title: Properties of retrovirus-like particles produced by a human breast carcinoma cell line: immunological relationship with mouse mammary tumor virus proteins.
abstract: Clonal derivatives 8 and 11 of the T47D human breast carcinoma cell line release particles that have the biochemical characteristics of a retrovirus. Particles recovered from cultures of [3H]uridine-labeled clone 11 had a density of 1.18 g/ml and contained 60-70S and 35S RNAs associated with reverse transcriptase activity. The production of these particles was steroid-dependent. Clone 8 particles had a higher density, 1.195 g/ml, and their production was independent of steroid hormone. By RIA, antigens crossreactive with the 52,000-dalton envelope glycoprotein gp52, the major external protein of mouse mammary tumor virus, were found associated with these particles and in the media. Most of the gp52-related antigen was in soluble form, but it was enriched in the particle preparation. A lesser amount of antigen was distributed within the cultured cells. Absorption of rabbit antibody to gp52 with clone 11 particle preparations eliminated the ability of this antibody to detect immunocytochemically a crossreactive antigen previously localized in tissue sections of human breast carcinoma. These results indicate that the particle isolates from T47D contain the same gp52-related antigen found in human breast carcinomas and constitute an excellent source for the purification and characterization of this antigen.
mesh_terms: D001943:Breast Neoplasms / Q000382:microbiology*; D002460:Cell Line; D002999:Clone Cells; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008324:Mammary Tumor Virus, Mouse / Q000235:genetics / Q000276:immunology*; D009693:Nucleic Acid Hybridization; D012367:RNA, Viral / Q000302:isolation & purification; D011863:Radioimmunoassay; D012190:Retroviridae / Q000235:genetics / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000032:analysis*
chemical_list: D012367:RNA, Viral; D014759:Viral Envelope Proteins