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À l’automne 2000, les psychoéducateurs célébraient les 20 ans de leur intégration au système professionnel. Ce moment marquant de leur histoire collective était en préparation depuis nombre d’années. Entre autres conséquences, le regroupement des psychoéducateurs dans un ordre a signifié la mise en place de structures d’accès, de surveillance et de discipline de l’exercice de la profession. Cet article pose un regard sur cette histoire, tenant compte du contexte de réforme des professions liées à la santé mentale et aux relations humaines, en cours depuis 2009 (PL 21). Après avoir retracé les principales étapes de développement de l’Ordre des psychoéducateurs et psychoéducatrices du Québec (OPPQ), quelques observations sur l’évolution de la pratique de ces professionnels sont présentées. Celles-ci pourraient avoir un impact sur les activités de l’Ordre dans l’avenir., In the autumn of 2021, psychoeducators will celebrate 20 years since their integration into Quebec’s professional services. This defining moment was a long time in the making. Among other effects, the consolidation of psychoeducators into a professional order has led to the establishment of structures of access, supervision, and discipline in the exercise of the profession. This article looks at this history in the context of the reform of mental health and human relations professions that has been ongoing since 2009 (PL21). After detailing the main stages of the development of the Order of Psychoeducators (OPPQ), some observations on the evolution of the professional practice are discussed along with their potential impacts on the future activities of the order.

A vaccine candidate to SARS-CoV-2 was constructed by coupling the viral receptor binding domain (RBD) to the surface of the papaya mosaic virus (PapMV) nanoparticle (nano) to generate the RBD-PapMV vaccine. Immunization of mice with the coupled RBD-PapMV vaccine enhanced the antibody titers and the T-cell mediated immune response directed to the RBD antigen as compared to immunization with the non-coupled vaccine formulation (RBD + PapMV nano). Anti-RBD antibodies, generated in vaccinated animals, neutralized SARS-CoV-2 infection in vitro against the ancestral, Delta and the Omicron variants. At last, immunization of mice susceptible to the infection by SARS-CoV-2 (K18-hACE2 transgenic mice) with the RBD-PapMV vaccine induced protection to the ancestral SARS-CoV-2 infectious challenge. The induction of the broad neutralization against SARS-CoV-2 variants induced by the RBD-PapMV vaccine demonstrate the potential of the PapMV vaccine platform in the development of efficient vaccines against viral respiratory infections.

Background: The papaya mosaic virus (PapMV) vaccine platform is a rod-shaped nanoparticle made of the recombinant PapMV coat protein (CP) self-assembled around a noncoding single-stranded RNA (ssRNA) template. The PapMV nanoparticle induces innate immunity through stimulation of the Toll-like receptors (TLR) 7 and 8. The display of the vaccine antigen at the surface of the nanoparticle, associated with the co-stimulation signal via TLR7/8, ensures a strong stimulation of the immune response, which is ideal for the development of candidate vaccines. In this study, we assess the impact of where the peptide antigen is fused, whether at the surface or at the extremities of the nanoparticles, on the immune response directed to that antigen. Methods: Two different peptides from influenza A virus were used as model antigens. The conserved M2e peptide, derived from the matrix protein 2 was chosen as the B-cell epitope, and a peptide derived from the nucleocapsid was chosen as the cytotoxic T lymphocytes (CTL) epitope. These peptides were coupled at two different positions on the PapMV CP, the N- (PapMV-N) or the C-terminus (PapMV-C), using the transpeptidase activity of Sortase A (SrtA). The immune responses, both humoral and CD8+ T-cell-mediated, directed to the peptide antigens in the two different fusion contexts were analyzed and compared. The impact of coupling density at the surface of the nanoparticle was also investigated. Conclusions: The results demonstrate that coupling of the peptide antigens at the N-terminus (PapMV-N) of the PapMV CP led to an enhanced immune response to the coupled peptide antigens as compared to coupling to the C-terminus. The difference between the two vaccine platforms is linked to the enhanced capacity of the PapMV-N vaccine platform to stimulate TLR7/8. We also demonstrated that the strength of the immune response increases with the density of coupling at the surface of the nanoparticles.

Inactivated influenza vaccines efficacy is variable and often poor. We conducted a phase 1 trial (NCT02188810), to assess the safety and immunogenicity of a novel nanoparticle Toll-like receptor 7/8 agonist adjuvant (Papaya Mosaic Virus) at different dose levels combined with trivalent influenza vaccine in healthy persons 18&ndash, 50 years of age. Hemagglutination-inhibition assays, antibody to Influenza A virus nucleoprotein and peripheral blood mononuclear cells for measurement of interferon-gamma ELISPOT response to influenza antigens, Granzyme B and IFN&gamma, IL-10 ratio were measured. The most common adverse events were transient mild to severe injection site pain and no safety signals were observed. A dose-related adjuvant effect was observed. Geometric mean hemagglutination-inhibition titers increased at day 28 in most groups and waned over time, but fold-antibody responses were poor in all groups. Cell mediated immunity results were consistent with humoral responses. The Papaya Mosaic Virus adjuvant in doses of 30 to 240 &micro, g combined with reduced influenza antigen content was safe with no signals up to 3 years after vaccination. A dose-related adjuvant effect was observed and immunogenicity results suggest that efficacy study should be conducted in influenza antigen-na&iuml, ve participants.

