Emmanuel Drouet - Academia.edu (original) (raw)

Papers by Emmanuel Drouet

Research paper thumbnail of Oncogenic Properties of the EBV ZEBRA Protein

Cancers, 2020

Epstein Barr Virus (EBV) is one of the most common human herpesviruses. After primary infection, ... more Epstein Barr Virus (EBV) is one of the most common human herpesviruses. After primary infection, it can persist in the host throughout their lifetime in a latent form, from which it can reactivate following specific stimuli. EBV reactivation is triggered by transcriptional transactivator proteins ZEBRA (also known as Z, EB-1, Zta or BZLF1) and RTA (also known as BRLF1). Here we discuss the structural and functional features of ZEBRA, its role in oncogenesis and its possible implication as a prognostic or diagnostic marker. Modulation of host gene expression by ZEBRA can deregulate the immune surveillance, allow the immune escape, and favor tumor progression. It also interacts with host proteins, thereby modifying their functions. ZEBRA is released into the bloodstream by infected cells and can potentially penetrate any cell through its cell-penetrating domain; therefore, it can also change the fate of non-infected cells. The features of ZEBRA described in this review outline its imp...

Research paper thumbnail of Structure of the full-length HCV IRES in solution

Nature Communications, 2013

Research paper thumbnail of Human initiation factor eIF3 subunit b interacts with HCV IRES RNA through its N‐terminal RNA recognition motif

FEBS Letters, 2008

Many viral mRNAs contain a 5′‐UTR RNA element called internal ribosome‐entry site (IRES), which b... more Many viral mRNAs contain a 5′‐UTR RNA element called internal ribosome‐entry site (IRES), which bypasses the requirement of some canonical initiation factors allowing cap‐independent translation. The IRES of hepatitis‐C virus drives translation by directly recruiting 40S ribosomal subunits and binds to eIF3 which plays a critical role in both cap‐dependent and cap‐independent translation. However, the molecular basis for eIF3 activity in either case remains enigmatic. Here we report that subunit b of the eIF3 complex directly binds to HCV IRES domain III via its N‐terminal‐RRM. Because eIF3b was previously shown to be involved in eIF3j binding, biological implications are discussed.

Research paper thumbnail of New insights into HCV replication in original cells from Aedes mosquitoes

Virology Journal, Aug 22, 2017

Background: The existing literature about HCV association with, and replication in mosquitoes is ... more Background: The existing literature about HCV association with, and replication in mosquitoes is extremely poor. To fill this gap, we performed cellular investigations aimed at exploring (i) the capacity of HCV E1E2 glycoproteins to bind on Aedes mosquito cells and (ii) the ability of HCV serum particles (HCVsp) to replicate in these cell lines. Methods: First, we used purified E1E2 expressing baculovirus-derived HCV pseudo particles (bacHCVpp) so we could investigate their association with mosquito cell lines from Aedes aegypti (Aag-2) and Aedes albopictus (C6/36). We initiated a series of infections of both mosquito cells (Ae aegypti and Ae albopictus) with the HCVsp (Lat straingenotype 3) and we observed the evolution dynamics of viral populations within cells over the course of infection via next-generation sequencing (NGS) experiments. Results: Our binding assays revealed bacHCVpp an association with the mosquito cells, at comparable levels obtained with human hepatocytes (HepaRG cells) used as a control. In our infection experiments, the HCV RNA (+) were detectable by RT-PCR in the cells between 21 and 28 days post-infection (p.i.). In human hepatocytes HepaRG and Ae aegypti insect cells, NGS experiments revealed an increase of global viral diversity with a selection for a quasi-species, suggesting a structuration of the population with elimination of deleterious mutations. The evolutionary pattern in Ae albopictus insect cells is different (stability of viral diversity and polymorphism). Conclusions: These results demonstrate for the first time that natural HCV could really replicate within Aedes mosquitoes, a discovery which may have major consequences for public health as well as in vaccine development.

