Identification of potential inhibitors of protein-protein interaction useful to fight against Ebola and other highly pathogenic viruses

16 p.-1 fig.-1 tab.Despite the efforts to develop new treatments against Ebola virus (EBOV) there is currently no antiviral drug licensed to treat patients with Ebola virus disease (EVD). Therefore, there is still an urgent need to find new drugs to fight against EBOV. In order to do this, a virtual screening was done on the druggable interaction between the EBOV glycoprotein (GP) and the host receptor NPC1 with a subsequent selection of compounds for further validation. This screening led to the identification of new small organic molecules with potent inhibitory action against EBOV infection using lentiviral EBOV-GP-pseudotype viruses. Moreover, some of these compounds have shown their ability to interfere with the intracellular cholesterol transport receptor NPC1 using an ELISA-based assay. These preliminary results pave the way to hit to lead optimization programs that lead to successful candidates.Funding from “la Caixa” Banking Foundation under the project code HR18-00469 is acknowledged. This research was partially supported through Instituto de Salud Carlos III (FIS PI 181007 and ISCIII-COV20/01007), CSIC (201980E024 and 202020E079), Spanish Ministry of Science and Innovation (RTI2018-097305-R-I00) and the European Commission Horizon 2020 Framework Programme (Project VIRUSCAN FETPROACT-2016 and VACDIVA-SFS-12-2019-1-862874).Peer reviewe

TLR7 activation in M-CSF-dependent monocyte-derived human macrophages potentiates inflammatory responses and prompts neutrophil recruitment

1 p.-4 fig.Toll-like receptor 7 (TLR7) is an endosomal Pathogen-Associated Molecular Pattern (PAMP) receptor that senses single-stranded RNA (ssRNA) and whose engagement results in the production of type I IFN and pro-inflammatory cytokines upon viral exposure. Recent genetic studies have established that a dysfunctional TLR7-initiated signaling is directly linked to the development of SARS-CoV-2-induced severe COVID-19. We previously showed that TLR7 is preferentially expressed by macrophages generated in the presence of M-CSF (M-MØ), whose MAFB-dependent transcriptome resembles pathogenic pulmonary monocyte-derived macrophage subsets in severe COVID-19. We now report that TLR7 activation in M-MØ triggers a weak MAPK, NFkB and STAT1 activation and leads to defective production of type I IFN. Nonetheless, TLR7 engagement re-programs MAFB+ M-MØ towards a distinctive transcriptional profile. Specifically, TLR7-activated M-MØ acquired the expression of genes that characterize inflammatory macrophage subsets in COVID-19 and other inflammatory diseases, including genes encoding neutrophil-attracting chemokines (CXCL1-3, CXCL5, CXCL8) reported as biomarkers for severe COVID-19. Functionally, TLR7-activated M-MØ displayed enhanced proinflammatory responses towards secondary stimulation and a robust production of neutrophil-attracting chemokines (CXCL1, CXCL5, CXCL8), which was dependent on the transcription factors MAFB and AhR. Interestingly, CXCL1 and CXCL5 release from M-MØ was also promoted by SARS-CoV-2 but not by Virus-like particles. As defective TLR7 signaling and enhanced pulmonary neutrophil/lymphocyte ratio associate with severe COVID-19, these results suggest that targeting macrophage TLR7 might be a therapeutic strategy for viral infections where monocyte-derived macrophages exhibit a pathogenic role.This research work was also funded by the European Commission – NextGenerationEU (Regulation EU 2020/2094), through CSIC's Global Health Platform (PTI Salud Global)Peer reviewe

Cross neutralization of SARS‐CoV‐2 omicron subvariants after repeated doses of COVID‐19 mRNA vaccines

We have measured the humoral response to messenger RNA (mRNA) vaccines in COVID-19 naïve and convalescent individuals. Third doses of mRNA COVID-19 vaccines induced a significant increase in potency and breadth of neutralization against SARS-CoV-2 variants of concern (VoC) including Omicron subvariants BA.1, BA.2, and BA.2.12.1, that were cross-neutralized at comparable levels and less for BA.4/5. This booster effect was especially important in naïve individuals that only after the third dose achieved a level that was comparable with that of vaccinated COVID-19 convalescents except for BA.4/5. Avidity of RBD-binding antibodies was also significantly increased in naïve individuals after the third dose, indicating an association between affinity maturation and cross neutralization of VoC. These results suggest that at least three antigenic stimuli by infection or vaccination with ancestral SARS-CoV-2 sequences are required to induce high avidity cross-neutralizing antibodies. Nevertheless, the circulation of new subvariants such as BA.4/5 with partial resistance to neutralization will have to be closely monitored and eventually consider for future vaccine developments

