title: The presence of retroviral particles in hybridoma cell lines.
abstract: The presence of very high numbers of type C and type A retroviral particles was repeatedly confirmed not only in myeloma cells NSI, Ag 8 and in thymoma cells BW5147, EL 4 but also in B and T cell hybridomas constructed from the myeloma and thymoma cells used. Retroviral particles were demonstrated by current electron-microscopic and physicochemical methods. Biological tests for the induction of possible malignant or any pathological changes in the artificially infected sensitive cells during long-term cultivations in vitro or in vivo gave negative results. Nevertheless, on account of the hitherto unknown action of retroviruses one can suppose that monoclonal products from B and T cell hybridomas, particularly when used for practical purposes, should be purified because of their infectious nature.
mesh_terms: D000818:Animals; D002471:Cell Transformation, Neoplastic; D006825:Hybridomas / Q000382:microbiology* / Q000648:ultrastructure; D051379:Mice; D008854:Microscopy, Electron; D012190:Retroviridae / Q000302:isolation & purification* / Q000648:ultrastructure