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  1. Article ; Online: Binding of Glycans to the SARS CoV-2 Spike Protein, an Open Question: NMR Data on Binding Site Localization, Affinity, and Selectivity.

    Maass, Thorben / Ssebyatika, George / Brückner, Marlene / Breckwoldt, Lea / Krey, Thomas / Mallagaray, Alvaro / Peters, Thomas / Frank, Martin / Creutznacher, Robert

    Chemistry (Weinheim an der Bergstrasse, Germany)

    2022  Volume 28, Issue 71, Page(s) e202202614

    Abstract: We have used NMR experiments to explore the binding of selected glycans and glycomimetics to the SARS CoV-2 spike glycoprotein (S-protein) and to its receptor binding domain (RBD). STD NMR experiments confirm the binding of sialoglycans to the S-protein ... ...

    Abstract We have used NMR experiments to explore the binding of selected glycans and glycomimetics to the SARS CoV-2 spike glycoprotein (S-protein) and to its receptor binding domain (RBD). STD NMR experiments confirm the binding of sialoglycans to the S-protein of the prototypic Wuhan strain virus and yield dissociation constants in the millimolar range. The absence of STD effects for sialoglycans in the presence of the Omicron/BA.1 S-protein reflects a loss of binding as a result of S-protein evolution. Likewise, no STD effects are observed for the deletion mutant Δ143-145 of the Wuhan S-protein, thus supporting localization of the binding site in the N-terminal domain (NTD). The glycomimetics Oseltamivir and Zanamivir bind weakly to the S-protein of both virus strains. Binding of blood group antigens to the Wuhan S-protein cannot be confirmed by STD NMR. Using
    MeSH term(s) Humans ; Severe Acute Respiratory Syndrome ; Spike Glycoprotein, Coronavirus ; COVID-19 ; Binding Sites ; Polysaccharides ; Magnetic Resonance Spectroscopy ; Protein Binding
    Chemical Substances spike protein, SARS-CoV-2 ; Spike Glycoprotein, Coronavirus ; Polysaccharides
    Language English
    Publishing date 2022-10-26
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 1478547-X
    ISSN 1521-3765 ; 0947-6539
    ISSN (online) 1521-3765
    ISSN 0947-6539
    DOI 10.1002/chem.202202614
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article: NMR Experiments Provide Insights into Ligand-Binding to the SARS-CoV-2 Spike Protein Receptor-Binding Domain

    Creutznacher, Robert / Maass, Thorben / Veselkova, Barbora / Ssebyatika, George / Krey, Thomas / Empting, Martin / Tautz, Norbert / Frank, Martin / Kölbel, Knut / Uetrecht, Charlotte / Peters, Thomas

    Journal of the American Chemical Society. 2022 July 13, v. 144, no. 29

    2022  

    Abstract: We have used chemical shift perturbation (CSP) and saturation transfer difference (STD) NMR experiments to identify and characterize the binding of selected ligands to the receptor-binding domain (RBD) of the spike glycoprotein (S-protein) of the severe ... ...

    Abstract We have used chemical shift perturbation (CSP) and saturation transfer difference (STD) NMR experiments to identify and characterize the binding of selected ligands to the receptor-binding domain (RBD) of the spike glycoprotein (S-protein) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We also subjected full-length S-protein to STD NMR experiments, allowing correlations with RBD-based results. CSPs reveal the binding sites for heparin and fondaparinux, and affinities were measured using CSP titrations. We then show that α-2,3-sialyllactose binds to the S-protein but not to the RBD. Finally, combined CSP and STD NMR experiments show that lifitegrast, a compound used for the treatment of dry eye, binds to the linoleic acid (LA) binding pocket with a dissociation constant in the μM range. This is an interesting finding, as lifitegrast lends itself well as a blueprint for medicinal chemistry, eventually furnishing novel entry inhibitors targeting the highly conserved LA binding site.
    Keywords Severe acute respiratory syndrome coronavirus 2 ; dissociation ; eyes ; glycoproteins ; heparin ; ligands ; linoleic acid
    Language English
    Dates of publication 2022-0713
    Size p. 13060-13065.
    Publishing place American Chemical Society
    Document type Article
    ZDB-ID 3155-0
    ISSN 1520-5126 ; 0002-7863
    ISSN (online) 1520-5126
    ISSN 0002-7863
    DOI 10.1021/jacs.2c05603
    Database NAL-Catalogue (AGRICOLA)

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  3. Article ; Online: Targeting cellular cathepsins inhibits hepatitis E virus entry.

