Publications of Laurent Gillet
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See detailKinetics and persistence of the cellular and humoral immune responses to BNT162b2 mRNA vaccine in SARS-CoV-2-naive and -experienced subjects
Desmecht, Salomé ULiege; Tashkeev, Aleksandr ULiege; Nicole Marechal, Nicole et al

E-print/Working paper (2022)

Background: Understanding and measuring the individual level of immune protection and its persistence at both humoral and cellular levels after SARS-CoV-2 vaccination is mandatory for the management of ... [more ▼]

Background: Understanding and measuring the individual level of immune protection and its persistence at both humoral and cellular levels after SARS-CoV-2 vaccination is mandatory for the management of the vaccination booster campaign. Our prospective study was designed to assess the immunogenicity of the BNT162b2 mRNA vaccine in triggering the humoral and the cellular immune response in healthcare workers up to 6 months after two doses vaccination. Methods: This prospective study enrolled 208 healthcare workers from the Liège University Hospital (CHU) of Liège in Belgium. All participants received two doses of BioNTech/Pfizer COVID-19 vaccine (BNT162b2). Fifty participants were SARS-CoV-2 experienced (self-reported SARS-CoV-2 infection) and 158 were naïve (no reported SARS-CoV-2 infection) before the vaccination. Blood sampling was performed at the day of the first (T0) and second (T1) vaccine doses administration, then at 2 weeks (T2), 4 weeks (T3) and 6 months (T4) after the 1st vaccine dose administration. A total of 1024 blood samples were collected. All samples were tested for the presence of anti-Spike antibodies using DiaSorin LIAISON SARS-CoV-2 TrimericS IgG assay. Neutralizing antibodies against the SARS-CoV-2 Wuhan-like variant strain were quantified in all samples using a Vero E6 cell-based neutralization-based assay. Cell-mediated immune response was evaluated at T4 on 80 participants by measuring the secretion of IFN- on peripheral blood lymphocytes using the QuantiFERON Human IFN- SARS-CoV-2, Qiagen. All participants were monitored on weekly-basis for the novo SARS-COV-2 infection for 4 weeks after the 1st vaccine dose administration. We analyzed separately the naïve and experienced participants. Findings: We found that anti-spike antibodies and neutralization capacity levels were significantly higher in SARS-CoV-2 experienced healthcare workers (HCWs) compared to naïve HCWs at all time points analyzed. Cellular immune response was similar in the two groups six months following 2nd dose of the vaccine. Reassuringly, most participants had a detectable cellular immune response to SARS-CoV-2 six months after vaccination. Besides the impact of SARS-CoV-2 infection history on immune response to BNT162b2 mRNA vaccine, we observed a significant negative correlation between age and persistence of humoral response. Cellular immune response was, however, not significantly correlated to age, although a trend towards a negative impact of age was observed. Conclusions: Our data strengthen previous findings demonstrating that immunization through vaccination combined with natural infection is better than 2 vaccine doses immunization or natural infection alone. It may have implications for personalizing mRNA vaccination regimens used to prevent severe COVID-19 and reduce the impact of the pandemic on the healthcare system. More specifically, it may help prioritizing vaccination, including for the deployment of booster doses. [less ▲]

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See detailThe First Random Observational Survey of Barrier Gestures against COVID-19
Renault, Véronique ULiege; Humblet, Marie-France ULiege; Parisi, Gianni ULiege et al

in International Journal of Environmental Research and Public Health (2021), 18(19), 9972

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See detailSingle-Virus Force Spectroscopy Discriminates the Intrinsic Role of Two Viral Glycoproteins upon Cell Surface Attachment.
Delguste, Martin; Brun, Grégoire Le; Cotin, Florian et al

in Nano Letters (2021), 21(1), 847-853

Viruses are one of the most efficient pathogenic entities on earth, resulting from millions of years of evolution. Each virus particle carries the minimum number of genes and proteins to ensure their ... [more ▼]

