22 research outputs found
SpeS: A Novel Superantigen and Its Potential as a Vaccine Adjuvant against Strangles.
Bacterial superantigens (sAgs) are powerful activators of the immune response that trigger unspecific T cell responses accompanied by the release of proinflammatory cytokines. Streptococcus equi (S. equi) and Streptococcus zooepidemicus (S. zooepidemicus) produce sAgs that play an important role in their ability to cause disease. Strangles, caused by S. equi, is one of the most common infectious diseases of horses worldwide. Here, we report the identification of a new sAg of S. zooepidemicus, SpeS, and show that mutation of the putative T cell receptor (TCR)-binding motif (YAY to IAY) abrogated TCR-binding, whilst maintaining interaction with major histocompatibility complex (MHC) class II molecules. The fusion of SpeS and SpeSY39I to six S. equi surface proteins using two different peptide linkers was conducted to determine if MHC class II-binding properties were maintained. Proliferation assays, qPCR and flow cytometry analysis showed that SpeSY39I and its fusion proteins induced less mitogenic activity and interferon gamma expression when compared to SpeS, whilst retaining Antigen-Presenting Cell (APC)-binding properties. Our data suggest that SpeSY39I-surface protein fusions could be used to direct vaccine antigens towards antigen-presenting cells in vivo with the potential to enhance antigen presentation and improve immune responses
Chikungunya Virus Infection during Pregnancy, RĂ©union, France, 2006
Except for prenatal hospital admissions for those infected, this virus had no effect on outcomes
Ătude des principaux facteurs influençant l'activitĂ© de la dĂ©gradation biologique des hydrocarbures dans le sol
Ce prĂ©sent travail avait pour but d'Ă©tudier et de comprendre l'action de certains paramĂštres biologiques et climatiques sur le processus de biodĂ©gradation des rejets huileux d'une raffinerie. Dans un premier temps, l'Ă©tude a portĂ© sur le rĂŽle jouĂ© par l'eau et le rĂŽle jouĂ© par l'aĂ©ration du sol en fonction de la vitesse de dĂ©gradation biologique des hydrocarbures. Plusieurs chaudiĂšres et carrĂ©s expĂ©rimentaux Ă©taient disponibles pour ces expĂ©riences. Pour chacune de celles-ci, le seul paramĂštre variant entre les carrĂ©s ou les chaudiĂšres Ă©tait le paramĂštre Ă©tudiĂ©. Il a ainsi Ă©tĂ© dĂ©montrĂ© qu'une quantitĂ© excessive d'eau inhibait effectivement dans une bonne mesure la biodĂ©gradation des hydrocarbures. De plus, la terre est plus apte Ă s'imbiber d'eau qu'elle ne l'est Ă s'imbiber d'huile, ce qui constitue Ă©videmment un autre facteur de nuisance. Les bactĂ©ries telluriques responsables de la biodĂ©gradation de l'huile sont dans une trĂšs large mesure aĂ©robies. Nous nous sommes donc intĂ©ressĂ©s au rĂŽle jouĂ© par le mĂ©lange mĂ©canique de la terre dans le but de visualiser les effets de l'aĂ©ration dans le processus Ă©tudiĂ©. Incidemment, le fait de retourner mĂ©caniquement la terre est utile Ă condition de ne pas dĂ©passer une frĂ©quence optimale. Cette frĂ©quence doit ĂȘtre dĂ©terminĂ©e pour chaque site en fonction du climat local et de la quantitĂ© de dĂ©chets traitĂ©s par semaine. En second lieu, nous nous sommes intĂ©ressĂ©s aux effets provoquĂ©s par des variations du pourcentage d'hydrocarbures dans le sol au niveau de la vitesse de biodĂ©gradation des huiles. En plaçant un volume de liquide constant de carrĂ© expĂ©rimental en carrĂ© expĂ©rimental, mais en faisant varier la quantitĂ© d'huile (donc le pourcentage d'huile) entre chaque carrĂ©, nous en sommes venus Ă la conclusion que plus un sol est riche en hydrocarbures, plus la biodĂ©gradation est efficace. La diminution des volumes de dĂ©chets huileux par des processus d'Ă©limination d'une forte quantitĂ© d'eau contenue dans ceux-ci nous ont amenĂ© Ă dĂ©terminer si les hydrocarbures contenus dans des boues huileuses Ă©paissies Ă©taient tout aussi bien biodĂ©gradables que les hydrocarbures contenus dans de l'huile brute. En incorporant diffĂ©rentes quantitĂ©s de boues dans la terre, nous avons pu constater que les hydrocarbures des dĂ©chets concentrĂ©s Ă©taient trĂšs bien biodĂ©gradables. Enfin, en Ă©tudiant le rĂŽle que pourrait jouer la tourbe dans le processus de dĂ©gradation biologique des huiles, nous en sommes venus Ă la conclusion que non seulement celle-ci n'Ă©tait pas efficace, mais qu'elle pouvait mĂȘme ĂȘtre nuisible Ă la biodĂ©gradation
