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This content will become publicly available on November 9, 2018

Title: Structure–function characterization of three human antibodies targeting the vaccinia virus adhesion molecule D8

Vaccinia virus (VACV) envelope protein D8 is one of three glycosaminoglycan adhesion molecules and binds to the linear polysaccharide chondroitin sulfate (CS). D8 is also a target for neutralizing antibody responses that are elicited by the smallpox vaccine, which has enabled the first eradication of a human viral pathogen and is a useful model for studying antibody responses. However, to date, VACV epitopes targeted by human antibodies have not been characterized at atomic resolution. Here in this paper, we characterized the binding properties of several human anti-D8 antibodies and determined the crystal structures of three VACV-mAb variants, VACV-66, VACV-138, and VACV-304, separately bound to D8. Although all these antibodies bound D8 with high affinity and were moderately neutralizing in the presence of complement, VACV-138 and VACV-304 also fully blocked D8 binding to CS-A, the low affinity ligand for D8. VACV-138 also abrogated D8 binding to the high-affinity ligand CS-E, but we observed residual CS-E binding was observed in the presence of VACV-304. Analysis of the VACV-138– and VACV-304–binding sites along the CS-binding crevice of D8, combined with different efficiencies of blocking D8 adhesion to CS-A and CS-E allowed us to propose that D8 has a high- and low-affinity CS-binding regionmore » within its central crevice. The crevice is amenable to protein engineering to further enhance both specificity and affinity of binding to CS-E. Finally, a wild-type D8 tetramer specifically bound to structures within the developing glomeruli of the kidney, which express CS-E. We propose that through structure-based protein engineering, an improved D8 tetramer could be used as a potential diagnostic tool to detect expression of CS-E, which is a possible biomarker for ovarian cancer.« less
Authors:
 [1] ;  [1] ;  [2] ;  [3] ;  [4] ;  [1] ;  [1] ;  [1] ;  [5] ;  [5] ;  [6] ;  [7] ;  [4] ;  [8] ;  [6] ;  [3] ;  [2] ; ORCiD logo [9]
  1. La Jolla Inst. for Allergy and Immunology (LJI), La Jolla, CA (United States). Division of Cell Biology
  2. Vanderbilt Univ., Nashville, TN (United States). Dept. of of Pediatrics, Pathology, Microbiology and Immunology
  3. California Inst. of Technology (CalTech), Pasadena, CA (United States). Howard Hughes Medical Inst., Division of Chemistry and Chemical Engineering
  4. La Jolla Inst. for Allergy and Immunology (LJI), La Jolla, CA (United States). Inflammation Biology Division
  5. Univ. of Texas Health Science Center, San Antonio, TX (United States). Dept. of Microbiology, Immunology and Molecular Genetics
  6. La Jolla Inst. for Allergy and Immunology (LJI), La Jolla, CA (United States). Vaccine Discovery Division
  7. SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Synchrotron Radiation Lightsource (SSRL)
  8. La Jolla Inst. for Allergy and Immunology (LJI), La Jolla, CA (United States). Vaccine Discovery Division; Univ. of California, San Diego, CA (United States)
  9. La Jolla Inst. for Allergy and Immunology (LJI), La Jolla, CA (United States). Division of Cell Biology; Ghent Univ., Ghent (Belgium). Dept. of Internal Medicine, Faculty of Medicine and Health Sciences
Publication Date:
Grant/Contract Number:
AC02-76SF00515; HHSN272200900048C; HHSN272200900047C; HHSN272201400024C
Type:
Accepted Manuscript
Journal Name:
Journal of Biological Chemistry
Additional Journal Information:
Journal Volume: 293; Journal Issue: 1; Journal ID: ISSN 0021-9258
Publisher:
American Society for Biochemistry and Molecular Biology
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org:
USDOE; National Institutes of Health (NIH)
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; antibody; glycosaminoglycan; protein crystallization; protein structure; vaccine viral protein; X-ray crystallography
OSTI Identifier:
1425344