Rod-shaped virus-like nanoparticles (VLNP) made of papaya mosaic virus (PapMV) coat proteins (CP) self-assembled around a single stranded RNA (ssRNA) were showed to be a TLR7 agonist. Their utilization as an immune modulator in cancer immunotherapy was shown to be promising. To establish a clinical relevance in human for PapMV VLNP, we showed that stimulation of human peripheral blood mononuclear cells (PBMC) with VLNP induces the secretion of interferon alpha (IFNα) and other pro-inflammatory cytokines and chemokines. Plasmacytoid dendritic cells (pDCs) were activated and secreted IFN-α upon VLNP exposure. Monocyte-derived dendritic cells upregulate maturation markers and produce IL-6 in response to PapMV VLNP stimulation, which suggests the activation of TLR8. Finally, when co-cultured with NK cells, PapMV induced pDCs promoted the NK cytolytic activity against cancer cells. These data obtained with primary human immune cells further strengthen the clinical relevance of PapMV VLNPs as a cancer immunotherapy agent.

Resume Objectif Le nombre de Drives a predominance alimentaire connait une progression fulgurante entre les annees 2010 et 2013, revolutionnant la culture de la grande distribution. Dans un contexte de defi economique, les enseignes repensent la conception des locaux et l’organisation du travail tout en minimisant les surcouts. Un Drive se definit par des points de retraits proposes par les enseignes de la grande distribution qui permettent la livraison des articles dans le coffre du vehicule du client. Il effectue au prealable une commande a distance sur un site Internet dedie ou une application mobile. Le client choisit le jour et le creneau horaire pour le retrait de ses articles. L’eclosion dans l’urgence de ces Drives interroge quant aux conditions de travail et aux consequences pour la sante-securite des salaries. Methodes Pour repondre a ces questions, deux outils complementaires sont deployes : une approche ergonomique pour analyser l’activite reelle des salaries dans les differentes enseignes et un auto-questionnaire passe aupres des preparateurs. L’objectif de l’etude ergonomique vise a identifier les contraintes de l’activite realisee et a preciser leurs determinants. L’autoquestionnaire apporte des renseignements complementaires sur les caracteristiques de la population, les douleurs evoquees et leurs ressentis quant aux contraintes physiques et psycho-organisationnelles. Resultats Les resultats montrent une population caracterisee par sa jeunesse, sa faible anciennete et son niveau de diplome eleve. Les plaintes exprimees sont importantes et affectent plus specifiquement la region lombaire, l’articulation de l’epaule et les membres inferieurs, ceci independamment des modeles de Drives. Au-dela des facteurs biomecaniques, cette approche souligne l’importance des facteurs psycho-organisationnels dans l’evocation des plaintes. Par ailleurs, cette etude ne montre pas de differences tant pour les contraintes physiques que psycho-organisationnelles entre les differents modeles de Drives. Conclusion Cette etude ouvre des perspectives d’amelioration des conditions de travail sur differents axes : organisationnel, materiel, dimensionnel et relationnel.

The increasing use of plant viruses for the development of new vaccines and immunotherapy approaches poses questions regarding the mechanism by which the mammalian immune system recognizes these viruses. For example, although natural Abs (NA) and complement are key components of the innate immune system involved in the opsonization, phagocytosis, and destruction of microorganisms infecting mammals, their implication in plant virus recognition and immunogenicity is not well defined. In this study, we address the involvement of NA and the complement system in the activation of innate immunity through engagement of TLR7 with papaya mosaic virus (PapMV)-like nanoparticles. We demonstrate that NA, although binding to PapMV, are not involved in its recognition by the immune system. On the other hand, C3 strongly binds to PapMV nanoparticles and its depletion significantly reduces PapMV’s interaction with immune cells. Unexpectedly, however, we observed increased immune cell activation following administration of PapMV to complement-depleted mice. TLR7 activation by PapMV in the absence of C3 induced higher IFN-α production, resulting in superior immune cell activation and increased immunotherapeutic properties. In conclusion, in this study we established the involvement of the complement system in the recognition and the phagocytosis of PapMV nanoparticles and identified an unsuspected role for C3 in regulating the production of IFN-α following TLR7 activation.

La progression rapide du nombre de Drives alimentaires entre 2010 et 2013 interrogeait sur la possibilite de travailler dans la duree avec des conditions de travail contraignantes. Pour repondre a ce questionnement les preparateurs de commandes de la region Grand-Est sont interroges a deux ans d’intervalle (T1 = 2015/2016 et T2 = 2017/2018) par auto-questionnaire (douleurs evoquees, contraintes physiques et psycho-organisationnelles). Des scores sont construits pour mesurer les contraintes physiques et psycho-organisationnelles. En 2015, les resultats ont montre une population caracterisee par sa jeunesse, sa faible anciennete et majoritairement diplomee BAC et plus. Les plaintes exprimees etaient importantes et affectaient plus specifiquement la region lombaire, l’articulation de l’epaule et les membres inferieurs. Au-dela des facteurs biomecaniques, l’importance des facteurs psycho-organisationnels etait evoquee. En 2017, seule la moitie des salaries interroges lors de la premiere phase est encore presente. L’analyse des salaries perdus de vue montre qu’il s’agit principalement de depart pour fin de contrat. Les conditions de travail et leur vecu ne semblent pas etre a l’origine des departs. Les comparaisons de tous les salaries presents en T1 (n = 279) et en T2 (n = 446) montrent que : – les caracteristiques des preparateurs sont semblables, a l’exception du niveau de diplome, en T2 une majorite de salaries a un BAC/BAC Professionnel ; – les scores de contraintes sont identiques et la contrainte physique reste a un niveau tres eleve (T1 : 74,7/100 T2 : 75,9/100) ; – le nombre de problemes articulaires declare reste stable : en moyenne 2,7 articulations douloureuses en T1 vs 2,9 en T2. L’analyse des 105 salaries presents aux deux temps de l’etude (apparies) nuancent ces resultats : – leurs caracteristiques different de celles des nouveaux repondants (plus âges, moins diplomes, plus de CDI, femmes) ; – leurs scores de contraintes physiques sont plus eleves en T2 qu’en T1 et la frequence de la penibilite ressentie est plus importante significativement pour les contraintes biomecaniques ; – leurs scores de contraintes psycho-organisationnelles sont egalement plus eleves en T2 qu’en T1, avec en particulier une degradation du sens du travail ; – le nombre de problemes articulaires quant a lui evolue significativement : en moyenne 3,0 articulations douloureuses en T1 vs 3,7 en T2. Cette etude montre l’absence d’amelioration des conditions de travail dans les drives qui restent extremement exigeantes. Elles semblent se traduire par une apparition precoce des problemes osteo-articulaires dans une population pourtant jeune.