The GSK3b-MAFB axis controls the pro-fibrotic gene profile of pathogenic monocyte-derived macrophages in severe COVID-19

1 p.-4 fig.MAF and MAFB are members of the “large MAF” transcription factor family that shape the transcriptome of antiinflammatory and pro-tumoral human macrophages. We have now determined the MAF- and MAFB-dependent gene profile of M-CSF-dependent monocyte-derived macrophages (M-MØ), and found that both factors exhibit overlapping transcriptional outcomes during monocyte-to-M-MØ differentiation, but differentially affect macrophage effector functions like production of monocyte-recruiting chemokines, T-cell activation and immunosuppression. Remarkably, MAFB was found to positively regulate the expression of the genesets that define the pathogenic monocyte-derived pulmonary macrophage subsets in COVID-19, as evidenced through siRNA-mediated silencing and analysis of MAFBoverexpressing M-MØ from a Multicentric Carpotarsal Osteolysis (MCTO) patient. MAFB silencing downregulated theexpression of genes coding for biomarkers of COVID-19 severity, and genome-wide mapping of MAFB-binding elements in M-MØ identified biomarkers of COVID-19 severity (CD163, IL10, HGF and CCL2) as direct MAFB targets. Further, and in line with the GSK3b-dependent expression of MAFB, GSK3b inhibition in M-MØ significantly boosted the expression of genes that characterize pathogenic macrophage subsets in severe COVID-19, an effect that was primarily dependent on MAFB. In addition, we have demonstrated that a large number of MAFB-dependent genes, as well as GSK3b-dependent expression of MAFB genes were modulated by SARS-Cov-2 infection on human macrophages. Globally, our results demonstrate that the GSK3b-MAFB axis controls the transcriptome of pathogenic pulmonary macrophages in COVID-19,and positively regulates the expression of biomarkers for COVID-19 severity. Thus, macrophage re-programming through modulation of GSK3 -MAFB axis has potential therapeutic strategy for COVID-19 and other inflammatory diseases.This research work was also funded by the European Commission– NextGenerationEU (Regulation EU 2020/2094), through CSIC's Global Health Platform (PTI Salud Global).Peer reviewe

Dendritic Cell‐Mediated Cross‐Priming by a Bispecific Neutralizing Antibody Boosts Cytotoxic T Cell Responses and Protects Mice against SARS‐CoV‐2

SARS-CoV-2 B.1.351 and B.1.167.2 viruses used in this study were obtained through the European Virus Archive Global (EVA-GLOBAL) project that has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 653316. SARS-CoV-2 B.1 (MAD6 isolate) was kindly provided by José M. Honrubia and Luis Enjuanes (CNB-CSIC, Madrid, Spain). The authors thank Centro de Investigación en Sanidad Animal (CISA)-Instituto Nacional de Investigaciones Agrarias (INIA-CSIC) (Valdeolmos, Madrid, Spain) for the BSL-3 facilities. Research in LAV laboratory was funded by the BBVA Foundation (Ayudas Fundación BBVA a Equipos de Investigación Científica SARS-CoV-2 y COVID19); the MCIN/AEI/10.13039/501100011033 (PID2020-117323RB-I00 and PDC2021-121711-I00), partially supported by the European Regional Development Fund (ERDF); the Carlos III Health Institute (ISCIII) (DTS20/00089), partially supported by the ERDF, the Spanish Association Against Cancer (AECC 19084); the CRIS Cancer Foundation (FCRISIFI-2018 and FCRIS-2021-0090), the Fundación Caixa-Health Research (HR21-00761 project IL7R_LungCan), and the Comunidad de Madrid (P2022/BMD-7225 NEXT_GEN_CART_MAD-CM). Work in the DS laboratory was funded by the CNIC; the European Union’s Horizon 2020 research and innovation program under grant agreement ERC-2016-Consolidator Grant 725091; MCIN/AEI/10.13039/501100011033 (PID2019-108157RB); Comunidad de Madrid (B2017/BMD-3733 Immunothercan-CM); Atresmedia (Constantes y Vitales prize); Fondo Solidario Juntos (Banco Santander); and “La Caixa” Foundation (LCF/PR/HR20/00075). The CNIC was supported by the ISCIII, the MCIN and the Pro CNIC Foundation and is a Severo Ochoa Center of Excellence (CEX2020- 001041-S funded by MCIN/AEI/10.13039/501100011033). Research in RD laboratory was supported by the ISCIII (PI2100989) and CIBERINFEC; the European Commission Horizon 2020 Framework Programme (grant numbers 731868 project VIRUSCAN FETPROACT-2016, and 101046084 project EPIC-CROWN-2); and the Fundación CaixaHealth Research (grant number HR18-00469 project StopEbola). Research in CNB-CSIC laboratory was funded by Fondo Supera COVID19 (Crue Universidades-Banco Santander) grant, CIBERINFEC, and Spanish Research Council (CSIC) grant 202120E079 (to J.G.-A.), CSIC grant 2020E84 (to M.E.), MCIN/AEI/10.13039/501100011033 (PID2020- 114481RB-I00 to J.G-A. and M.E.), and by the European CommissionNextGenerationEU, through CSIC’s Global Health Platform (PTI Salud Global) to J.G.-A. and M.E. Work in the CIB-CSIC laboratory was supported by MCIN/AEI/10.13039/501100011033 (PID2019-104544GB-I00 and 2023AEP105 to CA, and PID2020-113225GB-I00 to F.J.B.). Cryo-EM data were collected at the Maryland Center for Advanced Molecular Analyses which was supported by MPOWER (The University of Maryland Strategic Partnership). I.H.-M. receives the support of a fellowship from la Caixa Foundation (ID 100010434, fellowship code: LCF/BQ/IN17/11620074) and from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 71367. L.R.-P. was supported by a predoctoral fellowship from the Immunology Chair, Universidad Francisco de Vitoria/Merck.S

