Florian Douam

Florian Douam
Boston University | BU · Microbiology - NEIDL

Ph.D.

About

77
Publications
6,719
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
930
Citations
Introduction
Assistant Professor at Boston University School of Medicine; Principal Investigator, National Emerging Infectious Disease Laboratories (NEIDL).
Additional affiliations
July 2014 - July 2019
Princeton University
Position
  • PostDoc Position
January 2014 - June 2014
Centre International de recherche en infectiologie, CNRS, INSERM, ENS de LYON, UCBL
Position
  • PostDoc Position
September 2010 - December 2013
Centre International de recherche en infectiologie, CNRS, INSERM, ENS de LYON, UCBL
Position
  • PhD Student

Publications

Publications (77)
Article
Full-text available
The human immunological mechanisms defining the clinical outcome of SARS-CoV-2 infection remain elusive. This knowledge gap is mostly driven by the lack of appropriate experimental platforms recapitulating human immune responses in a controlled human lung environment. Here, we report a mouse model (i.e. HNFL mice) co-engrafted with human fetal lung...
Article
Full-text available
SARS-CoV-2, the causative agent of pandemic COVID-19, is rapidly evolving to be more transmissible and to exhibit evasive immune properties, compromising neutralization by antibodies from vaccinated individuals or convalescent-phase sera. Recently, SARS-CoV-2 variants B.1.617.1 (Kappa), B.1.617.2 (Delta), and B.1.618 with mutations within the spike...
Article
Full-text available
Animal models recapitulating COVID-19 are critical to enhance our understanding of SARS-CoV-2 pathogenesis. Intranasally inoculated transgenic mice expressing human angiotensin-converting enzyme 2 under the cytokeratin 18 promoter (K18-hACE2) represent a lethal model of SARS-CoV-2 infection. We evaluated the clinical and virological dynamics of SAR...
Article
Full-text available
Several animal models have been developed to study the pathophysiology of SARS-CoV-2 infection and to evaluate vaccines and therapeutic agents for this emerging disease. Similar to infection with SARS-CoV-1, infection of Syrian hamsters with SARS-CoV-2 results in moderate respiratory disease involving the airways and lung parenchyma but does not le...
Preprint
Coronavirus disease-2019 (COVID-19) provokes a hypercoagulable state with increased incidence of thromboembolism and mortality. Platelets are major effectors of thrombosis and hemostasis. Suitable animal models are needed to better understand COVID-19-associated coagulopathy (CAC) and underlying platelet phenotypes. Here, we assessed K18-hACE2 mice...
Article
SARS-CoV-2 can infect multiple organs, including lung, intestine, kidney, heart, liver, and brain. The molecular details of how the virus navigates through diverse cellular environments and establishes replication are poorly defined. Here, we generated a panel of phenotypically diverse, SARS-CoV-2-infectible human cell lines representing different...
Article
Full-text available
Many enveloped viruses induce multinucleated cells (syncytia), reflective of membrane fusion events caused by the same machinery that underlies viral entry. These syncytia are thought to facilitate replication and evasion of the host immune response. Here, we report that co-culture of human cells expressing the receptor ACE2 with cells expressing S...
Article
Full-text available
Coronavirus interaction with its viral receptor is a primary genetic determinant of host range and tissue tropism. SARS-CoV-2 utilizes ACE2 as the receptor to enter host cell in a species-specific manner. We and others have previously shown that ACE2 orthologs from New World monkey, koala and mouse cannot interact with SARS-CoV-2 to mediate viral e...
Article
Full-text available
The lack of coronavirus-specific antiviral drugs has instigated multiple drug repurposing studies to redirect previously approved medicines for the treatment of SARS-CoV-2, the coronavirus behind the ongoing COVID-19 pandemic. A recent, large-scale, retrospective clinical study showed that famotidine, when administered at a high dose to hospitalize...
Preprint
Animal models recapitulating the distinctive features of severe COVID-19 are critical to enhance our understanding of SARS-CoV-2 pathogenesis. Transgenic mice expressing human angiotensin-converting enzyme 2 (hACE2) under the cytokeratin 18 promoter (K18-hACE2) represent a lethal model of SARS-CoV-2 infection. However, the cause(s) and mechanisms o...