    Klöhn, Mara / Burkard, Thomas / Janzen, Juliana / Haase, Jil Alexandra / Gömer, André / Fu, Rebecca / Ssebyatika, George / Nocke, Maximilian K / Brown, Richard J P / Krey, Thomas / Dao Thi, Viet Loan / Kinast, Volker / Brüggemann, Yannick / Todt, Daniel / Steinmann, Eike

    Hepatology (Baltimore, Md.)

    2024  

    Abstract: Background and aims: The hepatitis E virus (HEV) is estimated to be responsible for 70,000 deaths annually, yet therapy options remain limited. In the pursuit of effective antiviral therapies, targeting viral entry holds promise and has proven effective ...

    Abstract Background and aims: The hepatitis E virus (HEV) is estimated to be responsible for 70,000 deaths annually, yet therapy options remain limited. In the pursuit of effective antiviral therapies, targeting viral entry holds promise and has proven effective for other viruses. However, the precise mechanisms and host factors required during HEV entry remain unclear. Cellular proteases have emerged as host factors required for viral surface protein activation and productive cell entry by many viruses. Hence, we investigated the functional requirement and therapeutic potentials of cellular proteases during HEV infection.
    Approach and results: Using our established HEV cell culture model and subgenomic HEV replicons, we found that blocking lysosomal cathepsins (CTS) with small molecule inhibitors, impedes HEV infection without affecting replication. Most importantly, the pan-cathepsin inhibitor K11777 suppressed HEV infections with an EC50 of ~ 0.01 nM. Inhibition by K11777, devoid of notable toxicity in hepatoma cells, was also observed in HepaRG and primary human hepatocytes. Furthermore, through time-of-addition and RNAscope experiments, we confirmed that HEV entry is blocked by inhibition of cathepsins. Cathepsin L (CTSL) knockout cells were less permissive to HEV, suggesting that CTSL is critical for HEV infection. Finally, we observed cleavage of the glycosylated ORF2 protein and virus particles by recombinant CTSL.
    Conclusions: In summary, our study highlights the pivotal role of lysosomal cathepsins, especially CTSL, in the HEV entry process. The profound anti-HEV efficacy of the pan-cathepsin inhibitor, K11777, especially with its notable safety profile in primary cells, further underscores its potential as a therapeutic candidate.
    Language English
    Publishing date 2024-05-10
    Publishing country United States
    Document type Journal Article
    ZDB-ID 604603-4
    ISSN 1527-3350 ; 0270-9139
    ISSN (online) 1527-3350
    ISSN 0270-9139
    DOI 10.1097/HEP.0000000000000912
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Conference proceedings: [No title information]

    Fehlau, Lukas / Klause, Tanja / Dinkelborg, Katja / Ssebyatika, George / Hüffner, Lucas / Wedemeyer, Heiner / Maasoumy, Benjamin / Pietschmann, Thomas / Krey, Thomas / Behrendt, Patrick

    Zeitschrift für Gastroenterologie

    2023  Volume 61, Issue 01

    Event/congress 39. Jahrestagung der Deutschen Arbeitsgemeinschaft zum Studium der Leber, Bochum, 2023-01-27
    Language German
    Publishing date 2023-01-01
    Publisher Georg Thieme Verlag
    Publishing place Stuttgart ; New York
    Document type Article ; Conference proceedings
    ZDB-ID 201387-3
    ISSN 1439-7803 ; 0044-2771 ; 0172-8504
    ISSN (online) 1439-7803
    ISSN 0044-2771 ; 0172-8504
    DOI 10.1055/s-0042-1760049
    Database Thieme publisher's database

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  5. Article: Viral modulation of type II interferon increases T cell adhesion and virus spread.

    Jürgens, Carina / Ssebyatika, George / Beyer, Sarah / Plückebaum, Nina / Kropp, Kai A / González-Motos, Víctor / Ritter, Birgit / Böning, Heike / Nikolouli, Eirini / Kinchington, Paul R / Lachmann, Nico / Depledge, Daniel Pearce / Krey, Thomas / Viejo-Borbolla, Abel

    bioRxiv : the preprint server for biology

    2023  

    Abstract: During primary infection, varicella zoster virus (VZV) infects epithelial cells in the respiratory lymphoid organs and mucosa. Subsequent infection of lymphocytes, T cells in particular, causes primary viremia allowing systemic spread throughout the host, ...

