scholarly journals hFUT1-based live cell assay to profile α1-2-fucosides enhanced influenza A virus infection

2019 ◽  
Author(s):  
Senlian Hong ◽  
Geramie Grande ◽  
Chenhua Yu ◽  
Digantkumar G. Chapla ◽  
Natalie Reigh ◽  
...  
Keyword(s):  
Cell Surface ◽  
Host Cell ◽  
Influenza A Virus ◽  
Influenza A ◽  
Host Cells ◽  
Viral Pathogen ◽  
Host Tropism ◽  
Host Cell Surface ◽  
Different Strains

AbstractHost cell-surface glycans play critical roles in influenza A virus (IAV) infection ranging from modulation of IAV attachment to membrane fusion and host tropism. Approaches for quick and sensitive profiling of the viral avidity towards a specific type of host-cell glycan can contribute to the understanding of tropism switching among different strains of IAV. In this study, we developed a method based on chemoenzymatic glycan engineering to investigate the possible involvement of α1-2-fucosides in IAV infections. Using a truncated human fucosyltransferase 1 (hFuT1), we were able to create α1-2-linked fucosides in situ on the host cell surface to assess their influence on the host cell binding to IAV hemagglutinin and the susceptibility of host cells toward IAV induced killing. We discovered that the newly added α1-2-fucosides on host cells enhanced the infection of several human pandemic IVA subtypes. These findings suggest that glycan epitopes other than sialic aicds should be taken into consideration for assessing the human pandemic risk of this viral pathogen.

scholarly journals A Single-Pass Type I Membrane Protein from the Apicomplexan Parasite Cryptosporidium parvum with Nanomolar Binding Affinity to Host Cell Surface

2021 ◽  
Vol 9 (5) ◽  
pp. 1015
Author(s):  
Tianyu Zhang ◽  
Xin Gao ◽  
Dongqiang Wang ◽  
Jixue Zhao ◽  
Nan Zhang ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Cell Surface ◽  
Host Cell ◽  
Binding Affinity ◽  
Cryptosporidium Parvum ◽  
Host Cells ◽  
Watery Diarrhea ◽  
Type I ◽  
Single Pass ◽  
Host Cell Surface

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.

scholarly journals Suppression of influenza A virus replication in human lung epithelial cells by noncytotoxic concentrations bafilomycin A1

2015 ◽  
Vol 308 (3) ◽  
pp. L270-L286 ◽  
Author(s):  
Behzad Yeganeh ◽  
Saeid Ghavami ◽  
Andrea L. Kroeker ◽  
Thomas H. Mahood ◽  
Gerald L. Stelmack ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Host Cell ◽  
Influenza A Virus ◽  
Influenza A ◽  
Life Cycles ◽  
Host Cells ◽  
Nuclear Accumulation ◽  
Low Concentration ◽  
High Concentrations ◽  
The Impact

Subcellular trafficking within host cells plays a critical role in viral life cycles, including influenza A virus (IAV). Thus targeting relevant subcellular compartments holds promise for effective intervention to control the impact of influenza infection. Bafilomycin A1(Baf-A1), when used at relative high concentrations (≥10 nM), inhibits vacuolar ATPase (V-ATPase) and reduces endosome acidification and lysosome number, thus inhibiting IAV replication but promoting host cell cytotoxicity. We tested the hypothesis that much lower doses of Baf-A1also have anti-IAV activity, but without toxic effects. Thus we assessed the antiviral activity of Baf-A1at different concentrations (0.1–100 nM) in human alveolar epithelial cells (A549) infected with IAV strain A/PR/8/34 virus (H1N1). Infected and mock-infected cells pre- and cotreated with Baf-A1were harvested 0–24 h postinfection and analyzed by immunoblotting, immunofluorescence, and confocal and electron microscopy. We found that Baf-A1had disparate concentration-dependent effects on subcellular organelles and suppressed affected IAV replication. At concentrations ≥10 nM Baf-A1inhibited acid lysosome formation, which resulted in greatly reduced IAV replication and release. Notably, at a very low concentration of 0.1 nM that is insufficient to reduce lysosome number, Baf-A1retained the capacity to significantly impair IAV nuclear accumulation as well as IAV replication and release. In contrast to the effects of high concentrations of Baf-A1, very low concentrations did not exhibit cytotoxic effects or induce apoptotic cell death, based on morphological and FACS analyses. In conclusion, our results reveal that low-concentration Baf-A1is an effective inhibitor of IAV replication, without impacting host cell viability.