Dendritic Cell-Mediated Cross-Priming by a Bispecific Neutralizing Antibody Boosts Cytotoxic T Cell Responses and Protects Mice against SARS-CoV-2

17 p.-4 fig.Administration of neutralizing antibodies (nAbs) has proved to be effective by providing immediate protection against SARS-CoV-2. However, dual strategies combining virus neutralization and immune response stimulation to enhance specific cytotoxic T cell responses, such as dendritic cell (DC) cross-priming, represent a promising field but have not yet been explored. Here, a broadly nAb, TNT, are first generated by grafting an anti-RBD biparatopic tandem nanobody onto a trimerbody scaffold. Cryo-EM data show that the TNT structure allows simultaneous binding to all six RBD epitopes, demonstrating a high-avidity neutralizing interaction. Then, by C-terminal fusion of an anti-DNGR-1 scFv to TNT, the bispecific trimerbody TNTDNGR-1 is generated to target neutralized virions to type 1 conventional DCs (cDC1s) and promote T cell cross-priming. Therapeutic administration of TNTDNGR-1, but not TNT, protects K18-hACE2 mice from a lethal SARS-CoV-2 infection, boosting virus-specific humoral responses and CD8+ T cell responses. These results further strengthen the central role of interactions with immune cells in the virus-neutralizing antibody activity and demonstrate the therapeutic potential of the Fc-free strategy that can be used advantageously to provide both immediate and long-term protection against SARS-CoV-2 and other viral infections.SARS-CoV-2 B.1.351 and B.1.167.2 viruses used in this study were obtained through the European Virus Archive Global (EVA-GLOBAL) project that has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 653316. SARS-CoV-2 B.1 (MAD6 isolate) was kindly provided by José M. Honrubia and Luis Enjuanes (CNB-CSIC, Madrid, Spain). The authors thank Centro de Investigación en Sanidad Animal (CISA)-Instituto Nacional de Investigaciones Agrarias (INIA-CSIC) (Valdeolmos, Madrid, Spain) for the BSL-3 facilities. Research in LA-V laboratory was funded by the BBVA Foundation (Ayudas Fundación BBVA a Equipos de Investigación Científica SARS-CoV-2 y COVID-19); the MCIN/AEI/10.13039/501100011033 (PID2020-117323RB-I00 and PDC2021-121711-I00), partially supported by the European Regional Development Fund (ERDF); the Carlos III Health Institute (ISCIII) (DTS20/00089), partially supported by the ERDF, the Spanish Association Against Cancer (AECC 19084); the CRIS Cancer Foundation (FCRIS-IFI-2018 and FCRIS-2021-0090), the Fundación Caixa-Health Research (HR21-00761 project IL7R_LungCan), and the Comunidad de Madrid (P2022/BMD-7225 NEXT_GEN_CART_MAD-CM). Work in the DS laboratory was funded by the CNIC; the European Union's Horizon 2020 research and innovation program under grant agreement ERC-2016-Consolidator Grant 725091; MCIN/AEI/10.13039/501100011033 (PID2019-108157RB); Comunidad de Madrid (B2017/BMD-3733 Immunothercan-CM); Atresmedia (Constantes y Vitales prize); Fondo Solidario Juntos (Banco Santander); and “La Caixa” Foundation (LCF/PR/HR20/00075). The CNIC was supported by the ISCIII, the MCIN and the Pro CNIC Foundation and is a Severo Ochoa Center of Excellence (CEX2020-001041-S funded by MCIN/AEI/10.13039/501100011033). Research in RD laboratory was supported by the ISCIII (PI2100989) and CIBERINFEC; the European Commission Horizon 2020 Framework Programme (grant numbers 731868 project VIRUSCAN FETPROACT-2016, and 101046084 project EPIC-CROWN-2); and the Fundación Caixa-Health Research (grant number HR18-00469 project StopEbola). Research in CNB-CSIC laboratory was funded by Fondo Supera COVID-19 (Crue Universidades-Banco Santander) grant, CIBERINFEC, and Spanish Research Council (CSIC) grant 202120E079 (to J.G.-A.), CSIC grant 2020E84 (to M.E.), MCIN/AEI/10.13039/501100011033 (PID2020-114481RB-I00 to J.G-A. and M.E.), and by the European Commission-NextGenerationEU, through CSIC's Global Health Platform (PTI Salud Global) to J.G.-A. and M.E. Work in the CIB-CSIC laboratory was supported by MCIN/AEI/10.13039/501100011033 (PID2019-104544GB-I00 and 2023AEP105 to CA, and PID2020-113225GB-I00 to F.J.B.). Cryo-EM data were collected at the Maryland Center for Advanced Molecular Analyses which was supported by MPOWER (The University of Maryland Strategic Partnership). I.H.-M. receives the support of a fellowship from la Caixa Foundation (ID 100010434, fellowship code: LCF/BQ/IN17/11620074) and from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 71367. L.R.-P. was supported by a predoctoral fellowship from the Immunology Chair, Universidad Francisco de Vitoria/Merck.Peer reviewe

