Comparative Pathogenesis of an Avian H5N2 and a Swine H1N1 Influenza Virus in Pigs

Pigs are considered intermediate hosts for the transmission of avian influenza viruses (AIVs) to humans but the basic organ pathogenesis of AIVs in pigs has been barely studied. We have used 42 four-week-old influenza naive pigs and two different inoculation routes (intranasal and intratracheal) to compare the pathogenesis of a low pathogenic (LP) H5N2 AIV with that of an H1N1 swine influenza virus. The respiratory tract and selected extra-respiratory tissues were examined for virus replication by titration, immunofluorescence and RT-PCR throughout the course of infection. Both viruses caused a productive infection of the entire respiratory tract and epithelial cells in the lungs were the major target. Compared to the swine virus, the AIV produced lower virus titers and fewer antigen positive cells at all levels of the respiratory tract. The respiratory part of the nasal mucosa in particular showed only rare AIV positive cells and this was associated with reduced nasal shedding of the avian compared to the swine virus. The titers and distribution of the AIV varied extremely between individual pigs and were strongly affected by the route of inoculation. Gross lung lesions and clinical signs were milder with the avian than with the swine virus, corresponding with lower viral loads in the lungs. The brainstem was the single extra-respiratory tissue found positive for virus and viral RNA with both viruses. Our data do not reject the theory of the pig as an intermediate host for AIVs, but they suggest that AIVs need to undergo genetic changes to establish full replication potential in pigs. From a biomedical perspective, experimental LP H5 AIV infection of pigs may be useful to examine heterologous protection provided by H5 vaccines or other immunization strategies, as well as for further studies on the molecular pathogenesis and neurotropism of AIVs in mammals

Contrôle de l'expression du gène de l'alpha-foetoprotéine par l'hormone thyroïdienne

Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe

Contrôle de l'expression du gène de l'alpha-foetoprotéine par l'hormone thyroïdienne

Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe

Assignment of the rat Crebbp and Rxrip13 genes to chromosome bands 10q12→q21 and 10q24 respectively by in situ hybridization

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Assignment of the hepatocyte nuclear factor 3 genes to rat chromosome bands 6q23-->q24 (alpha: Hnf3a), 3q41 (beta: Hnf3b) and 1q21-->q22 (gamma: Hnf3g) by in situ hybridization.

Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe

Assignment of the rat Crebbp and Rxrip13 to the chromosome bands 10q12-21 and 10q24 respectively by in situ hybridization

Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe

Stimulation of the α-fetoprotein promoter by unliganded thyroid hormone receptor in association with protein deacetylation

α-Fetoprotein (AFP) is a serum protein expressed during fetal life, the expression of which is shut off after birth. The activity of the mouse Afp gene promoter region comprised between -80 and -38 bp is regulated by the thyroid hormone receptor (T3R): negatively in the presence of T3 and positively in the absence of T3. The stimulating effect of unliganded T3R is, unexpectedly, antagonized by cofactors that have histone-acetyl-transferase activity, or by sodium butyrate, which inhibits histone acetylases (HDACs). The unliganded T3R stimulating activity effect is thus associated with protein deacetylation, contrary to the usual situation. In combination with previous results, our observations suggest that T3-mediated down regulation of the Afp promoter is due to T3-induced protein acetylation leading to loss of a nucleosomal structure (required for promoter activity) and chromatin opening. © 2002 Elsevier Science Ireland Ltd. All rights reserved.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Stimulation of the a-fetoprotein promoter by unliganted thyroid hormone receptor in association with protein deacetylation

info:eu-repo/semantics/publishe

Positive selection vectors to generate fused genes for the expression of his-tagged proteins.

Epitope tagging simplifies detection, characterization and purification of proteins. Gene fusion to combine the coding region of a well-characterized epitope with the coding region for a protein of interest generally requires several subcloning steps. Alternatively, a PCR strategy can be used to generate such a chimeric gene. In addition to its simplicity, this approach allows one to limit the size of the multiple cloning sites present in conventional expression vectors, thus reducing the introduction of artifactual amino-acid sequences into the fused protein. In this communication, we describe new vectors that allow PCR cloning and selection of chimeric genes coding for N- or C-terminal His-tagged proteins. These vectors are based on the control of cell death CcdB direct selection technology and are well adapted to the cloning of blunt-ended PCR products that were generated by using thermostable polymerases that provide proofreading activity.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe

Bifunctional lacZ alpha-ccdB genes for selective cloning of PCR products.

The use of PCR-amplified DNA-fragments is a classical approach to generate recombinant DNA. To facilitate the cloning of PCR products, we have constructed two new pKIL vectors that allow selection of recombinants. The multiple cloning sites (MCS) of these plasmids contain two adjacent Aspel sites and a unique HindII site. Cleavage of these vectors with Aspel produce linearized molecules with a single thymidine nucleotide at the 3' ends allowing TA cloning of Taq-amplified fragments. On the other hand, cleavage with HindII can be used for the cloning of blunt-ended PCR products generated by other DNA polymerases. The LacZ alpha-CcdB fusion protein produced by these plasmids has retained both the CcdB killer activity and the ability to alpha-complement the truncated LacZ delta M15. This bifunctionality allowed us to show that small PCR products (< 1000 bp) that do not disrupt lacZ alpha efficiently do inactivate CcdB, which demonstrates that the CcdB-based selection is well adapted for cloning of PCR products, especially for small size fragments.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe