Riffault, Sabine (19..-....).
Overview
| Works: | 9 works in 10 publications in 2 languages and 13 library holdings |
|---|---|
| Roles: | Other, Thesis advisor, Opponent, Author |
Publication Timeline
.
Most widely held works by
Sabine Riffault
Développement d'un vaccin contre le virus respiratoire syncytial, agent de la bronchite du nouveau- né : analyse des réponses
immunitaires au niveau du tractus respiratoire by
Xavier Pierre Marie Roux(
Book
)
in French and held by 3 WorldCat member libraries worldwide
Le virus respiratoire syncytial (VRS) est l'agent étiologique majeur des bronchiolites du nourisson. Au cours de mon travail de thèse, une stratégie de vaccination sous-unitaire par voie nasale basée sur la nucléoprotéine virale (N SRS) a été évaluée. Chez la souris adulte, N SRS induit une réponse protectrice contre une épreuve virale. Appliquée au souriceau, cette vaccination aboutit à un recrutement d'éosinophiles dans le poumon, signe d'une réponse immunopathologique de type Th2. Afin de comprendre les mécanismes gouvernant l'immunité du tractus respiratoire du nouveau-né, j'ai comparé l'activation et l'orientation des lymphocytes T CD4 du nouveau né et de l'adulte. La caractérisation phénotypique et fonctionnelle des cellules dendritiques pulmonaires n'a pas mis en évidence de différence liée à l'âge. En revanche j'ai confirmé chez le nouveau-né une orientation des lymphocytes T dans la voie Th2, qui corrèle avec la surexpression du facteur de transcription GATA-3
in French and held by 3 WorldCat member libraries worldwide
Le virus respiratoire syncytial (VRS) est l'agent étiologique majeur des bronchiolites du nourisson. Au cours de mon travail de thèse, une stratégie de vaccination sous-unitaire par voie nasale basée sur la nucléoprotéine virale (N SRS) a été évaluée. Chez la souris adulte, N SRS induit une réponse protectrice contre une épreuve virale. Appliquée au souriceau, cette vaccination aboutit à un recrutement d'éosinophiles dans le poumon, signe d'une réponse immunopathologique de type Th2. Afin de comprendre les mécanismes gouvernant l'immunité du tractus respiratoire du nouveau-né, j'ai comparé l'activation et l'orientation des lymphocytes T CD4 du nouveau né et de l'adulte. La caractérisation phénotypique et fonctionnelle des cellules dendritiques pulmonaires n'a pas mis en évidence de différence liée à l'âge. En revanche j'ai confirmé chez le nouveau-né une orientation des lymphocytes T dans la voie Th2, qui corrèle avec la surexpression du facteur de transcription GATA-3
A bovine respiratory syncytial virus model with high clinical expression in calves with specific passive immunity by Krister Blodörn(
)
1 edition published in 2015 in English and held by 2 WorldCat member libraries worldwide
1 edition published in 2015 in English and held by 2 WorldCat member libraries worldwide
Etude de la réponse immunitaire mucosale pulmonaire dans l'infection par Bacillus anthracis : rôle de l'interleukine-17 by
Kévin Garraud(
)
1 edition published in 2012 in French and held by 2 WorldCat member libraries worldwide
The pulmonary form of anthrax is caused by the inhalation of Bacillus anthracis spores, and is much feared because often fatal. This is the reason why B. anthracis is a pathogen of the military arsenal and bioterrorism.Recently, the role of interleukin (IL)-17, a proinflammatory cytokine, has been highlighted during the immune response after infection with various pulmonary pathogens, in particular through the recruitment of polymorphonuclear neutrophils (PMN). In this context, we study the role of the IL-17 in mice after intranasal infection with B. anthracis spores.Using various in vivo models (A / J mice and C57BL / 6), we showed that inhalational anthrax leads to a rapid secretion of IL-17 by the PMN. Furthermore, this production was dependent on the presence of B. anthracis toxins.Using knock out mice for the IL-17 receptor (IL-17ra-/-), we have shown the importance of IL-17 signal for self-recruitment of PMN, but also for the survival of animals infected with spores from the Sterne strain of B. anthracis, by intranasal or subcutaneous route. Surprisingly, infection with a virulent strain (toxigenic and encapsulated) did not affect the survival of IL-17ra-/- mouse.Finally, PMN depletion showed a decrease of time to death of the animals infected with the Sterne strain and decreased survival of animals infected with the virulent strain.This study demonstrates the complex role played by the IL-17 signal and the PNN during the immune response in inhalational anthrax
