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Zhang F, Schmidt F, Muecksch F, Wang Z, Gazumyan A, Nussenzweig MC, Gaebler C, Caskey M, Hatziioannou T, Bieniasz PD. SARS-CoV-2 spike glycosylation affects function and neutralization sensitivity. mBio 2024; 15:e0167223. [PMID: 38193662 PMCID: PMC10865855 DOI: 10.1128/mbio.01672-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 11/08/2023] [Indexed: 01/10/2024] Open
Abstract
The glycosylation of viral envelope proteins can play important roles in virus biology and immune evasion. The spike (S) glycoprotein of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) includes 22 N-linked glycosylation sequons and 17 O-linked glycosites. We investigated the effect of individual glycosylation sites on SARS-CoV-2 S function in pseudotyped virus infection assays and on sensitivity to monoclonal and polyclonal neutralizing antibodies. In most cases, the removal of individual glycosylation sites decreased the infectiousness of the pseudotyped virus. For glycosylation mutants in the N-terminal domain and the receptor-binding domain (RBD), reduction in pseudotype infectivity was predicted by a commensurate reduction in the level of virion-incorporated S protein and reduced S trafficking to the cell surface. Notably, the presence of a glycan at position N343 within the RBD had diverse effects on neutralization by RBD-specific monoclonal antibodies cloned from convalescent individuals. The N343 glycan reduced the overall sensitivity to polyclonal antibodies in plasma from COVID-19 convalescent individuals, suggesting a role for SARS-CoV-2 S glycosylation in immune evasion. However, vaccination of convalescent individuals produced neutralizing activity that was resilient to the inhibitory effect of the N343 glycan.IMPORTANCEThe attachment of glycans to the spike proteins of viruses during their synthesis and movement through the secretory pathway can affect their properties. This study shows that the glycans attached to the severe acute respiratory syndrome coronavirus-2 spike protein enable its movement to the cell surface and incorporation into virus particles. Certain glycans, including one that is attached to asparagine 343 in the receptor-binding domain of the spike protein, can also affect virus neutralization by antibodies. This glycan can increase or decrease sensitivity to individual antibodies, likely through direct effects on antibody epitopes and modulation of spike conformation. However, the overall effect of the glycan in the context of the polyclonal mixture of antibodies in convalescent serum is to reduce neutralization sensitivity. Overall, this study highlights the complex effects of glycosylation on spike protein function and immune evasion.
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Affiliation(s)
- Fengwen Zhang
- Laboratory of Retrovirology, The Rockefeller University, New York, New York, USA
| | - Fabian Schmidt
- Laboratory of Retrovirology, The Rockefeller University, New York, New York, USA
| | - Frauke Muecksch
- Laboratory of Retrovirology, The Rockefeller University, New York, New York, USA
| | - Zijun Wang
- Laboratory of Molecular Immunology, The Rockefeller University, New York, New York, USA
| | - Anna Gazumyan
- Laboratory of Molecular Immunology, The Rockefeller University, New York, New York, USA
- Howard Hughes Medical Institute, The Rockefeller University, New York, New York, USA
| | - Michel C. Nussenzweig
- Laboratory of Molecular Immunology, The Rockefeller University, New York, New York, USA
- Howard Hughes Medical Institute, The Rockefeller University, New York, New York, USA
| | - Christian Gaebler
- Laboratory of Molecular Immunology, The Rockefeller University, New York, New York, USA
| | - Marina Caskey
- Laboratory of Molecular Immunology, The Rockefeller University, New York, New York, USA
| | | | - Paul D. Bieniasz
- Laboratory of Retrovirology, The Rockefeller University, New York, New York, USA
- Howard Hughes Medical Institute, The Rockefeller University, New York, New York, USA
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Hanisch FG. Site-Specific O-glycosylation of SARS-CoV-2 Spike Protein and Its Impact on Immune and Autoimmune Responses. Cells 2024; 13:107. [PMID: 38247799 PMCID: PMC10814047 DOI: 10.3390/cells13020107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/02/2024] [Accepted: 01/03/2024] [Indexed: 01/23/2024] Open
Abstract
The world-wide COVID-19 pandemic has promoted a series of alternative vaccination strategies aiming to elicit neutralizing adaptive immunity in the human host. However, restricted efficacies of these vaccines targeting epitopes on the spike (S) protein that is involved in primary viral entry were observed and putatively assigned to viral glycosylation as an effective escape mechanism. Besides the well-recognized N-glycan shield covering SARS-CoV-2 spike (S) proteins, immunization strategies may be hampered by heavy O-glycosylation and variable O-glycosites fluctuating depending on the organ sites of primary infection and those involved in immunization. A further complication associated with viral glycosylation arises from the development of autoimmune antibodies to self-carbohydrates, including O-linked blood group antigens, as structural parts of viral proteins. This outline already emphasizes the importance of viral glycosylation in general and, in particular, highlights the impact of the site-specific O-glycosylation of virions, since this modification is independent of sequons and varies strongly in dependence on cell-specific repertoires of peptidyl-N-acetylgalactosaminyltransferases with their varying site preferences and of glycan core-specific glycosyltransferases. This review summarizes the current knowledge on the viral O-glycosylation of the SARS-CoV-2 spike protein and its impact on virulence and immune modulation in the host.
