Valutazione della prevalenza dell'allele HLA-B*57:01 in una popolazione di pazienti con infezione da HIV-1

La possibilità di predire la risposta farmacologica di un paziente sulla base del corredo genetico dell’individuo stesso è il concetto base della farmacogenetica. Per farmacogenetica si intende, infatti, lo “studio delle variazioni nelle caratteristiche del DNA in relazione alla risposta ai farmaci”. Lo sviluppo di questa branca della farmacologia generale è derivato innanzitutto dalla notevole quantità di informazioni riguardanti il genoma umano divenute accessibili all’intera comunità scientifica al completamento del Progetto Genoma Umano. Ciò che ha reso veramente possibile l’affermarsi della medicina personalizzata è stato lo sviluppo di nuove tecniche diagnostiche, altamente sensibili, specifiche e poco costose, in grado di analizzare in tempi brevi milioni di polimorfismi collegati al profilo individuale di risposta ad un farmaco. Con l’introduzione dei test genetici nella pratica clinica è possibile valutare a priori il rischio di eventi avversi e quindi di evitare di somministrare farmaci che potrebbero danneggiare il paziente. In Europa il primo test farmacogenetico ufficialmente riconosciuto valido ai fini delle informazioni per l’uso di un farmaco è la ricerca dell’allele HLA-B*57:01 per l’agente abacavir. E’ stato dimostrato infatti che l’allele HLA-B*57:01 in pazienti con infezione da HIV ha un significato altamente predittivo per l’individuazione dei soggetti ipersensibili. Abacavir è un inibitore nucleosidico della trascrittasi inversa, altamente efficace ed è approvato per il trattamento dell’HIV in combinazione con altri antiretrovirali. Sfortunatamente, però, il 4-8% di persone trattate mostrano una reazione di ipersensibilità a questo farmaco. La reazione sistemica avviene nelle prime 6 settimane di trattamento e può condurre a pesanti conseguenze patologiche. Le Linee Guida sull’utilizzo dei farmaci antiretrovirali raccomandano, quindi, fortemente l’esecuzione del test farmacogenetico prima di iniziare una terapia antiretrovirale contenente abacavir. Nell’anno 2014 l’Infettivologo responsabile dell’Ambulatorio di Malattie Infettive dell’Ospedale Maggiore di Bologna (sede distaccata dell’Unità Operativa di Malattie Infettive del Policlinico S. Orsola-Malpighi), in accordo con il Laboratorio Analisi dell’Ospedale Maggiore – settore di Biologia Molecolare e Citogenetica – ha programmato un piano di screening per la ricerca dell’allele HLA-B*57:01. Nel corso dell’intero anno sono stati screenati 788 pazienti afferenti all’Ambulatorio di Malattie Infettive. La procedura di analisi prevede l’estrazione in manuale del DNA dai linfociti di sangue periferico utilizzando il kit QIAamp DNA Blood Mini Kit della ditta QIAGEN (marcato œ IVD). Per l’identificazione dell’allele HLA-B*57:01 è stato utilizzato il kit HISTO TYPE B57 Happy Pack (marcato œ IVD) che sfrutta la tecnologia SSP-PCR (Sequence Specific Primers-PCR). Questo tipo di PCR impiega coppie di primers perfettamente complementari solo con un allele o con un gruppo di alleli, di modo che si verifichi l’amplificazione della sequenza bersaglio solo in presenza della sequenza di interesse. La separazione dei prodotti ottenuti con l’amplificazione è stata effettuata tramite gel di agarosio in elettroforesi orizzontale. Sono stati riportati in un file di Microsoft Excel i risultati ottenuti che hanno permesso di dividere i pazienti in due sottopopolazioni di soggetti positivi e negativi al test. Nell’ambito della sottopopolazione dei soggetti positivi è stata, pertanto, valutata la prevalenza dell’allele HLA-B*57:01. Sono state inoltre analizzate le differenze tra le due sottopopolazioni prendendo in considerazione oltre che l’età, il sesso e la provenienza, anche i seguenti parametri (ottenuti dallo stesso prelievo di sangue): la conta dei linfociti T CD4+, la conta dei linfociti T CD8+, il rapporto CD4+/CD8+ e la carica virale

