Activation of NF-kB mediates ICAM-1 induction in respiratory cells exposed to an adenovirus-derived vector

Gene transfer to the respiratory tract by replication-deficient adenoviruses is limited by the induction of inflammatory and immune responses. We previously demonstrated that a E1-E3-deleted recombinant adenovirus carrying the expression cassette for the cystic fibrosis gene (Ad.CFTR) upregulates the expression of the pro-inflammatory intercellular adhesion molecule-1 (ICAM-1) both in vitro and in vivo. In the present work we suggest a role for the nuclear factor-kB (NF-kB) in Ad.CFTR-dependent up-regulation of ICAM-1 in respiratory epithelial A549 cells. Specifically, Ad.CFTR induced translocation of NF-kB into the nucleus and binding to the proximal -228/-218 NF-kB consensus sequence on the ICAM-1 promoter. Ad.CFTR also stimulated a 13-fold increase in NF-kB-dependent expression of the CAT reporter gene under the control of a region of the ICAM-1 promoter, including the proximal NF-kB consensus sequence. The Ad.CFTR-dependent increase of ICAM-1 mRNA was abolished by inhibitors of NF-kB, such as N-acetyl-L-cysteine, pyrrolidine dithiocarbamate, parthenolide and the synthetic peptide SN50. All these inhibitors abolished both Ad.CFTR-induced NF-kB DNA binding and transactivating activities. These results indicate a critical role of NF-kB in the pro-inflammatory response elicited by replication-deficient adenoviral vectors in respiratory cells

Hydrophobic cluster analysis of G protein-coupled receptors: a powerful tool to derive structural and functional information from 2D-representation of protein sequences

Current methods for comparative analyses of protein sequences are 1D-alignments of amino acid sequences based on the maximization of amino acid identity (homology) and the prediction of secondary structure elements. This method has a major drawback once the amino acid identity drops below 20-25%, since maximization of a homology score does not take into account any structural information. A new technique called Hydrophobic Cluster Analysis (HCA) has been developed by Lemesle-Varloot et al. (Biochimie 72, 555-574), 1990). This consists of comparing several sequences simultaneously and combining homology detection with secondary structure analysis. HCA is primarily based on the detection and comparison of structural segments constituting the hydrophobic core of globular protein domains, with or without transmembrane domains. We have applied HCA to the analysis of different families of G-protein coupled receptors, such as catecholamine receptors as well as peptide hormone receptors. Utilizing HCA the thrombin receptor, a new and as yet unique member of the family of G-protein coupled receptors, can be clearly classified as being closely related to the family of neuropeptide receptors rather than to the catecholamine receptors for which the shape of the hydrophobic clusters and the length of their third cytoplasmic loop are very different. Furthermore, the potential of HCA to predict relationships between new putative and already characterized members of this family of receptors will be presente

Efficient generation of recombinant adenovirus vectors by homologous recombination in Escherichia coli.

Despite recent technical improvements, the construction of recombinant adenovirus vectors remains a time-consuming procedure which requires extensive manipulations of the viral genome in both Escherichia coli and eukaryotic cells. This report describes a novel system based on the cloning and manipulation of the full-length adenovirus genome as a stable plasmid in E. coli, by using the bacterial homologous recombination machinery. The efficiency and flexibility of the method are illustrated by the cloning of the wild-type adenovirus type 5 genome, the insertion of a constitutive promoter upstream from the E3 region, the replacement of the E1 region by an exogenous expression cassette, and the deletion of the E1 region. All recombinant viral DNAS were shown to be fully infectious in permissive cells, and the modified E3 region or the inserted foreign gene was correctly expressed in the infected cells