Expression of Marek's disease virus in producer and non-producer lymphoblastoid cell lines.

Continuous in vitro propagation of a producer Marek's disease (MD) lymphoblastoid cell line reduced the number of cells producing virus antigens and the inducibility of these antigens to 5-iododeoxyuridine (IUDR) but did not change the oncogenicity of the cells for chickens. In contrast, propagation of a non-producer MD cell line did not change the non-productivity of the cell line, but decreased the transplantability of the cells. The MD lines were free of replicating avian leukosis sarcoma viruses (LSV) and were susceptible to infection with LSV of subgroup A.