D614G mutation of SARS-CoV-2 spike protein enhances viral infectivity

Author(s):  
Jie Hu ◽  
Chang-Long He ◽  
Qing-Zhu Gao ◽  
Gui-Ji Zhang ◽  
Xiao-Xia Cao ◽  
...  

AbstractCoronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The spike (S) protein that mediates SARS-CoV-2 entry into host cells is a major target for vaccines and therapeutics. Thus, insights into its sequence variations are key to understanding the infection and antigenicity of SARS-CoV-2. A dominant mutational variant at position 614 of the S protein (aspartate to glycine, D614G mutation) was observed in the SARS-CoV-2 genome sequence obtained from the Nextstrain database. Using a pseudovirus-based assay, we identified that S-D614 and S-G614 protein pseudotyped viruses share a common receptor, human angiotensin-converting enzyme 2 (ACE2), which could be blocked by recombinant ACE2 with the fused Fc region of human IgG1. However, S-D614 and S-G614 protein demonstrated functional differences. First, S-G614 protein could be cleaved by serine protease elastase-2 more efficiently. Second, S-G614 pseudovirus infected 293T-ACE2 cells significantly more efficiently than did the S-D614 pseudovirus, especially in the presence of elastase-2. Third, an elastase inhibitor approved for clinical use blocked elastase-enhanced S-G614 pseudovirus infection. Moreover, 93% (65/70) convalescent sera from patients with COVID-19 could neutralize both S-D614 and S-G614 pseudoviruses with comparable efficiencies, but about 7% (5/70) convalescent sera showed reduced neutralizing activity against the S-G614 pseudovirus. These findings have important implications for SARS-CoV-2 transmission and immune interventions.

Biomedicines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1620
Author(s):  
Dharmendra Kumar Yadav ◽  
Desh Deepak Singh ◽  
Ihn Han ◽  
Yogesh Kumar ◽  
Eun-Ha Choi

The ongoing SARS-CoV-2 pandemic is a serious threat to public health worldwide and, to date, no effective treatment is available. Thus, we herein review the pharmaceutical approaches to SARS-CoV-2 infection treatment. Numerous candidate medicines that can prevent SARS-CoV-2 infection and replication have been proposed. These medicines include inhibitors of serine protease TMPRSS2 and angiotensin converting enzyme 2 (ACE2). The S protein of SARS-CoV-2 binds to the receptor in host cells. ACE2 inhibitors block TMPRSS2 and S protein priming, thus preventing SARS-CoV-2 entry to host cells. Moreover, antiviral medicines (including the nucleotide analogue remdesivir, the HIV protease inhibitors lopinavir and ritonavir, and wide-spectrum antiviral antibiotics arbidol and favipiravir) have been shown to reduce the dissemination of SARS-CoV-2 as well as morbidity and mortality associated with COVID-19.


2021 ◽  
Vol 28 ◽  
Author(s):  
Hao Lin ◽  
Srinivasulu Cherukupalli ◽  
Da Feng ◽  
Shenghua Gao ◽  
Dongwei Kang ◽  
...  

: COVID-19 is an infectious disease caused by SARS-CoV-2. The life cycle of SARS-CoV-2 includes the entry into the target cells, replicase translation, replicating and transcribing genomes, translating structural proteins, assembling and releasing new virions. Entering host cells is a crucial stage in the early life cycle of the virus, and blocking this stage can effectively prevent virus infection. SARS enters the target cells mediated by the interaction between the viral S protein and the target cell surface receptor angiotensin-converting enzyme 2 (ACE2), as well as the cleavage effect of type-II transmembrane serine protease (TMPRSS2) on the S protein. Therefore, the ACE2 receptor and TMPRSS2 are important targets for SARS-CoV-2 entry inhibitors. Herein, we provide a concise report/information on drugs with potential therapeutic value targeting virus-ACE2 or virus-TMPRSS2 interactions, to provide a reference for the design and discovery of potential entry inhibitors against SARS-CoV-2.


2008 ◽  
Vol 89 (11) ◽  
pp. 2741-2745 ◽  
Author(s):  
Alison C. Mathewson ◽  
Alexandra Bishop ◽  
Yongxiu Yao ◽  
Fred Kemp ◽  
Junyuan Ren ◽  
...  

Although in different groups, the coronaviruses severe acute respiratory syndrome-coronavirus (SARS-CoV) and NL63 use the same receptor, angiotensin converting enzyme (ACE)-2, for entry into the host cell. Despite this common receptor, the consequence of entry is very different; severe respiratory distress in the case of SARS-CoV but frequently only a mild respiratory infection for NL63. Using a wholly recombinant system, we have investigated the ability of each virus receptor-binding protein, spike or S protein, to bind to ACE-2 in solution and on the cell surface. In both assays, we find that the NL63 S protein has a weaker interaction with ACE-2 than the SARS-CoV S protein, particularly in solution binding, but the residues required for contact are similar. We also confirm that the ACE-2-binding site of NL63 S lies between residues 190 and 739. A lower-affinity interaction with ACE-2 might partly explain the different pathological consequences of infection by SARS-CoV and NL63.


