] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Accepted: 06/06/2017] [Indexed: 12/22/2022] Open
Abstract
Burkholderia ambifaria is an opportunistic respiratory pathogen belonging to the Burkholderia cepacia complex, a collection of species responsible for the rapidly fatal cepacia syndrome in cystic fibrosis patients. A fucose-binding lectin identified in the B. ambifaria genome, BambL, is able to adhere to lung tissue, and may play a role in respiratory infection. X-ray crystallography has revealed the bound complex structures for four fucosylated human blood group epitopes (blood group B, H type 1, H type 2, and Lex determinants). The present study employed computational approaches, including docking and molecular dynamics (MD), to extend the structural analysis of BambL-oligosaccharide complexes to include four additional blood group saccharides (A, Lea, Leb, and Ley) and a library of blood-group-related carbohydrates. Carbohydrate recognition is dominated by interactions with fucose via a hydrogen-bonding network involving Arg15, Glu26, Ala38, and Trp79 and a stacking interaction with Trp74. Additional hydrogen bonds to non-fucose residues are formed with Asp30, Tyr35, Thr36, and Trp74. BambL recognition is dominated by interactions with fucose, but also features interactions with other parts of the ligands that may modulate specificity or affinity. The detailed computational characterization of the BambL carbohydrate-binding site provides guidelines for the future design of lectin inhibitors.
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Affiliation(s)
- Tamir Dingjan
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash UniversityMelbourne, VIC, Australia
| | - Anne Imberty
- Centre de Recherches sur les Macromolécules Végétales, Centre National de la Recherche Scientifique UPR5301, Université Grenoble AlpesGrenoble, France
| | - Serge Pérez
- Département de Pharmacochimie Moléculaire, Centre National de la Recherche Scientifique, UMR5063, Université Grenoble AlpesGrenoble, France
| | - Elizabeth Yuriev
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash UniversityMelbourne, VIC, Australia
| | - Paul A Ramsland
- School of Science, RMIT UniversityMelbourne, VIC, Australia.,Department of Surgery Austin Health, University of MelbourneMelbourne, VIC, Australia.,Department of Immunology, Central Clinical School, Monash UniversityMelbourne, VIC, Australia.,Burnet InstituteMelbourne, VIC, Australia
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Antibody recognition of aberrant glycosylation on the surface of cancer cells. Curr Opin Struct Biol 2016; 44:1-8. [PMID: 27821276 DOI: 10.1016/j.sbi.2016.10.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 09/28/2016] [Accepted: 10/13/2016] [Indexed: 11/23/2022]
Abstract
Carbohydrate-binding antibodies and carbohydrate-based vaccines are being actively pursued as targeted immunotherapies for a broad range of cancers. Recognition of tumor-associated carbohydrates (glycans) by antibodies is predominantly towards terminal epitopes on glycoproteins and glycolipids on the surface of cancer cells. Crystallography along with complementary experimental and computational methods have been extensively used to dissect antibody recognition of glycan epitopes commonly found in cancer. We provide an overview of the structural biology of antibody recognition of tumor-associated glycans and propose potential rearrangements of these targets in the membrane that could dictate the complex biological activities of these antibodies against cancer cells.
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