Article
Hepatitis E virus (HEV) causes 14 million infections and 60,000 deaths per year globally, with immunocompromised persons and pregnant women experiencing severe symptoms. Although ribavirin can be used to treat chronic hepatitis E, toxicity in pregnant patients and the emergence of resistant strains are major concerns. Therefore there is an imminent...
Article
The human immunological mechanisms defining the clinical outcome of SARS-CoV-2 infection remain elusive. This knowledge gap is mostly driven by the lack of appropriate experimental platforms recapitulating human immune responses in a controlled human lung environment. Here, we report a mouse model (i.e., HNFL mice) co-engrafted with human fetal lun...
Preprint
Full-text available
Many enveloped viruses induce multinucleated cells (syncytia), reflective of membrane fusion events caused by the same machinery that underlies viral entry. These syncytia are thought to facilitate replication and evasion of the host immune response. Here, we report that co-culture of human cells expressing the receptor ACE2 with cells expressing S...
Preprint
SARS-CoV-2 can infect multiple organs, including lung, intestine, kidney, heart, liver, and brain. The molecular details of how the virus navigates through diverse cellular environments and establishes replication are poorly defined. Here, we performed global proteomic analysis of the virus-host interface in a newly established panel of phenotypica...
Preprint
Full-text available
Coronavirus interaction with its viral receptor is a primary genetic determinant of host range and tissue tropism. SARS-CoV-2 utilizes ACE2 as the receptor to enter host cell in a species-specific manner. We and others have previously shown that ACE2 orthologs from New World monkey, koala and mouse cannot interact with SARS-CoV-2 to mediate viral e...
Article
Full-text available
Flaviviruses are enveloped, arthropod-borne, positive-strand RNA viruses that cause significant human disease. While the basic mechanisms of flavivirus entry and fusion are understood, little is known about the postfusion events that precede RNA replication, such as nucleocapsid disassembly. We recently developed a sensitive, conditionally replicat...
Preprint
Full-text available
The lack of coronavirus-specific antiviral drugs has instigated multiple drug repurposing studies to redirect previously approved medicines for the treatment of SARS-CoV-2, the coronavirus behind the ongoing COVID-19 pandemic. A recent, large-scale, retrospective clinical study showed that famotidine, when administered at a high dose to hospitalize...
Article
Full-text available
While the basic mechanisms of flavivirus entry and fusion are understood, little is known about the postfusion events that precede RNA replication, such as nucleocapsid disassembly. We describe here a sensitive, conditionally replication-defective yellow fever virus (YFV) entry reporter, YFVΔSK/Nluc, to quantitively monitor the translation of incom...
Article
Full-text available
Live-attenuated vaccines (LAV) represent one of the most important medical innovations in human history. In the past three centuries, LAV have saved hundreds of millions of lives, and will continue to do so for many decades to come. Interestingly, the most successful LAVs, such as the smallpox vaccine, the measles vaccine, and the yellow fever vacc...
Preprint
Full-text available
While the basic mechanisms of flavivirus entry and fusion are understood, little is known about the post-fusion events that precede RNA replication, such as nucleocapsid disassembly. We describe here a sensitive, conditionally replication-defective yellow fever virus (YFV) entry reporter, YFVΔSK/Nluc, to quantitively monitor the translation of inco...
Article
The limited host tropism of numerous viruses causing disease in humans remains incompletely understood. One example is Zika virus (ZIKV), an RNA virus that has reemerged in recent years. Here, we demonstrate that ZIKV efficiently infects fibroblasts from humans, great apes, New and Old World monkeys, but not rodents. ZIKV infection in human-but not...
Article
Full-text available
Amino-acid coevolution can be referred to mutational compensatory patterns preserving the function of a protein. Viral envelope glycoproteins, which mediate entry of enveloped viruses into their host cells, are shaped by coevolution signals that confer to viruses the plasticity to evade neutralizing antibodies without altering viral entry mechanism...
Data
Detailed analysis of genotype 2 HCV E1E2 clusters. (DOCX)
Data
List of genotype 2 cluster blocks mapped on the E1E2 reference sequences (JFH-1; AB047639). For each block, the initial and final position of the block predicted by BIS and the name of the cluster it belongs to are given. Blocks from each cluster are numerated from 1 to x (Block N°) to easily identify their position on the E1E2 sequences in S7 Fig,...
