Transformation of Mouse Peritoneal Macrophages and Bone Marrow Cells by Simian Virus 40

Abstract

A fraction of cultured mouse peritoneal macrophages and bone marrow cells acquired the ability to divide after infection by simian virus 40 (SV40). Two types of transformed lines were obtained.Most transformants isolated 40-60 days after infection did not display macrophage specific properties such as ingestion of opsonized red blood cells, possession of Fe receptors and complement receptors, and acid phosphatase activity throughout the whole culture phase.Cells of the transformed lines isolated by trypsin selection 2-6 months after infection displayed these properties when the cell density became high and cell growth was arrested.In the cells of the latter type of transformed lines, SV40 T-antigen was intensely demonstrated by immunofluorescence in the growing phase, but weakly or not at all in the stationary phase.It is suggested that the reversion to the phenotype of the progenitor (expression of macrophage specific functions ) depends on the physiological state of the culture; however, it is uncertain whether the development of the macrophage functions is directly related to the SV40 T-antigen.

Cell growth and differentiation in vitro in mouse macrophages transformed by a tsA mutant of simian virus40. I. Cellular response in proliferative and phagocytic activities to the shift of temperature differs depending on the culture state in mouse bone marrow cells transformed by the tsA640 mutant of simian virus 40

“…Little difference was detected among the cell lines, although they were derived from primary cultures composed of heterogeneous cell populations. These results are similar to those obtained with the wild-type SV40 transformants established at 37 "C and examined at 37°C (Takayama, 1980). Most cells at point S had phagocytic ability and weakly expressed SV40 T antigen by immunofluorescence.…”

“…The medium was changed every 4 days. As the cells grew actively, they gradually lost their macrophage properties such as immune phagocytosis, whereas the cells gradually recovered their macrophage properties when they grew to a confluent cell (saturation) density of approximately 3.0 x lo6 per dish (see Results) (Takayama, 1980). …”

Cell growth and differentiation in vitro in mouse macrophages transformed by a tsA mutant of simian virus 40. II. Changes in the distribution of DNA content during the reversible transition between macrophage and nonmacrophage states in the cultures of tsA 640‐transformed macrophages

“…Cells lost their phagocytic ability as they resumed proliferation and became phagocytic again after their proliferation stopped at saturation density (3 x lo6 cells per 35-mm dish) (Fig. lB), as was reported in detail previously (Takayama, 1980;Tanigawa et al, 1983). Taking the mean DNA content of mouse peritoneal macrophages as 1 unit in the scale of fluorescence intensity in the flow cytogram, the cultures showed two distinct peaks-one located around the 1.0-unit position (peak 1.0) and the other around the 1.6-unit position (peak 1.61, and a plateau distribution continuing to 3.2 units.…”

Production of Interferon by an SV40‐Transformed Macrophage Line, BB‐W‐531–2

“…Mouse peritoneal macrophages and bone marrow cells can be transformed by simian virus 40 (SV40) and the resulting clonal lines have several unique properties (7,17). Rapidly growing cells having typical SV40 T-antigen gradually lose macrophage properties such as immune phagocytosis, but stationary cells with no or reduced amounts of SV40 T-antigen gradually recover their macrophage properties.…”