Long-term culture of B lymphocytes and their precursors from murine bone marrow.

Abstract

Growth of mature B cells and their precursors from mouse bone marrow was maintained in culture for > 1 yr. Feeder layers of adherent bone marrow cells, established in medium containing fetal calf serum and no exogenous steroids, were used to provide an in vitro environment that supported continuous growth and development of these cells. In such bone marrow cultures, the number of cells bearing membrane Ig increased gradually for 4 wk and then decreased. Between 10-14 wk, some of the cultures gave rise to continuously dividing B-cell populations that contained pre-B cells (producing .mu. H chains only and sensitive to transformation by Abelson murine leukemia virus) and mature B cells (synthesizing both L and H chains of IgM). Ig molecules synthesized by cells in these populations were heterogeneous in 2-dimensional gel analysis. Mature B cells apparently arose via maturation of pre-B cells in the cultures that involved rearrangement and expression of different variable region gene segments.