Modulation d'expression du CD23 et du IL2RB sur les monocytes et les lymphocytes humains par des médiateurs lipidiques (PAF, LTB4) et des cytokines (IL-4, IFNY)

Depuis quelques années, le groupe de Rola-Pleszczynski a mis en évidence le potentiel d'immunorégulation du leucotriène B4 (LTB4). Par exemple, il a démontré différents effets du LTB4 sur le mécanisme de cytotoxicité des lymphocytes et des monocytes humains. L'activité cytotoxique des lymphocytes, en particulier les cellules NK (CD56+) et des monocytes, est également augmentée par IL-2. On sait maintenant que la chaîne p du récepteur de l'IL-2 (IL2RB) est responsable de cet effet. A partir de ces données, nous avons étudié 1° l'effet du LTB4 sur l'activité cytotoxique des lymphocytes stimulés par IL-2, 2° le pouvoir modulateur de LTB4 sur l'expression du IL2RB à la surface des lymphocytes et des monocytes et 3° le pouvoir modulateur du LTB4 sur l'accumulation de l'ARNm du IL2RB chez les lymphocytes. Nous observons que le LTB4 augmente l'accumulation de l'ARNm du IL2RB chez les lymphocytes et augmente l'expression du IL2RB à la surface des lymphocytes, en particulier ceux ayant une activité dite "naturel killer" (NK). Ces dernières, lors d'un essai de cytotoxicité, deviennent plus sensibles à l'IL-2 lorsque prétraitées au LTB4. Nous obtenons également une augmentation d'expression du IL2RB chez les monocytes par le LTB4. De plus nous avons étudié l'effet du LTB4 et du PAF sur l'expression de l'antigène CD23, un récepteur des IgE, sur les monocytes et les cellules U937. Nous n'avons observé aucun pouvoir modulateur de ces médiateurs lipidiques sur le CD23 comparativement à l'IL-4 et l'IFNy qui eux augmentent l'expression du CD23. Les résultats obtenus montrent la modulation d'expression d'un récepteur de cytokine (IL2RpB) et d'un récepteur d'immunoglobuline (CD23) par différentes cytokines et médiateurs lipidiques est soumise à des mécanismes différents

Les sources du sentiment d’efficacité personnelle des conseillers pédagogiques en tant que formateurs d’adultes

Les conseillers pédagogiques des écoles élémentaires et secondaires offrent de la formation continue et un accompagnement pédagogique aux enseignants. Reconnus pour leur compétence élevée en ce qui concerne l’enseignement aux jeunes, ils n’ont généralement aucune expérience en matière d’enseignement aux adultes lors de leur entrée en fonction. Cet article rend compte des témoignages recueillis lors d’entrevues semi-dirigées auprès de onze conseillers pédagogiques pourtant sur les sources à partir desquelles ils parviennent à développer et à maintenir leur sentiment d’efficacité personnelle en tant que formateurs d’adultes, soit les expériences antérieures, les expériences vicariantes et lapersuasion verbale.Mots-clés : Conseillers pédagogiques, sentiment d’efficacité personnelle, formateursd’adulte

Tensões entre os atores e as funções de conservação e de desenvolvimento turístico: o ecoturismo como solução? O caso do Parque do Mont-Orford (Québec, Canadá)

The controversies that often arise around the issues of planning, implementation and management of national parks, and that put into play states, state corporations, local authorities, local communities, environmental groups and (eco) touristic business promoters, put dual issue about land management to accommodate a national park and ways of tourism that respect the natural environment and local people. Strategies used by players in a conflict over a park may explain the difficulty in reaching an agreement on the qualification process of a territory between protected areas and sustainable development area and also find a form of integration between development and conservation, which are collectively admitted, through a tourism shared project. As study case, it has been used the conflict of Mont-Orford National Park, its changes. The debate opposes two major kinds of values: 1) conservation through ecological and territorial integrity, 2) development of a modern and competitive tourism offer taking part of the attractiveness of a National Park host area. Thus the analysis of social players strategies draws lessons on ecotourism and territorial governance. In particular, the issue of ecotourism model is seen and discussed as a solution to the sustainable development of local communities. Finally, two key conditions for an ecotourism project establishment are highlighted: the first relates to the operating content innovation of the project; the second relates to the territorial management and the role of a key player - a committee, an association or another independent organization able to prioritize a protected area partnership management.As controvérsias que surgem frequentemente em torno das questões de planejamento, implementação e gestão de parques nacionais, e que colocam em cena estados, sociedades de estado, coletividades territoriais, comunidades locais, grupos ambientalistas e promotores (eco)turísticos privados, colocam a dupla questão de gestão do território para acolher um parque nacional e as formas de turismo que respeite o meio ambiente natural e as populações locais. As estratégias utilizadas pelos atores em um conflito em torno de um parque podem explicar a dificuldade em chegar a um acordo sobre o processo de qualificação de um território, entre áreas protegidas e área de desenvolvimento durável e também encontrar uma forma de integração entre desenvolvimento e conservação, coletivamente admitidos, através de um projeto turístico compartilhado. Como o conflito no Parque Nacional do Mont Orford (PNMO), que serve como caso de referência em nossa análise, a polarização do debate opõe globalmente dois grandes tipos de valores: 1) a conservação através da integridade ecológica e territorial; 2) a valorização pelo desenvolvimento de uma oferta turística moderna e competitiva, participando da capacidade de atração do território de acolhimento de um parque nacional. Assim, a análise das estratégias dos atores, de acordo com uma leitura às vezes diacrônica e sistêmica de um conflito, permite tirar lições em relação aos campos do ecoturismo e da gestão territorial, um dos pilares do desenvolvimento sustentável. Em particular, a questão do modelo do ecoturismo, visto como uma solução para o desenvolvimento viável das comunidades locais, é discutido através o caso do PNMO. Finalmente, duas condições essenciais para a implantação de um projeto de ecoturismo são destacadas: o primeiro diz respeito à inovação do conteúdo "operacional" do projeto; o segundo, ao dispositivo de gestão territorial e ao papel de ator-chave-comitê de direção, associação ou outra forma de organização independente, capaz de priorizar uma gestão de parceria e organização da área protegida

