A 38,000-Dalton Antigen Found in Namalwa Cells Induced by Newcastle Disease Virus

Abstract
An antigen was isolated from Namalwa cells, a [human] Burkitt lymphoma line, that was induced by Newcastle disease virus (NDV) for interferon production. The antigen was extracted by 3 M NaCl from ribonucleoprotein particles (RNP), obtained from the nuclear 0.01 M Tris extract, and was purified by hydroxylapatite chromatography, phosphocellulose chromatography and preparative sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Its MW was 38 kilodaltons (kDa) as determined by SDS-PAGE. The tryptic peptide map of 125I-labeled antigen contained 7 major peptides. The antigen was not found in human cervical carcinoma HeLa cells, normal human liver or in Namalwa cells that had not been induced by the virus. This result suggests that this antigen was produced in Namalwa cells as a result of induction by the NDV virus.