scholarly journals Heparan Sulfate Facilitates Spike Protein-Mediated SARS-CoV-2 Host Cell Invasion and Contributes to Increased Infection of SARS-CoV-2 G614 Mutant and in Lung Cancer

2021 ◽  
Vol 8 ◽  
Author(s):  
Jingwen Yue ◽  
Weihua Jin ◽  
Hua Yang ◽  
John Faulkner ◽  
Xuehong Song ◽  
...  

The severe acute respiratory syndrome (SARS)-like coronavirus disease (COVID-19) is caused by SARS-CoV-2 and has been a serious threat to global public health with limited treatment. Cellular heparan sulfate (HS) has been found to bind SARS-CoV-2 spike protein (SV2-S) and co-operate with cell surface receptor angiotensin-converting enzyme 2 (ACE2) to mediate SARS-CoV-2 infection of host cells. In this study, we determined that host cell surface SV2-S binding depends on and correlates with host cell surface HS expression. This binding is required for SARS-Cov-2 virus to infect host cells and can be blocked by heparin lyase, HS antagonist surfen, heparin, and heparin derivatives. The binding of heparin/HS to SV2-S is mainly determined by its overall sulfation with potential, minor contribution of specific SV2-S binding motifs. The higher binding affinity of SV2-S G614 mutant to heparin and upregulated HS expression may be one of the mechanisms underlying the higher infectivity of the SARS-CoV-2 G614 variant and the high vulnerability of lung cancer patients to SARS-CoV-2 infection, respectively. The higher host cell infection by SARS-CoV-2 G614 variant pseudovirus and the increased infection caused by upregulated HS expression both can be effectively blocked by heparin lyase and heparin, and possibly surfen and heparin derivatives too. Our findings support blocking HS-SV2-S interaction may provide one addition to achieve effective prevention and/treatment of COVID-19.

2021 ◽  
Author(s):  
Yang Yang ◽  
Daniil G. Ivanov ◽  
Igor A. Kaltashov

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 - 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.


2021 ◽  
Vol 41 (10) ◽  
Author(s):  
Vipul Kumar ◽  
Anissa Nofita Sari ◽  
Hazna Noor Meidinna ◽  
Jaspreet Kaur Dhanjal ◽  
Chandru Subramani ◽  
...  

Abstract Coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has become a global health emergency. Although new vaccines have been generated and being implicated, discovery and application of novel preventive and control measures are warranted. We aimed to identify compounds that may possess the potential to either block the entry of virus to host cells or attenuate its replication upon infection. Using host cell surface receptor expression (angiotensin-converting enzyme 2 (ACE2) and Transmembrane protease serine 2 (TMPRSS2)) analysis as an assay, we earlier screened several synthetic and natural compounds and identified candidates that showed ability to down-regulate their expression. Here, we report experimental and computational analyses of two small molecules, Mortaparib and MortaparibPlus that were initially identified as dual novel inhibitors of mortalin and PARP-1, for their activity against SARS-CoV-2. In silico analyses showed that MortaparibPlus, but not Mortaparib, stably binds into the catalytic pocket of TMPRSS2. In vitro analysis of control and treated cells revealed that MortaparibPlus caused down-regulation of ACE2 and TMPRSS2; Mortaparib did not show any effect. Furthermore, computational analysis on SARS-CoV-2 main protease (Mpro) that also predicted the inhibitory activity of MortaparibPlus. However, cell-based antiviral drug screening assay showed 30–60% viral inhibition in cells treated with non-toxic doses of either MortaparibPlus or Mortaparib. The data suggest that these two closely related compounds possess multimodal anti-COVID-19 activities. Whereas MortaparibPlus works through direct interactions/effects on the host cell surface receptors (ACE2 and TMPRSS2) and the virus protein (Mpro), Mortaparib involves independent mechanisms, elucidation of which warrants further studies.


2021 ◽  
Author(s):  
Vipul Kumar ◽  
Anissa Nofita Sari ◽  
Hazna Noor Meidinna ◽  
Jaspreet Kaur Dhanjal ◽  
Chandru Subramani ◽  
...  