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Affiliation(s)
- Franz-Georg Hanisch
- Center of Biochemistry, Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 52, 50931 Cologne, Germany
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Onigbinde S, Reyes CDG, Fowowe M, Daramola O, Atashi M, Bennett AI, Mechref Y. Variations in O-Glycosylation Patterns Influence Viral Pathogenicity, Infectivity, and Transmissibility in SARS-CoV-2 Variants. Biomolecules 2023; 13:1467. [PMID: 37892149 PMCID: PMC10604390 DOI: 10.3390/biom13101467] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 09/22/2023] [Accepted: 09/24/2023] [Indexed: 10/29/2023] Open
Abstract
The highly glycosylated S protein plays a vital role in host cell invasion, making it the principal target for vaccine development. Differences in mutations observed on the spike (S) protein of SARS-CoV-2 variants may result in distinct glycosylation patterns, thus influencing immunological evasion, infectivity, and transmissibility. The glycans can mask key epitopes on the S1 protein and alter its structural conformation, allowing the virus to escape the immune system. Therefore, we comprehensively characterize O-glycosylation in eleven variants of SARS-CoV-2 S1 subunits to understand the differences observed in the biology of the variants. In-depth characterization was performed with a double digestion strategy and an efficient LC-MS/MS approach. We observed that O-glycosylation is highly conserved across all variants in the region between the NTD and RBD, whereas other domains and regions exhibit variation in O-glycosylation. Notably, omicron has the highest number of O-glycosylation sites on the S1 subunit. Also, omicron has the highest level of sialylation in the RBD and RBM functional motifs. Our findings may shed light on how differences in O-glycosylation impact viral pathogenicity in variants of SARS-CoV-2 and facilitate the development of a robust vaccine with high protective efficacy against the variants of concern.
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Affiliation(s)
| | | | | | | | | | | | - Yehia Mechref
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409, USA; (S.O.); (C.D.G.R.); (M.F.); (O.D.); (M.A.); (A.I.B.)
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Zhang F, Schmidt F, Muecksch F, Wang Z, Gazumyan A, Nussenzweig MC, Gaebler C, Caskey M, Hatziioannou T, Bieniasz PD. SARS-CoV-2 spike glycosylation affects function and neutralization sensitivity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.30.547241. [PMID: 37425700 PMCID: PMC10327196 DOI: 10.1101/2023.06.30.547241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
The glycosylation of viral envelope proteins can play important roles in virus biology and immune evasion. The spike (S) glycoprotein of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) includes 22 N-linked glycosylation sequons and 17 O-linked glycosites. Here, we investigated the effect of individual glycosylation sites on SARS-CoV-2 S function in pseudotyped virus infection assays and on sensitivity to monoclonal and polyclonal neutralizing antibodies. In most cases, removal of individual glycosylation sites decreased the infectiousness of the pseudotyped virus. For glycosylation mutants in the N-terminal domain (NTD) and the receptor binding domain (RBD), reduction in pseudotype infectivity was predicted by a commensurate reduction in the level of virion-incorporated spike protein. Notably, the presence of a glycan at position N343 within the RBD had diverse effects on neutralization by RBD-specific monoclonal antibodies (mAbs) cloned from convalescent individuals. The N343 glycan reduced overall sensitivity to polyclonal antibodies in plasma from COVID-19 convalescent individuals, suggesting a role for SARS-CoV-2 spike glycosylation in immune evasion. However, vaccination of convalescent individuals produced neutralizing activity that was resilient to the inhibitory effect of the N343 glycan.
