Effect of a bcl-2 transgene on production and localization of precursor B cells in mouse bone marrow

Abstract

Many B cell precursors die while differentiating in mouse bone marrow. To ascertain the mechanisms involved in this process, populations of B lineage cells and their tissue localization were analyzed in bone marrow of transgenic mice overexpressing the apoptosis inhibitor, Bcl-2. Immunofluorescence labeling and mitotic arrest were used to quantitate the number and proliferative activity of μ- pro-B cells (terminal deoxynucleotidyl transferase [TdT]+B220-, TdT*B220+, and TdT-B220*); pre-B cells (cμ+); and B cells (sμ+). Mature B cells (IgM+IgD*) were increased 16- to 20-fold. In addition, immature B lymphocytes (IgM+IgD(- /low)), representing newly formed cells, were increased three- to sixfo..