scholarly journals The degree of polymerization and sulfation patterns in heparan sulfate are critical determinants of cytomegalovirus infectivity

2019 ◽  
Author(s):  
Mohammad H. Hasan ◽  
Rinkuben Parmar ◽  
Quntao Liang ◽  
Hong Qiu ◽  
Vaibhav Tiwari ◽  
...  

AbstractHerpesviruses attach to host cells by interacting with cell surface heparan sulfate (HS) proteoglycans prior to specific coreceptor engagement which culminates in virus-host membrane fusion and virus entry. Interfering with HS-herpesvirus interactions results in significant reduction in virus infectivity indicating that HS play important roles in initiating virus entry. In this study, we provide convincing evidence that specific sulfations as well as the degree of polymerization (dp) of HS govern human cytomegalovirus (CMV) infection and binding by following line of evidences. First, purified CMV extracellular virions preferentially bound to the sulfated longer chain of HS on a glycoarray compared to unsulfated glycosaminoglycans and shorter chain unsulfated HS. Second, the fraction of glycosaminoglycans (GAG) displaying higherdpand sulfation had a major impact on CMV infectivity and titers. Finally, cell lines knocked out for specific sulfotransferases Glucosaminyl 3-O-sulfotransferase (3-O-ST-1 and −4 and double −1/4) produced significantly reduced CMV titers compared to wild-type cells. Similarly, a peptide generated against sulfated-HS significantly reduced virus titers compared to the control peptide. Taken together, the above results highlight the significance of the chain length and sulfation patterns of HS in CMV binding and infectivity.ImportanceThe cell surface heparan sulfates (HS) are exploited by multiple viruses as they provide docking sites during cell entry and therefore are a promising target for the development of novel antivirals. In addition, the molecular diversity in HS chains generates unique binding sites for specific ligands and hence offers preferential binding for one virus over other. In the current study several HS mimics were analyzed for their ability to inhibit cytomegalovirus (CMV) infection. The results were corroborated by parallel studies in mutant mouse cells and virus binding to glycoarrays. Combined together, the data suggests that virus particles preferentially attach to specifically modified HS and thus the process is amenable to targeting by specifically designed HS mimics.

2021 ◽  
Vol 17 (8) ◽  
pp. e1009803
Author(s):  
Dipanwita Mitra ◽  
Mohammad H. Hasan ◽  
John T. Bates ◽  
Michael A. Bierdeman ◽  
Dallas R. Ederer ◽  
...  

Several enveloped viruses, including herpesviruses attach to host cells by initially interacting with cell surface heparan sulfate (HS) proteoglycans followed by specific coreceptor engagement which culminates in virus-host membrane fusion and virus entry. Interfering with HS-herpesvirus interactions has long been known to result in significant reduction in virus infectivity indicating that HS play important roles in initiating virus entry. In this study, we provide a series of evidence to prove that specific sulfations as well as the degree of polymerization (dp) of HS govern human cytomegalovirus (CMV) binding and infection. First, purified CMV extracellular virions preferentially bind to sulfated longer chain HS on a glycoarray compared to a variety of unsulfated glycosaminoglycans including unsulfated shorter chain HS. Second, the fraction of glycosaminoglycans (GAG) displaying higher dp and sulfation has a larger impact on CMV titers compared to other fractions. Third, cell lines deficient in specific glucosaminyl sulfotransferases produce significantly reduced CMV titers compared to wild-type cells and virus entry is compromised in these mutant cells. Finally, purified glycoprotein B shows strong binding to heparin, and desulfated heparin analogs compete poorly with heparin for gB binding. Taken together, these results highlight the significance of HS chain length and sulfation patterns in CMV attachment and infectivity.


2017 ◽  
Author(s):  
Shah Kamranur Rahman ◽  
Mairaj Ahmed Ansari ◽  
Pratibha Gaur ◽  
Imtiyaz Ahmad ◽  
Chandrani Chakravarty ◽  
...  

