@article{mbs:/content/journal/jgv/10.1099/0022-1317-65-11-1943, author = "Hays, Esther F. and Swanson, Stephen K. and Silva, Robert F.", title = "Several Classes of Retroviruses Are Produced by an AKR Mouse T Lymphoma Cell Line", journal= "Journal of General Virology", year = "1984", volume = "65", number = "11", pages = "1943-1953", doi = "https://doi.org/10.1099/0022-1317-65-11-1943", url = "https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-65-11-1943", publisher = "Microbiology Society", issn = "1465-2099", type = "Journal Article", keywords = "replication-defective virus", keywords = "AKR mice", keywords = "lymphomagenic retrovirus", abstract = "SUMMARY Characterization of the viruses produced by the spontaneous T lymphoma cell line SL3 is presented. Using supernatant fluids or direct co-cultivation of cells, the SL3 cell line was found to produce replication-defective viruses in excess of replication-competent viruses. The replication-competent viruses released were predominantly those negative in the XC plaque assay (XC−); XC+ viruses represented a minor population. However, when the SL3-derived viruses were passed in mouse embryo fibroblasts, XC− viruses were rarely recovered, and XC+ viruses were readily isolated. These viruses were all ecotropic and lymphomagenic. Viruses with dual host range and non-oncogenic ecotropic viruses were not isolated from the lymphoma cells. Two replication-defective viruses from SL3 cells were studied. Both could be rescued by non-oncogenic retroviruses and were then lymphomagenic. One defective virus appeared related to XC+ viruses. In these studies, the XC+ and XC− viruses appeared to represent two different interference classes using separate cell receptors. Taken together, these experiments show that the SL3 T lymphoma cells replicate a variety of viruses most of which are lymphomagenic. Virus replication and/or virus integration may be the means of maintaining the malignant phenotype of these T lymphoma cells.", }