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Affiliation(s)
- Fengwen Zhang
- Laboratory of Retrovirology, The Rockefeller University, New York, NY 10065, USA
| | - Fabian Schmidt
- Laboratory of Retrovirology, The Rockefeller University, New York, NY 10065, USA
- Current address: King Abdullah University of Science and Technology, Thuwal, Makkah, Saudi Arabia. Center for Integrative Infectious Disease Research, Universitätsklinikum Heidelberg, 69120 Heidleberg, Germany
| | - Frauke Muecksch
- Laboratory of Retrovirology, The Rockefeller University, New York, NY 10065, USA
| | - Zijun Wang
- Laboratory of Molecular Immunology, The Rockefeller University, New York, NY 10065, USA
| | - Anna Gazumyan
- Laboratory of Molecular Immunology, The Rockefeller University, New York, NY 10065, USA
- Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Michel C Nussenzweig
- Laboratory of Molecular Immunology, The Rockefeller University, New York, NY 10065, USA
- Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Christian Gaebler
- Laboratory of Molecular Immunology, The Rockefeller University, New York, NY 10065, USA
- Current address: Laboratory of Translational Immunology of Viral Infections, Charité - Universitätsmedizin Berlin, Germany
| | - Marina Caskey
- Laboratory of Molecular Immunology, The Rockefeller University, New York, NY 10065, USA
| | | | - Paul D Bieniasz
- Laboratory of Retrovirology, The Rockefeller University, New York, NY 10065, USA
- Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
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Yang Y, Ivanov DG, Kaltashov IA. The challenge of structural heterogeneity in the native mass spectrometry studies of the SARS-CoV-2 spike protein interactions with its host cell-surface receptor. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2021. [PMID: 34189525 DOI: 10.1101/2021.06.20.449191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Native mass spectrometry (MS) enjoyed tremendous success in the past two decades in a wide range of studies aiming at understanding the molecular mechanisms of physiological processes underlying a variety of pathologies and accelerating the drug discovery process. However, the success record of native MS has been surprisingly modest with respect to the most recent challenge facing the biomedical community â€" the novel coronavirus infection (COVID-19). The major reason for the paucity of successful studies that use native MS to target various aspects of SARS-CoV-2 interaction with its host is the extreme degree of structural heterogeneity of the viral protein playing a key role in the host cell invasion. Indeed, the SARS-CoV-2 spike protein (S-protein) is extensively glycosylated, presenting a formidable challenge for native mass spectrometry (MS) as a means of characterizing its interactions with both the host cell-surface receptor ACE2 and the drug candidates capable of disrupting this interaction. In this work we evaluate the utility of native MS complemented with the experimental methods using gas-phase chemistry (limited charge reduction) to obtain meaningful information on the association of the S1 domain of the S-protein with the ACE2 ectodomain, and the influence of a small synthetic heparinoid on this interaction. Native MS reveals the presence of several different S1 oligomers in solution and allows the stoichiometry of the most prominent S1/ACE2 complexes to be determined. This enables meaningful interpretation of the changes in native MS that are observed upon addition of a small synthetic heparinoid (the pentasaccharide fondaparinux) to the S1/ACE2 solution, confirming that the small polyanion destabilizes the protein/receptor binding.
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Kim KH, Bhatnagar N, Jeeva S, Oh J, Park BR, Shin CH, Wang BZ, Kang SM. Immunogenicity and Neutralizing Activity Comparison of SARS-CoV-2 Spike Full-Length and Subunit Domain Proteins in Young Adult and Old-Aged Mice. Vaccines (Basel) 2021; 9:316. [PMID: 33805473 PMCID: PMC8066235 DOI: 10.3390/vaccines9040316] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 03/23/2021] [Accepted: 03/24/2021] [Indexed: 12/30/2022] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to be expanding the pandemic disease across the globe. Although SARS-CoV-2 vaccines were rapidly developed and approved for emergency use of vaccination in humans, supply and production difficulties are slowing down the global vaccination program. The efficacy of many different versions of vaccine candidates and adjuvant effects remain unknown, particularly in the elderly. In this study, we compared the immunogenic properties of SARS-CoV-2 full-length spike (S) ectodomain in young adult and aged mice, S1 with receptor binding domain, and S2 with fusion domain. Full-length S was more immunogenic and effective in inducing IgG antibodies after low dose vaccination, compared to the S1 subunit. Old-aged mice induced SARS-CoV-2 spike-specific IgG antibodies with neutralizing activity after high dose S vaccination. With an increased vaccine dose, S1 was highly effective in inducing neutralizing and receptor-binding inhibiting antibodies, although both S1 and S2 subunit domain vaccines were similarly immunogenic. Adjuvant effects were significant for effective induction of IgG1 and IgG2a isotypes, neutralizing and receptor-binding inhibiting antibodies, and antibody-secreting B cell and interferon-γ secreting T cell immune responses. Results of this study provide information in designing SARS-CoV-2 spike vaccine antigens and effective vaccination in the elderly.
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Affiliation(s)
| | | | | | | | | | | | | | - Sang-Moo Kang
- Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30302, USA; (K.-H.K.); (N.B.); (S.J.); (J.O.); (B.R.P.); (C.H.S.); (B.-Z.W.)
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