Research paper thumbnail of Inhibition of the binding of HCV serum particles to human hepatocytes by E1E2-specific D32.10 monoclonal antibody

Journal of Medical Virology, Oct 1, 2009

The aim of this study was to determine the inhibition of binding activity of the monoclonal antib... more The aim of this study was to determine the inhibition of binding activity of the monoclonal antibody (mAb) D32.10 which recognizes a highly conserved discontinuous antigenic determinant (E1:297–306, E2:480–494, and E2:613–621) expressed on the surface of serum‐derived HCV particles (HCVsp) of genotypes 1a, 1b, 2a, and 3a. To this end, an in vitro direct cell‐binding assay based on the attachment of radiolabeled HCVsp was developed, and Scatchard plots were used to analyze ligand–receptor binding data. HCV adsorption was also assessed by quantitating cell‐associated viral RNA by a real‐time RT‐PCR method. Saturable concentration‐dependent specific binding of HCVsp to Huh‐7 or HepaRG cells was demonstrated. The Scatchard transformed data showed two‐site interaction for Huh‐7 and proliferative HepaRG cells: the high‐affinity binding sites (Kd1 = 0.1–0.5 µg/ml) and the low‐affinity binding sites (Kd1 = 5–10 µg/ml), and one‐site high‐affinity binding model between E1E2/D32.10‐positive HCVsp and hepatocyte‐like differentiated HepaRG cells. The E1E2‐specific mAb D32.10 inhibited efficiently (>60%) and selectively the binding with an IC50 ≤0.5 µg/ml in all the experimental approaches using serum HCV of genotype either 3 or 1b. This supports the involvement of the E1E2/D32.10 discontinuous antigenic determinant in the interactions between human hepatocytes and HCVsp, and suggests that D32.10‐like antibodies present in sera from patients infected with HCV could play a protective role. J. Med. Virol. 81:1726–1733, 2009. © 2009 Wiley‐Liss, Inc.

Research paper thumbnail of Lytic EBV infection investigated by detection of Soluble Epstein-Barr virus ZEBRA in the serum of patients with PTLD

Scientific Reports, 2017

The ZEBRA protein (encoded by the BZLF1 gene), is the major transcription factor of EBV, expresse... more The ZEBRA protein (encoded by the BZLF1 gene), is the major transcription factor of EBV, expressed upon EBV lytic cycle activation. Several studies highlighted the critical role of EBV lytic infection as a risk factor for lymphoproliferative disorders like post-transplant lymphoproliferative disease (PTLD). Here, we use an antigen-capture ELISA assay specifically designed to detecting the circulating soluble ZEBRA (sZEBRA) in serum samples (threshold value determined at 40ng/mL). We retrospectively investigated a population of 66 transplanted patients comprising 35 PTLD. All the samples from a control population (30 EBV-seronegative subjects and 25 immunocompetent individuals with EBV serological reactivation), classified as sZEBRA < 40ng/mL were assigned as negative. At PTLD diagnosis, EBV genome (quantified by qPCR with EBV DNA>200 copies/mL) and sZEBRA were detectable in 51% and 60% of cases, respectively. In the patients who developed a pathologically-confirmed PTLD, the m...

Research paper thumbnail of P.175 Interaction of serum-derived hepatitis C virus particles (HCVsp) and human hepatocytes: inhibition of binding by anti-E1E2 antibodies

Journal of Clinical Virology, 2006

Research paper thumbnail of Les récepteurs du virus de l'hépatite C : données actuelles

Data Revues 03998320 00250011 1011, Feb 29, 2008

Research paper thumbnail of Heparan Sulfate-Mediated Binding of Infectious Dengue Virus Type 2 and Yellow Fever Virus