1 edition published in 2012 in French and held by 2 WorldCat member libraries worldwide
The pulmonary form of anthrax is caused by the inhalation of Bacillus anthracis spores, and is much feared because often fatal. This is the reason why B. anthracis is a pathogen of the military arsenal and bioterrorism.Recently, the role of interleukin (IL)-17, a proinflammatory cytokine, has been highlighted during the immune response after infection with various pulmonary pathogens, in particular through the recruitment of polymorphonuclear neutrophils (PMN). In this context, we study the role of the IL-17 in mice after intranasal infection with B. anthracis spores.Using various in vivo models (A / J mice and C57BL / 6), we showed that inhalational anthrax leads to a rapid secretion of IL-17 by the PMN. Furthermore, this production was dependent on the presence of B. anthracis toxins.Using knock out mice for the IL-17 receptor (IL-17ra-/-), we have shown the importance of IL-17 signal for self-recruitment of PMN, but also for the survival of animals infected with spores from the Sterne strain of B. anthracis, by intranasal or subcutaneous route. Surprisingly, infection with a virulent strain (toxigenic and encapsulated) did not affect the survival of IL-17ra-/- mouse.Finally, PMN depletion showed a decrease of time to death of the animals infected with the Sterne strain and decreased survival of animals infected with the virulent strain.This study demonstrates the complex role played by the IL-17 signal and the PNN during the immune response in inhalational anthrax
A Single Shot Pre-fusion-Stabilized Bovine RSV F Vaccine is Safe and Effective in Newborn Calves with Maternally Derived Antibodies by
Sabine Riffault(
)
1 edition published in 2020 in English and held by 1 WorldCat member library worldwide
Achieving safe and protective vaccination against respiratory syncytial virus (RSV) in infants and in calves has proven a challenging task. The design of recombinant antigens with a conformation close to their native form in virus particles is a major breakthrough. We compared two subunit vaccines, the bovine RSV (BRSV) pre-fusion F (preF) alone or with nanorings formed by the RSV nucleoprotein (preF+N). PreF and N proteins are potent antigenic targets for neutralizing antibodies and T cell responses, respectively. To tackle the challenges of neonatal immunization, three groups of six one-month-old calves with maternally derived serum antibodies (MDA) to BRSV received a single intramuscular injection of PreF, preF+N with Montanide (TM) ISA61 VG (ISA61) as adjuvant or only ISA61 (control). One month later, all calves were challenged with BRSV and monitored for virus replication in the upper respiratory tract and for clinical signs of disease over one week, and then post-mortem examinations of their lungs were performed. Both preF and preF+N vaccines afforded safe, clinical, and virological protection against BRSV, with little difference between the two subunit vaccines. Analysis of immune parameters pointed to neutralizing antibodies and antibodies to preF as being significant correlates of protection. Thus, a single shot vaccination with preF appears sufficient to reduce the burden of BRSV disease in calves with MDA
1 edition published in 2020 in English and held by 1 WorldCat member library worldwide
Achieving safe and protective vaccination against respiratory syncytial virus (RSV) in infants and in calves has proven a challenging task. The design of recombinant antigens with a conformation close to their native form in virus particles is a major breakthrough. We compared two subunit vaccines, the bovine RSV (BRSV) pre-fusion F (preF) alone or with nanorings formed by the RSV nucleoprotein (preF+N). PreF and N proteins are potent antigenic targets for neutralizing antibodies and T cell responses, respectively. To tackle the challenges of neonatal immunization, three groups of six one-month-old calves with maternally derived serum antibodies (MDA) to BRSV received a single intramuscular injection of PreF, preF+N with Montanide (TM) ISA61 VG (ISA61) as adjuvant or only ISA61 (control). One month later, all calves were challenged with BRSV and monitored for virus replication in the upper respiratory tract and for clinical signs of disease over one week, and then post-mortem examinations of their lungs were performed. Both preF and preF+N vaccines afforded safe, clinical, and virological protection against BRSV, with little difference between the two subunit vaccines. Analysis of immune parameters pointed to neutralizing antibodies and antibodies to preF as being significant correlates of protection. Thus, a single shot vaccination with preF appears sufficient to reduce the burden of BRSV disease in calves with MDA
