Biological characterization of an Epstein-Barr nuclear antigen-positive American Burkitt's tumor-derived cell line

Two distinct cultures derived from a lymphoid cell line designated NAB were characterized immunologically, morphologically, and cytogenetically. Both cultures were positive for Epstein-Barr nuclear antigen. NAB I cultures were negative for virus capsid antigen and early antigen and were not affected by treatment with 5-iododeoxyurdine. NAB II cultures were positive for virus capsid antigen and early antigen, which increased with 5-iododeoxyuridine treatment. Both cultures were superinfected with virus prepared from P3HR-1 cells. Cell-free virus concentrates prepared from both cultures were inactive for transformation and infectivity. NAB I and NAB II cells were lymphoid as determined by light and electron microscopy. NAB II cells showed morphological alterations characteristic of herpes infection. 5-iododeoxyuridine-treated cells from both cultures revealed ultrastructural characteristics of cells infected with herpes-viruses but without particles. In addition, the induction of tubuloreticular structures within the endoplasmic reticulum was observed. Cytogenetic analysis of both cultures revealed a rearranged chromosome 14 and several other chromosome aberrations, three of which may be used as a reliable means of identifying NAB cultures.