Data
Putative functions of genotype 2 E1E2 coevolution clusters. We aligned 30 E1E2 amino acid sequences of HCV genotype 2 (2a and 2b) and, using the BIS method, we identified 21 clusters (S6 Fig; S3, S7 Table). Genotype 2 clusters harboring blocks that mapped residues previously reported in the literature to have a specific function are classified. The...
Data
Detailed analysis of genotype 1a HCV E1E2 clusters. (DOCX)
Data
Clusters of coevolving residues identified by BIS in DENV envelope glycoprotein E sequences of serotype 2. Clusters are computed with the BIS coevolution analysis method [22–24] and they correspond to maximum scores (symmetricity and environmental scores are set to 1, and the number of admissible exceptions to 0 or 1). For each cluster, the positio...
Data
Putative functions of genotype 1a E1E2 coevolution clusters. We aligned 25 E1E2 amino acids sequences of HCV genotype 1a and identified using BIS method 16 clusters (S3 Fig; S4 Table). Genotype 1a clusters harboring blocks that mapped residues previously reported in the literature to have a specific function (S4 Fig) are classified. The known role(...
Data
BIS methodology for coevolution analysis. Coevolution analyses require the identification of sequence variability and they are usually realized on families of homologous protein sequences, typically very divergent and represented by a large number of sequences. In contrast, studying viral sequences requires methods that can analyze serotypes and ge...
Data
Clusters of coevolving residues identified by BIS in DENV envelope glycoprotein E and PrM sequences of serotype 2. 17 amino acids sequences of DENV E and PrM serotype 2 were aligned and 14 Clusters were identified by BIS. Clusters are computed with the BIS coevolution analysis method [22–24] and they correspond to maximum scores (symmetricity and e...
Data
Mapping of genotype 1a cluster blocks on E1E2 reference sequences of genotype 1a (H77; AF009606) and genotype 2a (JFH-1; AB047639). Genotype 1a cluster blocks are represented as red horizontal bars positioned above the E1 and E2 H77 or JFH-1 aligned sequences. Each horizontal bar is numerated as follow: “Cluster ID-Block N°”. Respective positions o...
Data
Genotype 2 HCV E1E2 coevolution networks. The 21 gt2 clusters (illustrated by distinct colors) are displayed within “strips” representing the E1E2 sequence. For each cluster, positions of the coevolving blocks in the E1E2 sequence are indicated within the corresponding “strip” (see S7 Table for cluster positions). On the top of each coevolving bloc...
Data
BIS coevolution analysis of HCV E1E2 sequences. Ten groups of sequences were assembled and analyzed independently with the BIS method. Groups were constituted of E1E2 sequences from HCV types and sub-types from genotype 1a to 6a. Groups of sequences from genotypes 1 and 2 were constituted by pools of sequences from subtypes 1a and 1b (50 sequences)...
Data
Clusters of coevolving residues identified by BIS in HCV E1E2 sequences of genotype 1a. Clusters are computed with the BIS analysis method similarly to S1 Table. Note that residue positions displayed in this table are specific to the set of patient sequences analyzed. Hence, nucleotide gaps generated during the analysis of the patient sequences by...
Data
List of Genotype 1a cluster blocks mapped on E1E2 references sequences (H77, AF009606). For each block, the initial and final position of the block predicted by BIS and the name of the cluster it belongs to are given. Blocks from each cluster are numerated from 1 to x (Block N°) to easily identify their position on the E1E2 sequences in S4 Fig, whe...
Data
Clusters of coevolving residues identified by BIS in HCV E1E2 sequences of genotype 2. Clusters are computed with the BIS analysis method similarly to S1 Table. Note that residue positions displayed in this table are specific to the set of patient sequences analyzed. Hence, nucleotide gaps generated during the analysis of the patient sequences by B...
Data
Structural mapping of DENV E clusters. Mapping of the DENV E clusters 3 to 12 (illustrated by distinct colors) on the E dimeric structure (PDB 1K4R). For each cluster, positions of the coevolving blocks in E sequence are displayed within “strips” located above each structure (See S2 Table for cluster positions). Each cluster is identified by a dist...
Data
Mapping of genotype 2 cluster blocks on E1E2 reference sequences of genotype 1a (H77; AF009606) and genotype 2a (JFH-1; AB047639). Genotype 2 cluster blocks are represented as blue horizontal bars positioned above the E1 and E2 H77 or JFH-1 aligned sequences. Each horizontal bar is numerated as follow: “Cluster number-Block N°”. Respective position...
