Characterization of conserved properties of hemagglutinin of H5N1 and human influenza viruses: possible consequences for therapy and infection control

<p>Abstract</p> <p>Background</p> <p>Epidemics caused by highly pathogenic avian influenza virus (HPAIV) are a continuing threat to human health and to the world's economy. The development of approaches, which help to understand the significance of structural changes resulting from the alarming mutational propensity for human-to-human transmission of HPAIV, is of particularly interest. Here we compare informational and structural properties of the hemagglutinin (HA) of H5N1 virus and human influenza virus subtypes, which are important for the receptor/virus interaction.</p> <p>Results</p> <p>Presented results revealed that HA proteins encode highly conserved information that differ between influenza virus subtypes H5N1, H1N1, H3N2, H7N7 and defined an HA domain which may modulate interaction with receptor. We also found that about one third of H5N1 viruses which are isolated during the 2006/07 influenza outbreak in Egypt possibly evolve towards receptor usage similar to that of seasonal H1N1.</p> <p>Conclusion</p> <p>The presented results may help to better understand the interaction of influenza virus with its receptor(s) and to identify new therapeutic targets for drug development.</p

Live SIV vaccine correlate of protection: immune complex-inhibitory Fc receptor interactions that reduce target cell availability

Principles to guide design of an effective vaccine against HIV are greatly needed, particularly to protect women in the pandemic’s epicentre in Africa. We have been seeking these principles by identifying correlates of the robust protection associated with SIVmac239Δnef vaccination in the SIV-rhesus macaque animal model of HIV-1 transmission to women. We have identified one correlate of SIVmac239Δnef protection against vaginal challenge as a resident mucosal system for SIV-gp41 trimer antibody production and neonatal Fc receptor (FcRn)-mediated concentration of these antibodies on the path of virus entry to inhibit establishment of infected founder populations at the portal of entry. Here we identify as a second protection correlate, blocking CD4+ T cell recruitment to inhibit local expansion of infected founder populations. Virus-specific immune complex interactions with the inhibitory FcγRIIb receptor in the epithelium lining the cervix initiate expression of genes that block recruitment of target cells to fuel local expansion. Immune complex-FcγRIIb receptor interactions at mucosal frontlines to dampen the innate immune response to vaginal challenge could be a potentially general mechanism for the mucosal immune system to sense and modulate the response to a previously encountered pathogen. Designing vaccines to provide protection without eliciting these transmission-promoting innate responses could contribute to developing an effective HIV-1 vaccine

Live SIV vaccine correlate of protection: immune complex-inhibitory Fc receptor interactions that reduce target cell availability

Principles to guide design of an effective vaccine against HIV are greatly needed, particularly to protect women in the pandemic’s epicentre in Africa. We have been seeking these principles by identifying correlates of the robust protection associated with SIVmac239Δnef vaccination in the SIV-rhesus macaque animal model of HIV-1 transmission to women. We have identified one correlate of SIVmac239Δnef protection against vaginal challenge as a resident mucosal system for SIV-gp41 trimer antibody production and neonatal Fc receptor (FcRn)-mediated concentration of these antibodies on the path of virus entry to inhibit establishment of infected founder populations at the portal of entry. Here we identify as a second protection correlate, blocking CD4+ T cell recruitment to inhibit local expansion of infected founder populations. Virus-specific immune complex interactions with the inhibitory FcγRIIb receptor in the epithelium lining the cervix initiate expression of genes that block recruitment of target cells to fuel local expansion. Immune complex-FcγRIIb receptor interactions at mucosal frontlines to dampen the innate immune response to vaginal challenge could be a potentially general mechanism for the mucosal immune system to sense and modulate the response to a previously encountered pathogen. Designing vaccines to provide protection without eliciting these transmission-promoting innate responses could contribute to developing an effective HIV-1 vaccine

Entrée à l'école et métier d'élève : représentations d'éducatrices de la petite enfance et d'enseignantes de l'école enfantine

Notre mémoire porte essentiellement sur les représentations des enseignantes et des éducatrices de la petite enfance sur un enfant prêt à entrer à l'école. De plus nous avons poussé notre recherche sur la collaboration qu'il y a entre ses deux professionnelles. Ainsi que l'influence de celle-ci sur le parcours d'un enfant étant déjà allé dans une institution crèche. Ainsi constater s'il y a oui ou non des attentes différentes le concernant. Nous avons basé notre recherche sur différents facteurs comme : le métier d'élève, les formations, l'emplacement des différents établissements en définissant trois zones en fonction de la proximité des établissements… Il s'est avéré que les enseignantes contrairement aux éducatrices n'avait pas d'attentes particulières concernant les enfants qui entre à l'école qu'ils soient allés en crèche ou non. De plus, il y a peu de collaboration entre les deux institutions dû au secret professionnel