AbstractTo establish a productive infection in host cells, viruses often use one or multiple host membrane glycoprotein as their receptors. For Influenza A virus (IAV) such a glycoprotein receptor has not been described, to date. Here we show that IAV is using the host membrane glycoprotein CD66c as a receptor for entry into human epithelial lung cells. Neuraminidase (NA), a viral spike protein binds to CD66c on the cell surface during IAV entry into the host cells. Lung cells overexpressing CD66c showed an increase in virus binding and subsequent entry into the cell. Upon comparison, CD66c demonstrated higher binding capacity than other membrane glycoproteins (EGFR and DC-SIGN) reported earlier to facilitate IAV entry into host cells. siRNA mediated knockdown of CD66c from lung cells inhibited virus binding on cell surface and entry into cells. Blocking CD66c by antibody on the cell surface resulted in decreased virus entry. We found CD66c is a specific glycoprotein receptor for influenza A virus that did not affect entry of non-IAV RNA virus (Hepatitis C virus). Finally, IAV pre-incubated with recombinant CD66c protein when administered intranasally in mice showed decreased cytopathic effects in mice lungs. This publication is the first to report CD66c (CEACAM6) as a glycoprotein receptor for Influenza A virus.Significance StatementCells are enclosed by a semipermeable membrane that allows selective exchange of biomolecules between cells and their surroundings. A set of specialized proteins in this semipermeable membrane, work like gatekeepers to the cell and regulate entry of these biomolecules. One class of such surface proteins is termed as receptors. Viruses bind to one or more of these receptors and manipulate gatekeepers for their own successful entry into host-cells. A membrane protein that influenza A virus (Flu virus) uses for entry into the cells was not discovered till date. This study reports for the first time, a receptor for influenza A virus, that was sought after by researchers for decades. The viral receptor is a promising target that can be used to inhibit virus entry into host cells.


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.


Author(s):  
Mojtaba Bakhtiari ◽  
Kamyar Asadipooya

Abstract: A new coronavirus pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2], has been on the rise. This virus is fatal for broad groups of populations, including elderly, men, and patients with comorbidities among which obesity is a possible risk factor. The pathophysiologic connections between obesity/metainflammation and COVID-19 may be directly related to increasing soluble ACE2 (angiotensin-converting enzyme 2] levels which potentiates the viral entrance into the host cells, or indirectly related to dysregulation of immune system, microvascular injury and hypercoagulability. The SARS-CoV-2 S-glycoprotein interacts mainly with ACE2 or possibly DDP4 receptors to enter into the host cells. The host proteases, especially TMPRSS2 (transmembrane protease serine 2], support the fusion process and virus entry. While membranous ACE2 is considered a port of entry to the cell for SARS-CoV-2, it seems that soluble ACE2 retains its virus binding capability and enhances its entry into the cells. Interestingly, ACE2 on cell membrane may have protective roles by diminishing cytokine storm-related injuries to the organs. Applying medications that can reduce soluble ACE2 levels, antagonizing TMPRSS2 or blocking DDP4 can improve the outcomes of COVID-19. Metformin and statins through immunomodulatory activities, Orlistat by reducing viral replication, and thiazolidinediones by upregulating ACE2 expression have potential beneficial effects against COVID-19. However, the combination of dipeptidyl peptidase-4 (DDP4] inhibitors and spironolactone/eplerenone seems to be more effective by reducing soluble ACE2 level, antagonizing TMPRSS2, maintaining ACE2 on cell membrane and reducing risk of viral entry into the cells.


mBio ◽  
2016 ◽  
Vol 7 (6) ◽  
Author(s):  
Samantha D. O’Hara ◽  
Robert L. Garcea