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 ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Cell Surface ◽  
Heparan Sulfate ◽  
Host Cell ◽  
Host Cells ◽  
Cell Surface Receptor ◽  
Spike Protein ◽  
Effective Prevention ◽  
Heparin Derivatives ◽  
Host Cell Surface

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.

scholarly journals Mechanism of CD150 (SLAM) Down Regulation from the Host Cell Surface by Measles Virus Hemagglutinin Protein

2004 ◽  
Vol 78 (18) ◽  
pp. 9666-9674 ◽  
Author(s):  
G. Grant Welstead ◽  
Eric C. Hsu ◽  
Caterina Iorio ◽  
Shelly Bolotin ◽  
Christopher D. Richardson
Keyword(s):  
Cell Surface ◽  
Host Cell ◽  
Measles Virus ◽  
Host Cells ◽  
Down Regulation ◽  
Cellular Receptors ◽  
Regulatory Molecule ◽  
Hemagglutinin Protein ◽  
Host Cell Surface ◽  
H Protein

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.

scholarly journals EnP1, a Microsporidian Spore Wall Protein That Enables Spores To Adhere to and Infect Host Cells In Vitro

2007 ◽  
Vol 6 (8) ◽  
pp. 1354-1362 ◽  
Author(s):  
Timothy R. Southern ◽  
Carrie E. Jolly ◽  
Melissa E. Lester ◽  
J. Russell Hayman
Keyword(s):  
Cell Surface ◽  
Host Cell ◽  
Spore Wall ◽  
Site Directed Mutagenesis ◽  
Host Cells ◽  
Binding Motif ◽  
Heparin Binding ◽  
Cell Infection ◽  
Host Cell Surface

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.

scholarly journals Identification of a Neospora caninum Microneme Protein (NcMIC1) Which Interacts with Sulfated Host Cell Surface Glycosaminoglycans

2002 ◽  
Vol 70 (6) ◽  
pp. 3187-3198 ◽  
Author(s):  
Nadine Keller ◽  
Arunasalam Naguleswaran ◽  
Angela Cannas ◽  
Nathalie Vonlaufen ◽  
Marianne Bienz ◽  
...  
Keyword(s):  
Cell Surface ◽  
Host Cell ◽  
Solid Phase ◽  
Neospora Caninum ◽  
Host Cells ◽  
Sequence Motif ◽  
Host Cell Surface ◽  
Adhesive Proteins ◽  
Microneme Protein ◽  
Microneme Proteins

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.

scholarly journals Late Endosomal/Lysosomal Cholesterol Accumulation Is a Host Cell-Protective Mechanism Inhibiting Endosomal Escape of Influenza A Virus

mBio ◽  
2018 ◽  
Vol 9 (4) ◽  
Author(s):  
Alexander Kühnl ◽  
Agnes Musiol ◽  
Nicole Heitzig ◽  
Danielle E. Johnson ◽  
Christina Ehrhardt ◽  
...  
Keyword(s):  
Host Cell ◽  
Influenza A Virus ◽  
Influenza A ◽  
Membrane Lipids ◽  
Endosomal Escape ◽  
Host Cells ◽  
Protective Mechanism ◽  
Cholesterol Accumulation ◽  
Protective Function ◽  
Cell Defense

ABSTRACTTo transfer the viral genome into the host cell cytoplasm, internalized influenza A virus (IAV) particles depend on the fusion of the IAV envelope with host endosomal membranes. The antiviral host interferon (IFN) response includes the upregulation of interferon-induced transmembrane protein 3 (IFITM3), which inhibits the release of the viral content into the cytosol. Although IFITM3 induction occurs concomitantly with late endosomal/lysosomal (LE/L) cholesterol accumulation, the functional significance of this process is not well understood. Here we report that LE/L cholesterol accumulation itself plays a pivotal role in the early antiviral defense. We demonstrate that inducing LE/L cholesterol accumulation is antiviral in non-IFN-primed cells, restricting incoming IAV particles and impairing mixing of IAV/endosomal membrane lipids. Our results establish a protective function of LE/L cholesterol accumulation and suggest endosomal cholesterol balance as a possible antiviral target.IMPORTANCEWith annual epidemics occurring in all parts of the world and the risk of global outbreaks, influenza A virus (IAV) infections remain a major threat to public health. Infected host cells detect viral components and mount an interferon (IFN)-mediated response to restrict virus propagation and spread of infection. Identification of cellular factors and underlying mechanisms that establish such an antiviral state can provide novel strategies for the development of antiviral drugs. The contribution of LE/L cholesterol levels, especially in the context of the IFN-induced antiviral response, has remained controversial so far. Here, we report that accumulation of cholesterol in the LE/L compartment contributes to the IFN-induced host cell defense against incoming IAV. Our results establish cholesterol accumulation in LE/Lper seas a novel antiviral barrier and suggest the endosomal cholesterol balance as a putative druggable host cell factor in IAV infection.

