Helper virus is not required for in vitro erythroid transformation of hematopoietic cells by Friend virus

Abstract

The Friend polycythemia virus complex (FVP)

A tagged helper-free Friend virus causes clonal erythroblast immortality by specific proviral integration in the cellular genome

“…Thus, our results support earlier evidence that helper-free SFFV efficiently stimulates polyclonal proliferation and differentiation of infected BFU-E erythroblasts (1,3,8,41,42). This mitogenic stimulation of BFU-E apparently requires expression of the SFFV env gene product gp55 on the surfaces of infected cells (13).…”

Acid Rain: Statistical Analysis of Ionic Correlations Questioned

“…Affected cell populations containing transforming DNA expanded out of control and caused a fulminating disease. Previous work in vitro with helper-deficient virus preparations suggested that SFFV alone can transform hematopoietic cells (18), an observation that is extended by our experiments in vivo. It is now clear that the oncogenic potential of SFFV can be realized without the spread of virus and recruitment of cells.…”

Shut‐down of virus synthesis during progression of erythroleukemia induced by friend virus in mice

“…It might be required for early SFFV replication to ensure the establishment of rapid erythroleukemia. Previous studies in other laboratories revealed that the defective SFFV alone was able to induce erythroleukemia in adult mice after a long latent period of infection (Eckner and Hettrick, 1979) and helper F-MuLV is not required for in vitro erythroid transformation by SFEV (Hankins and Krantz, 1980). Last but not least, the present studies support the notion that FV-induced erythroleukemia is a multistage disease: an early phase characterized by proliferative effects on erythroid progenitor cells and a later phase characterized by the presence of truly malignant FV-transformed cells (Levy et al, 1979;Tambourin et al, 1979).…”