Effects of the components of Newcastle disease virus on the structural order of lipid assemblies.

The membrane M-protein of Newcastle disease virus is localized directly beneath the lipid bilayer. Although this protein is the major constituent of the virus, its structural relationship to the lipid or to the other viral component hemagglutinin-neuraminidase, the so called HN-glycoprotein, is still unknown. The effects of either M-protein alone or both M-protein and HN-glycoprotein on the lipid assemblies in reconstituted liposomes were determined by differential polarized phase fluorometry, steady-state fluorescence anisotropy and emission lifetime measurements.

[Membrane protein formation in cells infected with the NDV virus and treated with theophylline].

The effect of theophylline on the synthesis of NDV membrane protein which plays an essential role in the production of virions was followed up. It was found that the replication of the virus in chick embryo fibroblasts was inhibited when the cells were treated with 1 mM theophylline. Inhibition was found to concern the final phase of virus replication--the formation of mature infection particles.

[Demonstration of the M-protein of the Newcastle disease virus by current immunochemical methods].

The immunosorbent micromethod with the use of nitrocellulose paper was employed for the first time to demonstrate subviral antigens from animal origin, such as the M-protein of the Newcastle Disease virus. The method proved to be highly effective. It was useful in discovering amounts as high as 10-20 ng of the antigen, while with the use of the enzyme-linked immunosorbent assay (ELISA) amounts of about 200 ng could be evaluated.

[Demonstration of ligands for antibodies against the M protein on the virion surface of the Newcastle disease virus (NDV)].

Demonstrated was the presence of ligands for antibodies to the M-protein on the surface of NDV virions, using the hemagglutination-inhibition reaction, the immunodiffusion test in agar gel, the indirect variant of the enzyme-linked immunosorbent assay, and the immunosorbent micromethod with nitrocellulose membranes. Data spoke of transmembrane interactions between the M-protein and the glycoproteins of the envelope, which was of basic importance with regard to the biologic role played by this essential structural virus protein. The presence of ligands made it reasonable to believe that the M-protein played a part in the building up of antiviral immunity.

[Development of ELISA for demonstrating antibodies to the swine pestivirus].

An indirect variant of the enzyme linked immunosorbent assay with the classic form of swine fever has been worked out. The test makes it possible to assess the level of antibodies with a great number of animals over a short period of time with no special equipment. The method has proved promising in taking prophylactic measures.