Analysis by RNA-seq of transcriptomic changes elicited by heat shock in Leishmania major

Besides their medical relevance, Leishmania is an adequate model for studying post-transcriptional mechanisms of gene expression. In this microorganism, mRNA degradation/stabilization mechanisms together with translational control and post-translational modifications of proteins are the major drivers of gene expression. Leishmania parasites develop as promastigotes in sandflies and as amastigotes in mammalians, and during host transmission, the parasite experiences a sudden temperature increase. Here, changes in the transcriptome of Leishmania major promastigotes after a moderate heat shock were analysed by RNA-seq. Several of the up-regulated transcripts code for heat shock proteins, other for proteins previously reported to be amastigote-specific and many for hypothetical proteins. Many of the transcripts experiencing a decrease in their steady-state levels code for transporters, proteins involved in RNA metabolism or translational factors. In addition, putative long noncoding RNAs were identified among the differentially expressed transcripts. Finally, temperature-dependent changes in the selection of the spliced leader addition sites were inferred from the RNA-seq data, and particular cases were further validated by RT-PCR and Northern blotting. This study provides new insights into the post-transcriptional mechanisms by which Leishmania modulate gene expressionThis work was supported by grants (to B.A. and J.M.R.) from Ministerio de Economía, Industria y Competitividad, project number SAF2017-86965-R (co-funded with FEDER funds), and by the Network of Tropical Diseases Research RICET (RD16/0027/0008), co-funded with FEDER funds. The CBMSO receives institutional grants from the Fundación Ramón Areces and from the Fundación Banco de Santande

Coadministration of the Three Antigenic Leishmania infantum Poly (A) Binding Proteins as a DNA Vaccine Induces Protection against Leishmania major Infection in BALB/c Mice

Highly conserved intracellular proteins from Leishmania have been described as antigens in natural and experimental infected mammals. The present study aimed to evaluate the antigenicity and prophylactic properties of the Leishmania infantum Poly (A) binding proteins (LiPABPs). Three different members of the LiPABP family have been described. Recombinant tools based on these proteins were constructed: recombinant proteins and DNA vaccines. The three recombinant proteins were employed for coating ELISA plates. Sera from human and canine patients of visceral leishmaniasis and human patients of mucosal leishmaniasis recognized the three LiPABPs. In addition, the protective efficacy of a DNA vaccine based on the combination of the three Leishmania PABPs has been tested in a model of progressive murine leishmaniasis: BALB/c mice infected with Leishmania major. The induction of a Th1-like response against the LiPABP family by genetic vaccination was able to down-regulate the IL-10 predominant responses elicited by parasite LiPABPs after infection in this murine model. This modulation resulted in a partial protection against L. major infection. LiPABP vaccinated mice showed a reduction on the pathology that was accompanied by a decrease in parasite burdens, in antibody titers against Leishmania antigens and in the IL-4 and IL-10 parasite-specific mediated responses in comparison to control mice groups immunized with saline or with the non-recombinant plasmid. The results presented here demonstrate for the first time the prophylactic properties of a new family of Leishmania antigenic intracellular proteins, the LiPABPs. The redirection of the immune response elicited against the LiPABP family (from IL-10 towards IFN-γ mediated responses) by genetic vaccination was able to induce a partial protection against the development of the disease in a highly susceptible murine model of leishmaniasis.The study was supported in Spain by grants from Ministerio de Ciencia e Innovación FIS PI11/00095 and FISPI14/00366 from the Instituto de Salud Carlos III within the Network of Tropical Diseases Research (VI P I+D+I 2008-2011, ISCIII -Subdirección General de Redes y Centros de Investigación Cooperativa (RD12/0018/0009)). This work was also supported in Brazil by a grant from CNPq (Ciencia sem Fronteiras-PVE 300174/2014-4)Peer Reviewe

Cathepsin L3 from fasciola hepatica induces NLRP3 inflammasome alternative activation in murine dendritic cells

