Inhibition of influenza A virus reproduction by a ribozyme targeted against PB1 mRNA.

A ribozyme gene directed at a specific cleavage of mRNA coding for PB1 protein, a component of RNA-dependent RNA-polymerase of influenza A virus, was constructed. The avian adenovirus CELO virus-associated RNA (VA RNA CELO) promoter and human cytomegalovirus (CMV) promoter were used for the permanent expression of the ribozyme in cell lines. The cells were infected with influenza A virus strains A/Singapore/1/57 and A/WSN/33, and the suppression of the virus reproduction and virus-specific protein synthesis was measured.

Use of the bovine leukaemia virus LTR U3 promoter for expressing antisense antiviral RNAs and competitive inhibition of viral infection in cell culture.

Use of viral inducible promoters which can be activated by virus-specific transactivator proteins to drive expression of antisense (as)RNA genes appears to be an attractive approach to inhibit virus infections in vivo. To this end, we have constructed an asRNA gene expressed from the bovine leukaemia virus (BLV) U3 promoter that is complementary to the R-U5 region of the BLV genome. This is the region that is most susceptible to inhibition by asRNA.

Avian adenovirus induces ion channels in model bilayer lipid membranes.

The action of duck egg drop syndrome 1976 (EDS-76) adenovirus on model bilayer lipid membranes (BLM) has been investigated on planar egg phosphatidylcholine membranes and small unilamellar vesicles. It was found that the adenovirus formed channels in planar BLM in a pH-dependent manner. The addition of EDS-76 to planar BLM at pH 5 induced voltage-independent channel activity of about 60 pS conductivity after a lag phase.

Thiophilic adsorption: rapid purification of F(ab)2 and Fc fragments of IgG1 antibodies from murine ascitic fluid.

A thiophilic adsorption method has been developed for rapid purification and separation of mouse F(ab)2 and Fc fragments obtained after proteolytic digestion of IgG1 monoclonal antibodies. Partially purified Mabs were digested with papain. Thiophilic chromatography was performed using stepwise elution with decreasing concentrations of ammonium sulphate.

Expression of the gene encoding secreted placental alkaline phosphatase (SEAP) by a nondefective adenovirus vector.

A nondefective recombinant human adenovirus 5 (Ad5) carrying the SEAP gene, encoding human secreted placental alkaline phosphatase, in the E3 region of the Ad5 genome was obtained. The expression of SEAP at the early and late stages of Ad5 infection was demonstrated in permissive and semi-permissive cell cultures. The amount of SEAP in the culture medium of the 293 cells was 13.