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1.
EBioMedicine ; 74: 103712, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1536515

ABSTRACT

BACKGROUND: Despite clinical success with anti-spike vaccines, the effectiveness of neutralizing antibodies and vaccines has been compromised by rapidly spreading SARS-CoV-2 variants. Viruses can hijack the glycosylation machinery of host cells to shield themselves from the host's immune response and attenuate antibody efficiency. However, it remains unclear if targeting glycosylation on viral spike protein can impair infectivity of SARS-CoV-2 and its variants. METHODS: We adopted flow cytometry, ELISA, and BioLayer interferometry approaches to assess binding of glycosylated or deglycosylated spike with ACE2. Viral entry was determined by luciferase, immunoblotting, and immunofluorescence assays. Genome-wide association study (GWAS) revealed a significant relationship between STT3A and COVID-19 severity. NF-κB/STT3A-regulated N-glycosylation was investigated by gene knockdown, chromatin immunoprecipitation, and promoter assay. We developed an antibody-drug conjugate (ADC) that couples non-neutralization anti-spike antibody with NGI-1 (4G10-ADC) to specifically target SARS-CoV-2-infected cells. FINDINGS: The receptor binding domain and three distinct SARS-CoV-2 surface N-glycosylation sites among 57,311 spike proteins retrieved from the NCBI-Virus-database are highly evolutionarily conserved (99.67%) and are involved in ACE2 interaction. STT3A is a key glycosyltransferase catalyzing spike glycosylation and is positively correlated with COVID-19 severity. We found that inhibiting STT3A using N-linked glycosylation inhibitor-1 (NGI-1) impaired SARS-CoV-2 infectivity and that of its variants [Alpha (B.1.1.7) and Beta (B.1.351)]. Most importantly, 4G10-ADC enters SARS-CoV-2-infected cells and NGI-1 is subsequently released to deglycosylate spike protein, thereby reinforcing the neutralizing abilities of antibodies, vaccines, or convalescent sera and reducing SARS-CoV-2 variant infectivity. INTERPRETATION: Our results indicate that targeting evolutionarily-conserved STT3A-mediated glycosylation via an ADC can exert profound impacts on SARS-CoV-2 variant infectivity. Thus, we have identified a novel deglycosylation method suitable for eradicating SARS-CoV-2 variant infection in vitro. FUNDING: A full list of funding bodies that contributed to this study can be found in the Acknowledgements section.


Subject(s)
Benzamides/pharmacology , COVID-19/drug therapy , Glycosylation/drug effects , Hexosyltransferases/antagonists & inhibitors , Membrane Proteins/antagonists & inhibitors , Sulfonamides/pharmacology , Virus Internalization/drug effects , A549 Cells , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Cell Line , HEK293 Cells , Hexosyltransferases/metabolism , Humans , Membrane Proteins/metabolism , Mice , Mice, Inbred C57BL , SARS-CoV-2/growth & development , Spike Glycoprotein, Coronavirus/metabolism
2.
J Clin Invest ; 131(21)2021 11 01.
Article in English | MEDLINE | ID: covidwho-1495789

ABSTRACT

To explore how the immune system controls clearance of SARS-CoV-2, we used a single-cell, mass cytometry-based proteomics platform to profile the immune systems of 21 patients who had recovered from SARS-CoV-2 infection without need for admission to an intensive care unit or for mechanical ventilation. We focused on receptors involved in interactions between immune cells and virus-infected cells. We found that the diversity of receptor repertoires on natural killer (NK) cells was negatively correlated with the viral clearance rate. In addition, NK subsets expressing the receptor DNAM1 were increased in patients who more rapidly recovered from infection. Ex vivo functional studies revealed that NK subpopulations with high DNAM1 expression had cytolytic activities in response to target cell stimulation. We also found that SARS-CoV-2 infection induced the expression of CD155 and nectin-4, ligands of DNAM1 and its paired coinhibitory receptor TIGIT, which counterbalanced the cytolytic activities of NK cells. Collectively, our results link the cytolytic immune responses of NK cells to the clearance of SARS-CoV-2 and show that the DNAM1 pathway modulates host-pathogen interactions during SARS-CoV-2 infection.


Subject(s)
COVID-19/immunology , COVID-19/virology , Killer Cells, Natural/immunology , Receptors, Natural Killer Cell/immunology , SARS-CoV-2/immunology , Adolescent , Adult , Aged , Animals , Antigens, Differentiation, T-Lymphocyte/immunology , Cell Adhesion Molecules/immunology , Cohort Studies , Cytotoxicity, Immunologic , Female , Heterografts , Host Microbial Interactions/immunology , Humans , Immunophenotyping , In Vitro Techniques , Ligands , Male , Mice , Mice, SCID , Middle Aged , NK Cell Lectin-Like Receptor Subfamily D/immunology , Pandemics , Receptors, Immunologic/immunology , Receptors, Virus/immunology , Viral Load , Young Adult
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