COVID-19 pandemic caused by SARS-CoV-2 virus has become a global health emergency. Although new vaccines have been generated and being implicated, discovery and application of novel preventive and control measures are warranted. We aimed to identify compound/s that may possess the potential to either block the entry of virus to host cells or attenuate its replication upon infection. Using host cell surface receptor expression (Angiotensin-converting enzyme 2 (ACE2) and Transmembrane protease serine 2 (TMPRSS2) analysis as an assay, we earlier screened several synthetic and natural compounds and identified candidates that showed ability to downregulate their expression. Here, we report experimental and computational analyses of two small molecules, Mortaparib and MortaparibPlus that were initially identified as dual novel inhibitors of mortalin and PARP-1, for their activity against SARS-CoV-2. In silico analyses showed that MortaparibPlus, but not Mortaparib, stably binds into the catalytic pocket of TMPRSS2. In vitro analysis of control and treated cells revealed that MortaparibPlus caused downregulation of ACE2 and TMPRSS2; Mortaparib did not show any effect. Furthermore, computational analysis on SARS-CoV-2 main protease (Mpro) that also predicted the inhibitory activity of MortaparibPlus.  However, cell based anti-virus drug screening assay showed 30~60% viral inhibition in cells treated with non-toxic doses of either MortaparibPlus or Mortaparib. The data suggests that these two closely related compounds possess multimodal anti-COVID 19 activities. Whereas MortaparibPlus works through direct interactions/effects on the host cell surface receptors (ACE2 and TMPRSS2) and the virus protein (Mpro), Mortaparib involves independent mechanisms, elucidation of which warrants further studies.


2021 ◽  
Vol 9 (5) ◽  
pp. 1015
Author(s):  
Tianyu Zhang ◽  
Xin Gao ◽  
Dongqiang Wang ◽  
Jixue Zhao ◽  
Nan Zhang ◽  
...  

Cryptosporidium parvum is a globally recognized zoonotic parasite of medical and veterinary importance. This parasite mainly infects intestinal epithelial cells and causes mild to severe watery diarrhea that could be deadly in patients with weakened or defect immunity. However, its molecular interactions with hosts and pathogenesis, an important part in adaptation of parasitic lifestyle, remain poorly understood. Here we report the identification and characterization of a C. parvum T-cell immunomodulatory protein homolog (CpTIPH). CpTIPH is a 901-aa single-pass type I membrane protein encoded by cgd5_830 gene that also contains a short Vibrio, Colwellia, Bradyrhizobium and Shewanella (VCBS) repeat and relatively long integrin alpha (ITGA) N-terminus domain. Immunofluorescence assay confirmed the location of CpTIPH on the cell surface of C. parvum sporozoites. In congruence with the presence of VCBS repeat and ITGA domain, CpTIPH displayed high, nanomolar binding affinity to host cell surface (i.e., Kd(App) at 16.2 to 44.7 nM on fixed HCT-8 and CHO-K1 cells, respectively). The involvement of CpTIPH in the parasite invasion is partly supported by experiments showing that an anti-CpTIPH antibody could partially block the invasion of C. parvum sporozoites into host cells. These observations provide a strong basis for further investigation of the roles of CpTIPH in parasite-host cell interactions.


2006 ◽  
Vol 74 (3) ◽  
pp. 1795-1799 ◽  
Author(s):  
Richard S. Stephens ◽  
Jesse M. Poteralski ◽  
Lynn Olinger

ABSTRACT The hypothesis that host cell surface heparan sulfate is required to promote chlamydial infection was tested using a cell line (CHO-18.4) containing a single retroviral insertion and the concomitant loss of heparan sulfate biosynthesis. Tests of chlamydial infectivity of heparan sulfate-deficient CHO-18.4 cells and parental cells, CHO-22, demonstrated that both were equally sensitive to infection by Chlamydia trachomatis serovars L2 and D. These data do not support the hypothesis and demonstrate that host cell surface heparan sulfate does not serve an essential functional role in chlamydial infectivity.