    Abstract During primary infection, varicella zoster virus (VZV) infects epithelial cells in the respiratory lymphoid organs and mucosa. Subsequent infection of lymphocytes, T cells in particular, causes primary viremia allowing systemic spread throughout the host, including the skin. This results in the expression of cytokines, including interferons (IFNs) which partly limit primary infection. VZV also spreads from skin keratinocytes to lymphocytes prior to secondary viremia. How VZV infects lymphocytes from epithelial cells while evading the cytokine response has not been fully established. Here, we show that VZV glycoprotein C (gC) binds IFN-γ and modifies its activity. Transcriptomic analysis revealed that gC in combination with IFN-γ increased the expression of a small subset of IFN-stimulated genes (ISGs), including intercellular adhesion molecule 1 (
    Language English
    Publishing date 2023-05-26
    Publishing country United States
    Document type Preprint
    DOI 10.1101/2023.05.26.542397
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: NMR Experiments Provide Insights into Ligand-Binding to the SARS-CoV-2 Spike Protein Receptor-Binding Domain.

    Creutznacher, Robert / Maass, Thorben / Veselkova, Barbora / Ssebyatika, George / Krey, Thomas / Empting, Martin / Tautz, Norbert / Frank, Martin / Kölbel, Knut / Uetrecht, Charlotte / Peters, Thomas

    Journal of the American Chemical Society

    2022  Volume 144, Issue 29, Page(s) 13060–13065

    Abstract: We have used chemical shift perturbation (CSP) and saturation transfer difference (STD) NMR experiments to identify and characterize the binding of selected ligands to the receptor-binding domain (RBD) of the spike glycoprotein (S-protein) of the severe ... ...

    Abstract We have used chemical shift perturbation (CSP) and saturation transfer difference (STD) NMR experiments to identify and characterize the binding of selected ligands to the receptor-binding domain (RBD) of the spike glycoprotein (S-protein) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We also subjected full-length S-protein to STD NMR experiments, allowing correlations with RBD-based results. CSPs reveal the binding sites for heparin and fondaparinux, and affinities were measured using CSP titrations. We then show that α-2,3-sialyllactose binds to the S-protein but not to the RBD. Finally, combined CSP and STD NMR experiments show that lifitegrast, a compound used for the treatment of dry eye, binds to the linoleic acid (LA) binding pocket with a dissociation constant in the μM range. This is an interesting finding, as lifitegrast lends itself well as a blueprint for medicinal chemistry, eventually furnishing novel entry inhibitors targeting the highly conserved LA binding site.
    MeSH term(s) Angiotensin-Converting Enzyme 2 ; Binding Sites ; COVID-19/drug therapy ; Humans ; Ligands ; Magnetic Resonance Spectroscopy ; Peptidyl-Dipeptidase A/chemistry ; Peptidyl-Dipeptidase A/metabolism ; Protein Binding ; SARS-CoV-2 ; Spike Glycoprotein, Coronavirus/chemistry
    Chemical Substances Ligands ; Spike Glycoprotein, Coronavirus ; spike protein, SARS-CoV-2 ; Peptidyl-Dipeptidase A (EC 3.4.15.1) ; Angiotensin-Converting Enzyme 2 (EC 3.4.17.23)
    Language English
    Publishing date 2022-07-13
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 3155-0
    ISSN 1520-5126 ; 0002-7863
    ISSN (online) 1520-5126
    ISSN 0002-7863
    DOI 10.1021/jacs.2c05603
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Book ; Article ; Online: Viral modulation of type II interferon increases T cell adhesion and virus spread

    Jürgens, Carina / Ssebyatika, George / Beyer, Sarah / Plückebaum, Nina / Kropp, Kai A. / González-Motos, Víctor / Ritter, Birgit / Böning, Heike / Nikolouli, Eirini / Kinchington, Paul R. / Lachmann, Nico / Depledge, Daniel Pearce / Krey, Thomas / Viejo-Borbolla, Abel

    2023  

    Abstract: During primary infection, varicella zoster virus (VZV) infects epithelial cells in the respiratory lymphoid organs and mucosa. Subsequent infection of lymphocytes, T cells in particular, causes primary viremia allowing systemic spread throughout the host, ...