Proteome analysis of bronchoalveolar lavage from calves infected with bovine respiratory syncytial virus-Insights in pathogenesis
and perspectives for new treatments by Sara Hägglund(
)
1 edition published in 2017 in English and held by 1 WorldCat member library worldwide
Human and bovine respiratory syncytial viruses (HRSV/BRSV) are major causes of severe lower respiratory tract infections in children and calves, respectively. Shared epidemiological, clinical, pathological and genetic characteristics of these viruses make comparative research highly relevant. To characterise the host response against BRSV infection, bronchoalveolar lavage supernatant (BAL) from i) non-vaccinated, BRSV-infected ii) vaccinated, BRSV-infected and iii) non-infected calves was analysed by tandem mass spectrometry. Proteins were semi-quantified and protein expression was validated by immunoblotting. Correlations between selected proteins and pathology, clinical signs and virus shedding were investigated. Calves with BRSV-induced disease had increased total protein concentrations and a decreased number of proteins identified in BAL. The protein profile was characterised by neutrophil activation and a reduction in identified antioxidant enzymes. The presence of neutrophils in alveolar septa, the expression level of neutrophil-related or antioxidant proteins and LZTFL1 correlated significantly with disease. Citrullinated histone 3, an indicator of extracellular traps (ETs), was only detected in non-vaccinated, BRSV-infected animals. By bringing disequilibrium in the release and detoxification of reactive oxygen species, generating ETs and causing elastine degradation, exaggerated neutrophil responses might exacerbate RSV-induced disease. Neutrophil-mitigating or antioxidant treatments should be further explored
1 edition published in 2017 in English and held by 1 WorldCat member library worldwide
Human and bovine respiratory syncytial viruses (HRSV/BRSV) are major causes of severe lower respiratory tract infections in children and calves, respectively. Shared epidemiological, clinical, pathological and genetic characteristics of these viruses make comparative research highly relevant. To characterise the host response against BRSV infection, bronchoalveolar lavage supernatant (BAL) from i) non-vaccinated, BRSV-infected ii) vaccinated, BRSV-infected and iii) non-infected calves was analysed by tandem mass spectrometry. Proteins were semi-quantified and protein expression was validated by immunoblotting. Correlations between selected proteins and pathology, clinical signs and virus shedding were investigated. Calves with BRSV-induced disease had increased total protein concentrations and a decreased number of proteins identified in BAL. The protein profile was characterised by neutrophil activation and a reduction in identified antioxidant enzymes. The presence of neutrophils in alveolar septa, the expression level of neutrophil-related or antioxidant proteins and LZTFL1 correlated significantly with disease. Citrullinated histone 3, an indicator of extracellular traps (ETs), was only detected in non-vaccinated, BRSV-infected animals. By bringing disequilibrium in the release and detoxification of reactive oxygen species, generating ETs and causing elastine degradation, exaggerated neutrophil responses might exacerbate RSV-induced disease. Neutrophil-mitigating or antioxidant treatments should be further explored
INDUCTION VIRALE D'INTERFERON-/ : ETUDE IN VIVO DES CELLULES PRODUCTRICES DANS LES TISSUS LYMPHOIDES ET DES MODIFICATIONS
LOCALEMENT INDUITES PAR L'INTERFERON by
Sabine Riffault(
Book
)
in French and held by 1 WorldCat member library worldwide