Data
Structural analysis of genotype 3 clusters involving E1 and the BL. Genotype 3 cluster 4 (blue), cluster 8 (red) and cluster 9 (green) are plotted on a tridimensional view of the E2core structure (PDB 4MWF) and on a vertical linear representation of E1. Each cluster is composed of blocks harboring a similar color. The Stem region (Stem) is represen...
Data
Biophysical properties and ELISA detection of soluble BLd-H77. (A) Amino acid sequence of the soluble BLd-H77. Dotted lines represent internal disulfide bridges that might be involved in the functional folding of the soluble BLd-H77. (B) Detection of BLd-H77 in reducing and non-reducing condition following SDS-Page electrophoresis and coomassie blu...
Data
BLd-H77 transmembranous form inhibits HCV infection. (A) Cell surface staining of C46 and BLd-tm following transduction of Huh7.5. Expression of C46 and BLd-tm (white) was measured by flow cytometry using an anti-hinge human IgG2 antibody and compared to the level of expression within non-transduced Huh7.5 (Grey). (B) CD81, SR-BI, Claudin-1 and Occ...
Data
Functional linkage of E1 and BL coevolving residues identified by BIS. (A) Protein sequence alignment of E1E2 J6 and 2b1. Level of conservation for each amino acid position is indicated. Position of the coevolving blocks that belong to gt2 fusion cluster 5 are indicated by red rectangles. Position of the interchanged amino acid regions between J6 a...
Data
BIS analysis of the coevolution of the transmembranes of E1 and E2. List of clusters identified by BIS that connect the transmembrane of E1 and E2. Six clusters were identified across the two major HCV genotypes. Location of the transmembrane domains within E1 and E2 are indicated for each genotype and sub-types. Position of the coevolving blocks l...
Data
Coevolution analysis of HCV E1E2 genotype 1a sequences. The 16 gt1a clusters (illustrated by distinct colors) are displayed within “strips” representing the E1E2 sequence. For each cluster, positions of the coevolving blocks in the E1E2 sequence are indicated within the corresponding “strip” (see S4 Table for cluster positions). On the top of each...
Data
Structural analysis of genotype 1a HCV E1E2 clusters. HCV E1E2 gt1a multifunctional clusters 4 (blue) and 16 (orange) (A), structural clusters 11 (orange), 2 (green) and 6 (red) (B) and undefined role clusters 3 (pink), 9 (emerald green), 13 (brown), 14 (blue) and 15 (yellow) (C) are plotted on a vertical linear representation of E1 and on a tridim...
Data
Structural analysis of the genotype 2 HCV E1E2 clusters. (A) Plot of the gt2 structural cluster 19 on a tridimensional view of the E2core structure (PDB 4MWF). Gt2 structural (B), multifunctional (C), structural and multifunction (D), fusion (E) and undefined (F) clusters were plotted both on a vertical linear representation of E1 and onto the E2 c...
Data
Construction of E1-E2 genotype 1a chimera to challenge BIS predictions. Protein sequence alignment of E1E2 H77 and A40. Level of conservation for each amino acid position is indicated. Position of the E1 and E2 block of interest belonging to the gt1a cluster 5 are indicated by red asterisks. Position of the three H77 amino acid residues that will b...
Data
BLd-H77 inhibits HCV infection. (A) Quantification of HCVcc infectious titers following dose-dependent neutralization of HCVcc H77/JFH-1 by BLd-H77. Four days following BLd-H77 dose-dependent neutralization of HCVcc H77/JFH-1 infection (see Fig 4F), Huh7.5 cell culture supernatants were harvested and used to infect naïve Huh7.5 cells. Four days pos...
Data
Effect of BLd-H77 on E2 and HCV pseudoparticles binding. (A) BLd-H77 effect on E2 and HCVpp binding to Huh7.5 cells (Left). Huh7.5 cells, pre-incubated with PBS (top panels) or BLd-H77 (50μg/ml) (bottom panels), were mixed (white) or not (grey), at 37°C for 1h with soluble E2 or with concentrated H77-HCVpp. Bound soluble E2 or HCVpp were then stain...
Data
Effect of BLd-H77 on cell-cell fusion. (A) LTRhiv-luciferase vector transduced 293T cells expressing H77 HCV (left panel) or VSV (right panel) envelope glycoproteins were co-cultured with Tat-expressing Huh7.5 cells. Co-culture were pre-incubated for 1h with 50μg/ml of BLd-H77 or PBS, washed and incubated for 3 min with a pH7 (red) or pH5 (orange)...