Viruses are one of the most efficient pathogenic entities on earth, resulting from millions of years of evolution. Each virus particle carries the minimum number of genes and proteins to ensure their reproduction within host cells, hijacking some host replication machinery. However, the role of some viral proteins is not yet unraveled, with some appearing even redundant. For example, murid herpesvirus 4, the current model for human gammaherpesvirus infection, can bind to cell surface glycosaminoglycans using both glycoproteins gp70 and gH/gL. Here, using atomic force microscopy, we discriminate their relative contribution during virus binding to cell surface glycosaminoglycans. Single-virus force spectroscopy experiments demonstrate that gH/gL is the main actor in glycosaminoglycan binding, engaging more numerous and more stable interactions. We also demonstrated that Fab antibody fragments targeting gH/gL or gp70 appear to be a promising treatment to prevent the attachment of virions to cell surfaces. [less ▲]

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See detailL’infection par un herpèsvirus gamma protège l’hôte du développement de l’asthme allergique
Machiels, Bénédicte ULiege; Gillet, Laurent ULiege

in MS. Medecine Sciences (2018), 34(10), 774-777

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See detailCorrection to: A gammaherpesvirus provides protection against allergic asthma by inducing the replacement of resident alveolar macrophages with regulatory monocytes (Nature Immunology, (2017), 18, 12, (1310-1320), 10.1038/ni.3857)
Machiels, Bénédicte ULiege; Dourcy, Mickael ULiege; Xiao, X. et al

in Nature Immunology (2018), 19(9), 1035

In the version of this article initially published, the accession code for the RNA-seq data set deposited in the NCBI public repository Sequence Read Archive was missing from the ‘Data availability’ ... [more ▼]

In the version of this article initially published, the accession code for the RNA-seq data set deposited in the NCBI public repository Sequence Read Archive was missing from the ‘Data availability’ subsection of the Methods section. The accession code is SRP125477. © 2017, The Author(s). [less ▲]

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See detailViral glycoprotein gp150 promotes sexual transmission of Murid Herpesvirus-4
Zeippen, Caroline ULiege; Javaux, Justine ULiege; Xiao, Xue ULiege et al

Poster (2016, November 28)

Gammaherpesviruses are important pathogens in human and veterinary medicine. During co-evolution with their hosts, they developed many strategies allowing them to shed infectious particles in presence of ... [more ▼]

Gammaherpesviruses are important pathogens in human and veterinary medicine. During co-evolution with their hosts, they developed many strategies allowing them to shed infectious particles in presence of immune response. Understanding these strategies is likely to be important to control infection. Interestingly, we recently observed that Murid herpesvirus 4 (MuHV-4), a gammaherpesvirus infecting laboratory mice, could be sexually transmitted between mice. This model offers therefore the opportunity to understand the mechanisms underlying natural transmission. Some of these mechanisms could rely on the glycoprotein 150 (gp150), which could limit virus neutralization and promote the release of infectious particles from cells. In this study, we tested therefore the importance of gp150 in the context of MuHV-4 sexual transmission. Briefly, female mice were infected with WT or gp150- strains expressing luciferase. They were imaged with an in vivo imaging system to follow infection. When lytic replication was observed in the genital tract, infected females were mated with naïve males to compare the capacity of transmission of the two strains. Our results show that, while the gp150- strain has no deficit in reaching and replicating in the female genital tract, it displays a major deficit of sexual transmission in comparison with WT virions. Interestingly, this deficit appears to reflect a deficit of virions release from vaginal epithelial cells. Altogether, our results show that, while gp150 is not required for efficient dissemination and maintenance of MuHV-4 within its host, it is essential for efficient transmission, by promoting the releasing of infectious particles from the mucosal cells. [less ▲]

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See detailNo Evidence of Herpesvirus Infection in West Highland Terriers with Canine Idiopathic Pulmonary Fibrosis
Roels, Elodie ULiege; Dourcy, Mickael ULiege; Holopainen, S. et al

in Veterinary Pathology (2016)

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See detailCanine idopathic pulmonary fibrosis is not associated with herpes virus infection
Roels, Elodie ULiege; Dourcy, Mickael ULiege; Holopainen, S. et al

Poster (2015, October)

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See detailThe alpha2,3-Sialyltransferase Encoded by Myxoma Virus Is a Virulence Factor that Contributes to Immunosuppression.
Boutard, Berengere; Vankerckhove, Sophie; Markine-Goriaynoff, Nicolas ULiege et al

in PLoS ONE (2015), 10(2), 0118806

Myxoma virus (MYXV) induces a lethal disease called Myxomatosis in European rabbits. MYXV is one of the rare viruses that encodes an alpha2,3-sialyltransferase through its M138L gene. In this study, we ... [more ▼]