UNE SOUS-POPULATION DE LEUCOCYTES, QUI PRODUISENT DE FORTES QUANTITES D'IFN- APRES INDUCTION IN VITRO PAR DES STRUCTURES VIRALES NON INFECTIEUSES, A ETE DECRITE A PARTIR DE CELLULES MONONUCLEEES DU SANG PERIPHERIQUE. CES CELLULES, NOMMEES CELLULES NATURELLEMENT PRODUTRICES D'INTERFERON (NIP), SONT DISTINCTES DES LYMPHOCYTES T, DES LYMPHOCYTES B, DES CELLULES NK ET DES MONOCYTES. EN REVANCHE, ELLES EXPRIMENT LES MOLECULES DU COMPLEXE MAJEUR D'HISTOCOMPATIBILITE (CMH) DE CLASSE II ET LE MARQUEUR CD4 ET POURRAIENT S'APPARENTER AUX CELLULES DENDRITIQUES IMMATURES. DEUX ETUDES REALISEES IN VIVO ONT MONTRE LA PRESENCE DE CELLULES SECRETRICES D'IFN-/ DANS LES TISSUS LYMPHOIDES SUITE A L'INJECTION DE PREPARATIONS VIRALES NON INFECTIEUSES. L'OBJECTIF DE CETTE THESE A ETE D'ETUDIER LE MECANISME D'INDUCTION DES CELLULES NIP IN VIVO, DE DETERMINER LEUR LOCALISATION ET LEUR PHENOTYPE IN VIVO ET ENFIN D'ANALYSER LE ROLE IMMUNOMODULATEUR DE CETTE SYNTHESE D'IFN-/. NOUS AVONS MONTRE QUE LA GLYCOPROTEINE M DE L'ENVELOPPE VIRALE DU CORONAVIRUS DE LA GASTROENTERITE TRANSMISSIBLE (TGEV) EST NECESSAIRE A L'INDUCTION D'IFN- IN VIVO COMME CELA A ETE DECRIT IN VITRO. CEPENDANT, DES VIROSOMES RECONSTITUES A PARTIR DES PROTEINES DE L'ENVELOPPE VIRALE ET DONT LA PROTEINE M COMPORTE LES EPITOPES NECESSAIRES A L'INDUCTION D'IFN- ONT PERDU LE POUVOIR INTEREFEROGENE DU VIRUS NATIF. CES RESULTATS SUGGERENT QUE D'AUTRES ELEMENTS VIRAUX QUE LA PROTEINE M INTERAGISSENT AVEC LES CELLULES NIP POUR INDUIRE L'IFN-. LE MODELE EXPERIMENTAL D'INDUCTION D'IFN- CHEZ LE PORCELET NOUVEAU-NE, PAR INJECTION INTRA-VEINEUSE DE TGEV NON INFECTIEUX, NOUS A PERMIS DE MONTRER QUE LES CELLULES NIP INDUITES IN VIVO SONT PRESENTES PARMI LES SPLENOCYTES MAIS ABSENTES DES CELLULES DU SANG PERIPHERIQUE. NOUS AVONS ALORS DETERMINE PAR IMMUNOHISTOCHIMIE, LA LOCALISATION TISSULAIRE ET LE PHENOTYPE IN SITU DES CELLULES NIP PORCINES DETECTEES DANS LA RATE. CES CELLULES SONT DISTINCTES DES CELLULES T ET B MAIS ELLES FORMENT UNE POPULATION HETEROGENE SUR LA BASE DE L'EXPRESSION DES MOLECULES DU CMH DE CLASSE II ET D'UN MARQUEUR DES GRANULOCYTES/MACROPHAGES. ELLES SONT LOCALISEES DANS LE MANCHON LYMPHATIQUE PERIARTERIOLAIRE EN CONTACT AVEC LES CELLULES T ET LES CELLULES EXPRIMANT LES MOLECULES DU CMH DE CLASSE II. L'IFN- EST DONC SECRETE AU SITE D'INITIATION DE LA REPONSE IMMUNITAIRE ANTI-TGEV ET POURRAIT AINSI MODULER CETTE REPONSE. LE MODELE EXPERIMENTAL D'INDUCTION D'IFN-/ CHEZ LA SOURIS A ETE DEVELOPPE DE MANIERE A INDUIRE UNE REPONSE IFN-/ LOCALISEE DANS LE GANGLION DRAINANT LE SITE D'INJECTION (L'OREILLE) DU VIRUS DE L'HERPES SIMPLEX DE TYPE I NON INFECTIEUX, LES TISSUS CONTRALATERAUX (OREILLE ET GANGLION) CONSTITUANT DES TEMOINS INTERNES. CE MODELE NOUS A PERMIS DE MONTRER QUE L'IFN-/, SECRETE LOCALEMENT PAR LES CELLULES NIP, PROVOQUE UN RECRUTEMENT LEUCOCYTAIRE DANS LE GANGLION DRAINANT ET AUGMENTE L'EXPRESSION DE CYTOKINES VIRO-INDUITES (IFN- ET IL-12) IMPLIQUEES DANS LA DIFFERENCIATION DES LYMPHOCYTES T VERS LE PHENOTYPE TH1. CES RESULTATS ETABLISSENT DONC LES BASES DE L'ANALYSE IN VIVO DES FONCTIONS IMMUNOMODULATRICES DE L'IFN-/ PRODUIT LOCALEMENT PAR LES CELLULES NIP LORS DE L'INITIATION D'UNE REPONSE IMMUNITAIRE ANTIVIRALE
in French and held by 1 WorldCat member library worldwide
UNE SOUS-POPULATION DE LEUCOCYTES, QUI PRODUISENT DE FORTES QUANTITES D'IFN- APRES INDUCTION IN VITRO PAR DES STRUCTURES VIRALES NON INFECTIEUSES, A ETE DECRITE A PARTIR DE CELLULES MONONUCLEEES DU SANG PERIPHERIQUE. CES CELLULES, NOMMEES CELLULES NATURELLEMENT PRODUTRICES D'INTERFERON (NIP), SONT DISTINCTES DES LYMPHOCYTES T, DES LYMPHOCYTES B, DES CELLULES NK ET DES MONOCYTES. EN REVANCHE, ELLES EXPRIMENT LES MOLECULES DU COMPLEXE MAJEUR D'HISTOCOMPATIBILITE (CMH) DE CLASSE II ET LE MARQUEUR CD4 ET POURRAIENT S'APPARENTER AUX CELLULES DENDRITIQUES IMMATURES. DEUX ETUDES REALISEES IN VIVO ONT MONTRE LA PRESENCE DE CELLULES SECRETRICES D'IFN-/ DANS LES TISSUS LYMPHOIDES SUITE A L'INJECTION DE PREPARATIONS VIRALES NON INFECTIEUSES. L'OBJECTIF DE CETTE THESE A ETE D'ETUDIER LE MECANISME D'INDUCTION DES CELLULES NIP IN VIVO, DE DETERMINER LEUR LOCALISATION ET LEUR PHENOTYPE IN VIVO ET ENFIN D'ANALYSER LE ROLE IMMUNOMODULATEUR DE CETTE SYNTHESE D'IFN-/. NOUS AVONS MONTRE QUE LA GLYCOPROTEINE M DE L'ENVELOPPE VIRALE DU CORONAVIRUS DE LA GASTROENTERITE TRANSMISSIBLE (TGEV) EST NECESSAIRE A L'INDUCTION D'IFN- IN VIVO COMME CELA A ETE DECRIT IN VITRO. CEPENDANT, DES VIROSOMES RECONSTITUES A PARTIR DES PROTEINES DE L'ENVELOPPE VIRALE ET DONT LA PROTEINE