Dans un contexte de developpement rapide des Drives a predominance alimentaire, les equipes sante-travail se sont interrogees sur les conditions de travail de cette nouvelle activite par rapport au metier traditionnel des Employes Libre-Service (ELS) des grandes surfaces. L’objectif est de comparer les effets sur la sante de ces deux activites sur la base d’un meme auto-questionnaire (douleurs evoquees, expositions physiques et contraintes psycho-organisationnelles). Des scores sont construits pour mesurer les contraintes physiques et psycho-organisationnelles. Tous les preparateurs de commandes des drives de 34 grandes surfaces adherentes a 4 Services de Sante au Travail de la region Grand-Est (n = 446) et des ELS (n = 396 tires au sort dans ces commerces parmi les moins de 50 ans) ont ete interroges en 2017. Toutes les caracteristiques populationnelles different : les preparateurs des drives sont plus jeunes que les ELS (28,1 ans ± 8,2 vs 33,3 ans ± 9,1), moins souvent en couple/avec enfants, en CDI, a temps plein et avec une plus faible anciennete au poste. Ils sont plus nombreux a avoir un diplome BAC ou plus. En ajustant sur l’âge et le genre, le score de contraintes physiques est plus important chez les salaries des drives que chez les ELS (OR = 1,69 IC [1,27-2,26]). Les preparateurs des drives rapportent significativement plus souvent que les ELS : – des efforts/ports de charges lourdes (OR = 1,78 [1,25-2,54]) ; – d’importants deplacements a pied (OR = 3,95 [2,29-6,84]). Le score de contraintes psycho-organisationnelles est cote plus fortement par les salaries des drives que par les ELS (OR = 1,345 [1,003-1,805]). En regardant les composantes de ce score : – l’organisation du travail semble plus defavorable pour les preparateurs de commandes que pour les ELS (OR = 1,83 IC [1,35-2,47]) ; – les relations de travail semblent plus favorables pour les preparateurs de commandes que pour les ELS (OR = 0,63 IC [0,47-0,85]). La derniere partie de l’analyse porte sur l’etat de sante. Aucune difference (p = 0,5) n’est retrouvee pour les douleurs osteo-articulaire entre les salaries des drives et les ELS (respectivement 3,1 articulations douloureuses en moyenne versus 3,0). Le reclassement d’un ELS, pour restriction d’aptitude en lien avec des troubles osteoarticulaires, au poste de preparateur au drive n’est pas pertinent en raison des contraintes physiques et organisationnelles plus importantes dans ce dernier. A l’inverse, le reclassement d’un preparateur au drive vers le poste d’ELS doit s’evaluer au cas par cas en raison d’un niveau de contraintes eleve a ce poste dans certains rayons. Seule l’affectation a un secteur ou l’activite est moins sollicitante peut s’envisager.

Influenza virus infections are a significant public threat and the best approach to prevent them is through vaccination. Because of the perpetual changes of circulating influenza strains, the efficacy of influenza vaccines rarely exceeds 50%. To improve the protection efficacy, we have designed a novel vaccine formulation that shows a broad range of protection. The formulation is made of the matrix protein 2 (M2e) and the nucleoprotein (NP) antigens. The multimerization of NP into nanoparticles improved significantly the immune response to NP. The combination of the NP nanoparticles with the PapMV-M2e nanoparticles enhances significantly the immune response directed to NP revealing the adjuvant property of the PapMV platform. The vaccine formulation combining these two types of nanoparticles protects mice from infectious challenges by two different influenza strains (H1N1 and H3N2) and is a promising influenza A vaccine capable to elicit a broad protection.

International audience; Vaccines are considered one of the greatest medical achievements in the battle against infectious diseases. However, the intractability of various diseases such as hepatitis C, HIV/AIDS, malaria, tuberculosis, and cancer poses persistent hurdles given that traditional vaccine-development methods have proven to be ineffective; as such, these challenges have driven the emergence of novel vaccine design approaches. In this regard, much effort has been put into the development of new safe adjuvants and vaccine platforms. Of particular interest, the utilization of plant virus-like nanoparticles and recombinant plant viruses has gained increasing significance as an effective tool in the development of novel vaccines against infectious diseases and cancer. The present review summarizes recent advances in the use of plant viruses as nanoparticle-based vaccines and adjuvants and their mechanism of action. Harnessing plant-virus immunogenic properties will enable the design of novel, safe, and efficacious prophylactic and therapeutic vaccines against disease.