Myxoma virus (MYXV) induces a lethal disease called Myxomatosis in European rabbits. MYXV is one of the rare viruses that encodes an alpha2,3-sialyltransferase through its M138L gene. In this study, we showed that although the absence of the enzyme was not associated with any in vitro deficit, the M138L deficient strains are highly attenuated in vivo. Indeed, while all rabbits infected with the parental and the revertant strains died within 9 days post-infection from severe myxomatosis, all but one rabbit inoculated with the M138L deficient strains survived the infection. In primary lesions, this resistance to the infection was associated with an increased ability of innate immune cells, mostly neutrophils, to migrate to the site of virus replication at 4 days post-infection. This was followed by the development of a better specific immune response against MYXV. Indeed, at day 9 post-infection, we observed an important proliferation of lymphocytes and an intense congestion of blood vessels in lymph nodes after M138L knockouts infection. Accordingly, in these rabbits, we observed an intense mononuclear cell infiltration throughout the dermis in primary lesions and higher titers of neutralizing antibodies. Finally, this adaptive immune response provided protection to these surviving rabbits against a challenge with the MYXV WT strain. Altogether, these results show that expression of the M138L gene contributes directly or indirectly to immune evasion by MYXV. In the future, these results could help us to better understand the pathogenesis of myxomatosis but also the importance of glycans in regulation of immune responses. [less ▲]

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See detailLa virothérapie oncolytique médiée par le virus de la myxomatose
Krygier, David; Gillet, Laurent ULiege; Marlier, Didier ULiege

in Annales de Médecine Vétérinaire (2013), 157(1), 5-14

Le virus de la myxomatose est un poxvirus du genre Leporipoxvirus qui induit une pathologie spécifique, la myxomatose, chez le lapin européen (Oryctolagus cuniculus). Ce virus a la particularité d’être ... [more ▼]

Le virus de la myxomatose est un poxvirus du genre Leporipoxvirus qui induit une pathologie spécifique, la myxomatose, chez le lapin européen (Oryctolagus cuniculus). Ce virus a la particularité d’être non pathogène pour les autres espèces de vertébrés y compris l’homme. Le virus de la myxomatose (MYXV) présente aussi, de manière inattendue, un tropisme pour les cellules cancéreuses humaines in vitro ainsi qu’un potentiel oncolytique in vivo. La tolérance de ces cellules au MYXV est intimement liée au niveau intracellulaire d’Akt phosphorylée. Cette enzyme, est une serine/thréonine protéine kinase qui joue un rôle essentiel dans de nombreux processus cellulaires et fait partie de la voie de signalisation PI3k/Akt/mTOR (mammalian target of rapamycin), fréquemment amplifiée par l’oncogénèse. La protéine virale à répétitions ankyrines, M-T5, interagit avec Akt ce qui module le tropisme du MYXV pour les cellules tumorales humaines. Un régulateur de la croissance cellulaire et du métabolisme situé en aval d’Akt, mTOR, est spécifiquement inhibé par la rapamycine. Ainsi, l’utilisation de la rapamycine en combinaison avec le MYXV permet d’augmenter la concentration d’Akt phosphorylée, et par conséquent, d’amplifier l’oncolyse. Un meilleur contrôle chimique de la voie de signalisation d’Akt ou de la modification génétique de son génome constituera une étape décisive pour que le MYXV devienne l’un des nouveaux traitements des cancers chez l’homme [less ▲]

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See detailProteomic characterization of murid herpesvirus 4 extracellular virions.
Vidick, Sarah ULiege; Leroy, Baptiste; Palmeira, Leonor ULiege et al

in PLoS ONE (2013), 8(12), 83842

Gammaherpesvirinae, such as the human Epstein-Barr virus (EBV) and the Kaposi's sarcoma associated herpesvirus (KSHV) are highly prevalent pathogens that have been associated with several neoplastic ... [more ▼]

