title: Newcastle disease virus infection of L cells.
abstract: Newcastle disease virus (NDV) California strain reportedly grows poorly in L cells but replicates very well in chicken embryo cells. NDV-infected L cell cultures show a characteristic virus growth curve with respect to uridine incorporation, but plaque assays of the virus produced 24 h postinfection (PI) show no infectious particles when assayed on L cell monolayers and only a very low titer on chick cell monolayers. Plasma membranes isolated and purified from infected L cells 8 h PI contain all of the major virion proteins. In addition, NDV-infected L cells show a 50% loss of H-2 antigenic activity, a phenomenon previously observed in cells productively infected with vesicular stomatitis virus. These results suggest that at least part of the normal process of NDV maturation occurs in NDV-infected L cells. Sodium dodecyl sulfate-polyacrylamide gel patterns of supernatant virus purified from cells radiolabeled with amino acids from 3 to 24 h PI in the presence of actinomycin D show that all the major NDV structural proteins are present. Electron micrographs of NDV-infected L cells show extensive virus maturation at cell membranes. It can be concluded that infection of L cells with NDV results in a normal production of virus-specific RNA, synthesis of all the major structural proteins, association of the viral envelope proteins with the L cell plasma membrane, and the loss of cell surface H-2 antigenic activity. However, most of the virus particles produced are noninfectious.
mesh_terms: D000818:Animals; D002250:Carbon Radioisotopes; D002462:Cell Membrane / Q000032:analysis; D003609:Dactinomycin / Q000494:pharmacology; D006649:Histocompatibility Antigens / Q000032:analysis; D066298:In Vitro Techniques; D007739:L Cells / Q000187:drug effects / Q000276:immunology; D008854:Microscopy, Electron; D009522:Newcastle disease virus / Q000254:growth & development*; D014529:Uridine; D014764:Viral Proteins / Q000032:analysis; D014779:Virus Replication
chemical_list: D002250:Carbon Radioisotopes; D006649:Histocompatibility Antigens; D014764:Viral Proteins; D003609:Dactinomycin; D014529:Uridine