Heterogeneity of Hematopoietic Cells Immortalized by v-myc/v-raf Recombinant Retrovirus Infection of Bone Marrow or Fetal Liver

The J2 recombinant retrovirus expressing v-myc/v-raf (also known as MYC/RAF1) immortalized macro-phages from the bone marrow of lipopolysaccharide-responsive mouse strains, producing the ANA-1 cell line from C57BL/6 mice and the INF-3A cell line from C3H/HeN mice. In contrast, J2 recombinant retrovirus infection of the fetal liver from C57BL/6-Ly-5a mice immortalized a cell line (GGD) that did not exhibit the characteristics of mature macrophages. The GGD cell line was classified as leuko-cytic on the basis of its expression of the Ly-6B.2, FcγR, and Ly-5.2 antigens. Our results indicate that the J2 recombinant retrovirus selectively immortalizes macrophages from the bone marrow of C57BL/6 and C3H/HeN mice but immortalizes cells without definitive macrophage characteristics from murine fetal liver under the same culture conditions. [J Natl Cancer Inst 81: 1492–1496, 1989]