Gammaherpesvirinae, such as the human Epstein-Barr virus (EBV) and the Kaposi's sarcoma associated herpesvirus (KSHV) are highly prevalent pathogens that have been associated with several neoplastic diseases. As EBV and KSHV are host-range specific and replicate poorly in vitro, animal counterparts such as Murid herpesvirus-4 (MuHV-4) have been widely used as models. In this study, we used MuHV-4 in order to improve the knowledge about proteins that compose gammaherpesviruses virions. To this end, MuHV-4 extracellular virions were isolated and structural proteins were identified using liquid chromatography tandem mass spectrometry-based proteomic approaches. These analyses allowed the identification of 31 structural proteins encoded by the MuHV-4 genome which were classified as capsid (8), envelope (9), tegument (13) and unclassified (1) structural proteins. In addition, we estimated the relative abundance of the identified proteins in MuHV-4 virions by using exponentially modified protein abundance index analyses. In parallel, several host proteins were found in purified MuHV-4 virions including Annexin A2. Although Annexin A2 has previously been detected in different virions from various families, its role in the virion remains controversial. Interestingly, despite its relatively high abundance in virions, Annexin A2 was not essential for the growth of MuHV-4 in vitro. Altogether, these results extend previous work aimed at determining the composition of gammaherpesvirus virions and provide novel insights for understanding MuHV-4 biology. [less ▲]

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See detailFeeding Cyprinus carpio with infectious materials mediates cyprinid herpesvirus 3 entry through infection of pharyngeal periodontal mucosa
Fournier, Guillaume ULiege; Boutier, Maxime ULiege; Victor, Stalin Raj et al

in Veterinary Research (2012), 43(6),

Cyprinid herpesvirus 3 (CyHV-3), also known as Koi herpesvirus, is the etiological agent of a mortal disease in common and koi carp. Recently, we investigated the entry of CyHV-3 in carp using ... [more ▼]

Cyprinid herpesvirus 3 (CyHV-3), also known as Koi herpesvirus, is the etiological agent of a mortal disease in common and koi carp. Recently, we investigated the entry of CyHV-3 in carp using bioluminescence imaging and a CyHV-3 recombinant strain expressing luciferase (LUC). We demonstrated that the skin is the major portal of entry after inoculation of carp by immersion in water containing CyHV-3. While this model of infection mimics some natural conditions in which infection takes place, other epidemiological conditions could favour entry of virus through the digestive tract. Here, we investigated whether ingestion of infectious materials mediates CyHV-3 entry through the digestive tract. Carp were fed with materials contaminated with the CyHV-3 LUC recombinant (oral contamination) or immersed in water containing the virus (contamination by immersion). Bioluminescence imaging analyses performed at different times post-infection led to the following observations: (i) the pharyngeal periodontal mucosa is the major portal of entry after oral contamination, while the skin is the major portal of entry after contamination by immersion. (ii) Both modes of inoculation led to the spreading of the infection to the various organs tested. However, the timing and the sequence in which some of the organs turned positive were different between the two modes of inoculation. Finally, we compared the disease induced by the two inoculation modes. They led to comparable clinical signs and mortality rate. The results of the present study suggest that, based on epidemiological conditions, CyHV-3 can enter carp either by skin or periodontal pharyngeal mucosal infection. [less ▲]

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See detailMyeloid infection links epithelial and B cell tropisms of murid herpesvirus-4.
Frederico, Bruno; Milho, Ricardo; May, Janet S. et al

in PLoS Pathogens (2012), 8(9), 1002935

Gamma-herpesviruses persist in lymphocytes and cause disease by driving their proliferation. Lymphocyte infection is therefore a key pathogenetic event. Murid Herpesvirus-4 (MuHV-4) is a rhadinovirus that ... [more ▼]