    Abstract During primary infection, varicella zoster virus (VZV) infects epithelial cells in the respiratory lymphoid organs and mucosa. Subsequent infection of lymphocytes, T cells in particular, causes primary viremia allowing systemic spread throughout the host, including the skin. This results in the expression of cytokines, including interferons (IFNs) which partly limit primary infection. VZV also spreads from skin keratinocytes to lymphocytes prior to secondary viremia. How VZV infects lymphocytes from epithelial cells while evading the cytokine response has not been fully established. Here, we show that VZV glycoprotein C (gC) binds IFN-γ and modifies its activity. Transcriptomic analysis revealed that gC in combination with IFN-γ increased the expression of a small subset of IFN-stimulated genes (ISGs), including intercellular adhesion molecule 1 (ICAM1), as well as several chemokines and immunomodulatory genes. The higher ICAM1 protein level at the plasma membrane of epithelial cells resulted in lymphocyte function-associated antigen 1 (LFA-1)-dependent T cell adhesion. This gC activity required a stable interaction with IFN-γ and signalling through the IFN-γ receptor. Finally, the presence of gC during infection increased VZV spread from epithelial cells to peripheral blood mononuclear cells. This constitutes the discovery of a novel strategy to modulate the activity of IFN-γ, inducing the expression of a subset of ISGs, leading to enhanced T cell adhesion and virus spread.
    Subject code 570
    Language English
    Publishing country de
    Document type Book ; Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  8. Article ; Conference proceedings: [No title information]

    Laue, Fenja / Nörenberg, Pia / Kohn, Martin / Dinkelborg, Katja / Ssebyatika, George / Hüffner, Lucas / Zeiß, Frithjof / Wedemeyer, Heiner / Pietschmann, Thomas / Krey, Thomas / Behrendt, Patrick

    Zeitschrift für Gastroenterologie

    2023  Volume 61, Issue 01

    Event/congress 39. Jahrestagung der Deutschen Arbeitsgemeinschaft zum Studium der Leber, Bochum, 2023-01-27
    Language German
    Publishing date 2023-01-01
    Publisher Georg Thieme Verlag
    Publishing place Stuttgart ; New York
    Document type Article ; Conference proceedings
    ZDB-ID 201387-3
    ISSN 1439-7803 ; 0044-2771 ; 0172-8504
    ISSN (online) 1439-7803
    ISSN 0044-2771 ; 0172-8504
    DOI 10.1055/s-0042-1760045
    Database Thieme publisher's database

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  9. Article ; Online: Recruitment of phospholipase Cγ1 to the non-structural membrane protein pK15 of Kaposi Sarcoma-associated herpesvirus promotes its Src-dependent phosphorylation.

    Samarina, Naira / Ssebyatika, George / Tikla, Tanvi / Waldmann, Ja-Yun / Abere, Bizunesh / Nanna, Vittoria / Marasco, Michelangelo / Carlomagno, Teresa / Krey, Thomas / Schulz, Thomas F

    PLoS pathogens

    2021  Volume 17, Issue 6, Page(s) e1009635

    Abstract: Kaposi Sarcoma-associated herpesvirus (KSHV) causes three human malignancies, Kaposi Sarcoma (KS), Primary Effusion Lymphoma (PEL) and the plasma cell variant of multicentric Castleman's Disease (MCD), as well as an inflammatory cytokine syndrome (KICS). ...