Virology, 2002

Dengue virus type 2 and Yellow fever virus are arthropod-borne flaviviruses causing hemorrhagic f... more Dengue virus type 2 and Yellow fever virus are arthropod-borne flaviviruses causing hemorrhagic fever in humans. Identification of virus receptors is important in understanding flavivirus pathogenesis. The aim of this work was to study the role of cellular heparan sulfate in the adsorption of infectious Yellow fever and Dengue type 2 viruses. Virus attachment was assessed by adsorbing virus to cells, washing unbound virus away, releasing cell-bound virus by freezing/thawing, and then titrating the released infectious virus. Treatment of cells by heparin-lyase, desulfation of cellular heparan sulfate, or treatment of the virus with heparin inhibited cell binding of both viruses. Heparin also inhibited Yellow fever virus infection by 97%. Using infectious virus, the present work shows the importance of heparan sulfate in binding and infection of these two flaviviruses.

Research paper thumbnail of Micro-RNAs: viral genome and robustness of gene expression in the host

Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2009

For comparing RNA rings or hairpins with reference or random ring sequences, circular versions of... more For comparing RNA rings or hairpins with reference or random ring sequences, circular versions of distances and distributions like those of Hamming and Gumbel are needed. We define these circular versions and we apply these new tools to the comparison of RNA relics (such as micro-RNAs and tRNAs) with viral genomes that have coevolved with them. Then we show how robust are the regulation networks incorporating in their boundary micro-RNAs as sources or new feedback loops involving ubiquitous proteins like p53 (which is a micro-RNA transcription factor) or oligopeptides regulating protein translation. Eventually, we propose a new coevolution game between viral and host genomes.

Research paper thumbnail of Antibodies Directed Against Hepatitis C Virus E1E2 Complex, Compositions of HCV Particles, and Pharmaceutical Compositions

Research paper thumbnail of New insights into HCV replication in original cells from Aedes mosquitoes

Virology journal, Aug 22, 2017

The existing literature about HCV association with, and replication in mosquitoes is extremely po... more The existing literature about HCV association with, and replication in mosquitoes is extremely poor. To fill this gap, we performed cellular investigations aimed at exploring (i) the capacity of HCV E1E2 glycoproteins to bind on Aedes mosquito cells and (ii) the ability of HCV serum particles (HCVsp) to replicate in these cell lines. First, we used purified E1E2 expressing baculovirus-derived HCV pseudo particles (bacHCVpp) so we could investigate their association with mosquito cell lines from Aedes aegypti (Aag-2) and Aedes albopictus (C6/36). We initiated a series of infections of both mosquito cells (Ae aegypti and Ae albopictus) with the HCVsp (Lat strain - genotype 3) and we observed the evolution dynamics of viral populations within cells over the course of infection via next-generation sequencing (NGS) experiments. Our binding assays revealed bacHCVpp an association with the mosquito cells, at comparable levels obtained with human hepatocytes (HepaRG cells) used as a control...

Research paper thumbnail of Monitoring levels of human cytomegalovirus DNA in blood after liver transplantation

Journal of Clinical Microbiology, 1995

We evaluated a semiquantitative PCR assay prospectively in 40 liver transplant recipients as an a... more We evaluated a semiquantitative PCR assay prospectively in 40 liver transplant recipients as an aid in making a prompt diagnosis of cytomegalovirus (CMV) infection. For 2 months after transplantation, clinical specimens from patients were tested weekly by PCR, virus isolation from peripheral blood and urine, and CMV serology. The incidence of active CMV infection was 70%. The levels of CMV DNA determined by hybridization of PCR samples and densitometric scanning of blots were assigned a score of 1 to 4 by comparison with four external standards amplified in parallel and corresponding to a range of 80 to 80,000 genomes. The first detection of CMV in blood by PCR occurred at a mean of 15 days, and high-level PCR scores of 3 or 4 were obtained 21 days after transplantation, whereas viremia occurred 33 days after transplantation. Significantly higher levels of CMV DNA were seen in patients with CMV disease (P < 0.05) than in asymptomatic patients. The prevalence of symptomatic CMV in...