Background Flexuous rod-shaped nanoparticles made of the coat protein (CP) of papaya mosaic virus (PapMV) have been shown to trigger innate immunity through engagement of toll-like receptor 7 (TLR7). PapMV nanoparticles can also serve as a vaccine platform as they can increase the immune response to fused peptide antigens. Although this approach shows great potential, fusion of antigens directly to the CP open reading frame (ORF) is challenging because the fused peptides can alter the structure of the CP and its capacity to self assemble into nanoparticles—a property essential for triggering an efficient immune response to the peptide. This represents a serious limitation to the utility of this approach as fusion of small peptides only is tolerated. Results We have developed a novel approach in which peptides are fused directly to pre-formed PapMV nanoparticles. This approach is based on the use of a bacterial transpeptidase (sortase A; SrtA) that can attach the peptide directly to the nanoparticle. An engineered PapMV CP harbouring the SrtA recognition motif allows efficient coupling. To refine our engineering, and to predict the efficacy of coupling with SrtA, we modeled the PapMV structure based on the known structure of PapMV CP and on recent reports revealing the structure of two closely related potexviruses: pepino mosaic virus (PepMV) and bamboo mosaic virus (BaMV). We show that SrtA can allow the attachment of long peptides [Influenza M2e peptide (26 amino acids) and the HIV-1 T20 peptide (39 amino acids)] to PapMV nanoparticles. Consistent with our PapMV structural model, we show that around 30% of PapMV CP subunits in each nanoparticle can be fused to the peptide antigen. As predicted, engineered nanoparticles were capable of inducing a strong antibody response to the fused antigen. Finally, in a challenge study with influenza virus, we show that mice vaccinated with PapMV-M2e are protected from infection. Conclusions This technology will allow the development of vaccines harbouring long peptides containing several B and/or T cell epitopes that can contribute to a broad and robust protection from infection. The design can be fast, versatile and can be adapted to the development of vaccines for many infectious diseases as well as cancer vaccines. Electronic supplementary material The online version of this article (doi:10.1186/s12951-017-0289-y) contains supplementary material, which is available to authorized users.

Background Inactivated influenza vaccines (IV) efficacy is variable and sometimes poor. In this phase 1 trial the safety and immunogenicity of a novel nanoparticle adjuvant (Papaya Mosaic Virus (PapMV or PAL) at different dose levels combined with inactivated trivalent IV (TIV; FLUVIRAL® 2013–2014, GSK, Kirkland PQ) was assessed. Nonpathogenic in mammals, PAL is recognized as a pathogen-associated molecular pattern (PAMP) which stimulates innate, cell-mediated immunity (CMI) and adaptive immunity in naïve mice through activation of toll like receptor 7 and 8. Methods Healthy persons 18–50 years of age were randomized to one of 6 study groups: 30 µg, 60 µg, 120 µg or 240 µg of PAL with 0.25 mL TIV, 240 µg of PAL with 0.125 mL TIV, or control (0.5 mL TIV). Solicited local and general adverse events (AE) were collected Day (D)0 to 6, unsolicited AE to D28, and serious AE to D1095. Hemagglutination-inhibition assays (HI), antibody to Influenza A virus nucleoprotein (NP), and peripheral blood mononuclear cells (PBMC) for measurement of interferon-gamma (IFNg) ELISPOT (response to PepMix influenza A H2N2 Ann Arbour NP, MP1, and an influenza peptide pool), granzyme B, and IFNg:IL:10 ratio were collected on D0, 7, 28, 120, and 180. Results The most common solicited AEs were transient mild-to-moderate local pain (62.5%–87.5% of participants/group), drowsiness (≤37.5% of participants/group) and generalized muscle aches (12.5–50% of participants/group). There was one unrelated SAE. All participants had HI and anti-NP titers at baseline. HI GMTs increased at D28 post vaccine in most groups (Figure 1) and waned over time. HI fold Ab (Far) responses to TIV strains were poor in all groups (≤37.5% of participants/group had 4-Far to any strain). CMI results were consistent with humoral responses. Conclusion The PAL adjuvant in doses of 30 to 240µg combined with reduced TIV dosages was safe with no signals up to 3 years after vaccine. Reduced doses of TIV co-presented with 240 µg PAL had similar HI GMTs as TIV. The CMI results suggest that the assessment of PAL efficacy on TIV immunization would have to be conducted in an influenza naïve population. Disclosures Scott Halperin, MD, GlaxoSmithKline: Ad hoc advisory boards, Other Financial or Material Support, Research Grant; Janssen Pharm: Research Grant; sanofi pasteur: Ad hoc advisory boards, Other Financial or Material Support, Research Grant.

Background: Flexuous rod-shape nanoparticles—made of the coat protein of papaya mosaic virus (PapMV)—provide a promising vaccine platform for the presentation of viral antigens to immune cells. The PapMV nanoparticles can be combined with viral antigens or covalently linked to them. The coupling to PapMV was shown to improve the immune response triggered against peptide antigens (Methods: Two full-length recombinant viral proteins, the influenza nucleoprotein (NP) and the simian immunodeficiency virus group-specific protein antigen (GAG) were coupled to PapMV nanoparticles using sortase A. Mice were immunized with the nanoparticles coupled to the antigens and the immune response directed to the antigens were analyzed by ELISA and ELISPOT. Results: We showed the feasibility of coupling two different full-length proteins (GAG and NP) to the nanoparticle. We also showed that the coupling to PapMV nanoparticles improved significantly the humoral and the cytotoxic T lymphocyte (CTL) immune response to the antigens. Conclusion: This proof of concept demonstrates the versatility and the efficacy of the PapMV vaccine platform in the design of vaccines against viral diseases.