Article
Full-text available
The past decade has seen tremendous progress in understanding hepatitis C virus (HCV) biology and its related disease, hepatitis C. Major advances in characterizing viral replication have led to the development of direct-acting anti-viral therapies that have considerably improved patient treatment outcome and can even cure chronic infection. Howeve...
Article
Full-text available
Infectious diseases are the second leading cause of death worldwide. Although the host multitropism of some pathogens has rendered their manipulation possible in animal models, the human-restricted tropism of numerous viruses, bacteria, fungi, and parasites has seriously hampered our understanding of these pathogens. Hence, uncovering the genetic b...
Article
Full-text available
Importance: Hepatitis C Virus (HCV) mainly replicates within the liver. However, it has been shown that patient-derived HCV particles can slightly infect lymphocytes in vitro and in vivo, highlighting the existence of lymphotropism determinants within HCV viral proteins. We isolated HCV envelope glycoproteins from patient B-lymphocytes that confer...
Article
Full-text available
The development of lentiviral vectors for expression of a specific antibody can be achieved through the transduction of mature B cells. This approach would provide a versatile tool for active immunotherapy strategies for infectious diseases or cancer, as well as for protein engineering. Here, we created a lentiviral expression system mimicking the...
Article
Unlabelled: In our study, we characterized the effect of monensin, an ionophore that is known to raise the intracellular pH, on the hepatitis C virus (HCV) life cycle. We showed that monensin inhibits HCV entry in a pangenotypic and dose-dependent manner. Monensin induces an alkalization of intracellular organelles, leading to an inhibition of the...
Article
Hepatitis C virus (HCV) is a major cause of liver disease worldwide. Acute infection often progresses to chronicity resulting frequently in fibrosis, cirrhosis, and in rare cases, in the development of hepatocellular carcinoma (HCC). Although HCV has proven to be an arduous object of research and has raised important technical challenges, several e...
Article
Hepatitis C virus (HCV) is an enveloped, positive strand RNA virus classified within the Flaviviridae family and is a major cause of liver disease worldwide. HCV life cycle and propagation are tightly linked to several aspects of lipid metabolism. HCV propagation depends on and also shapes several aspects of lipid metabolism such as cholesterol upt...
Article
Full-text available
Hepatitis C virus (HCV) is a leading cause of cirrhosis and liver cancer worldwide. We recently characterized for the first time the expression of Signaling Lymphocyte Activating Molecule 3 (SLAMF3) in human hepatocytes and here, we report that SLAMF3 interacts with the HCV viral protein E2 and is implicated in HCV entry process. We found a strong...
Article
Full-text available
Hepatitis C virus (HCV) establishes infection using host lipid metabolism pathways that are thus considered potential targets for indirect anti-HCV strategies. HCV enters the cell via clathrin-dependent endocytosis, interacting with several receptors, and virus-cell fusion, which depends on acidic pH and the integrity of cholesterol-rich domains of...
Article
Unlabelled: Hepatitis C virus (HCV) envelope glycoproteins E1 and E2 are important mediators for productive cell entry. However, knowledge about their structure, intra- or intermolecular dialogs, and conformational changes is scarce, limiting the design of therapeutic strategies targeting E1E2. Here we sought to investigate how certain domains of...
Article
Trends in conventional plant breeding and in biotechnology research are analyzed with a focus on production and productivity of individual organisms. Our growing understanding of the productive/adaptive potential of (crop) plants is a prerequisite to increasing this potential and also its expression under environmental constraints. This review conc...
Article
Unlabelled: Hepatitis C virus (HCV) is a major cause of chronic liver disease. Despite recent success in improving anti-HCV therapy, additional progress is still needed to develop cheaper and interferon (IFN)-free treatments. Here, we report that ferroquine (FQ), an antimalarial ferrocenic analog of chloroquine, is a novel inhibitor of HCV. FQ pot...
Article
Full-text available
The protonation of histidine in acidic environments underpins its role in regulating the function of pH-sensitive proteins. For pH-sensitive viral fusion proteins, histidine protonation in the endosome leads to the activation of their membrane fusion function. The HCV (hepatitis C virus) glycoprotein E1-E2 heterodimer mediates membrane fusion withi...

Network