Research paper thumbnail of Inhibition of the binding of HCV serum particles to human hepatocytes by E1E2-specific D32.10 monoclonal antibody

Journal of Medical Virology, 2009

The aim of this study was to determine the inhibition of binding activity of the monoclonal antib... more The aim of this study was to determine the inhibition of binding activity of the monoclonal antibody (mAb) D32.10 which recognizes a highly conserved discontinuous antigenic determinant (E1:297-306, E2:480-494, and E2:613-621) expressed on the surface of serum-derived HCV particles (HCVsp) of genotypes 1a, 1b, 2a, and 3a. To this end, an in vitro direct cell-binding assay based on the attachment of radiolabeled HCVsp was developed, and Scatchard plots were used to analyze ligand-receptor binding data. HCV adsorption was also assessed by quantitating cell-associated viral RNA by a real-time RT-PCR method. Saturable concentration-dependent specific binding of HCVsp to Huh-7 or HepaRG cells was demonstrated. The Scatchard transformed data showed two-site interaction for Huh-7 and proliferative HepaRG cells: the high-affinity binding sites (K(d1) = 0.1-0.5 microg/ml) and the low-affinity binding sites (K(d1) = 5-10 microg/ml), and one-site high-affinity binding model between E1E2/D32.10-positive HCVsp and hepatocyte-like differentiated HepaRG cells. The E1E2-specific mAb D32.10 inhibited efficiently (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;60%) and selectively the binding with an IC(50) &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;or=0.5 microg/ml in all the experimental approaches using serum HCV of genotype either 3 or 1b. This supports the involvement of the E1E2/D32.10 discontinuous antigenic determinant in the interactions between human hepatocytes and HCVsp, and suggests that D32.10-like antibodies present in sera from patients infected with HCV could play a protective role.

Research paper thumbnail of The Gulf War syndrome

Journal of Clinical Pathology, 1997

Research paper thumbnail of Oncogenic Properties of the EBV ZEBRA Protein

Cancers, 2020

Epstein Barr Virus (EBV) is one of the most common human herpesviruses. After primary infection, ... more Epstein Barr Virus (EBV) is one of the most common human herpesviruses. After primary infection, it can persist in the host throughout their lifetime in a latent form, from which it can reactivate following specific stimuli. EBV reactivation is triggered by transcriptional transactivator proteins ZEBRA (also known as Z, EB-1, Zta or BZLF1) and RTA (also known as BRLF1). Here we discuss the structural and functional features of ZEBRA, its role in oncogenesis and its possible implication as a prognostic or diagnostic marker. Modulation of host gene expression by ZEBRA can deregulate the immune surveillance, allow the immune escape, and favor tumor progression. It also interacts with host proteins, thereby modifying their functions. ZEBRA is released into the bloodstream by infected cells and can potentially penetrate any cell through its cell-penetrating domain; therefore, it can also change the fate of non-infected cells. The features of ZEBRA described in this review outline its imp...

Research paper thumbnail of Structure of the full-length HCV IRES in solution

Nature Communications, 2013

Research paper thumbnail of Human initiation factor eIF3 subunit b interacts with HCV IRES RNA through its N‐terminal RNA recognition motif

FEBS Letters, 2008

Many viral mRNAs contain a 5′‐UTR RNA element called internal ribosome‐entry site (IRES), which b... more Many viral mRNAs contain a 5′‐UTR RNA element called internal ribosome‐entry site (IRES), which bypasses the requirement of some canonical initiation factors allowing cap‐independent translation. The IRES of hepatitis‐C virus drives translation by directly recruiting 40S ribosomal subunits and binds to eIF3 which plays a critical role in both cap‐dependent and cap‐independent translation. However, the molecular basis for eIF3 activity in either case remains enigmatic. Here we report that subunit b of the eIF3 complex directly binds to HCV IRES domain III via its N‐terminal‐RRM. Because eIF3b was previously shown to be involved in eIF3j binding, biological implications are discussed.