scholarly journals The C-type Lectin Langerin Functions as a Receptor for Attachment and Infectious Entry of Influenza A Virus

2015 ◽  
Vol 90 (1) ◽  
pp. 206-221 ◽  
Author(s):  
Wy Ching Ng ◽  
Sarah L. Londrigan ◽  
Najla Nasr ◽  
Anthony L. Cunningham ◽  
Stuart Turville ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Cell Surface ◽  
Influenza A Virus ◽  
Cho Cells ◽  
Influenza A ◽  
Chinese Hamster ◽  
Host Cells ◽  
Cell Surface Receptor ◽  
Infectious Entry ◽  
Attachment Factor

ABSTRACTIt is well established that influenza A virus (IAV) attachment to and infection of epithelial cells is dependent on sialic acid (SIA) at the cell surface, although the specific receptors that mediate IAV entry have not been defined and multiple receptors may exist. Lec2 Chinese hamster ovary (CHO) cells are SIA deficient and resistant to IAV infection. Here we demonstrate that the expression of the C-type lectin receptor langerin in Lec2 cells (Lec2-Lg) rendered them permissive to IAV infection, as measured by replication of the viral genome, transcription of viral mRNA, and synthesis of viral proteins. Unlike SIA-dependent infection of parental CHO cells, IAV attachment and infection of Lec2-Lg cells was mediated via lectin-mediated recognition of mannose-rich glycans expressed by the viral hemagglutinin glycoprotein. Lec2 cells expressing endocytosis-defective langerin bound IAV efficiently but remained resistant to IAV infection, confirming that internalization via langerin was essential for infectious entry. Langerin-mediated infection of Lec2-Lg cells was pH and dynamin dependent, occurred via clathrin- and caveolin-mediated endocytic pathways, and utilized early (Rab5+) but not late (Rab7+) endosomes. This study is the first to demonstrate that langerin represents an authentic receptor that binds and internalizes IAV to facilitate infection. Moreover, it describes a unique experimental system to probe specific pathways and compartments involved in infectious entry following recognition of IAV by a single cell surface receptor.IMPORTANCEOn the surface of host cells, sialic acid (SIA) functions as the major attachment factor for influenza A viruses (IAV). However, few studies have identified specific transmembrane receptors that bind and internalize IAV to facilitate infection. Here we identify human langerin as a transmembrane glycoprotein that can act as an attachment factor and abone fideendocytic receptor for IAV infection. Expression of langerin by an SIA-deficient cell line resistant to IAV rendered cells permissive to infection. As langerin represented the sole receptor for IAV infection in this system, we have defined the pathways and compartments involved in infectious entry of IAV into cells following recognition by langerin.

scholarly journals Mathematical Modelling of Actin treadmill in Apicomplexans

2018 ◽  
Author(s):  
Mahendra Prajapat ◽  
Samridhi Pathak ◽  
Ricka Gauba ◽  
Avinash Kale ◽  
Supreet Saini
Keyword(s):  
Cell Surface ◽  
Host Cell ◽  
Host Cells ◽  
Tight Control ◽  
Nucleation Time ◽  
Host Cell Membrane ◽  
Host Cell Surface ◽  
Average Size ◽  
Fine Tune ◽  
Representative Member

AbstractPlasmodium parasite, a representative member of phylum Apicomplexa is a causative agent of malaria in human as well as other animals. To infect host cells, Plasmodium first finds receptors on the host cell surface, then binds specifically, and finally penetrates host cell membrane to acquire the host cellular resources. The motility for moving on the cell surface is equipped by the precise and tight control of actin treadmill. Several regulators are required to achieve precision and robustness in the control of actin treadmill. However, the mechanistic detail of the treadmill regulatory network and the cross-talk among regulators are not well understood. We developed a stochastic model of treadmill regulation and explored the dynamics of filament growth, nucleation time, and elongation time. Our study mainly highlighted on how and what helps cells to maintain an average size of the actin filaments within a species. This is particularly important, since, excessive growth of filament can lead to cell lysis. Moreover, we also explore how the regulators interact to fine-tune the control elements in the actin treadmill.

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