Murine hematopoietic cells with pre-B or pre-B/myeloid characteristics are generated by in vitro transformation with retroviruses containing fes, ras, abl, and src oncogenes.

In vitro infection of bone marrow or fetal liver cells with retroviruses containing fes, abl, ras, or src oncogenes resulted in the transformation of early B lineage cells. All cell lines tested possessed rearrangements at the Ig heavy chain locus and some had rearrangements at the K chain locus. The majority of the lines corresponded phenotypically to Lyb-2+, Ly-5(B220)+, ThB- large pre-B cells, although some were classified as pro-B cells because of their Lyb-2+, Ly-17+, Ly-5(B220)- phenotype. We identified two cell lines that contained subpopulations of cells that coexpressed the B lineage antigens Lyb-2 and Ly-5(B220) and the myeloid lineage antigen Mac-1. Single-cell FMF cloning of these subpopulations showed that Mac-1+ cells were derived from Mac-1- cells and that these Mac-1+-cloned cells further differentiated into cells with phenotypic and functional characteristics of mature macrophages.