The production of IL-1-family cytokines such as IL-1β and IL-18 is finely regulated by inflammasome activation after the recognition of pathogens associated molecular pattern (PAMPs) and danger associated molecular patterns (DAMPs). However, little is known about the helminth-derived molecules capable of activating the inflammasome. In the case of the helminth trematode Fasciola hepatica, the secretion of different cathepsin L cysteine peptidases (FhCL) is crucial for the parasite survival. Among these enzymes, cathepsin L3 (FhCL3) is expressed mainly in the juvenile or invasive stage. The ability of FhCL3 to digest collagen has demonstrated to be critical for intestinal tissue invasion during juvenile larvae migration. However, there is no information about the interaction of FhCL3 with the immune system. It has been shown here that FhCL3 induces a non-canonical inflammasome activation in dendritic cells (DCs), leading to IL-1β and IL-18 production without a previous microbial priming. Interestingly, this activation was depending on the cysteine protease activity of FhCL3 and the NLRP3 receptor, but independent of caspase activation. We also show that FhCL3 is internalized by DCs, promoting pro-IL-1β cleavage to its mature and biologically active form IL-1β, which is released to the extracellular environment. The FhCL3-induced NLRP3 inflammasome activation conditions DCs to promote a singular adaptive immune response, characterized by increased production of IFN-γ and IL-13. These data reveal an unexpected ability of FhCL3, a helminth-derived molecule, to activate the NLRP3 inflammasome, which is independent of the classical mechanism involving caspase activation.Fil: Celias, Daiana Pamela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Corvo, Ileana. Universidad de la República; UruguayFil: Silvane, Leonardo Micael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Tort, José Francisco. Universidad de la República; UruguayFil: Chiapello, Laura Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Fresno, Manuel. Centro de Biología Molecular Severo Ochoa; EspañaFil: Arranz, Alicia. Centro de Biología Molecular Severo Ochoa; EspañaFil: Motran, Claudia Cristina. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Cervi, Laura Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentin

Human adipose tissue–derived mesenchymal stromal cells promote B-cell motility and chemoattraction

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Genomic and transcriptomic alterations in Leishmania donovani lines experimentally resistant to antileishmanial drugs

Leishmaniasis is a serious medical issue in many countries around the World, but it remains largely neglected in terms of research investment for developing new control and treatment measures. No vaccines exist for human use, and the chemotherapeutic agents currently used are scanty. Furthermore, for some drugs, resistance and treatment failure are increasing to alarming levels. The aim of this work was to identify genomic and trancriptomic alterations associated with experimental resistance against the common drugs used against VL: trivalent antimony (SbIII, S line), amphotericin B (AmB, A line), miltefosine (MIL, M line) and paromomycin (PMM, P line). A total of 1006 differentially expressed transcripts were identified in the S line, 379 in the A line, 146 in the M line, and 129 in the P line. Also, changes in ploidy of chromosomes and amplification/deletion of particular regions were observed in the resistant lines regarding the parental one. A series of genes were identified as possible drivers of the resistance phenotype and were validated in both promastigotes and amastigotes from Leishmania donovani, Leishmania infantum and Leishmania major species. Remarkably, a deletion of the gene LinJ.36.2510 (coding for 24-sterol methyltransferase, SMT) was found to be associated with AmB-resistance in the A line. In the P line, a dramatic overexpression of the transcripts LinJ.27.T1940 and LinJ.27.T1950 that results from a massive amplification of the collinear genes was suggested as one of the mechanisms of PMM resistance. This conclusion was reinforced after transfection experiments in which significant PMM-resistance was generated in WT parasites over-expressing either gene LinJ.27.1940 (coding for a D-lactate dehydrogenase-like protein, D-LDH) or gene LinJ.27.1950 (coding for an aminotransferase of branched-chain amino acids, BCAT). This work allowed to identify new drivers, like SMT, the deletion of which being associated with resistance to AmB, and the tandem D-LDH-BCAT, the amplification of which being related to PMM resistance.This work was supported by grants (to B.A. and J.M.R.) from Proyecto del Ministerio de Economía, Industria y Competitividad (SAF2013-47556-R and SAF2017-86965-R, co-financed with FEDER funds), and from ISCIII, proyecto " RD16/0027/0008″ Red de Enfermedades Tropicales, Subprograma RETICS del Plan Estatal de I + D + I 2013–2016 y cofinanciado FEDER: Una manera de hacer Europa. The CBMSO receives institutional grants from the Fundación Ramón Areces and from the Fundación Banco Santander. Also, this work was supported by the Spanish Grant Proyecto de Excelencia, Junta de Andalucía, Ref. CTS-7282 (to F.G.