Ătude des principaux facteurs influençant l'activitĂ© de la dĂ©gradation biologique des hydrocarbures dans le sol
Ce prĂ©sent travail avait pour but d'Ă©tudier et de comprendre l'action de certains paramĂštres biologiques et climatiques sur le processus de biodĂ©gradation des rejets huileux d'une raffinerie. Dans un premier temps, l'Ă©tude a portĂ© sur le rĂŽle jouĂ© par l'eau et le rĂŽle jouĂ© par l'aĂ©ration du sol en fonction de la vitesse de dĂ©gradation biologique des hydrocarbures. Plusieurs chaudiĂšres et carrĂ©s expĂ©rimentaux Ă©taient disponibles pour ces expĂ©riences. Pour chacune de celles-ci, le seul paramĂštre variant entre les carrĂ©s ou les chaudiĂšres Ă©tait le paramĂštre Ă©tudiĂ©. Il a ainsi Ă©tĂ© dĂ©montrĂ© qu'une quantitĂ© excessive d'eau inhibait effectivement dans une bonne mesure la biodĂ©gradation des hydrocarbures. De plus, la terre est plus apte Ă s'imbiber d'eau qu'elle ne l'est Ă s'imbiber d'huile, ce qui constitue Ă©videmment un autre facteur de nuisance. Les bactĂ©ries telluriques responsables de la biodĂ©gradation de l'huile sont dans une trĂšs large mesure aĂ©robies. Nous nous sommes donc intĂ©ressĂ©s au rĂŽle jouĂ© par le mĂ©lange mĂ©canique de la terre dans le but de visualiser les effets de l'aĂ©ration dans le processus Ă©tudiĂ©. Incidemment, le fait de retourner mĂ©caniquement la terre est utile Ă condition de ne pas dĂ©passer une frĂ©quence optimale. Cette frĂ©quence doit ĂȘtre dĂ©terminĂ©e pour chaque site en fonction du climat local et de la quantitĂ© de dĂ©chets traitĂ©s par semaine. En second lieu, nous nous sommes intĂ©ressĂ©s aux effets provoquĂ©s par des variations du pourcentage d'hydrocarbures dans le sol au niveau de la vitesse de biodĂ©gradation des huiles. En plaçant un volume de liquide constant de carrĂ© expĂ©rimental en carrĂ© expĂ©rimental, mais en faisant varier la quantitĂ© d'huile (donc le pourcentage d'huile) entre chaque carrĂ©, nous en sommes venus Ă la conclusion que plus un sol est riche en hydrocarbures, plus la biodĂ©gradation est efficace. La diminution des volumes de dĂ©chets huileux par des processus d'Ă©limination d'une forte quantitĂ© d'eau contenue dans ceux-ci nous ont amenĂ© Ă dĂ©terminer si les hydrocarbures contenus dans des boues huileuses Ă©paissies Ă©taient tout aussi bien biodĂ©gradables que les hydrocarbures contenus dans de l'huile brute. En incorporant diffĂ©rentes quantitĂ©s de boues dans la terre, nous avons pu constater que les hydrocarbures des dĂ©chets concentrĂ©s Ă©taient trĂšs bien biodĂ©gradables. Enfin, en Ă©tudiant le rĂŽle que pourrait jouer la tourbe dans le processus de dĂ©gradation biologique des huiles, nous en sommes venus Ă la conclusion que non seulement celle-ci n'Ă©tait pas efficace, mais qu'elle pouvait mĂȘme ĂȘtre nuisible Ă la biodĂ©gradation
Reflections on the growing use of sounds in systematics and synecology: why an acoustic signal cannot become an onomatophore
International audienc
Harnessing superantigen activity to generate an enhanced vaccine response
International audienc
Laying the foundations of evolutionary and systematic studies in crickets (Insecta, Orthoptera): a multilocus phylogenetic analysis
International audienc
Mortality and severe morbidity of very preterm infants: comparison of two French cohort studies
International audienceBACKGROUND:In Reunion Island, a French overseas department, the burden of preterm birth and perinatal mortality exceed those observed in mainland France, despite similar access to standard perinatal care. The purpose of the study was to compare the outcome of two cohorts of NICU-admitted very preterm infants born between 24 and 31âweeks of gestation (WG): the registry-based OGP (Observatoire de la Grande PrĂ©maturitĂ©, Reunion Island, 2008-2013) cohort, and the nationwide EPIPAGE-2 (mainland France, 2011) observational cohort.METHODS:The primary outcome was adverse neonatal outcomes defined as a composite indicator of in-hospital mortality or any of three following severe morbidities: bronchopulmonary dysplasia (BPD), necrotising enterocolitis, or severe neurological injury (periventricular leukomalacia or grade III-IV intraventricular haemorrhages). Logistic regression modelling adjusting for confounders was performed.RESULTS:A total of 1272 very preterm infants from the Reunionese OGP cohort and 3669 peers from the