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. 2004 Nov 12;324(2):773-81.
doi: 10.1016/j.bbrc.2004.09.106.

Receptor-binding domain of SARS-CoV spike protein induces highly potent neutralizing antibodies: implication for developing subunit vaccine

Yuxian He  1 , Yusen Zhou, Shuwen Liu, Zhihua Kou, Wenhui Li, Michael Farzan, Shibo Jiang
Affiliations

Receptor-binding domain of SARS-CoV spike protein induces highly potent neutralizing antibodies: implication for developing subunit vaccine

Yuxian He et al. Biochem Biophys Res Commun. .

Abstract

The spike (S) protein of severe acute respiratory syndrome (SARS) coronavirus (CoV), a type I transmembrane envelope glycoprotein, consists of S1 and S2 domains responsible for virus binding and fusion, respectively. The S1 contains a receptor-binding domain (RBD) that can specifically bind to angiotensin-converting enzyme 2 (ACE2), the receptor on target cells. Here we show that a recombinant fusion protein (designated RBD-Fc) containing 193-amino acid RBD (residues 318-510) and a human IgG1 Fc fragment can induce highly potent antibody responses in the immunized rabbits. The antibodies recognized RBD on S1 domain and completely inhibited SARS-CoV infection at a serum dilution of 1:10,240. Rabbit antisera effectively blocked binding of S1, which contains RBD, to ACE2. This suggests that RBD can induce highly potent neutralizing antibody responses and has potential to be developed as an effective and safe subunit vaccine for prevention of SARS.

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Figures

Fig. 1
Fig. 1
Schematic diagram of SAR-CoV S protein and the recombinant fusion protein RBD-Fc. The S protein consists of S1 and S2 domains. There is a signal peptide (SP) located at the N-terminus of the S protein. The S1 domain contains a receptor-binding domain (RBD). The S2 domain contains a cytoplasm domain (CP), a transmembrane domain (TM), and an ectodomain composed of a putative internal fusion peptide (FP) and heptad repeat 1 and 2 (HR1 and HR2) regions. RBD-Fc consists of RBD and a human IgG-Fc fragment. S1-C9 contains S protein S1 domain and a C9 fragment.
Fig. 2
Fig. 2
Rabbit antisera contained high titers of antibodies binding to RBD. (A) Binding to RBD-Fc by antisera (1:10,000) collected from rabbits before immunization (pre-immune) and 10 days after each boost; (B) binding to RBD-Fc by rabbit antisera collected 10 days after the first boost at a series of 5-fold dilutions; (C) binding to S1-C9 by antisera (1:10,000) collected from rabbits before immunization (pre-immune) and 10 days after each boost; and (D) binding to S1-C9 protein by rabbit antisera collected 10 days after the first boost at a series of 5-fold dilutions. All samples were tested in duplicate and data presented are mean values of two tests (same for the following figures).
Fig. 3
Fig. 3
Neutralization of SARS-CoV by rabbit antisera directed against RBD-Fc. SARS-CoV was incubated with Vero E6 monolayer in the presence of rabbit antisera in a series of 2-fold dilutions. The CPE caused by SARS-CoV infection was recorded under microscope and the virus-neutralizing titers were calculated.
Fig. 4
Fig. 4
Neutralization of HIV/SARS-CoV S pseudovirus infection by rabbit antisera. Inhibition of a single-cycle infection of 293T cells expressing ACE2 by the pseudovirus was determined in a luciferase assay.
Fig. 5
Fig. 5
Effect of depletion of human IgG-Fc specific antibodies from the rabbit antisera on binding to S1 and virus-neutralizing activity. The binding activity of anti-Fc-depleted and untreated rabbit antisera to human IgG (A) and S1 (B) was tested at 1:50 dilution by ELISA. The neutralizing activity of the anti-Fc-depleted rabbit antisera against HIV/SARS-CoV S was compared with that of untreated rabbit antisera (C).
Fig. 6
Fig. 6
Rabbit antisera inhibited S1 binding to ACE2. (A) inhibition of S1 binding to soluble ACE2 by rabbit antisera was measured by ELISA; (B) inhibition of S1 binding to cell-expressed ACE2 by rabbit antisera was measured by flow cytometry. In the positive control, no rabbit serum was added while in the negative control, neither rabbit serum nor S1-C9 was added; (C) rabbit antisera inhibited S1 binding to ACE2-expressing cells in a dose-dependent manner.
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References

