Antanasijevic, Aleksandar / Bowman, Charles A. / Kirchdoerfer, Robert N. / Cottrell, Christopher 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. From structure to sequence: Antibody discovery using cryoEM. 2022-01, Science advances, Vol. 8, p. eabk2039
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.