In vitro, in cellulo and structural characterizations of the interaction between the integrase of Porcine Endogenous Retrovirus A/C and proteins of the BET family.

Retroviral integrase (IN) proteins catalyze the permanent integration of the viral genome into host DNA. They can productively recruit cellular proteins, and the human Bromodomain and Extra-Terminal domain (hBET) proteins have been shown to be co-factors for integration of gamma-retroviruses such as Murine Leukemia Virus (MLV) into human cells. By using two-hybrid, co-immunoprecipitation and in vitro interaction assays, we showed that IN of the gamma- Porcine Endogenous Retrovirus-A/C (PERV IN) interacts through its C-terminal domain (CTD) with hBET proteins.

Transfer of the Cystic Fibrosis Transmembrane Conductance Regulator to Human Cystic Fibrosis Cells Mediated by Extracellular Vesicles.

Cystic fibrosis (CF) is a genetic disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene, resulting in a deficiency in chloride channel activity. In this study, extracellular vesicles (EVs), microvesicles, and exosomes were used as vehicles to deliver exogenous CFTR glycoprotein and its encoding mRNA (mRNA(GFP-CFTR)) to CF cells to correct the CFTR chloride channel function. We isolated microvesicles and exosomes from the culture medium of CFTR-positive Calu-3 cells, or from A549 cells transduced with an adenoviral vector overexpressing a GFP-tagged CFTR (GFP-CFTR).

In vitro functional analyses of the human immunodeficiency virus type 1 (HIV-1) integrase mutants give new insights into the intasome assembly.

A functional study of mutants of the human immunodeficiency virus type 1 (HIV-1) integrase (IN) was conducted with the support of a recently proposed HIV-1 intasome model. Firstly, we investigated the predicted position of the C-terminal domain (CTD) and the flexibility of the alpha-6 helix by mutating the residue Ile-203. This had no impact on the 3'-processing reaction but reduced the strand transfer reaction and the formation of tetramers.

Functional analyses of mutants of the central core domain of an Avian Sarcoma/Leukemia Virus integrase.

Integrase (IN) is the enzyme responsible for the integration of the retroviral genome into the host cell DNA. Herein, three mutants of conserved residues (V79, S85 and I146) of the central core domain (CCD) of an Avian Sarcoma/Leukemia Virus IN were analyzed in vitro. Our data revealed (i) the inability of S85T mutant to form dimers and tetramers in the absence of DNA and (ii) a slightly reduced ability of V79A IN in tetramers formation.

Avian sarcoma and leukemia virus (ASLV) integration in vitro: mutation or deletion of integrase (IN) recognition sequences does not prevent but only reduces the efficiency and accuracy of DNA integration.

Integrase (IN) is the enzyme responsible for provirus integration of retroviruses into the host cell genome. We used an Avian Sarcoma and Leukemia Viruses (ASLV) integration assay to investigate the way in which IN integrates substrates mutated or devoid of one or both IN recognition sequences. We found that replacing U5 by non-viral sequences (U5del) or U3 by a mutated sequence (pseudoU3) resulted in two and three fold reduction of two-ended integration (integration of the two ends from a donor DNA) respectively, but had a slight effect on concerted integration (integration of both ends at the same site of target DNA).

Molecular characterization of lentiviruses from goats from Poland based on gag gene sequence analysis.

Caprine arthritis-encephalitis virus (CAEV) infection in goats is worldwide but with higher prevalence in industrialized countries. While positive serology of CAEV in Polish goats was reported there was no genetic study of this virus. In this study, we described the molecular characterization of lentiviruses isolated from seropositive goats from Poland.

Clearance of a productive lentivirus infection in calves experimentally inoculated with caprine arthritis-encephalitis virus.

Lentiviruses have long been considered host-specific pathogens, but several recent observations demonstrated their capacity to conquer new hosts from different species, genera, and families. From these cross-species infections emerged new animal and human infectious diseases. The successful colonization and adaptation of a lentivirus to a nonnatural host depends on unspecific and specific host barriers.

Specific G2 arrest of caprine cells infected with a caprine arthritis encephalitis virus expressing vpr and vpx genes from simian immunodeficiency virus.

Primate lentivirus (HIV and SIV) vpr accessory genes encode 12- to 14-kDa proteins which induce cell cycle arrest at the G2 phase of infected cells, preventing them from going through mitosis. Members of the HIV-2/SIVmac/SIVsmm group also encode a second closely related accessory protein called Vpx. Vpx and HIV Vpr are critical for virus replication in nondividing cells due to their participation in nuclear import of the preintegration complex.