Structure and immune recognition of the porcine epidemic diarrhea virus spike protein

• Published in: Structure (London) Vol. 29; no. 4; pp. 385 - 392.e5
• Main Authors: Kirchdoerfer, Robert N., Bhandari, Mahesh, Martini, Olnita, Sewall, Leigh M., Bangaru, Sandhya, Yoon, Kyoung-Jin, Ward, Andrew B.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01.04.2021
• Subjects: Animals; Antibodies, Viral - metabolism; Cell Line; Coronavirus Infections - immunology; Cryoelectron Microscopy; Epitopes - immunology; Fatty Acids, Monounsaturated - chemistry; glycoprotein; Models, Molecular; Molecular Conformation; palmitoleic acid; polyclonal antibody; Polysaccharides - chemistry; porcine epidemic diarrhea virus; Porcine epidemic diarrhea virus - chemistry; Porcine epidemic diarrhea virus - immunology; Porcine epidemic diarrhea virus - metabolism; Protein Binding; Sf9 Cells; Spike Glycoprotein, Coronavirus - chemistry; Spike Glycoprotein, Coronavirus - immunology; Swine; palmitoleic acid; glycoprotein; cryoelectron microscopy; porcine epidemic diarrhea virus; polyclonal antibody
• ISSN: 0969-2126; 1878-4186; 1878-4186
• DOI: 10.1016/j.str.2020.12.003

Porcine epidemic diarrhea virus (PEDV) is an alphacoronavirus responsible for significant morbidity and mortality in pigs. A key determinant of viral tropism and entry, the PEDV spike protein is a key target for the host antibody response and a good candidate for a protein-based vaccine immunogen. We used electron microscopy to evaluate the PEDV spike structure, as well as pig polyclonal antibody responses to viral infection. The structure of the PEDV spike reveals a configuration similar to that of HuCoV-NL63. Several PEDV protein-protein interfaces are mediated by non-protein components, including a glycan at Asn264 and two bound palmitoleic acid molecules. The polyclonal antibody response to PEDV infection shows a dominance of epitopes in the S1 region. This structural and immune characterization provides insights into coronavirus spike stability determinants and explores the immune landscape of viral spike proteins. [Display omitted] •PEDV spike protein resembles HuCoV-NL63 spike in its domain configuration•Protein-protein interfaces are mediated by glycans and palmitoleic acid•Antibody responses are directed at epitopes in S1 domain A as well as domains C and D Kirchdoerfer et al. use cryoelectron microscopy of the porcine epidemic diarrhea virus spike ectodomain to identify glycans and fatty acids in protein-protein interfaces and delineate epitopes targeted by the pig immune response to infection.