Lineage Switch of a Mouse Pre-B-Cell Line (SPMG-1) to Macrophage-like Cells After Incubation with Phorbol Ester and Calcium Ionophore

Overexpression of the bcl-2 oncogene in the mouse pre-B cell line SPGM-1 protects from apoptosis, but does not affect blocked B-lineage differentiation and lineage switch towards macrophage like cells

“…The bipotent mouse pre-B-1 cell-line SPGM-1 switches its lineage commitment towards macrophage differentiation Table 1 Summary of substances tested to induce B-lymphoid differentiation in SPGM-1 20% WEHI 3BD conditioned medium (interleukin-3) 20% AG8-IL5 conditioned medium (interleukin 5) 20% ST-2 conditioned medium (interleukin 7) 20%P388D1 conditioned medium (interleukin 6 and 1) 20% EL-4 conditioned medium (interleukin 2) 20% interleukin 10 containing conditioned medium 2ng/ml recombinant human interleukin 1b 50 mg/ml lipopolysaccharide (LPS) from E.coli (Sigma) 1 mg/ml anti cm antibody from hybridoma E4.2 50 nM 12-O-tetradecanoylphorbol-13-acetate (Sigma) 1 mg/ml ionomycin (Sigma) 20 mM all-trans retinoic acid (RA, Sigma) 1.5% dimethylsulfoxide (DMSO, Sigma) upon treatment with IL-3 (Martin et al, 1993) or a combination of calcium ionophore and phorbolester (Spencker et al, 1995). The aim of this study was to investigate the ability of this cell line to differentiate to a mature B-cell expressing an intact immunoglobulin antigen receptor.…”

“…SPGM-1 cells represent immortalized pre-B cells, as shown by phenotypic and genotypic characterization. Upon treatment with either IL-3 (Martin et al, 1993) or a combination of phorbolester (PMA) and calcium ionophore (ionomycin) (Spencker et al, 1995) SPGM-1 cells lose their pre-B characteristics and acquire macrophage-like features. This differentiation pathway is documented in detail, however, it is not known whether SPGM-1 cells are also able to develop to a more advanced B-cell stage.…”

In VitroandIn VivoPhagocytic Ability of Mouse B-1 Cells

“…Several investigators have demonstrated that CD5 + pre-B cells can differentiate into macrophage-like cells. 9,10 A recent report has shown that undifferentiated B-1 cells express both myeloid and lymphoid lineage-specific transcription factors, whereas after undergoing differentiation into phagocytes, they predominantly display a myeloid profile. 7 In addition, the CD5 and IgM antigens, which are markers classically associated with the lymphoid lineage, are lost when B-1 cells migrate from the peritoneal cavity in response inflammatory stimuli.…”

True

“…The same schema used in Figure 1 was employed here to illustrate the cytogenetic changes that were observed in the macrophage-like tumor. The following band desigations for recurrent, non-reciprocal breaksites were determined by the combined SKY, inverted DAPI and CGH analysis: Rb(Del1,Del1)T(Del 1H;2H), T(2H1;10B5 → C1), T(5C → D;13B)Rb(5,19), T(5F;6F1), T(6C2;14A3 → B), Rb(6,16)T((16C;10B);(6D;14A → B)), T(7E → F1;12A1), T(7E → F1;15D), T(7E → F1;15D)Rb (7,19), Rb (8,8)T(8C;1D → E), Is(9;17D → E1)T(18E;5F)Rb (17,6) …”

“…The cells were cultured in RPMI 1640 containing 10% fetal calf serum, 200 mM L-glutamine and 50 M 2-mercaptoethanol at 37°C in a humidified atmosphere containing 5% CO 2 in air. The conversion of P388 lymphoma cells to macrophage-like cells was induced by treatment for 3 days with 50 M TPA (12-O-tetradecanoylphorbol-13-acetate) and 500 ng/ml ionomycine 17 followed by 3 more days in culture in the absence of inducing agents. The differentiation process was monitored by assessing the fraction of adherent cells in the culture dish by microscopy, analyzing changes in morphology in Wright's Giemsa-stained cytofuge specimens, determining the production of lysozyme and macrophage-typical esterases, and evaluating the ability of P388 'macrophages' to ingest small latex beads.…”