Nanoparticles composed of the coat protein of a plant virus (papaya mosaic virus; PapMV) and a single-stranded RNA (ssRNA) trigger a strong innate immune stimulation in the lungs of the animals a few hours following instillation. A rapid recruitment of neutrophils, monocytes/macrophages and lymphocytes follows. This treatment was able to provide protection to an influenza challenge that lasts at least 5 days. Protection could be recalled for longer periods by repeating the instillations once per week for more than 10 weeks. The treatment also conferred protection to a lethal challenge with Streptococcus pneumoniae--the major cause of bacterial pneumonia. Finally, we also showed that the nanoparticles could be used to treat mice infected with influenza and significantly decrease morbidity. These data strengthen the potential for using PapMV nanoparticles as non-specific inducers of the innate immune response in lungs during viral pandemics or to combat bioterrorist attack.In this study, virus-like nanoparticles were utilized to induce innate immune responses in a mouse model. They were also demonstrated to provide enhanced immune responses during actual pneumonia and ongoing viral infection. Strategies like this may become very helpful in human applications, including bioterrorism countermeasures.

Background The addition of an adjuvant to a vaccine is a promising approach to increasing strength and immunogenicity towards antigens. Despite the fact that adjuvants have been used in vaccines for decades, their mechanisms of action and their influence on the kinetics of the immune response are still not very well understood. The use of papaya mosaic virus (PapMV) nanoparticles-a novel TLR7 agonist-was recently shown to improve and broaden the immune response directed to trivalent inactivated flu vaccine (TIV) in mice and ferrets. Results We investigated the capacity of PapMV nanoparticles to increase the speed of the immune response toward TIV. PapMV nanoparticles induced a faster and stronger humoral response to TIV that was measured as early as 5 days post-immunization. The addition of PapMV nanoparticles was shown to speed up the differentiation of B-cells into early plasma cells, and increased the growth of germinal centers in a CD4+ dependent manner. TIV vaccination with PapMV nanoparticles as an adjuvant protected mice against a lethal infection as early as 10 days post-immunization. Conclusion In conclusion, PapMV nanoparticles are able to accelerate a broad humoral response to TIV. This property is of the utmost importance in the field of vaccination, especially in the case of pandemics, where populations need to be protected as soon as possible after vaccination. Electronic supplementary material The online version of this article (doi:10.1186/s12951-016-0200-2) contains supplementary material, which is available to authorized users.

International audience; The recent development of novel immunotherapies is revolutionizing cancer treatment. These include, for example, immune checkpoint blockade, immunomodulation, or therapeutic vaccination. Although effective on their own, combining multiple approaches will most likely be required in order to achieve the maximal therapeutic benefit. In this regard, the papaya mosaic virus nanoparticle (PapMV) has shown tremendous potential as (i) an immunostimulatory molecule, (ii) an adjuvant, and (iii) a vaccine platform through its intrinsic capacity to activate the innate immune response in an IFN-α-dependent manner. Here, we demonstrate that intratumor administration of PapMV significantly slows down melanoma progression and prolongs survival. This correlates with enhanced chemokine and pro-inflammatory-cytokine production in the tumor and increased immune-cell infiltration. Proportions of total and tumor-specific CD8(+) T cells dramatically increase following PapMV treatment whereas those of myeloid-derived suppressor cells (MDSC) concomitantly decrease. Moreover, systemic PapMV administration prevents metastatic tumor-implantation in the lungs. Importantly, PapMV also synergistically improves the therapeutic benefit of dendritic cell (DC)-based vaccination and PD-1 blockade by potentiating antitumor immune responses. This study illustrates the immunostimulatory potential of a plant virus-derived nanoparticle for cancer therapy either alone or in conjunction with other promising immunotherapies in clinical development.

In general, the structure of the papaya mosaic virus (PapMV) and other members of the potexviruses is poorly understood. Production of PapMV coat proteins in a bacterial expression system and their self-assembly in vitro into nanoparticles is a very useful tool to study the structure of this virus. Using recombinant PapMV nanoparticles that are similar in shape and appearance to the plant virus, we evaluated surface-exposed regions by two different methods, immunoblot assay and chemical modification with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide or diethyl-pyrocarbonate followed by mass spectrometry. Three regions were targeted by the two techniques. The N- and C-termini were shown to be surfaced exposed as expected. However, the region 125–136 was revealed for the first time as the major surface-exposed region of the nanoparticles. The presence of linear peptides at the surface was finally confirmed using antibodies directed to those peptides. It is likely that region 125–136 plays a key role in the lifecycle of PapMV and other members of the potexvirus group.

Resume But de l’etude Les auteurs assurent depuis longtemps le suivi medical d’une population fortement exposee au plomb. Etant donne l’evolution des enjeux en prevention, ils etudient les possibilites d’amelioration de cette surveillance. Methode L’analyse de la litterature met en lumiere l’existence d’une toxicite du plomb a des valeurs de plombemies nettement plus basses que celles couramment admises et notamment bien inferieures aux valeurs limites professionnelles. Avec la diminution des apports exterieurs, c’est le plomb osseux qui joue maintenant un role preponderant dans la survenue differee de pathologies non specifiques notamment cardiovasculaires et cognitives. La mesure directe de ce plomb osseux est possible par la fluorescence X mais on peut aussi en obtenir une bonne approche par le calcul de la plombemie cumulee qui se definit comme le produit de la plombemie et de la duree d’exposition ou plus precisement comme la somme des plombemies moyennes annuelles. La valeur limite du plomb osseux est de 15 a 20 μg/g d’os tibial, ce qui correspondrait selon les auteurs a des valeurs de plombemies cumulees de 400 a 600 μg/annees par decilitre. Resultats L’utilisation de cet indice de plombemie cumulee apporte une nouvelle perspective au suivi des operateurs concernes. Les plombemies ont beaucoup baisse, et il ne s’agit plus tant d’eviter une pathologie specifique que d’agir maintenant sur un facteur de risque plus banal. L’etude d’une population de 275 operateurs exposes depuis 25 ans nous montre l’absence de tout saturnisme declare, pourtant 28 % presentent une plombemie cumulee superieure a 800 μg/annees par decilitre, ce qui ne sera probablement pas sans repercussion medicale pour une partie d’entre eux.