2021 ◽  
Vol 5 (01) ◽  
pp. 1-4
Author(s):  
Hayder M. Al-Kuraishy ◽  
Marwa S. Al-Niemi ◽  
Nawar R. Hussain ◽  
Ali I. Al-Gareeb ◽  
Claire Lugnier

Primary infection of SARS-CoV-2 (novel coronavirus or 2019-nCoV), which leads to Covid-19, targets specific cells, such as nasal, bronchial epithelial and pneumocytes, through the viral structural spike (S) protein that binds to the angiotensin-converting enzyme 2 (ACE2) receptor. Also, type 2 transmembrane serine protease (TMPRSS2) present in the host cell promotes viral uptake by cleaving ACE2 and triggering the SARS-CoV-2 S protein, which facilitates SARS-CoV-2 entry into host cells. One of the TMPRSS2 inhibitors with a greater distribution capacity into the lung tissue is bromhexine hydrochloride which attenuates the entry and proliferation of SARS-CoV-2. Bromhexine is an effective drug in the management and treatment of Covid-19 pneumonia via targeting ACE2/ TMPRSS2 pathway. However, prospective and controlled clinical trials are recommended to confirm this observation.


2021 ◽  
Vol 8 ◽  
Author(s):  
Yalda Rahbar Saadat ◽  
Seyed Mahdi Hosseiniyan Khatibi ◽  
Sepideh Zununi Vahed ◽  
Mohammadreza Ardalan

The ongoing pandemic illustrates limited therapeutic options for controlling SARS-CoV-2 infections, calling a need for additional therapeutic targets. The viral spike S glycoprotein binds to the human receptor angiotensin-converting enzyme 2 (ACE2) and then is activated by the host proteases. Based on the accessibility of the cellular proteases needed for SARS-S activation, SARS-CoV-2 entrance and activation can be mediated by endosomal (such as cathepsin L) and non-endosomal pathways. Evidence indicates that in the non-endosomal pathway, the viral S protein is cleaved by the furin enzyme in infected host cells. To help the virus enter efficiently, the S protein is further activated by the serine protease 2 (TMPRSS2), provided that the S has been cleaved by furin previously. In this review, important roles for host proteases within host cells will be outlined in SARS-CoV-2 infection and antiviral therapeutic strategies will be highlighted. Although there are at least five highly effective vaccines at this time, the appearance of the new viral mutations demands the development of therapeutic agents. Targeted inhibition of host proteases can be used as a therapeutic approach for viral infection.


2021 ◽  
Vol 22 (3) ◽  
pp. 992
Author(s):  
Laura Kate Gadanec ◽  
Kristen Renee McSweeney ◽  
Tawar Qaradakhi ◽  
Benazir Ali ◽  
Anthony Zulli ◽  
...  

The occurrence of the novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), responsible for coronavirus disease 2019 (COVD-19), represents a catastrophic threat to global health. Protruding from the viral surface is a densely glycosylated spike (S) protein, which engages angiotensin-converting enzyme 2 (ACE2) to mediate host cell entry. However, studies have reported viral susceptibility in intra- and extrapulmonary immune and non-immune cells lacking ACE2, suggesting that the S protein may exploit additional receptors for infection. Studies have demonstrated interactions between S protein and innate immune system, including C-lectin type receptors (CLR), toll-like receptors (TLR) and neuropilin-1 (NRP1), and the non-immune receptor glucose regulated protein 78 (GRP78). Recognition of carbohydrate moieties clustered on the surface of the S protein may drive receptor-dependent internalization, accentuate severe immunopathological inflammation, and allow for systemic spread of infection, independent of ACE2. Furthermore, targeting TLRs, CLRs, and other receptors (Ezrin and dipeptidyl peptidase-4) that do not directly engage SARS-CoV-2 S protein, but may contribute to augmented anti-viral immunity and viral clearance, may represent therapeutic targets against COVID-19.


2020 ◽  
Author(s):  
Sarah A. Clark ◽  
Lars E. Clark ◽  
Junhua Pan ◽  
Adrian Coscia ◽  
Lindsay G.A. McKay ◽  
...  