Interacción y relevancia biológica de la lectina DC-SIGN con la envuelta del virus emergente SARS-CoV-2

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Biológicas, leída el 06/03/2023.La lectina de tipo C DC-SIGN (Dendritic Cell-Specific Intercellular adhesion molecule-3-Grabbing Non-integrin), también llamada CD209 o molécula de adhesión intracelular 3 no asociada a integrina (ICAM-3) específica de células dendríticas (DC), es una proteína transmembrana dependiente de Ca+ que reconoce estructuras con un alto contenido en manosa como las glicosilaciones presentes en los receptores de superficie de la envuelta de multitud de virus, mediante un dominio lectina C-terminal de reconocimiento de carbohidratos (CDR). El reconocimiento de DC-SIGN de patrones específicos de carbohidratos presentes en las envueltas víricas resulta de gran importancia para el estudio de los mecanismos de infección y diseminación viral de los mismos. DC-SIGN se expresa concretamente en células dendríticas inmaduras de tejidos periféricos y podemos localizarla en diversos lugares como amigadlas, tejidos mucosos, ganglios linfáticos y bazo. Las células dendríticas (DCs) forman parte de un sistema de vigilancia especializado contra las infecciones formado por las llamadas células presentadoras de antígeno (APC), las cuales resultan cruciales en el reconocimiento de antígenos ya que su funcionalidad determina el tipo de célula T efectora que mediará la respuesta inmune. Las DCs son una de las primeras líneas de defensa ante la invasión patógena siendo fundamentales en la regulación de la respuesta inmune capturando, procesando y presentando antígenos a linfocitos T para generar respuestas inmune específicas, es por ello por lo que las DCs actúan como nexo entre la inmunidad innata y adaptativa...DC-SIGN type C lectin (Dendritic Cell-Specific Intercellular adhesion molecule-3-Grabbing Non-integrin), also known as CD209 or intracellular adhesion molecule 3 non associated to integrin (ICAM-3) specific to dendritic cells (DC), is a transmembrane protein dependent on Ca+ that recognizes structures with a high content of mannose, like glycosylations present in multitude of viral envelope surface receptors, through a C-terminal lectin carbohydrate domain recognition (CDR). Recognition of DC-SIGN carbohydrate specific patterns present in the viral envelopes is of great importance for the study of infection mechanisms and viral dissemination. DC-SIGN is revealed concretely in immature dendritic cells of peripheral tissues and we can locate it in various places like the tonsils, mucous tissues, lymph nodes, and the spleen. Dendritic cells (DCs) are part of a vigilance system specialized against infections, made up by the so-called antigen presenting cells (APC), which are crucial in the recognition of antigens due to its functionality defining the effector T cell type that will mediate the immune response. DCs are one of the main lines of defence against pathogen invasion, being essential in the regulation of the immune response by capturing, processing and presenting antigens to T lymphocytes to generate specific immune responses, it is because of this that DCs act as a nexus between innate and adaptative immunity...Fac. de Ciencias BiológicasTRUEunpu