The Core protein of hepatitis C virus is involved in several interactions other than the encapsidation of viral RNA. We recently proposed that this is related to the fact that the N-terminal half of this protein (C82) is an intrinsically unstructured protein (IUP) domain. IUP domains can adopt a secondary structure when they are interacting with another molecule, such as a nucleic acid or a protein. It is also possible to mimic these conditions by modifying the environment of the protein. We investigated the propensity of this protein to fold as a function of salt concentration, detergent, pH, and 2,2,2-trifluoro-ethanol (TFE); only the addition of TFE resulted in a structural change. The effect of TFE addition was studied by circular dichroism, structural, and dynamic data obtained by NMR. The data indicate that C82 can adopt an α-helical structure; this conformation is likely relevant to one of the functional roles of the HCV Core protein.

With the emergence of highly virulent influenza viruses and the consequent risk of pandemics, new approaches to designing universal influenza vaccines are urgently needed. In this report, we demonstrate the potential of using a papaya mosaic virus (PapMV) platform carrying the universal M2e influenza epitope (PapMV-CP-M2e) as a candidate flu vaccine. We show that PapMV-CP-M2e virus-like particles (VLPs) can induce production in mice of anti-M2e antibodies that can recognize influenza-infected cells. PapMV-CP-M2e discs made of 20 coat protein (CP) subunits were shown to be poorly immunogenic compared to PapMV-CP-M2e VLPs composed of several hundred CP subunits. We also show that addition of either alum or PapMV-CP VLPs as adjuvant dramatically increased the immunogenicity of PapMV-CP-M2e-containing vaccine, and led to 100% protection against a challenge of 4LD(50) with the WSN/33 strain. These results show, for the first time, the potential of a recombinant plant virus protein to serve as both peptide delivery system and adjuvant in the crucial field of influenza vaccine development.

A filamentous virus isolated from Malva neglecta Wallr. (common mallow) and propagated in Chenopodium quinoa was grown, cloned and the complete nucleotide sequence was determined (GenBank accession # DQ660333 ). The genomic RNA is 6858 nt in length and contains five major open reading frames (ORFs). The genomic organization is similar to members and the viral encoded proteins shared homology with the group of the Potexvirus genus in the Flexiviridae family. Phylogenetic analysis revealed a close relationship with narcissus mosaic virus (NMV), scallion virus X (ScaVX) and, to a lesser extent, to Alstroemeria virus X (AlsVX) and pepino mosaic virus (PepMV). A novel putative pseudoknot structure is predicted in the 3′-UTR of a subgroup of potexviruses, including this newly described virus. The consensus GAAAA sequence is detected at the 5′-end of the genomic RNA and experimental data strongly suggest that this motif could be a distinctive hallmark of this genus. The name Malva mosaic virus is proposed.

The assembly of hepatitis C virus (HCV) is not well understood. We investigated HCV nucleocapsid assembly in vitro and the role of electrostatic/hydrophobic interactions in this process. We developed a simple and rapid in vitro assay in which the progress of assembly is monitored by measuring an increase in turbidity, thereby allowing the kinetics of assembly to be determined. Assembly is performed using a truncated HCV core (C1–82), containing the minimal assembly domain, purified from Escherichia coli. The increase in turbidity is linked to the formation of nucleocapsid-like particles (NLPs) in solution, and nucleic acids are essential to initiate nucleocapsid assembly under the experimental conditions used. The sensitivity of NLP formation to salt strongly suggests that electrostatic forces govern in vitro assembly. Mutational analysis of C1–82 demonstrated that it is the global positive charge of C1–82 rather than any specific basic residue that is important for the assembly process. Our in vitro assembly assay provides an easy and efficient means of screening for assembly inhibitors, and we have identified several inhibitory peptides that could represent a starting point for drug design.

Plant-virus-based vaccines have emerged as a promising avenue in vaccine development. This report describes the engineering of an innovative vaccine platform using the papaya mosaic virus (PapMV) capsid protein (CP) as a carrier protein and a C-terminal fused hepatitis C virus (HCV) E2 epitope as the immunogenic target. Two antigen organizations of the PapMV-based vaccines were tested: a virus-like-particle (VLP; PapMVCP-E2) and a monomeric form (PapMVCP27–215-E2). While the two forms of the vaccine were both shown to be actively internalized in vitro in bone-marrow-derived antigen presenting cells (APCs), immunogenicity was demonstrated to be strongly dependent on antigen organization. Indeed, C3H/HeJ mice injected twice with the multimeric VLP vaccine showed a long-lasting humoral response (more than 120 days) against both the CP and the fused HCV E2 epitope. The antibody profile (production of IgG1, IgG2a, IgG2b, IgG3) suggests a Th1/Th2 response. Immunogenicity of the PapMV vaccine platform was not observed when the monomer PapMVCP-E2 was injected. These results demonstrate for the first time the potential of the PapMV vaccine platform and the critical function of multimerization in its immunogenicity.

Cauliflower mosaic virus (CaMV) coat protein precursor (pre-CP) has 489 amino acids (p57) and is processed by the viral proteinase into three major forms: p44, p39, and p37. The N- and C-terminal extensions of pre-CP are released during maturation by the virus-encoded proteinase. We showed that these extensions are phosphorylated at several sites by host casein kinase II (CKII). We have identified the phosphorylated amino acids using an in vitro phosphorylation assay and tested the effect of mutation of these sites on viral infectivity. Mutation of serines S66, S68, and S72 to alanine in the N-terminal extension abolished phosphorylation of the protein in vitro. Also, mutation of all S and T residues in the C-terminus (450 to 489) made this region insensitive to CKII. Amino acid substitutions also were introduced into a full-length infectious clone of CaMV. Mutated forms of the virus with S66, S68, and S72 substituted with A or D showed a delay in symptom development and affected the infectivity of the virus. However, a mutant with an A substitution of all the S and T residues of the C-terminal extension of CP was not infectious. These results suggest that phosphorylation of the N- and C-termini of CaMV pre-CP plays an important role in the initiation of viral infection.