Research paper thumbnail of New insights into HCV replication in original cells from Aedes mosquitoes

Virology Journal, Aug 22, 2017

Background: The existing literature about HCV association with, and replication in mosquitoes is ... more Background: The existing literature about HCV association with, and replication in mosquitoes is extremely poor. To fill this gap, we performed cellular investigations aimed at exploring (i) the capacity of HCV E1E2 glycoproteins to bind on Aedes mosquito cells and (ii) the ability of HCV serum particles (HCVsp) to replicate in these cell lines. Methods: First, we used purified E1E2 expressing baculovirus-derived HCV pseudo particles (bacHCVpp) so we could investigate their association with mosquito cell lines from Aedes aegypti (Aag-2) and Aedes albopictus (C6/36). We initiated a series of infections of both mosquito cells (Ae aegypti and Ae albopictus) with the HCVsp (Lat straingenotype 3) and we observed the evolution dynamics of viral populations within cells over the course of infection via next-generation sequencing (NGS) experiments. Results: Our binding assays revealed bacHCVpp an association with the mosquito cells, at comparable levels obtained with human hepatocytes (HepaRG cells) used as a control. In our infection experiments, the HCV RNA (+) were detectable by RT-PCR in the cells between 21 and 28 days post-infection (p.i.). In human hepatocytes HepaRG and Ae aegypti insect cells, NGS experiments revealed an increase of global viral diversity with a selection for a quasi-species, suggesting a structuration of the population with elimination of deleterious mutations. The evolutionary pattern in Ae albopictus insect cells is different (stability of viral diversity and polymorphism). Conclusions: These results demonstrate for the first time that natural HCV could really replicate within Aedes mosquitoes, a discovery which may have major consequences for public health as well as in vaccine development.

Research paper thumbnail of Inhibition of the binding of HCV serum particles to human hepatocytes by E1E2-specific D32.10 monoclonal antibody

Journal of Medical Virology, Oct 1, 2009

The aim of this study was to determine the inhibition of binding activity of the monoclonal antib... more The aim of this study was to determine the inhibition of binding activity of the monoclonal antibody (mAb) D32.10 which recognizes a highly conserved discontinuous antigenic determinant (E1:297–306, E2:480–494, and E2:613–621) expressed on the surface of serum‐derived HCV particles (HCVsp) of genotypes 1a, 1b, 2a, and 3a. To this end, an in vitro direct cell‐binding assay based on the attachment of radiolabeled HCVsp was developed, and Scatchard plots were used to analyze ligand–receptor binding data. HCV adsorption was also assessed by quantitating cell‐associated viral RNA by a real‐time RT‐PCR method. Saturable concentration‐dependent specific binding of HCVsp to Huh‐7 or HepaRG cells was demonstrated. The Scatchard transformed data showed two‐site interaction for Huh‐7 and proliferative HepaRG cells: the high‐affinity binding sites (Kd1 = 0.1–0.5 µg/ml) and the low‐affinity binding sites (Kd1 = 5–10 µg/ml), and one‐site high‐affinity binding model between E1E2/D32.10‐positive HCVsp and hepatocyte‐like differentiated HepaRG cells. The E1E2‐specific mAb D32.10 inhibited efficiently (&gt;60%) and selectively the binding with an IC50 ≤0.5 µg/ml in all the experimental approaches using serum HCV of genotype either 3 or 1b. This supports the involvement of the E1E2/D32.10 discontinuous antigenic determinant in the interactions between human hepatocytes and HCVsp, and suggests that D32.10‐like antibodies present in sera from patients infected with HCV could play a protective role. J. Med. Virol. 81:1726–1733, 2009. © 2009 Wiley‐Liss, Inc.