M COMPORTE LES EPITOPES NECESSAIRES A L'INDUCTION D'IFN- ONT PERDU LE POUVOIR INTEREFEROGENE DU VIRUS NATIF. CES RESULTATS SUGGERENT QUE D'AUTRES ELEMENTS VIRAUX QUE LA PROTEINE M INTERAGISSENT AVEC LES CELLULES NIP POUR INDUIRE L'IFN-. LE MODELE EXPERIMENTAL D'INDUCTION D'IFN- CHEZ LE PORCELET NOUVEAU-NE, PAR INJECTION INTRA-VEINEUSE DE TGEV NON INFECTIEUX, NOUS A PERMIS DE MONTRER QUE LES CELLULES NIP INDUITES IN VIVO SONT PRESENTES PARMI LES SPLENOCYTES MAIS ABSENTES DES CELLULES DU SANG PERIPHERIQUE. NOUS AVONS ALORS DETERMINE PAR IMMUNOHISTOCHIMIE, LA LOCALISATION TISSULAIRE ET LE PHENOTYPE IN SITU DES CELLULES NIP PORCINES DETECTEES DANS LA RATE. CES CELLULES SONT DISTINCTES DES CELLULES T ET B MAIS ELLES FORMENT UNE POPULATION HETEROGENE SUR LA BASE DE L'EXPRESSION DES MOLECULES DU CMH DE CLASSE II ET D'UN MARQUEUR DES GRANULOCYTES/MACROPHAGES. ELLES SONT LOCALISEES DANS LE MANCHON LYMPHATIQUE PERIARTERIOLAIRE EN CONTACT AVEC LES CELLULES T ET LES CELLULES EXPRIMANT LES MOLECULES DU CMH DE CLASSE II. L'IFN- EST DONC SECRETE AU SITE D'INITIATION DE LA REPONSE IMMUNITAIRE ANTI-TGEV ET POURRAIT AINSI MODULER CETTE REPONSE. LE MODELE EXPERIMENTAL D'INDUCTION D'IFN-/ CHEZ LA SOURIS A ETE DEVELOPPE DE MANIERE A INDUIRE UNE REPONSE IFN-/ LOCALISEE DANS LE GANGLION DRAINANT LE SITE D'INJECTION (L'OREILLE) DU VIRUS DE L'HERPES SIMPLEX DE TYPE I NON INFECTIEUX, LES TISSUS CONTRALATERAUX (OREILLE ET GANGLION) CONSTITUANT DES TEMOINS INTERNES. CE MODELE NOUS A PERMIS DE MONTRER QUE L'IFN-/, SECRETE LOCALEMENT PAR LES CELLULES NIP, PROVOQUE UN RECRUTEMENT LEUCOCYTAIRE DANS LE GANGLION DRAINANT ET AUGMENTE L'EXPRESSION DE CYTOKINES VIRO-INDUITES (IFN- ET IL-12) IMPLIQUEES DANS LA DIFFERENCIATION DES LYMPHOCYTES T VERS LE PHENOTYPE TH1. CES RESULTATS ETABLISSENT DONC LES BASES DE L'ANALYSE IN VIVO DES FONCTIONS IMMUNOMODULATRICES DE L'IFN-/ PRODUIT LOCALEMENT PAR LES CELLULES NIP LORS DE L'INITIATION D'UNE REPONSE IMMUNITAIRE ANTIVIRALE
Biologie cellulaire des endosomes IRAP+ dans les cellules dendritiques by
Joël Babdor(
)
1 edition published in 2014 in French and held by 1 WorldCat member library worldwide
Par leur activité permanente à l'état basal et en situation infectieuse, les cellules dendritiques (DC) de l'organisme orchestrent la tolérance du soi et l'élimination du non-soi, en façonnant les réponses immunes. Ce rôle immunologique complexe des DC repose en grande partie sur des mécanismes de biologie cellulaire spécifiques, qui font l'objet d'un effort considérable de caractérisation. Le travail réalisé au cours de cette thèse met en lumière une sous-population endosomale jouant un rôle clé dans les processus cellulaires de modulation de l'immunité par les DC : les endosomes IRAP+ (insulin responsive aminopeptidase). Etudiée dans différents contextes biologiques depuis 1930, IRAP s'est récemment révélée être impliquée dans l'apprêtement endo-phagosomal des antigènes exogènes par les DC, en vue de leur présentation croisée aux lymphocytes T (Saveanu et al., 2009; Weimershaus et al., 2012). Cette découverte a attiré notre attention sur les endosomes IRAP+/RAB14+ peu étudiés dans les DC. Ce travail étudie la place des endosomes IRAP dans la biologie cellulaire des DC ainsi que le rôle de ces endosomes dans les fonctions biologiques des DC. Nous avons étudié l'influence des endosomes IRAP sur les autres compartiments cellulaires et démontré leur implication dans un système endolysosomal de régulation de la réponse inflammatoire aux pathogènes. Nous avons également étudié l'impact de IRAP sur les processus de maturation des phagosomes et montré leur influence sur les processus subséquent d'élimination des pathogènes et de présentation croisée. Les endosomes IRAP+ sont donc mis en jeu dans la modulation de la maturation phagosomale et de l'inflammation, mais également dans l'optimisation de la présentation des antigènes aux lymphocytes T ; trois processus qui reposent sur une régulation fine de la compartimentation intracellulaire. L'ensemble des résultats de cette thèse définit les endosomes IRAP+ comme un des acteurs majeurs de la « régulation compartimentée » des processus cellulaires des DC, au cœur de la machinerie qui régit les équilibres de l'immunité
1 edition published in 2014 in French and held by 1 WorldCat member library worldwide