ABSTRACTVirus binding to the cell surface triggers an array of host responses, including activation of specific signaling pathways that facilitate steps in virus entry. Using mouse polyomavirus (MuPyV), we identified host signaling pathways activated upon virus binding to mouse embryonic fibroblasts (MEFs). Pathways activated by MuPyV included the phosphatidylinositol 3-kinase (PI3K), FAK/SRC, and mitogen-activated protein kinase (MAPK) pathways. Gangliosides and α4-integrin are required receptors for MuPyV infection. MuPyV binding to both gangliosides and the α4-integrin receptors was required for activation of the PI3K pathway; however, either receptor interaction alone was sufficient for activation of the MAPK pathway. Using small-molecule inhibitors, we confirmed that the PI3K and FAK/SRC pathways were required for MuPyV infection, while the MAPK pathway was dispensable. Mechanistically, the PI3K pathway was required for MuPyV endocytosis, while the FAK/SRC pathway enabled trafficking of MuPyV along microtubules. Thus, MuPyV interactions with specific cell surface receptors facilitate activation of signaling pathways required for virus entry and trafficking. Understanding how different viruses manipulate cell signaling pathways through interactions with host receptors could lead to the identification of new therapeutic targets for viral infection.IMPORTANCEVirus binding to cell surface receptors initiates outside-in signaling that leads to virus endocytosis and subsequent virus trafficking. How different viruses manipulate cell signaling through interactions with host receptors remains unclear, and elucidation of the specific receptors and signaling pathways required for virus infection may lead to new therapeutic targets. In this study, we determined that gangliosides and α4-integrin mediate mouse polyomavirus (MuPyV) activation of host signaling pathways. Of these pathways, the PI3K and FAK/SRC pathways were required for MuPyV infection. Both the PI3K and FAK/SRC pathways have been implicated in human diseases, such as heart disease and cancer, and inhibitors directed against these pathways are currently being investigated as therapies. It is possible that these pathways play a role in human PyV infections and could be targeted to inhibit PyV infection in immunosuppressed patients.


2002 ◽  
Vol 76 (16) ◽  
pp. 8400-8407 ◽  
Author(s):  
Honey V. Reddi ◽  
Howard L. Lipton

ABSTRACT The mechanisms by which Theiler's murine encephalomyelitis virus (TMEV) binds and enters host cells and the molecules involved are not completely understood. In this study, we demonstrate that the high-neurovirulence TMEV GDVII virus uses the glycosaminoglycan heparan sulfate (HS) as an attachment factor that is required for efficient infection. Studies based on soluble HS-mediated inhibition of attachment and infection, removal of HS with specific enzymes, and blocking with anti-HS antibodies establish that HS mediates GDVII virus entry into mammalian cells. Data from defined proteoglycan-deficient Chinese hamster ovary mutant cells further support the role of HS in GDVII infection and indicate that the extent of sulfation is critical for infection. Neuraminidase treatment of proteoglycan-deficient cells restores permissiveness to GDVII virus, indicating that sialic acid hinders direct access of virus to the protein entry receptor. A model of the potential steps in GDVII virus entry into mammalian cells involving HS is proposed.


2003 ◽  
Vol 77 (6) ◽  
pp. 3460-3469 ◽  
Author(s):  
David L. Wensel ◽  
Weihua Li ◽  
James M. Cunningham

ABSTRACT During ongoing C-type retrovirus infection, the probability of leukemia caused by insertional gene activation is markedly increased by the emergence of recombinant retroviruses that repeatedly infect host cells. The murine mink cell focus-inducing (MCF) viruses with this property have acquired characteristic changes in the N-terminal domain of their envelope glycoprotein that specify binding to a different receptor than the parental ecotropic virus. In this report, we show that MCF virus infection occurs through binding to this receptor (termed Syg1) and, remarkably, by a second mechanism that does not utilize the Syg1 receptor. By the latter route, the N-terminal domain of the ecotropic virus glycoprotein expressed on the cell surface in a complex with its receptor activates the fusion mechanism of the MCF virus in trans. The rate of MCF virus spread through a population of permissive human cells was increased by establishment of trans activation, indicating that Syg1 receptor-dependent and -independent pathways function in parallel. Also, trans activation shortened the interval between initial infection and onset of cell-cell fusion associated with repeated infection of the same cell. Our findings indicate that pathogenic retrovirus infection may be initiated by virus binding to cell receptors or to the virus envelope glycoprotein of other viruses expressed on the cell surface. Also, they support a broader principle: that cooperative virus-virus interactions, as well as virus-host interactions, shape the composition and properties of the retrovirus quasispecies.