Research paper thumbnail of Lytic EBV infection investigated by detection of Soluble Epstein-Barr virus ZEBRA in the serum of patients with PTLD

Scientific Reports, 2017

The ZEBRA protein (encoded by the BZLF1 gene), is the major transcription factor of EBV, expresse... more The ZEBRA protein (encoded by the BZLF1 gene), is the major transcription factor of EBV, expressed upon EBV lytic cycle activation. Several studies highlighted the critical role of EBV lytic infection as a risk factor for lymphoproliferative disorders like post-transplant lymphoproliferative disease (PTLD). Here, we use an antigen-capture ELISA assay specifically designed to detecting the circulating soluble ZEBRA (sZEBRA) in serum samples (threshold value determined at 40ng/mL). We retrospectively investigated a population of 66 transplanted patients comprising 35 PTLD. All the samples from a control population (30 EBV-seronegative subjects and 25 immunocompetent individuals with EBV serological reactivation), classified as sZEBRA < 40ng/mL were assigned as negative. At PTLD diagnosis, EBV genome (quantified by qPCR with EBV DNA>200 copies/mL) and sZEBRA were detectable in 51% and 60% of cases, respectively. In the patients who developed a pathologically-confirmed PTLD, the m...

Research paper thumbnail of P.175 Interaction of serum-derived hepatitis C virus particles (HCVsp) and human hepatocytes: inhibition of binding by anti-E1E2 antibodies

Journal of Clinical Virology, 2006

Research paper thumbnail of Les récepteurs du virus de l'hépatite C : données actuelles

Data Revues 03998320 00250011 1011, Feb 29, 2008

Research paper thumbnail of Heparan Sulfate-Mediated Binding of Infectious Dengue Virus Type 2 and Yellow Fever Virus

Virology, 2002

Dengue virus type 2 and Yellow fever virus are arthropod-borne flaviviruses causing hemorrhagic f... more Dengue virus type 2 and Yellow fever virus are arthropod-borne flaviviruses causing hemorrhagic fever in humans. Identification of virus receptors is important in understanding flavivirus pathogenesis. The aim of this work was to study the role of cellular heparan sulfate in the adsorption of infectious Yellow fever and Dengue type 2 viruses. Virus attachment was assessed by adsorbing virus to cells, washing unbound virus away, releasing cell-bound virus by freezing/thawing, and then titrating the released infectious virus. Treatment of cells by heparin-lyase, desulfation of cellular heparan sulfate, or treatment of the virus with heparin inhibited cell binding of both viruses. Heparin also inhibited Yellow fever virus infection by 97%. Using infectious virus, the present work shows the importance of heparan sulfate in binding and infection of these two flaviviruses.

Research paper thumbnail of Micro-RNAs: viral genome and robustness of gene expression in the host

Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2009

For comparing RNA rings or hairpins with reference or random ring sequences, circular versions of... more For comparing RNA rings or hairpins with reference or random ring sequences, circular versions of distances and distributions like those of Hamming and Gumbel are needed. We define these circular versions and we apply these new tools to the comparison of RNA relics (such as micro-RNAs and tRNAs) with viral genomes that have coevolved with them. Then we show how robust are the regulation networks incorporating in their boundary micro-RNAs as sources or new feedback loops involving ubiquitous proteins like p53 (which is a micro-RNA transcription factor) or oligopeptides regulating protein translation. Eventually, we propose a new coevolution game between viral and host genomes.

