From Structure to Sequence: Identification of polyclonal antibody families using cryoEM

• Published in: bioRxiv 2021-04
• Main Authors: Antanasijevic, Aleksandar, Bowman, Charles A, Kirchdoerfer, Robert N, Cottrell, Cristopher A, Ozorowski, Gabriel, Upadhyay, Amit A, Cirelli, Kimberly M, Carnathan, Diane G, Enemuo, Chiamaka A, Sewall, Leigh M, Nogal, Bartek, Zhao, Fangzhu, Groschel, Bettina, Schief, William R, Sok, Devin, Silvestri, Guido, Crotty, Shane, Bosinger, Steven E, Ward, Andrew B
• Format: Article
• Language: English
• Subjects: Antigens; Complementarity; Immune response; Immunology; Light chains; Monoclonal antibodies; Next-generation sequencing; Patent applications; Polyclonal antibodies; Vaccines
• ISSN: 2692-8205
• DOI: 10.1101/2021.04.13.439712

One of the rate-limiting steps in analyzing immune responses to vaccines or infections is the isolation and characterization of monoclonal antibodies. Here, we present a hybrid structural and bioinformatic approach to directly assign the heavy and light chains, identify complementarity- determining regions and discover sequences from cryoEM density maps of serum-derived polyclonal antibodies bound to an antigen. When combined with next generation sequencing of immune repertoires we were able to specifically identify clonal family members, synthesize the monoclonal antibodies and confirm that they interact with the antigen in a manner equivalent to the corresponding polyclonal antibodies. This structure-based approach for identification of monoclonal antibodies from polyclonal sera opens new avenues for analysis of immune responses and iterative vaccine design. Competing Interest Statement A.A, C.A.B., R.N.K., C.A.C., G.O., and A.B.W. are inventors on the US patent application no: 63/154447, entitled Sequencing polyclonal antibodies directly from single particle cryoEM data. Footnotes * This version of the manuscript has been revised to correct the spelling of an author's name.