Par leur activité permanente à l'état basal et en situation infectieuse, les cellules dendritiques (DC) de l'organisme orchestrent la tolérance du soi et l'élimination du non-soi, en façonnant les réponses immunes. Ce rôle immunologique complexe des DC repose en grande partie sur des mécanismes de biologie cellulaire spécifiques, qui font l'objet d'un effort considérable de caractérisation. Le travail réalisé au cours de cette thèse met en lumière une sous-population endosomale jouant un rôle clé dans les processus cellulaires de modulation de l'immunité par les DC : les endosomes IRAP+ (insulin responsive aminopeptidase). Etudiée dans différents contextes biologiques depuis 1930, IRAP s'est récemment révélée être impliquée dans l'apprêtement endo-phagosomal des antigènes exogènes par les DC, en vue de leur présentation croisée aux lymphocytes T (Saveanu et al., 2009; Weimershaus et al., 2012). Cette découverte a attiré notre attention sur les endosomes IRAP+/RAB14+ peu étudiés dans les DC. Ce travail étudie la place des endosomes IRAP dans la biologie cellulaire des DC ainsi que le rôle de ces endosomes dans les fonctions biologiques des DC. Nous avons étudié l'influence des endosomes IRAP sur les autres compartiments cellulaires et démontré leur implication dans un système endolysosomal de régulation de la réponse inflammatoire aux pathogènes. Nous avons également étudié l'impact de IRAP sur les processus de maturation des phagosomes et montré leur influence sur les processus subséquent d'élimination des pathogènes et de présentation croisée. Les endosomes IRAP+ sont donc mis en jeu dans la modulation de la maturation phagosomale et de l'inflammation, mais également dans l'optimisation de la présentation des antigènes aux lymphocytes T ; trois processus qui reposent sur une régulation fine de la compartimentation intracellulaire. L'ensemble des résultats de cette thèse définit les endosomes IRAP+ comme un des acteurs majeurs de la « régulation compartimentée » des processus cellulaires des DC, au cœur de la machinerie qui régit les équilibres de l'immunité
Conception de nouveaux vaccins anti-VIH basés sur des épitopes conformationels cross clade de gp41 issus d'anticorps muqueux
protecteurs de sujets exposés au VIH mais restant séronégatifs (ESN) by
Marwa Khamassi(
)
1 edition published in 2019 in French and held by 1 WorldCat member library worldwide
AIDS is an infection transmitted mainly in the genital mucosa. It is at this level that an effective barrier should be developed to block infection from the initial entry of HIV-1 in the genitals, before establishment of mucosal reservoirs. IgA is the main protective antibody at the genital mucosa and has been suggested to be protective in vivo against HIV-1. Hence, mucosal gp41-specific IgA with strong cross-clade antiviral activity are a major protective correlate in Highly HIV- Exposed individuals that remain SeroNegative (ESN) despite unprotected sexual intercourse with infected partners. However, genital mucosa are also protected by IgG whose origin and role are currently reevaluated. In this work, we have analyzed the influence of the antibody isotype, IgA or IgG, on the epitope specificity, antiviral functions of HIV-1 protective antibodies and evaluated new antiviral functions mediated by the constant IgA regions. For this purpose we have used a library of protective Fab IgA derived from ESN women that are specific for conserved regions of the HIV-1 envelope gp41 subunit, already characterized in the laboratory (Tudor et al., Mucosal Immunol, 2009). By genetic engineering, we have first transformed two of these Fab IgA (FabA) into their corresponding Fab IgG (FabG), having the same paratopes but differing from each other by their CH1 domain (alpha or gamma). These two FabA/FabG couples were then analyzed comparatively for their epitope specificity and functional activities. We have shown that the isotype and particularly the CH1 domain influences (i) the affinity of Fabs for their antigens (gp41 and P1 of clades A, B and C) using surface plasmon resonance and ELISA : FabA have a 50- to 100-fold higher affinity than corresponding FabG ; (ii) antiviral functions: FabA more effectively neutralize CD4+ T-cells infection and transfer of HIV-1 from Langerhans cells to CD4+ T-cells than their corresponding FabG. In a second step, taking as experimental model the neutralizing HIV-1 antibody 2F5 as IgA, we demonstrated that IgA specific for gp41 were