    1. Ksiazek T.G., Erdman D., Goldsmith C.S., Zaki S.R., Peret T., Emery S., Tong S., Urbani C., Comer J.A., Lim W., Rollin P.E., Dowell S.F., Ling A.E., Humphrey C.D., Shieh W.J., Guarner J., Paddock C.D., Rota P., Fields B., DeRisi J., Yang J.Y., Cox N., Hughes J.M., LeDuc J.W., Bellini W.J., Anderson L.J. A novel coronavirus associated with severe acute respiratory syndrome. N. Engl. J. Med. 2003;348:1953–1966. - PubMed
    1. Drosten C., Gunther S., Preiser W., Van Der W.S., Brodt H.R., Becker S., Rabenau H., Panning M., Kolesnikova L., Fouchier R.A., Berger A., Burguiere A.M., Cinatl J., Eickmann M., Escriou N., Grywna K., Kramme S., Manuguerra J.C., Muller S., Rickerts V., Sturmer M., Vieth S., Klenk H.D., Osterhaus A.D., Schmitz H., Doerr H.W. Identification of a novel coronavirus in patients with severe acute respiratory syndrome. N. Engl. J. Med. 2003;348:1967–1976. - PubMed
    1. Peiris J.S., Lai S.T., Poon L.L., Guan Y., Yam L.Y., Lim W., Nicholls J., Yee W.K., Yan W.W., Cheung M.T., Cheng V.C., Chan K.H., Tsang D.N., Yung R.W., Ng T.K., Yuen K.Y. Coronavirus as a possible cause of severe acute respiratory syndrome. Lancet. 2003;361:1319–1325. - PMC - PubMed
    1. Marra M.A., Jones S.J.M., Astell C.R., Holt R.A., Brooks-Wilson A., Butterfield Y.S.N., Khattra J., Asano J.K., Barber S.A., Chan S.Y., Cloutier A., Coughlin S.M., Freeman D., Girn N., Griffith O.L., Leach S.R., Mayo M., McDonald H., Montgomery S.B., Pandoh P.K., Petrescu A.S., Robertson A.G., Schein J.E., Siddiqui A., Smailus D.E., Stott J.M., Yang G.S., Plummer F., Andonov A., Artsob H., Bastien N., Bernard K., Booth T.F., Bowness D., Czub M., Drebot M., Fernando L., Flick R., Garbutt M., Gray M., Grolla A., Jones S., Feldmann H., Meyers A., Kabani A., Li Y., Normand S., Stroher U., Tipples G.A., Tyler S., Vogrig R., Ward D., Watson B., Brunham R.C., Krajden M., Petric M., Skowronski D.M., Upton C., Roper R.L. The genome sequence of the SARS-associated coronavirus. Science. 2003;300:1399–1404. - PubMed
    1. Rota P.A., Oberste M.S., Monroe S.S., Nix W.A., Campagnoli R., Icenogle J.P., Penaranda S., Bankamp B., Maher K., Chen M.H., Tong S., Tamin A., Lowe L., Frace M., DeRisi J.L., Chen Q., Wang D., Erdman D.D., Peret T.C.T., Burns C., Ksiazek T.G., Rollin P.E., Sanchez A., Liffick S., Holloway B., Limor J., McCaustland K., Olsen-Rasmussen M., Fouchier R., Gunther S., Osterhaus A.D.M.E., Drosten C., Pallansch M.A., Anderson L.J., Bellini W.J. Characterization of a novel coronavirus associated with severe acute respiratory syndrome. Science. 2003;300:1394–1399. - PubMed