Analysis of the antigenic and prophylactic properties of the Leishmania translation initiation factors eIF2 and eIF2B in natural and experimental leishmaniasis

Los diferentes miembros de las familias de proteínas intracelulares son reconocidos por el sistema inmunológico del huésped vertebrado infectado por parásitos del género Leishmania. Aquí hemos analizado las propiedades antigénicas e inmunogénicas de los factores de iniciación de la traducción de Leishmania eIF2 y eIF2B. Una búsqueda in silico en las bases de datos de secuencias de Leishmania infantum permitió la identificación de los genes que codifican las subunidades α, β y γ y las subunidades α, β y δ de los supuestos ortólogos de Leishmania de los factores de iniciación eucarióticos F2 (LieIF2) o F2B (LieIF2B), respectivamente. La antigenicidad de estos factores fue analizada por ELISA utilizando versiones recombinantes de las diferentes subunidades. Se encontraron anticuerpos contra las diferentes subunidades LieIF2 y LieIF2B en los sueros de pacientes con leishmaniosis visceral humana y canina, y también en los sueros de hámsteres infectados experimentalmente con L. infantum. En ratones desafiados por L. infantum (BALB/c) y Leishmania major (BALB/c o C57BL/6) se detectó una respuesta humoral moderada contra estos factores proteicos. Cabe destacar que estas proteínas provocaron una producción de IL-10 por parte de los esplenocitos derivados de ratones infectados, independientemente de la especie de Leishmania empleada para el desafío experimental. Cuando se administraron vacunas de ADN basadas en la expresión de los genes codificantes de las subunidades LieIF2 o LieIF2B en ratones, se observó una secreción específica de antígenos de citoquinas IFN-γ e IL-10. Además, se generó en los ratones vacunados una protección parcial contra el desarrollo de la CL murina debido a la infección por L. major. Además, en este trabajo mostramos que la subunidad LieIF2α y las subunidades LieIF2Bβ y δ tienen la capacidad de estimular la secreción de IL-10 por las células del bazo de los ratones ingenuos. Los linfocitos B fueron identificados como los mayores productores de esta citoquina antiinflamatoria. Teniendo en cuenta los datos encontrados en este estudio, se puede formular la hipótesis de que estas proteínas actúan como factores de virulencia implicados en la inducción de respuestas humorales, así como en la producción de la citoquina IL-10 de regulación descendente, favoreciendo un resultado patológico. Por lo tanto, estas proteínas podrían considerarse marcadores de enfermedad.Different members of intracellular protein families are recognized by the immune system of the vertebrate host infected by parasites of the genus Leishmania. Here, we have analyzed the antigenic and immunogenic properties of the Leishmania eIF2 and eIF2B translation initiation factors. An in silico search in Leishmania infantum sequence databases allowed the identification of the genes encoding the α, β, and γ subunits and the α, β, and δ subunits of the putative Leishmania orthologs of the eukaryotic initiation factors F2 (LieIF2) or F2B (LieIF2B), respectively. The antigenicity of these factors was analyzed by ELISA using recombinant versions of the different subunits. Antibodies against the different LieIF2 and LieIF2B subunits were found in the sera from human and canine visceral leishmaniasis patients, and also in the sera from hamsters experimentally infected with L. infantum. In L. infantum (BALB/c) and Leishmania major (BALB/c or C57BL/6) challenged mice, a moderate humoral response against these protein factors was detected. Remarkably, these proteins elicited an IL-10 production by splenocytes derived from infected mice independently of the Leishmania species employed for experimental challenge. When DNA vaccines based on the expression of the LieIF2 or LieIF2B subunit encoding genes were administered in mice, an antigen-specific secretion of IFN-γ and IL-10 cytokines was observed. Furthermore, a partial protection against murine CL development due to L. major infection was generated in the vaccinated mice. Also, in this work we show that the LieIF2α subunit and the LieIF2Bβ and δ subunits have the capacity to stimulate IL-10 secretion by spleen cells from naïve mice. B-lymphocytes were identified as the major producers of this anti-inflammatory cytokine. Taking into account the data found in this study, it may be hypothesized that these proteins act as virulence factors implicated in the induction of humoral responses as well as in the production of the down-regulatory IL-10 cytokine, favoring a pathological outcome. Therefore, these proteins might be considered markers of disease.• Ministerio de Ciencia e Innovación y Fondos FEDER. Proyectos FISPI14/00366, FISPI14/00366 • Fondo de Investigaciones Sanitarias. Proyecto ISCIII-RETICRD16/0027/0008-FEDER • Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brasil). Program 300174/2014-4 • Centro de Biología Molecular Severo Ochoa. Ayuda • Fundación Ramón Areces. Ayuda • Banco de Santander. AyudapeerReviewe