able to lyse HIV-1 infected cells in a process mediated by their Fc alpha domain, namely antibody mediated cell cytoxicity (ADCC), a function usually attributed to IgG. Furthermore, anti-gp41 IgA and IgG work in synergy to increase HIV-1-infected cell lysis. Altogether, the results show the isotype (the CH1 domain) has an influence on the recognition and affinity for the antigen, but also on the quality of the secondary immune response (antiviral functions). Finally, we characterized epitopes specific from the two FabA/FabG couples using biopanning followed by in silico analysis. Cross clade 3-dimensional epitopes were mapped on gp41 from Clade A, B and C, each in pre- or post-fusion conformation. These analyses allowed to define cross clade 3-dimensional epitopes targeted by these protective antibodies derived from ESN subjects. These epitopes could serve as immunogen in a vaccine strategy aiming at recapitulating the protective ESN IgA response. Altogether, we have used the strategy of Reverse Vaccinology 2.0 to characterize novel immunogens based on 3D-epitopes targeted by mucosal antibodies from individuals resisting HIV infection. These results should be taken into account in the design of an effective vaccine against the active clades of HIV-1 in the world (A, B and C). Such mucosal vaccine approach is necessary to decrease the number of new HIV infections among women (the most affected) but also in men, which remains a huge public health challenge
1 edition published in 2019 in French and held by 1 WorldCat member library worldwide
AIDS is an infection transmitted mainly in the genital mucosa. It is at this level that an effective barrier should be developed to block infection from the initial entry of HIV-1 in the genitals, before establishment of mucosal reservoirs. IgA is the main protective antibody at the genital mucosa and has been suggested to be protective in vivo against HIV-1. Hence, mucosal gp41-specific IgA with strong cross-clade antiviral activity are a major protective correlate in Highly HIV- Exposed individuals that remain SeroNegative (ESN) despite unprotected sexual intercourse with infected partners. However, genital mucosa are also protected by IgG whose origin and role are currently reevaluated. In this work, we have analyzed the influence of the antibody isotype, IgA or IgG, on the epitope specificity, antiviral functions of HIV-1 protective antibodies and evaluated new antiviral functions mediated by the constant IgA regions. For this purpose we have used a library of protective Fab IgA derived from ESN women that are specific for conserved regions of the HIV-1 envelope gp41 subunit, already characterized in the laboratory (Tudor et al., Mucosal Immunol, 2009). By genetic engineering, we have first transformed two of these Fab IgA (FabA) into their corresponding Fab IgG (FabG), having the same paratopes but differing from each other by their CH1 domain (alpha or gamma). These two FabA/FabG couples were then analyzed comparatively for their epitope specificity and functional activities. We have shown that the isotype and particularly the CH1 domain influences (i) the affinity of Fabs for their antigens (gp41 and P1 of clades A, B and C) using surface plasmon resonance and ELISA : FabA have a 50- to 100-fold higher affinity than corresponding FabG ; (ii) antiviral functions: FabA more effectively neutralize CD4+ T-cells infection and transfer of HIV-1 from Langerhans cells to CD4+ T-cells than their corresponding FabG. In a second step, taking as experimental model the neutralizing HIV-1 antibody 2F5 as IgA, we demonstrated that IgA specific for gp41 were able to lyse HIV-1 infected cells in a process mediated by their Fc alpha domain, namely antibody mediated cell cytoxicity (ADCC), a function usually attributed to IgG. Furthermore, anti-gp41 IgA and IgG work in synergy to increase HIV-1-infected cell lysis. Altogether, the results show the isotype (the CH1 domain) has an influence on the recognition and affinity for the antigen, but also on the quality of the secondary immune response (antiviral functions). Finally, we characterized epitopes specific from the two FabA/FabG couples using biopanning followed by in silico analysis. Cross clade 3-dimensional epitopes were mapped on gp41 from Clade A, B and C, each in pre- or post-fusion conformation. These analyses allowed to define cross clade 