Structural basis for the synergistic neutralization of coxsackievirus B1 by a triple-antibody cocktail

Cell Host Microbe. 2022 Sep 14;30(9):1279-1294.e6. doi: 10.1016/j.chom.2022.08.001. Epub 2022 Aug 23.

Abstract

Coxsackievirus B1 (CVB1) is an emerging pathogen associated with severe neonatal diseases including aseptic meningitis, myocarditis, and pancreatitis and also with the development of type 1 diabetes. We characterize the binding and therapeutic efficacies of three CVB1-specific neutralizing antibodies (nAbs) identified for their ability to inhibit host receptor engagement. High-resolution cryo-EM structures showed that these antibodies recognize different epitopes but with an overlapping region in the capsid VP2 protein and specifically the highly variable EF loop. Moreover, they perturb capsid-receptor interactions by binding various viral particle forms. Antibody combinations achieve synergetic neutralization via a stepwise capsid transition and virion disruption, indicating dynamic changes in the virion in response to multiple nAbs targeting the receptor-binding site. Furthermore, this three-antibody cocktail protects against lethal challenge in neonatal mice and limits pancreatitis and viral replication in a non-obese diabetic mouse model. These results illustrate the utility of nAbs for rational design of therapeutics against picornaviruses such as CVB.

Keywords: antibody cocktail; coxsackievirus; cryo-EM; synergy; virus uncoating.

MeSH terms

  • Animals
  • Antibodies, Neutralizing
  • Antibodies, Viral*
  • Capsid / chemistry
  • Capsid Proteins
  • Epitopes
  • Mice
  • Pancreatitis*

Substances

  • Antibodies, Neutralizing
  • Antibodies, Viral
  • Capsid Proteins
  • Epitopes