The primary function of the hepatitis C virus (HCV) core protein is genome encapsidation. Core protein is also subject to post-translational modifications that can impact on the assembly process. In this report, we have studied the effect of cAMP-dependent protein kinase A (PKA) phosphorylation on its assembly and stability in a yeast Pichia pastoris expression system. We have recently shown that co-expression of the human signal peptide peptidase and core protein (amino acids 1–191) in yeast leads to the formation of nucleocapsid-like particles (NLPs) that are morphologically similar to the wild-type HCV capsid. In this system, we expressed mutants S53A and S116A and mutants S53D and S116D to abolish or mimic PKA phosphorylation, respectively. None of these mutations affected HCV assembly, but S116D led to the degradation of core protein. We also showed that nonenveloped NLPs were labelled in vitro by PKA, suggesting that the phosphorylation sites are available at the surface of the NLPs. The co-expression of human PKA with core and human signal peptide peptidase in yeast did not produce phosphorylated NLPs and led to a decreased accumulation of nonenveloped particles. Mutation S116A restored the core protein content. These results suggest that PKA phosphorylation can modulate HCV core levels in infected cells.

The emergence of highly virulent influenza strains and the risks of pandemics as well as the limited efficiency of the current seasonal vaccines are important public health concerns. There is a major need for new influenza vaccines that would be broadly cross-protective. The ectodomain of matrix protein 2 (M2e) is highly conserved amongst different influenza strains and could be used as a broad spectrum antigen. To overcome its low immunogenicity we have fused a short peptide epitope derived from the human consensus sequence of M2e (amino acids 6-14, EVETPIRNE) to the N-terminus of papaya mosaic virus coat protein. The fusion harboring coat proteins were assembled around a single stranded RNA into virus-like particles (PapMV-sM2e). The resulting PapMV-sM2e rod-shaped particle was stable and indistinguishable from regular PapMV particles. A single intramuscular immunization with PapMV-sM2e was sufficient to mount appreciable levels of CD4 dependent M2e specific total IgG and IgG2a antibody in mice sera. PapMV-sM2e proved to be self-adjuvanting since the addition of PapMV as an exogenous adjuvant did not result in significantly improved antibody titers. In addition, we confirmed the adjuvant property of PapMV-sM2e using the trivalent inactivated flu vaccine as antigen and demonstrated that the newly engineered nanoparticles areas efficacious as an adjuvant than the original PapMV nanoparticles. Upon infection with a sub-lethal dose of influenza, PapMV-sM2e vaccinated animals were completely protected from virus induced morbidity and mortality. Mice immunized with decreasing amounts of PapMV-sM2e and challenged with a more stringent dose of influenza virus displayed dose-dependent levels of protection. Seventy percent of the mice immunized once with the highest dose of PapMV-sM2e survived the challenged. The survival of the mice correlated mainly with the levels of anti-M2e IgG2a antibodies obtained before the infection. These results demonstrate that PapMV-sM2e can be an important component of a broadly cross-reactive influenza vaccine.

Papaya mosaic virus (PapMV) is a flexuous rod shape virus made of 1400 subunits that assemble around a plus sense genomic RNA. The structure determination of PapMV and of flexuous viruses in general is a major challenge for both NMR and X-ray crystallography. In this report, we present the characterization of a truncated version of the PapMV coat protein (CP) that is suitable for NMR study. The deletion of the N-terminal 26 amino acids of the PapMV CP (CP27-215) generates a monomer that can be expressed to high level and easily purified for production of an adequate NMR sample. The RNA gel shift assay showed that CP27-215 lost its ability to bind RNA in vitro, suggesting that the multimerization of the subunit is important for this function. The fusion of a 6x His tag at the C-terminus improved the solubility of the monomer and allowed its concentration to 0.2 mM. The CD spectra of the truncated and the wild-type proteins were similar, suggesting that both proteins are well ordered and have a similar secondary structure. CP27-215 was 15N labeled for NMR studies and a 2D 1H-15N-HSQC spectrum confirmed the presence of a well-ordered structure and the monomeric form of the protein. These results show that CP27-215 is amenable to a complete and exhaustive NMR study that should lead to the first three-dimensional structure determination of a flexuous rod shape virus.

The delivery of the double-stranded DNA viral genome into the nucleus is a critical step for the type member of Caulimoviridae, cauliflower mosaic virus (CaMV). The nucleocapsid (NC) of CaMV is directly involved in this process. A nuclear localization signal located at the N-terminus of the NC was shown to be exposed at the surface of the virion. This nuclear localization signal appears to be important to direct the virus to the nuclear pore complex. The nuclear targeting of the NC needs to be tightly regulated because the process of virus assembly, which also involves the viral NC, occurs in the cytosol. It is now accepted that the N- and C-terminal extensions of the viral NC precursor are efficient regulatory sequences that determine the localization of the viral NC in infected leaves. Proteolytic maturation and phosphorylation of the N- and C-terminal extensions are also important in the regulation of this process. Despite these recent discoveries, the transport of CaMV toward and into the nucleus during early events in the infection cycle remains unclear. In this review, we summarize recent advances that explain the mechanisms of targeting of the CaMV genome to the nucleus and extract from other related animal and plant viruses mechanisms that could hint at the possible strategies used by CaMV to enter the nucleus.