Enhancing genetic mapping of complex genomes through the design of highly-multiplexed SNP arrays: application to the large and unsequenced genomes of white spruce and black spruce

<p>Abstract</p> <p>Background</p> <p>To explore the potential value of high-throughput genotyping assays in the analysis of large and complex genomes, we designed two highly multiplexed Illumina bead arrays using the GoldenGate SNP assay for gene mapping in white spruce (<it>Picea glauca </it>[Moench] Voss) and black spruce (<it>Picea mariana </it>[Mill.] B.S.P.).</p> <p>Results</p> <p>Each array included 768 SNPs, identified by resequencing genomic DNA from parents of each mapping population. For white spruce and black spruce, respectively, 69.2% and 77.1% of genotyped SNPs had valid GoldenGate assay scores and segregated in the mapping populations. For each of these successful SNPs, on average, valid genotyping scores were obtained for over 99% of progeny. SNP data were integrated to pre-existing ALFP, ESTP, and SSR markers to construct two individual linkage maps and a composite map for white spruce and black spruce genomes. The white spruce composite map contained 821 markers including 348 gene loci. Also, 835 markers including 328 gene loci were positioned on the black spruce composite map. In total, 215 anchor markers (mostly gene markers) were shared between the two species. Considering lineage divergence at least 10 Myr ago between the two spruces, interspecific comparison of homoeologous linkage groups revealed remarkable synteny and marker colinearity.</p> <p>Conclusion</p> <p>The design of customized highly multiplexed Illumina SNP arrays appears as an efficient procedure to enhance the mapping of expressed genes and make linkage maps more informative and powerful in such species with poorly known genomes. This genotyping approach will open new avenues for co-localizing candidate genes and QTLs, partial genome sequencing, and comparative mapping across conifers.</p

Physico-chemical characteristics and methanogen communities in swine and dairy manure storage tanks: Spatio-temporal variations and impact on methanogenic activity

Greenhouse gas emissions represent a major environmental problem associated with the management of manure from the livestock industry. Methane is the primary GHG emitted during manure outdoor storage. In this paper, the variability of two swine and two dairy manure storage tanks was surveyed, in terms of physico-chemical and microbiological parameters. The impact of the inter-tank and spatio-temporal variations of these parameters on the methanogenic activity of manure was ascertained. A Partial Least Square regression was carried out, which demonstrated that physico-chemical as well as microbiological parameters had a major influence on the methanogenic activity. Among the 19 parameters included in the regression, the concentrations of VFAs had the strongest negative influence on the methane emission rate of manure, resulting from their well-known inhibitory effect. The relative abundance of two amplicons in archaeal fingerprints was found to positively influence the methanogenic activity, suggesting that Methanoculleus spp. and possibly Methanosarcina spp. are major contributors to methanogenesis in storage tanks. This work gave insights into the mechanisms, which drive methanogenesis in swine and dairy manure storage tanks

Activation of the extracellular signal-regulated protein kinase (ERK) cascade by membrane-type-1 matrix metalloproteinase (MT1-MMP)