DataSheet_1_The role of DC-SIGN as a trans-receptor in infection by MERS-CoV.pdf

DC-SIGN is a C-type lectin expressed in myeloid cells such as immature dendritic cells and macrophages. Through glycan recognition in viral envelope glycoproteins, DC-SIGN has been shown to act as a receptor for a number of viral agents such as HIV, Ebola virus, SARS-CoV, and SARS-CoV-2. Using a system of Vesicular Stomatitis Virus pseudotyped with MERS-CoV spike protein, here, we show that DC-SIGN is partially responsible for MERS-CoV infection of dendritic cells and that DC-SIGN efficiently mediates trans-infection of MERS-CoV from dendritic cells to susceptible cells, indicating a potential role of DC-SIGN in MERS-CoV dissemination and pathogenesis.</p

Precision Glycodendrimers for DC-SIGN Targeting

Multivalent ligands of the C-type lectin receptor DC-SIGN have emerged as effective antiadhesive agents against various pathogens. Some years ago, we described a hexavalent DC-SIGN ligand, Polyman-26, designed to bridge two of the four binding sites displayed by the receptor. Here we present our efforts to accomplish simultaneous coordination of all four carbohydrate binding sites of DC-SIGN through the synthesis of cross-shaped glycodendrimers. The tailored rigid scaffold allowed multivalent presentation of glycomimetics in a spatially defined fashion, while providing good water solubility to the constructs. Evaluation of the biological activity by SPR assays revealed strong binding avidity towards DC-SIGN and increased selectivity over langerin. Inhibition of DC-SIGN binding to SARS-CoV-2 spike protein and of DC-SIGN mediated Ebola virus trans-infection testifies for the glycodendrimers potential application in infection diseases. The tetravalent platform described here is easily accessible and can be used in modular fashion with different ligands, thus lending itself to multiple applications

Precision glycodendrimers for DC‐SIGN targeting

International audienceMultivalent ligands of the C‐type lectin receptor DC‐SIGN have emerged as effective antiadhesive agents against various pathogens. Some years ago, we described a hexavalent DC‐SIGN ligand, Polyman‐26, designed to bridge two of the four binding sites displayed by the receptor. In this work, we present our efforts to accomplish simultaneous coordination of all four carbohydrate binding sites of DC‐SIGN through the synthesis of cross‐shaped glycodendrimers. The tailored rigid scaffold allowed multivalent presentation of glycomimetics in a spatially defined fashion, while providing good water solubility to the constructs. Evaluation of the biological activity by SPR assays revealed strong binding avidity towards DC‐SIGN and increased selectivity over langerin. Inhibition of DC‐SIGN binding to SARS‐CoV‐2 spike protein and of DC‐SIGN mediated Ebola virus trans‐infection testifies for the glycodendrimers potential application in infection diseases. The tetravalent platform described here is easily accessible and can be used in modular fashion with different ligands, thus lending itself to multiple applications.Multivalent antagonists able to reach the four carbohydrate recognition domains (CRD) of DC‐SIGN have been prepared. The extended rigid core of these glycodendrimers allows multivalent presentation of glycomimetic molecules in a spatially defined fashion, providing high affinity towards DC‐SIGN and selectivity over other C‐type lectins featuring distinct CRD arrangements. The constructs successfully inhibit DC‐SIGN binding to SARS‐CoV‐2 spike protein and DC‐SIGN mediated trans‐infection by Ebola virus