Coadministration of the three antigenic Leishmania infantum poly (A) binding proteins as a DNA vaccine induces protection against Leishmania major infection in BALB/c Mice

Antecedentes Las proteínas intracelulares de Leishmania, altamente conservadas, han sido descritas como antígenos en mamíferos infectados natural y experimentalmente. El objetivo del presente estudio es evaluar la antigenicidad y propiedades profilácticas del Leishmania infantum Poly (A) las proteínas (LiPABPs). Metodología/Resultados principales Se han descrito tres diferentes miembros de la familia LiPABP. Se han elaborado herramientas recombinantes basadas en estas proteínas: proteínas recombinantes y vacunas de ADN. Las tres proteínas recombinantes fueron empleadas para recubrir las placas ELISA. Los sueros de pacientes humanos y caninos de leishmaniasis visceral y de pacientes humanos de leishmaniasis mucosa han reconoció los tres LiPABPs. Además, la eficacia protectora de la vacuna de ADN basada en la combinación de los tres Leishmania PABPs ha sido probado en un modelo murino de leishmaniosis progresiva: ratones BALB/c infectados con Leishmania major. La inducción de Th1 como respuesta contra la familia LiPABP por vacunación génica fue capaz de regular a la baja la IL-10 con respuestas predominantes suscitadas por el parásito LiPABPs tras la infección en este modelo murino. Esta modulación se tradujo en una protección parcial contra la infección por L. major. Los ratones vacunados con LiPABP mostraron una reducción de la patología que fue acompañada por una disminución de la carga parasitaria, en títulos de anticuerpos contra antígenos de Leishmania y de la IL-4 y la IL-10 las respuestas mediadas específicas del parásito en comparación con el control de grupos de ratones inmunizados con solución salina o con no-plásmidos recombinantes. Conclusión/significación Los resultados aquí presentados demuestran por primera vez las propiedades profilácticas de una nueva familia de proteínas intracelulares antigénicas de Leishmania, la LiPABPs. La redirección de la respuesta inmune desencadenada frente contra la familia LiPABP (de IL-10 hacia las respuestas mediadas por IFN-γ) por vacunación génica fue capaz de inducir una protección parcial contra el desarrollo de la enfermedad en un modelo murino altamente susceptible de leishmaniasis.Background Highly conserved intracellular proteins from Leishmania have been described as antigens in natural and experimental infected mammals. The present study aimed to evaluate the antigenicity and prophylactic properties of the Leishmania infantum Poly (A) binding proteins (LiPABPs). Methodology/Principal Findings Three different members of the LiPABP family have been described. Recombinant tools based on these proteins were constructed: recombinant proteins and DNA vaccines. The three recombinant proteins were employed for coating ELISA plates. Sera from human and canine patients of visceral leishmaniasis and human patients of mucosal leishmaniasis recognized the three LiPABPs. In addition, the protective efficacy of a DNA vaccine based on the combination of the three Leishmania PABPs has been tested in a model of progressive murine leishmaniasis: BALB/c mice infected with Leishmania major. The induction of a Th1-like response against the LiPABP family by genetic vaccination was able to down-regulate the IL-10 predominant responses elicited by parasite LiPABPs after infection in this murine model. This modulation resulted in a partial protection against L. major infection. LiPABP vaccinated mice showed a reduction on the pathology that was accompanied by a decrease in parasite burdens, in antibody titers against Leishmania antigens and in the IL-4 and IL-10 parasite-specific mediated responses in comparison to control mice groups immunized with saline or with the non-recombinant plasmid. Conclusion/Significance The results presented here demonstrate for the first time the prophylactic properties of a new family of Leishmania antigenic intracellular proteins, the LiPABPs. The redirection of the immune response elicited against the LiPABP family (from IL-10 towards IFN-γ mediated responses) by genetic vaccination was able to induce a partial protection against the development of the disease in a highly susceptible murine model of leishmaniasis.• Ministerio de Ciencia e Innovación. Proyectos FISPI14/00366 y FISPI11/00095 del Instituto de Salud Carlos III dentro de la Red de Investigación de Enfermedades Tropicales. Proyecto VI P I D I 2008-2011, ISCIII - Subdirección General de Redes y Centros de Investigación Cooperativa (RD12/0018/0009) • CNPq (Ciencia sem Fronteiras), Brasil: PVE 300174/2014-4 • Fundación Ramón Areces: Subvenciones al Centro de Biología Molecular Severo Ochoa (CBMSO).peerReviewe