2016 ◽  
Vol 90 (13) ◽  
pp. 6097-6111 ◽  
Author(s):  
Bethany A. Rhein ◽  
Rachel B. Brouillette ◽  
Grace A. Schaack ◽  
John A. Chiorini ◽  
Wendy Maury

ABSTRACTPhosphatidylserine (PtdSer) receptors that are responsible for the clearance of dying cells have recently been found to mediate enveloped virus entry. Ebola virus (EBOV), a member of theFiloviridaefamily of viruses, utilizes PtdSer receptors for entry into target cells. The PtdSer receptors human and murine T-cell immunoglobulin mucin (TIM) domain proteins TIM-1 and TIM-4 mediate filovirus entry by binding to PtdSer on the virion surface via a conserved PtdSer binding pocket within the amino-terminal IgV domain. While the residues within the TIM-1 IgV domain that are important for EBOV entry are characterized, the molecular details of virion–TIM-4 interactions have yet to be investigated. As sequences and structural alignments of the TIM proteins suggest distinct differences in the TIM-1 and TIM-4 IgV domain structures, we sought to characterize TIM-4 IgV domain residues required for EBOV entry. Using vesicular stomatitis virus pseudovirions bearing EBOV glycoprotein (EBOV GP/VSVΔG), we evaluated virus binding and entry into cells expressing TIM-4 molecules mutated within the IgV domain, allowing us to identify residues important for entry. Similar to TIM-1, residues in the PtdSer binding pocket of murine and human TIM-4 (mTIM-4 and hTIM-4) were found to be important for EBOV entry. However, additional TIM-4-specific residues were also found to impact EBOV entry, with a total of 8 mTIM-4 and 14 hTIM-4 IgV domain residues being critical for virion binding and internalization. Together, these findings provide a greater understanding of the interaction of TIM-4 with EBOV virions.IMPORTANCEWith more than 28,000 cases and over 11,000 deaths during the largest and most recent Ebola virus (EBOV) outbreak, there has been increased emphasis on the development of therapeutics against filoviruses. Many therapies under investigation target EBOV cell entry. T-cell immunoglobulin mucin (TIM) domain proteins are cell surface factors important for the entry of many enveloped viruses, including EBOV. TIM family member TIM-4 is expressed on macrophages and dendritic cells, which are early cellular targets during EBOV infection. Here, we performed a mutagenesis screening of the IgV domain of murine and human TIM-4 to identify residues that are critical for EBOV entry. Surprisingly, we identified more human than murine TIM-4 IgV domain residues that are required for EBOV entry. Defining the TIM IgV residues needed for EBOV entry clarifies the virus-receptor interactions and paves the way for the development of novel therapeutics targeting virus binding to this cell surface receptor.


2010 ◽  
Vol 85 (3) ◽  
pp. 532-540 ◽  
Author(s):  
Anna Luganini ◽  
Andrea Giuliani ◽  
Giovanna Pirri ◽  
Lorena Pizzuto ◽  
Santo Landolfo ◽  
...  

2012 ◽  
Vol 56 (10) ◽  
pp. 5278-5288 ◽  
Author(s):  
Manuela Donalisio ◽  
Marco Rusnati ◽  
Valeria Cagno ◽  
Andrea Civra ◽  
Antonella Bugatti ◽  
...  

ABSTRACTRespiratory syncytial virus (RSV) interacts with cell surface heparan sulfate proteoglycans (HSPGs) to initiate infection. The interaction of RSV with HSPGs thus presents an attractive target for the development of novel inhibitors of RSV infection. In the present study, a minilibrary of linear, dimeric, and dendrimeric peptides containing clusters of basic amino acids was screened with the aim of identifying peptides able to bind HSPGs and thus block RSV attachment and infectivity. Of the compounds identified, the dendrimer SB105-A10 was the most potent inhibitor of RSV infectivity, with 50% inhibitory concentrations (IC50s) of 0.35 μM and 0.25 μM measured in Hep-2 and A549 cells, respectively. SB105-A10 was found to bind to both cell types via HSPGs, suggesting that its antiviral activity is indeed exerted by competing with RSV for binding to cell surface HSPGs. SB105-A10 prevented RSV infection when added before the viral inoculum, in line with its proposed HSPG-binding mechanism of action; moreover, antiviral activity was also exhibited when SB105-A10 was added postinfection, as it was able to reduce the cell-to-cell spread of the virus. The antiviral potential of SB105-A10 was further assessed using human-derived tracheal/bronchial epithelial cells cultured to form a pseudostratified, highly differentiated model of the epithelial tissue of the human respiratory tract. SB105-A10 strongly reduced RSV infectivity in this model and exhibited no signs of cytotoxicity or proinflammatory effects. Together, these features render SB105-A10 an attractive candidate for further development as a RSV inhibitor to be administered by aerosol delivery.


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