Rapid sequence-independent cellular response to oligodeoxynucleotides

AbstractThe presence of receptors for oligodeoxynucleotides (OdN) on the surface of L929 cells has previously been described. To study the possible coupling of the receptor to cellular signal transducing systems, the effect of phosphodiester OdN of different sequences on cellular phospholipase C and protein kinase C (PKC) activities in L929 fibroblasts was studied. Treatment of cells with OdN induced an increase in 32P labeling of phosphatidic acid which was accompanied by a gradual decrease in diacylglycerol. These effects seem to be independent of the OdN sequence. PKC activity in membranes isolated from OdN-treated cells was found to be lower than that in membranes of control cells. SDS-PAGE of the 32P-labeled cellular proteins revealed that OdN treatment caused a decrease in phosphorylation of the 26 and 73 kDa cellular proteins in the cells

Leukocytes and drug-resistant cancer cells are targets for intracellular delivery by adenoviral dodecahedron

One of the major factors limiting the effectiveness of cancer chemotherapy is inefficient drug delivery. Systems enabling efficient delivery and enhanced intracellular uptake appear particularly promising in this respect. Virus-like particle, adenoviral dodecahedron (Dd), employs receptor-mediated endocytosis for cell penetration and is able to deliver intracellularly dozens of cargo molecules attached to one particle. We focused on studying Dd properties in the context of cancer treatment, showing that intratumoral injection of Dd, assessed in mouse xenograft model, results in vector accumulation in tumor without spreading in off-target organs. Moreover, we demonstrated that Dd is a promising vector targeting leukocytes and drug-resistant cancer cells. Dd uptake by human blood cells analyzed in vitro indicated the preference for leukocytes in comparison to red blood cells and platelets. Furthermore, internalization of Dd-doxorubicin conjugate by drug-resistant cells leads to increased nuclear accumulation of doxorubicin and significant enhancement of cytotoxicity against target cancer cells

Faithful chaperones

This review describes the properties of some rare eukaryotic chaperones that each assist in the folding of only one target protein. In particular, we describe (1) the tubulin cofactors, (2) p47, which assists in the folding of collagen, (3) α-hemoglobin stabilizing protein (AHSP), (4) the adenovirus L4-100 K protein, which is a chaperone of the major structural viral protein, hexon, and (5) HYPK, the huntingtin-interacting protein. These various-sized proteins (102–1,190 amino acids long) are all involved in the folding of oligomeric polypeptides but are otherwise functionally unique, as they each assist only one particular client. This raises a question regarding the biosynthetic cost of the high-level production of such chaperones. As the clients of faithful chaperones are all abundant proteins that are essential cellular or viral components, it is conceivable that this necessary metabolic expenditure withstood evolutionary pressure to minimize biosynthetic costs. Nevertheless, the complexity of the folding pathways in which these chaperones are involved results in error-prone processes. Several human disorders associated with these chaperones are discussed

Virus-like particles as vaccine.

This review presents data on commercial and experimental virus-like particle (VLP) vaccines, including description of VLP vaccines against influenza. Virus-like particles are multimeric, sometimes multiprotein nanostructures assembled from viral structural proteins and are devoid of any genetic material. VLPs present repetitive high-density displays of viral surface proteins. Importantly, they contain functional viral proteins responsible for cell penetration by the virus, ensuring efficient cell entry and thus tissue-specific targeting, determined by the origin of the virus. The foremost application of VLPs is in vaccinology, where they provide delivery systems that combine good safety profiles with strong immunogenicity and constitute a safe alternative to inactivated infectious viruses. These stable and versatile nanoparticles display excellent adjuvant properties capable of inducing innate and cognate immune responses. They present both, high-density B-cell epitopes, for antibody production and intracellular T- cell epitopes, thus inducing, respectively, potent humoral and cellular immune responses. Uptake of VLPs by antigen-presenting cells leads to efficient immune responses resulting in control of pathogenic microorganisms

Recrutement d'ubiquitine-ligases par la protéine de l'adenovirus humain responsable de l'internalisation virale

Les adénovirus humains sont des virus faiblement pathogènes, utilisés comme vecteur de transfert de gènes en thérapie génique. De nombreuses protéines cellulaires, impliquées dans la réussite de l'infection virale, n'ont pas été identifiées. Le criblage d'une banque d'expression de cDNA avec la protéine virale base du penton, impliquée dans l'internalisation du virus dans la cellule hôte, a permis d'identifier des protéines ubiquitine-ligase cellulaires de la famille Nedd4-like. Grâce à l'expression de formes mutantes de la protéine base du penton, nous sommes parvenus à caractériser in vitro et dans la cellule les motifs de chacun des partenaires responsables des interactions entre la protéine virale et les ubiquitine-ligases WWP1, WWP2 et AIP4. Nous apportons des premiers éléments de réponse quant aux conséquences de ces interactions sur l'infection virale, et sur la protéine base du penton elle-même.GRENOBLE1-BU Sciences (384212103) / SudocSudocFranceF

Virus-like particles as drug delivery vectors

Virus-like particles (VLPs) assemble spontaneously during the viral cycle or in heterologous systems during expression of viral structural protein. Depending on the complexity of the VLPs, they can be obtained by expression in prokaryotic or eukaryotic expression system from the suitable recombinant vectors, or formed in cell-free conditions. Moreover, they can be built from proteins of a single virus, or can present the proteins or peptides derived from a virus or cell on a platform derived from any other single virus, thus forming chimeric VLPs. VLPs are best known for their immunogenic properties, but the versatility of VLPs allows a wide variety of applications. They are lately in the centre of investigations in vaccinology, drug delivery and gene therapy. This review focuses on utilization of VLPs for drug delivery

Interactions moléculaires entre l'adénovirus entérique de sérotype 41 et la cellule hôte

L'adénovirus de sérotype 41 (Ad41) présente plusieurs particularités qui le différencient des autres adénovirus humains, telles que son tropisme ciblé pour le tractus digestif et la présence de deux protéines "fibres" de différentes longueurs, une courte et une longue. Les autres adénovirus humains présentent un seul type de fibre et un tropisme cellulaire moins restreint. Un certain nombre d'observations suggèrent que la fibre courte est impliquée dans le tropisme de l'Ad41. Nous avons utilisé le domaine "tête" de la fibre courte de l'Ad41 comme "appât" pour rechercher les partenaires cellulaires de l'Ad41, en détectant les interaction protéine-protéine survenant in vivo, dans la levure (système du double-hybride). Notre travail a permis de développer des outils propres à l'étude de l'Ad41, d'établir les conditions de production de l'Ad41 et de mettre en évidence le comportement atypique des pentons de l'Ad41 en électrophorèse des protéines et de déterminer la longueur et la stoechiométrie des fibres ontenues dans le virion. Nous avons identifié plusieurs partenaires cellulaires intéragissant avec la fibre courte de l'Ad41. Certaines de ces protéines interagissent communément avec les fibres des différents sérotypes(Ad2,Ad3 et Ad41) alors que d'autres semblent spécifiques de l'Ad41. Enfin, nous avons montré que, dans un environnemnt acide proche de celui du tractus digestif humain, l'Ad41 est plus stable que l'Ad2. Ces résultats indiquent que plusieurs facteurs distinguent l'Ad41 des autres adénovirus humains et peuvent influencer le tropisme de l'Ad41 pour le tractus digestif.GRENOBLE1-BU Sciences (384212103) / SudocSudocFranceF