2004 ◽  
Vol 78 (18) ◽  
pp. 9666-9674 ◽  
Author(s):  
G. Grant Welstead ◽  
Eric C. Hsu ◽  
Caterina Iorio ◽  
Shelly Bolotin ◽  
Christopher D. Richardson

ABSTRACT Measles virus has been reported to enter host cells via either of two cellular receptors, CD46 and CD150 (SLAM). CD46 is found on most cells of higher primates, while SLAM is expressed on activated B, T, and dendritic cells and is an important regulatory molecule of the immune system. Previous reports have shown that measles virus can down regulate expression of its two cellular receptors on the host cell surface during infection. In this study, the process of down regulation of SLAM by measles virus was investigated. We demonstrated that expression of the hemagglutinin (H) protein of measles virus was sufficient for down regulation. Our studies provided evidence that interactions between H and SLAM in the endoplasmic reticulum (ER) can promote the down regulation of SLAM but not CD46. In addition, we demonstrated that interactions between H and SLAM at the host cell surface can also contribute to SLAM down regulation. These results indicate that two mechanisms involving either intracellular interactions between H and SLAM in the ER or receptor-mediated binding to H at the surfaces of host cells can lead to the down regulation of SLAM during measles virus infection.


2007 ◽  
Vol 6 (8) ◽  
pp. 1354-1362 ◽  
Author(s):  
Timothy R. Southern ◽  
Carrie E. Jolly ◽  
Melissa E. Lester ◽  
J. Russell Hayman

ABSTRACT Microsporidia are spore-forming fungal pathogens that require the intracellular environment of host cells for propagation. We have shown that spores of the genus Encephalitozoon adhere to host cell surface glycosaminoglycans (GAGs) in vitro and that this adherence serves to modulate the infection process. In this study, a spore wall protein (EnP1; Encephalitozoon cuniculi ECU01_0820) from E. cuniculi and Encephalitozoon intestinalis is found to interact with the host cell surface. Analysis of the amino acid sequence reveals multiple heparin-binding motifs, which are known to interact with extracellular matrices. Both recombinant EnP1 protein and purified EnP1 antibody inhibit spore adherence, resulting in decreased host cell infection. Furthermore, when the N-terminal heparin-binding motif is deleted by site-directed mutagenesis, inhibition of adherence is ablated. Our transmission immunoelectron microscopy reveals that EnP1 is embedded in the microsporidial endospore and exospore and is found in high abundance in the polar sac/anchoring disk region, an area from which the everting polar tube is released. Finally, by using a host cell binding assay, EnP1 is shown to bind host cell surfaces but not to those that lack surface GAGs. Collectively, these data show that given its expression in both the endospore and the exospore, EnP1 is a microsporidian cell wall protein that may function both in a structural capacity and in modulating in vitro host cell adherence and infection.


2002 ◽  
Vol 70 (6) ◽  
pp. 3187-3198 ◽  
Author(s):  
Nadine Keller ◽  
Arunasalam Naguleswaran ◽  
Angela Cannas ◽  
Nathalie Vonlaufen ◽  
Marianne Bienz ◽  
...  

ABSTRACT The invasive stages of apicomplexan parasites enter their host cells through mechanisms which are largely conserved throughout the phylum. Host cell invasion is divided into two distinct events, namely, adhesion onto the host cell surface and the actual host cell entry process. The former is mediated largely through microneme proteins which are secreted at the onset of establishing contact with the host cell surface. Many of the microneme proteins identified so far contain adhesive domains. We here present the genomic and corresponding cDNA sequences coding for a 460-amino-acid (aa) microneme protein in Neospora caninum tachyzoites which, due to its homology to MIC1 in Toxoplasma gondii (TgMIC1), was named NcMIC1. The deduced NcMIC1 polypeptide sequence contains an N-terminal signal peptide of 20 aa followed by two tandemly internal repeats of 48 and 44 aa, respectively. Integrated into each repeat is a CXXXCG sequence motif reminiscent of the thrombospondin-related family of adhesive proteins. The positioning of this motif is strictly conserved in TgMIC1 and NcMIC1. The C-terminal part, comprised of 278 aa, was expressed in Escherichia coli, and antibodies affinity purified on recombinant NcMIC1 were used to confirm the localization within the micronemes by immunofluorescence and immunogold transmission electron microscopy of tachyzoites. Immunohistochemistry of mouse brains infected with tissue cysts showed that expression of this protein is reduced in the bradyzoite stage. Upon initiation of secretion by elevating the temperature to 37°C, NcMIC1 is released into the medium supernatant. NcMIC1 binds to trypsinized, rounded Vero cells, as well as to Vero cell monolayers. Removal of glycosaminoglycans from the host cell surface and modulation of host cell surface glycosaminoglycan sulfation significantly reduces the binding of NcMIC1 to the host cell surface. Solid-phase binding assays employing defined glycosaminoglycans confirmed that NcMIC1 binds to sulfated glycosaminoglycans.


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