AbstractThe SARS-CoV-2 viral spike (S) protein mediates attachment and entry into host cells and is a major target of vaccine and drug design. Potent SARS-CoV-2 neutralizing antibodies derived from closely related antibody heavy chain genes (IGHV3-53 or 3-66) have been isolated from multiple COVID-19 convalescent individuals. These usually contain minimal somatic mutations and bind the S receptor-binding domain (RBD) to interfere with attachment to the cellular receptor angiotensin-converting enzyme 2 (ACE2). We used antigen-specific single B cell sorting to isolate S-reactive monoclonal antibodies from the blood of a COVID-19 convalescent individual. The seven most potent neutralizing antibodies were somatic variants of the same IGHV3-53-derived antibody and bind the RBD with varying affinity. We report X-ray crystal structures of four Fab variants bound to the RBD and use the structures to explain the basis for changes in RBD affinity. We show that a germline revertant antibody binds tightly to the SARS-CoV-2 RBD and neutralizes virus, and that gains in affinity for the RBD do not necessarily correlate with increased neutralization potency, suggesting that somatic mutation is not required to exert robust antiviral effect. Our studies clarify the molecular basis for a heavily germline-biased human antibody response to SARS-CoV-2.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Kushal Suryamohan ◽  
Devan Diwanji ◽  
Eric W. Stawiski ◽  
Ravi Gupta ◽  
Shane Miersch ◽  
...  

AbstractCOVID-19 is a respiratory illness caused by a novel coronavirus called SARS-CoV-2. The viral spike (S) protein engages the human angiotensin-converting enzyme 2 (ACE2) receptor to invade host cells with ~10–15-fold higher affinity compared to SARS-CoV S-protein, making it highly infectious. Here, we assessed if ACE2 polymorphisms can alter host susceptibility to SARS-CoV-2 by affecting this interaction. We analyzed over 290,000 samples representing >400 population groups from public genomic datasets and identified multiple ACE2 protein-altering variants. Using reported structural data, we identified natural ACE2 variants that could potentially affect virus–host interaction and thereby alter host susceptibility. These include variants S19P, I21V, E23K, K26R, T27A, N64K, T92I, Q102P and H378R that were predicted to increase susceptibility, while variants K31R, N33I, H34R, E35K, E37K, D38V, Y50F, N51S, M62V, K68E, F72V, Y83H, G326E, G352V, D355N, Q388L and D509Y were predicted to be protective variants that show decreased binding to S-protein. Using biochemical assays, we confirmed that K31R and E37K had decreased affinity, and K26R and T92I variants showed increased affinity for S-protein when compared to wildtype ACE2. Consistent with this, soluble ACE2 K26R and T92I were more effective in blocking entry of S-protein pseudotyped virus suggesting that ACE2 variants can modulate susceptibility to SARS-CoV-2.


Author(s):  
Mohammad Reza Dayer

The disease of COVID-19 comprises the most serious against human health worldwide with a high rate of virulence and mortality. The disease is caused by the 2019-nCoV virus from the beta coronavirus family. The virus makes use of its surface glycoprotein named S protein or spike to enter the human cells. The virus attached to its receptor named angiotensin-converting enzyme 2 on host cells surface via its receptor-binding domain and its fusion is mediated by cleavage at S2' site that is carried out by surface protease. Vaccines or drugs interfering with S protein binding or cleavage sites could be considered as drugs to get rid of the infection. In the current work and though docking and molecular dynamic experiments we have checked more than 100 drugs with high enough molecular weights for their shielding potency toward S protein binding sites and processing S2' sites. Our results indicate the shielding potency of: fidaxomicin > ivermectin > heparin > azithromycin > clarithromycin > eryhthromycin > niclosamide > ritonavir. Considering affluent reports regarding the complex disturbance in the immune system and multi-organ involvement in the disease there is no single or binary drug regime for cure expectedly and instead, we claim the multi-drug regime should be the choice in this context. Accordingly, we suggest our extracted drugs as an adjuvant for clinical trials.


Biomedicines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 437
Author(s):  
Dean Gilham ◽  
Audrey L. Smith ◽  
Li Fu ◽  
Dalia Y. Moore ◽  
Abenaya Muralidharan ◽  
...  

Effective therapeutics are urgently needed to counter infection and improve outcomes for patients suffering from COVID-19 and to combat this pandemic. Manipulation of epigenetic machinery to influence viral infectivity of host cells is a relatively unexplored area. The bromodomain and extraterminal (BET) family of epigenetic readers have been reported to modulate SARS-CoV-2 infection. Herein, we demonstrate apabetalone, the most clinical advanced BET inhibitor, downregulates expression of cell surface receptors involved in SARS-CoV-2 entry, including angiotensin-converting enzyme 2 (ACE2) and dipeptidyl-peptidase 4 (DPP4 or CD26) in SARS-CoV-2 permissive cells. Moreover, we show that apabetalone inhibits SARS-CoV-2 infection in vitro to levels comparable to those of antiviral agents. Taken together, our study supports further evaluation of apabetalone to treat COVID-19, either alone or in combination with emerging therapeutics.


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