3-dimensional epitopes targeted by these protective antibodies derived from ESN subjects. These epitopes could serve as immunogen in a vaccine strategy aiming at recapitulating the protective ESN IgA response. Altogether, we have used the strategy of Reverse Vaccinology 2.0 to characterize novel immunogens based on 3D-epitopes targeted by mucosal antibodies from individuals resisting HIV infection. These results should be taken into account in the design of an effective vaccine against the active clades of HIV-1 in the world (A, B and C). Such mucosal vaccine approach is necessary to decrease the number of new HIV infections among women (the most affected) but also in men, which remains a huge public health challenge
Single-Shot Vaccines against Bovine Respiratory Syncytial Virus (BRSV) Comparative Evaluation of Long-Term Protection after
Immunization in the Presence of BRSV-Specific Maternal Antibodies by
Jean Francois Valarcher(
)
1 edition published in 2021 in English and held by 1 WorldCat member library worldwide
The induction of long-lasting clinical and virological protection is needed for a successful vaccination program against the bovine respiratory syncytial virus (BRSV). In this study, calves with BRSV-specific maternally derived antibodies were vaccinated once, either with (i) a BRSV pre-fusion protein (PreF) and Montanide(TM) ISA61 VG (ISA61, n = 6), (ii) BRSV lacking the SH gene (Delta SHrBRSV, n = 6), (iii) a commercial vaccine (CV, n = 6), or were injected with ISA61 alone (n = 6). All calves were challenged with BRSV 92 days later and were euthanized 13 days post-infection. Based on clinical, pathological, and proteomic data, all vaccines appeared safe. Compared to the controls, PreF induced the most significant clinical and virological protection post-challenge, followed by Delta SHrBRSV and CV, whereas the protection of PreF-vaccinated calves was correlated with BRSV-specific serum immunoglobulin (Ig)G antibody responses 84 days post-vaccination, and the IgG antibody titers of Delta SHrBRSV- and CV-vaccinated calves did not differ from the controls on this day. Nevertheless, strong anamnestic BRSV- and PreF-specific IgG responses occurred in calves vaccinated with either of the vaccines, following a BRSV challenge. In conclusion, PreF and Delta SHrBRSV are two efficient one-shot candidate vaccines. By inducing a protection for at least three months, they could potentially improve the control of BRSV in calves
1 edition published in 2021 in English and held by 1 WorldCat member library worldwide
The induction of long-lasting clinical and virological protection is needed for a successful vaccination program against the bovine respiratory syncytial virus (BRSV). In this study, calves with BRSV-specific maternally derived antibodies were vaccinated once, either with (i) a BRSV pre-fusion protein (PreF) and Montanide(TM) ISA61 VG (ISA61, n = 6), (ii) BRSV lacking the SH gene (Delta SHrBRSV, n = 6), (iii) a commercial vaccine (CV, n = 6), or were injected with ISA61 alone (n = 6). All calves were challenged with BRSV 92 days later and were euthanized 13 days post-infection. Based on clinical, pathological, and proteomic data, all vaccines appeared safe. Compared to the controls, PreF induced the most significant clinical and virological protection post-challenge, followed by Delta SHrBRSV and CV, whereas the protection of PreF-vaccinated calves was correlated with BRSV-specific serum immunoglobulin (Ig)G antibody responses 84 days post-vaccination, and the IgG antibody titers of Delta SHrBRSV- and CV-vaccinated calves did not differ from the controls on this day. Nevertheless, strong anamnestic BRSV- and PreF-specific IgG responses occurred in calves vaccinated with either of the vaccines, following a BRSV challenge. In conclusion, PreF and Delta SHrBRSV are two efficient one-shot candidate vaccines. By inducing a protection for at least three months, they could potentially improve the control of BRSV in calves
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Related Identities
- Taylor, Geraldine
- Valarcher, Jean Francois Author
- Hägglund, Sara Author
- Vargmar, Karin
- Näslund, Katarina
- Roux, Xavier Pierre Marie (1978-....). Author
- Université de Versailles-Saint-Quentin-en-Yvelines Degree grantor
- Jouneau, Luc
- Centre de recherches du Service de santé des armées (France) Other
- Gauthier, David