Coadministration of the Three Antigenic Leishmania infantum Poly (A) Binding Proteins as a DNA Vaccine Induces Protection against Leishmania major Infection in BALB/c Mice

Highly conserved intracellular proteins from Leishmania have been described as antigens in natural and experimental infected mammals. The present study aimed to evaluate the antigenicity and prophylactic properties of the Leishmania infantum Poly (A) binding proteins (LiPABPs). Three different members of the LiPABP family have been described. Recombinant tools based on these proteins were constructed: recombinant proteins and DNA vaccines. The three recombinant proteins were employed for coating ELISA plates. Sera from human and canine patients of visceral leishmaniasis and human patients of mucosal leishmaniasis recognized the three LiPABPs. In addition, the protective efficacy of a DNA vaccine based on the combination of the three Leishmania PABPs has been tested in a model of progressive murine leishmaniasis: BALB/c mice infected with Leishmania major. The induction of a Th1-like response against the LiPABP family by genetic vaccination was able to down-regulate the IL-10 predominant responses elicited by parasite LiPABPs after infection in this murine model. This modulation resulted in a partial protection against L. major infection. LiPABP vaccinated mice showed a reduction on the pathology that was accompanied by a decrease in parasite burdens, in antibody titers against Leishmania antigens and in the IL-4 and IL-10 parasite-specific mediated responses in comparison to control mice groups immunized with saline or with the non-recombinant plasmid. The results presented here demonstrate for the first time the prophylactic properties of a new family of Leishmania antigenic intracellular proteins, the LiPABPs. The redirection of the immune response elicited against the LiPABP family (from IL-10 towards IFN-γ mediated responses) by genetic vaccination was able to induce a partial protection against the development of the disease in a highly susceptible murine model of leishmaniasisThe study was supported in Spain by grants from Ministerio de Ciencia e Innovación FIS PI11/00095 and FISPI14/00366 from the Instituto de Salud Carlos III within the Network of TropicalDiseases Research (VI P I+D+I 2008-2011, ISCIII -Subdirección General de Redes y Centros de Investigación Cooperativa (RD12/0018/0009)). This work was also supported in Brazil by a grant from CNPq (Ciencia sem Fronteiras-PVE 300174/2014-4). A CBMSO institutional grant from Fundación Ramón Areces is also acknowledged. EAFC is a grant recipient of CNPq. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscrip

Les droits disciplinaires des fonctions publiques : « unification », « harmonisation » ou « distanciation ». A propos de la loi du 26 avril 2016 relative à la déontologie et aux droits et obligations des fonctionnaires

The production of tt‾ , W+bb‾ and W+cc‾ is studied in the forward region of proton–proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98±0.02 fb−1 . The W bosons are reconstructed in the decays W→ℓν , where ℓ denotes muon or electron, while the b and c quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions.The production of $t\overline{t}$, $W+b\overline{b}$ and $W+c\overline{c}$ is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98 $\pm$ 0.02 \mbox{fb}^{-1}. The $W$ bosons are reconstructed in the decays $W\rightarrow\ell\nu$, where $\ell$ denotes muon or electron, while the $b$ and $c$ quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions