ChAdOx1 COVID vaccines express RBD open prefusion SARS-CoV-2 spikes on the cell surface

Zhang, P.; Gilbert, S.; Radecke, J.; Ni, T.; Mendonca, L.; Zhu, Y.; Howe, A.; Shah, P. M.; Sheng, Y.; Krebs, A.-S.; Duyvesteyn, H. M. E.; Allen, E.; Lambe, T.; Bissett, C.; Morris, S.; Spencer, A.; Stuart, D. I.

doi:10.1101/2023.05.22.541685

bioRxiv · 10.1101/2023.05.22.541685

ChAdOx1 COVID vaccines express RBD open prefusion SARS-CoV-2 spikes on the cell surface

Zhang, P.·Gilbert, S.·Radecke, J.·Ni, T.·Mendonca, L.·Zhu, Y.·Howe, A.·Shah, P. M.·Sheng, Y.·Krebs, A.-S.·Duyvesteyn, H. M. E.·Allen, E.·Lambe, T.·Bissett, C.·Morris, S.·Spencer, A.·Stuart, D. I.

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Abstract

Vaccines against SARS-CoV-2 have been proven to be an effective means of decreasing COVID-19 mortality, hospitalization rates, and transmission. One of the vaccines deployed worldwide is ChAdOx1 nCoV-19, which uses an adenovirus vector to drive the expression of the original SARS-CoV-2 spike on the surface of transduced cells. Using cryo-electron tomography and subtomogram averaging, we determined the native structures of the vaccine product expressed on cell surfaces in situ. We show that ChAdOx1-vectored vaccines expressing the Beta SARS-CoV-2 variant produce abundant native prefusion spikes predominantly in one-RBD-up conformation. Furthermore, the ChAdOx1 vectored HexaPro stabilized spike yields higher cell surface expression, enhanced RBD exposure, and reduced shedding of S1 compared to the wild-type. We demonstrate in situ structure determination as a powerful means for studying antigen design options in future vaccine development against emerging novel SARS-CoV-2 variants and broadly against other infectious viruses.

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Zhang, P., Gilbert, S., Radecke, J., Ni, T., Mendonca, L., Zhu, Y., Howe, A., Shah, P. M., Sheng, Y., Krebs, A.-S., Duyvesteyn, H. M. E., Allen, E., Lambe, T., Bissett, C., Morris, S., Spencer, A., Stuart, D. I.. 2023-05-24. ChAdOx1 COVID vaccines express RBD open prefusion SARS-CoV-2 spikes on the cell surface. https://doi.org/10.1101/2023.05.22.541685

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