Papaya mosaic potexvirus (PapMV) coat protein (CP) was expressed (CPdeltaN5) in Escherichia coli and showed to self assemble into nucleocapsid like particles (NLPs). Twenty per cent of the purified protein was found as NLPs of 50 nm in length and 80% was found as a multimer of 450 kDa (20 subunits) arranged in a disk. Two mutants in the RNA binding domain of the PapMV CP, K97A and E128A showed interesting properties. The proteins of both mutants could be easily purified and CD spectra of these proteins showed secondary and tertiary structures similar to the WT protein. The mutant K97A was unable to self assemble and bind RNA. On the contrary, the mutant E128A showed an improved affinity for RNA and self assembled more efficiently in NLPs. E128A NLPs were longer (150 nm) than the recombinant CPdeltaN5 and 100% percent of the protein was found as NLPs in bacteria. E128A NLPs were more resistant to digestion by trypsin than the CPdeltaN5 but were more sensitive to denaturation by heat. We discuss the possible role of K97 and E128 in the assembly of PapMV.

The maturation of the core protein (C) ofHepatitis Cvirus(HCV) is controlled by the signal peptidase (sp) and signal peptide peptidase (spp) of the host. To date, it remains unknown whether spp cleavage influences viral infectivity and/or the assembly process. Here, evidence is provided that cleavage by spp is not required for assembly of nucleocapsid-like particles (NLPs) in yeast (Pichia pastoris). The immature NLPs (not processed by spp) show a density of 1·11 g ml−1on sucrose gradients and a diameter of 50 nm. Co-expression of human spp (hspp) with C generates the 21 kDa mature form of the protein and promotes the accumulation of non-enveloped particles. The amount of non-enveloped particles accumulating in the cell was correlated directly with the expression level of hspp. Furthermore, immunocapture studies showed that hspp was embedded in the membranes of enveloped particles. These results suggest that maturation of the C protein can occur after formation of the enveloped particles and that the abundance of hspp influences the types of particle accumulating in the cells.

Similar to several other viruses, human T cell leukemia virus type I (HTLV-I) induces the formation of multinucleated giant cells (also known as syncytium) when amplified in tissue culture. These syncytia result from the fusion of infected cells with uninfected cells. Due to the intrinsic difficulty of infecting cells with cell-free HTLV-I virions, syncytium formation has become an important tool in the study of HTLV-I infection and transmission. Since most HTLV-I-based cell fusion assays rely on the use of non-T cells, the aim of this study was to optimize a new HTLV-I-induced cell fusion assay in which HTLV-I-infected T cell lines are co-cultured with T cells that have been transfected with an HTLV-I long terminal repeat (LTR) luciferase reporter construct. We demonstrate that co-culture of various HTLV-I-infected T cells with different transfected T cell lines resulted in induction of luciferase activity. Cell-to-cell contact and expression of the viral gp46 envelope protein was crucial for this induction while other cell surface proteins (including HSC70) did not have a significant effect. This quantitative assay was shown to be very sensitive. In this assay, the cell fusion-mediated activation of NF-κB and the HTLV-I LTR occurred through previously described Tax-dependent signaling pathways. This assay also showed that cell fusion could activate Tax-inducible cellular promoters. These results thus demonstrate that this new quantitative HTLV-I-dependent cell fusion assay is versatile, highly sensitive, and can provide an important tool to investigate cellular promoter activation and intrinsic signaling cascades that modulate cellular gene expression.

Cauliflower mosaic virus (CaMV) open reading frame (ORF) IV encodes a coat protein precursor (pre-CP) harboring an N-terminal extension that is cleaved off by the CaMV-encoded protease. In transfected cells, pre-CP is present in the cytoplasm, while the processed form (p44) of CP is targeted to the nucleus, suggesting that the N-terminal extension might be involved in keeping the pre-CP in the cytoplasm for viral assembly. This study reports for the first time the intracellular localization of the N-terminal extension during CaMV infection in Brassica rapa. Immunogold-labeling electron microscopy using polyclonal antibodies directed to the N-terminal extension of the pre-CP revealed that this region is closely associated with viral particles present in small aggregates, which we called small bodies, adjacent to the main inclusion bodies typical of CaMV infection. Based on these results, we propose a model for viral assembly of CaMV.

The primary goal of this paper is to examine cross-national variations in the perceived importance of communication competencies of tour guides. Tour guides play an important role as cultural buffers and also serve as communication links between tourists and host populations, and yet their communication competence is perhaps the least emphasized aspect in tourism research. Communication research provides a theoretical framework to investigate this topic and this research represents a first bridge between these two disciplines. This study takes a behavioral-cognitive approach, based on two assumptions: (1) that individuals hold cognitive notions about what comprises communication competence, and (2) they then use these expectations as guidelines to judge their own and others' behaviors. In this study, tourists visiting the US Southwest from France, Germany, and the United States completed a questionnaire asking for their perceptions of the importance of 4 nonverbal dimensions (approachability, poise, attentiveness, and touch) and three verbal dimensions (language adaptability, interpersonal inclusion, and assertiveness) of intercultural communication competence of tour guides. Results indicate that there are significant differences in the perceptions of important communication competencies among the three nationality groups. For the most part, the French and German tourists ranked the dimensions differently from the American tourists. That is, the Americans ranked most nonverbal and verbal competence behaviors as more important than the European tourists. This study makes several important contributions to both the communication and the tourism fields. The cultural differences found in this study fit theoretically with prior research investigating US and European patterns of communication. In addition, the study raises some questions about the appropriateness of applying US competence frameworks to other cultural groups. Finally, the study contributes to the field of tourism in suggesting ways that tour guides might enhance their perceived competence depending on the nationality of the group they are leading.