    Abstract Kaposi Sarcoma-associated herpesvirus (KSHV) causes three human malignancies, Kaposi Sarcoma (KS), Primary Effusion Lymphoma (PEL) and the plasma cell variant of multicentric Castleman's Disease (MCD), as well as an inflammatory cytokine syndrome (KICS). Its non-structural membrane protein, pK15, is among a limited set of viral proteins expressed in KSHV-infected KS tumor cells. Following its phosphorylation by Src family tyrosine kinases, pK15 recruits phospholipase C gamma 1 (PLCγ1) to activate downstream signaling cascades such as the MEK/ERK, NFkB and PI3K pathway, and thereby contributes to the increased proliferation and migration as well as the spindle cell morphology of KSHV-infected endothelial cells. Here, we show that a phosphorylated Y481EEVL motif in pK15 preferentially binds into the PLCγ1 C-terminal SH2 domain (cSH2), which is involved in conformational changes occurring during the activation of PLCγ1 by receptor tyrosine kinases. We determined the crystal structure of a pK15 12mer peptide containing the phosphorylated pK15 Y481EEVL motif in complex with a shortened PLCγ1 tandem SH2 (tSH2) domain. This structure demonstrates that the pK15 peptide binds to the PLCγ1 cSH2 domain in a position that is normally occupied by the linker region connecting the PLCγ1 cSH2 and SH3 domains. We also show that longer pK15 peptides containing the phosphorylated pK15 Y481EEVL motif can increase the Src-mediated phosphorylation of the PLCγ1 tSH2 region in vitro. This pK15-induced increase in Src-mediated phosphorylation of PLCγ1 can be inhibited with the small pK15-derived peptide which occupies the PLCγ1 cSH2 domain. Our findings thus suggest that pK15 may act as a scaffold protein to promote PLCγ1 activation in a manner similar to the cellular scaffold protein SLP-76, which has been shown to promote PLCγ1 activation in the context of T-cell receptor signaling. Reminiscent of its positional homologue in Epstein-Barr Virus, LMP2A, pK15 may therefore mimic aspects of antigen-receptor signaling. Our findings also suggest that it may be possible to inhibit the recruitment and activation of PLCγ1 pharmacologically.
    MeSH term(s) HEK293 Cells ; Herpesviridae Infections/metabolism ; Herpesvirus 8, Human/physiology ; Humans ; Phospholipase C gamma/metabolism ; Phosphorylation ; Viral Nonstructural Proteins/metabolism ; Virus Activation/physiology ; Virus Latency/physiology ; Virus Replication/physiology ; src-Family Kinases/metabolism
    Chemical Substances Viral Nonstructural Proteins ; src-Family Kinases (EC 2.7.10.2) ; PLCG1 protein, human (EC 3.1.4.11) ; Phospholipase C gamma (EC 3.1.4.3)
    Language English
    Publishing date 2021-06-18
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2205412-1
    ISSN 1553-7374 ; 1553-7366
    ISSN (online) 1553-7374
    ISSN 1553-7366
    DOI 10.1371/journal.ppat.1009635
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: A CMV-induced adaptive human Vδ1+ γδ T cell clone recognizes HLA-DR.

    Deseke, Malte / Rampoldi, Francesca / Sandrock, Inga / Borst, Eva / Böning, Heike / Ssebyatika, George Liam / Jürgens, Carina / Plückebaum, Nina / Beck, Maleen / Hassan, Ahmed / Tan, Likai / Demera, Abdi / Janssen, Anika / Steinberger, Peter / Koenecke, Christian / Viejo-Borbolla, Abel / Messerle, Martin / Krey, Thomas / Prinz, Immo

    The Journal of experimental medicine

    2022  Volume 219, Issue 9

    Abstract: The innate and adaptive roles of γδ T cells and their clonal γδ T cell receptors (TCRs) in immune responses are still unclear. Recent studies of γδ TCR repertoire dynamics showed massive expansion of individual Vδ1+ γδ T cell clones during viral ... ...

    Abstract The innate and adaptive roles of γδ T cells and their clonal γδ T cell receptors (TCRs) in immune responses are still unclear. Recent studies of γδ TCR repertoire dynamics showed massive expansion of individual Vδ1+ γδ T cell clones during viral infection. To judge whether such expansion is random or actually represents TCR-dependent adaptive immune responses, information about their cognate TCR ligands is required. Here, we used CRISPR/Cas9-mediated screening to identify HLA-DRA, RFXAP, RFX5, and CIITA as required for target cell recognition of a CMV-induced Vγ3Vδ1+ TCR, and further characterization revealed a direct interaction of this Vδ1+ TCR with the MHC II complex HLA-DR. Since MHC II is strongly upregulated by interferon-γ, these results suggest an inflammation-induced MHC-dependent immune response of γδ T cells.
    MeSH term(s) Clone Cells ; Cytomegalovirus Infections ; HLA-DR Antigens ; Humans ; Intraepithelial Lymphocytes ; Receptors, Antigen, T-Cell, gamma-delta ; T-Lymphocyte Subsets
    Chemical Substances HLA-DR Antigens ; Receptors, Antigen, T-Cell, gamma-delta
    Language English
    Publishing date 2022-07-19
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 218343-2
    ISSN 1540-9538 ; 0022-1007
    ISSN (online) 1540-9538
    ISSN 0022-1007
    DOI 10.1084/jem.20212525
    Database MEDical Literature Analysis and Retrieval System OnLINE

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