mainland EPIPAGE-2 cohort were compared. Adverse neonatal outcomes were more likely observed in the OGP cohort (32.6% versus 26.6%, pâ<â 0.001), as result of both increased in-hospital mortality across all gestational age strata and increased BPD among the survivors of the 29-31 WG stratum. After adjusting for gestational age, gender and multiple perinatal factors, the risk of adverse neonatal outcomes was higher in the OGP cohort than in the EPIPAGE-2 cohort across all gestational age strata.CONCLUSIONS:Despite similar guidelines for standard perinatal care, very preterm infants born in Reunion Island have a higher risk for death or severe morbidity compared with those born in mainland France
Low Plasma Protein Levels at Birth Are Associated with Poor Cardiovascular Adaptation and Serious Adverse Outcome in Infants with Gestational Age <32 Weeks: The ProHĂ©mie Study.
International audienceBackground: Retrospective studies suggest that early hypoproteinemia has prognostic value for adverse outcome in preemies, but the underlying pathophysiology is unknown. We hypothesized that the prognostic relevance of hypoproteinemia could be related to its association with impaired cardiovascular function and organ perfusion during transition. Objectives: To describe the plasma protein status and the measures of cardiovascular function according to the outcome in infants <32 weeks' gestation. Methods: One hundred and twenty-eight infants were prospectively included from birth to discharge. During the first 24 h of life, we assessed the cardiovascular function and systemic and organ blood flow by Doppler ultrasound, and monitored cerebral and renal regional oxygen saturation (cRSO2, rRSO2) using near-infrared spectroscopy. These measures were analyzed in relationship to hypoproteinemia (total plasma protein level <40 g/L at 12 h of life) and severe adverse outcome (death or survival with severe neurological injury). Results: Hypoproteinemia was associated with a higher risk of a severe adverse outcome after adjustment of confounding variables (adjusted OR = 6.8; 95% CI 1.3-34). Compared to normoproteinemic infants and after adjustment for gestational age, hypoproteinemic ones had more significantly: hypotension (7 vs. 13%, p = 0.03), abnormal capillary refilling time (20 vs. 36%, p < 0.001), abnormal renal blood flow (resistive index 0.78 ± 0.11 vs. 0.85 ± 0.09, p = 0.04), lower rRSO2 (82.9 ± 9.2 vs. 73.6 ± 10.5%, p = 0.04), and lower systemic vascular resistance (0.155 ± 0.058 vs. 0.108 ± 0.037 mm Hg/L/kg; p = 0.04). The cRSO2 patterns were significantly decreased in infants with severe adverse outcome and independent from protein status. Conclusion: Hypoproteinemia is associated with impaired cardiovascular function. Further studies are required to elucidate the interplay between changes in protein levels, postnatal hemodynamics and clinical outcome
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SpeS: A Novel Superantigen and Its Potential as a Vaccine Adjuvant against Strangles
Bacterial superantigens (sAgs) are powerful activators of the immune response that trigger unspecific T cell responses accompanied by the release of proinflammatory cytokines. Streptococcus equi (S. equi) and Streptococcus zooepidemicus (S. zooepidemicus) produce sAgs that play an important role in their ability to cause disease. Strangles, caused by S. equi, is one of the most common infectious diseases of horses worldwide. Here, we report the identification of a new sAg of S. zooepidemicus, SpeS, and show that mutation of the putative T cell receptor (TCR)-binding motif (YAY to IAY) abrogated TCR-binding, whilst maintaining interaction with major histocompatibility complex (MHC) class II molecules. The fusion of SpeS and SpeSY39I to six S. equi surface proteins using two different peptide linkers was conducted to determine if MHC class II-binding properties were maintained. Proliferation assays, qPCR and flow cytometry analysis showed that SpeSY39I and its fusion proteins induced less mitogenic activity and interferon gamma expression when compared to SpeS, whilst retaining Antigen-Presenting Cell (APC)-binding properties. Our data suggest that SpeSY39I-surface protein fusions could be used to direct vaccine antigens towards antigen-presenting cells in vivo with the potential to enhance antigen presentation and improve immune responses