Research paper thumbnail of Antibodies Directed Against Hepatitis C Virus E1E2 Complex, Compositions of HCV Particles, and Pharmaceutical Compositions

Research paper thumbnail of New insights into HCV replication in original cells from Aedes mosquitoes

Virology journal, Aug 22, 2017

The existing literature about HCV association with, and replication in mosquitoes is extremely po... more The existing literature about HCV association with, and replication in mosquitoes is extremely poor. To fill this gap, we performed cellular investigations aimed at exploring (i) the capacity of HCV E1E2 glycoproteins to bind on Aedes mosquito cells and (ii) the ability of HCV serum particles (HCVsp) to replicate in these cell lines. First, we used purified E1E2 expressing baculovirus-derived HCV pseudo particles (bacHCVpp) so we could investigate their association with mosquito cell lines from Aedes aegypti (Aag-2) and Aedes albopictus (C6/36). We initiated a series of infections of both mosquito cells (Ae aegypti and Ae albopictus) with the HCVsp (Lat strain - genotype 3) and we observed the evolution dynamics of viral populations within cells over the course of infection via next-generation sequencing (NGS) experiments. Our binding assays revealed bacHCVpp an association with the mosquito cells, at comparable levels obtained with human hepatocytes (HepaRG cells) used as a control...

Research paper thumbnail of Monitoring levels of human cytomegalovirus DNA in blood after liver transplantation

Journal of Clinical Microbiology, 1995

We evaluated a semiquantitative PCR assay prospectively in 40 liver transplant recipients as an a... more We evaluated a semiquantitative PCR assay prospectively in 40 liver transplant recipients as an aid in making a prompt diagnosis of cytomegalovirus (CMV) infection. For 2 months after transplantation, clinical specimens from patients were tested weekly by PCR, virus isolation from peripheral blood and urine, and CMV serology. The incidence of active CMV infection was 70%. The levels of CMV DNA determined by hybridization of PCR samples and densitometric scanning of blots were assigned a score of 1 to 4 by comparison with four external standards amplified in parallel and corresponding to a range of 80 to 80,000 genomes. The first detection of CMV in blood by PCR occurred at a mean of 15 days, and high-level PCR scores of 3 or 4 were obtained 21 days after transplantation, whereas viremia occurred 33 days after transplantation. Significantly higher levels of CMV DNA were seen in patients with CMV disease (P < 0.05) than in asymptomatic patients. The prevalence of symptomatic CMV in...

Research paper thumbnail of Inhibition of the binding of HCV serum particles to human hepatocytes by E1E2-specific D32.10 monoclonal antibody

Journal of Medical Virology, 2009

The aim of this study was to determine the inhibition of binding activity of the monoclonal antib... more The aim of this study was to determine the inhibition of binding activity of the monoclonal antibody (mAb) D32.10 which recognizes a highly conserved discontinuous antigenic determinant (E1:297-306, E2:480-494, and E2:613-621) expressed on the surface of serum-derived HCV particles (HCVsp) of genotypes 1a, 1b, 2a, and 3a. To this end, an in vitro direct cell-binding assay based on the attachment of radiolabeled HCVsp was developed, and Scatchard plots were used to analyze ligand-receptor binding data. HCV adsorption was also assessed by quantitating cell-associated viral RNA by a real-time RT-PCR method. Saturable concentration-dependent specific binding of HCVsp to Huh-7 or HepaRG cells was demonstrated. The Scatchard transformed data showed two-site interaction for Huh-7 and proliferative HepaRG cells: the high-affinity binding sites (K(d1) = 0.1-0.5 microg/ml) and the low-affinity binding sites (K(d1) = 5-10 microg/ml), and one-site high-affinity binding model between E1E2/D32.10-positive HCVsp and hepatocyte-like differentiated HepaRG cells. The E1E2-specific mAb D32.10 inhibited efficiently (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;60%) and selectively the binding with an IC(50) &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;or=0.5 microg/ml in all the experimental approaches using serum HCV of genotype either 3 or 1b. This supports the involvement of the E1E2/D32.10 discontinuous antigenic determinant in the interactions between human hepatocytes and HCVsp, and suggests that D32.10-like antibodies present in sera from patients infected with HCV could play a protective role.

Research paper thumbnail of The Gulf War syndrome

Journal of Clinical Pathology, 1997