Gamma-herpesviruses persist in lymphocytes and cause disease by driving their proliferation. Lymphocyte infection is therefore a key pathogenetic event. Murid Herpesvirus-4 (MuHV-4) is a rhadinovirus that like the related Kaposi's Sarcoma-associated Herpesvirus persists in B cells in vivo yet infects them poorly in vitro. Here we used MuHV-4 to understand how virion tropism sets the path to lymphocyte colonization. Virions that were highly infectious in vivo showed a severe post-binding block to B cell infection. Host entry was accordingly an epithelial infection and B cell infection a secondary event. Macrophage infection by cell-free virions was also poor, but improved markedly when virion binding improved or when macrophages were co-cultured with infected fibroblasts. Under the same conditions B cell infection remained poor; it improved only when virions came from macrophages. This reflected better cell penetration and correlated with antigenic changes in the virion fusion complex. Macrophages were seen to contact acutely infected epithelial cells, and cre/lox-based virus tagging showed that almost all the virus recovered from lymphoid tissue had passed through lysM(+) and CD11c(+) myeloid cells. Thus MuHV-4 reached B cells in 3 distinct stages: incoming virions infected epithelial cells; infection then passed to myeloid cells; glycoprotein changes then allowed B cell infection. These data identify new complexity in rhadinovirus infection and potentially also new vulnerability to intervention. [less ▲]

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See detailSequencing of Bovine herpesvirus 4 V.test strain reveals important genome features
Palmeira, Leonor ULiege; Machiels, Bénédicte ULiege; Lété, Céline ULiege et al

in Virology Journal (2011), 8(1), 406

Background Bovine herpesvirus 4 (BoHV-4) is a useful model for the human pathogenic gammaherpesviruses Epstein-Barr virus and Kaposi's Sarcoma-associated Herpesvirus. Although genome manipulations of this ... [more ▼]

Background Bovine herpesvirus 4 (BoHV-4) is a useful model for the human pathogenic gammaherpesviruses Epstein-Barr virus and Kaposi's Sarcoma-associated Herpesvirus. Although genome manipulations of this virus have been greatly facilitated by the cloning of the BoHV-4 V.test strain as a Bacterial Artificial Chromosome (BAC), the lack of a complete genome sequence for this strain limits its experimental use. Methods In this study, we have determined the complete sequence of BoHV-4 V.test strain by a pyrosequencing approach. Results The long unique coding region (LUR) consists of 108,241 bp encoding at least 79 open reading frames and is flanked by several polyrepetitive DNA units (prDNA). As previously suggested, we showed that the prDNA unit located at the left prDNA-LUR junction (prDNA-G) differs from the other prDNA units (prDNA-inner). Namely, the prDNA-G unit lacks the conserved pac-2 cleavage and packaging signal in its right terminal region. Based on the mechanisms of cleavage and packaging of herpesvirus genomes, this feature implies that only genomes bearing left and right end prDNA units are encapsulated into virions. Conclusions In this study, we have determined the complete genome sequence of the BAC-cloned BoHV-4 V.test strain and identified genome organization features that could be important in other herpesviruses. [less ▲]

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See detailAntibody evasion by a gammaherpesvirus o-glycan shield.
Machiels, Bénédicte ULiege; Lété, Céline ULiege; Guillaume, Antoine ULiege et al

in PLoS Pathogens (2011), 7(11), 1002387

All gammaherpesviruses encode a major glycoprotein homologous to the Epstein-Barr virus gp350. These glycoproteins are often involved in cell binding, and some provide neutralization targets. However, the ... [more ▼]

All gammaherpesviruses encode a major glycoprotein homologous to the Epstein-Barr virus gp350. These glycoproteins are often involved in cell binding, and some provide neutralization targets. However, the capacity of gammaherpesviruses for long-term transmission from immune hosts implies that in vivo neutralization is incomplete. In this study, we used Bovine Herpesvirus 4 (BoHV-4) to determine how its gp350 homolog - gp180 - contributes to virus replication and neutralization. A lack of gp180 had no impact on the establishment and maintenance of BoHV-4 latency, but markedly sensitized virions to neutralization by immune sera. Antibody had greater access to gB, gH and gL on gp180-deficient virions, including neutralization epitopes. Gp180 appears to be highly O-glycosylated, and removing O-linked glycans from virions also sensitized them to neutralization. It therefore appeared that gp180 provides part of a glycan shield for otherwise vulnerable viral epitopes. Interestingly, this O-glycan shield could be exploited for neutralization by lectins and carbohydrate-specific antibody. The conservation of O-glycosylation sites in all gp350 homologs suggests that this is a general evasion mechanism that may also provide a therapeutic target. [less ▲]

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