AbstractThe mechanisms underlying membrane-type-1 matrix metalloproteinase (MT1-MMP)-dependent induction of cell migration were investigated. Overexpression of MT1-MMP induced a marked increase in cell migration, this increase being dependent on the presence of the cytoplasmic domain of the protein. MT1-MMP-dependent migration was inhibited by a mitogen-activated protein kinase kinase 1 inhibitor, suggesting the involvement of the extracellular signal-regulated protein kinase (ERK) cascade in the induction of migration. Accordingly, MT1-MMP overexpression induced the activation of ERK, this process being also dependent on the presence of its cytoplasmic domain. MT1-MMP-induced activation of both migration and ERK required the catalytic activity of the enzyme as well as attachment of the cells to matrix proteins. The MT1-MMP-dependent activation of ERK was correlated with the activation of transcription through the serum response element, whereas other promoters were unaffected. Taken together, these results indicate that MT1-MMP trigger important changes in cellular signal transduction events, leading to cell migration and to gene transcription, and that these signals possibly originate from the cytoplasmic domain of the protein

Transition et socialisation professionnelles d’une nouvelle professeure d’université : dynamiques collectives et institutionnelles en question

En contexte nord-américain, la plupart des nouveaux professeurs d’université ont eu l’occasion d’entrevoir certains aspects du professorat au cours de leurs études doctorales et de se faire une idée assez juste de ce qui les attend, à la condition qu’ils aient eu la possibilité d’occuper les fonctions d’assistant de recherche ou de chargé d’enseignement. Les doctorants sont habituellement conscients que la charge de travail du professeur peut être lourde ; dès leur entrée dans cette catégorie d’emploi, cette crainte semble se confirmer, parfois au-delà de leurs appréhensions. En s’appuyant sur un entretien de recherche semi-dirigé et l’analyse de celui-ci, cet article fait état du processus transitoire effectué par une nouvelle professeure d’université ainsi que des étapes et des écueils de sa socialisation à sa nouvelle profession. Le besoin d’un soutien institutionnel mieux ciblé et l’importance, pour le professeur novice, d’être accueilli au sein d’une équipe de collègues seront aussi discutés.In the North-American context, most new university professors come to better understand what a faculty position entails while they are completing their doctoral studies, and if they have had the opportunity to work as a research assistant or a lecturer, they have a fairly accurate idea of what awaits them. PhD students are usually aware that the workload of a professor can be heavy. Once employed, they realize that this fear may have been well-founded, and that the workload may even exceed their initial apprehensions. Based on the analysis of one semi-structured interview, this article examines the process of transition as well as the steps and challenges of the process of socialisation of a new university professor beginning her faculty career. The importance and need for more directed institutional support and for a welcoming team for early career professors will also be discussed in this article

Comparison of primary virus isolation in pulmonary alveolar macrophages and four different continuous cell lines for type 1 and type 2 porcine reproductive and respiratory syndrome virus

Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) has a highly restricted cellular tropism. In vivo, the virus primarily infects tissue-specific macrophages in the nose, lungs, tonsils, and pharyngeal lymphoid tissues. In vitro however, the MARC-145 cell line is one of the few PRRSV susceptible cell lines that are routinely used for in vitro propagation. Previously, several PRRSV non-permissive cell lines were shown to become susceptible to PRRSV infection upon expression of recombinant entry receptors (e.g., PK15Sn-CD163, PK15S10-CD163). In the present study, we examined the suitability of different cell lines as a possible replacement of primary pulmonary alveolar macrophages (PAM) cells for isolation and growth of PRRSV. The susceptibility of four different cell lines (PK15Sn-CD163, PK15S10-CD163, MARC-145, and MARC-145Sn) for the primary isolation of PRRSV from PCR positive sera (both PRRSV1 and PRRSV2) was compared with that of PAM. To find possible correlations between the cell tropism and the viral genotype, 54 field samples were sequenced, and amino acid residues potentially associated with the cell tropism were identified. Regarding the virus titers obtained with the five different cell types, PAM gave the highest mean virus titers followed by PK15Sn-CD163, PK15S10-CD163, MARC-145Sn, and MARC-145. The titers in PK15Sn-CD163 and PK15S10-CD163 cells were significantly correlated with virus titers in PAM for both PRRSV1 (p < 0.001) and PRRSV2 (p < 0.001) compared with MARC-145Sn (PRRSV1: p = 0.22 and PRRSV2: p = 0.03) and MARC-145 (PRRSV1: p = 0.04 and PRRSV2: p = 0.12). Further, a possible correlation between cell tropism and viral genotype was assessed using PRRSV whole genome sequences in a Genome-Wide-Association Study (GWAS). The structural protein residues GP2:187L and N:28R within PRRSV2 sequences were associated with their growth in MARC-145. The GP5:78I residue for PRRSV2 and the Nsp11:155F residue for PRRSV1 was linked to a higher replication on PAM. In conclusion, PK15Sn-CD163 and PK15S10-CD163 cells are phenotypically closely related to the in vivo target macrophages and are more suitable for virus isolation and titration than MARC-145/MARC-145Sn cells. The residues of PRRSV proteins that are potentially related with cell tropism will be further investigated in the future