Differentiation of normal human pre-B cells in vitro.
The differentiation of surface Ig- pre-B cells into surface Ig+ B cells is a critical transition in mammalian B cell ontogeny. Elucidation of the growth factor requirements and differentiative potential of human pre-B cells has been hampered by the absence of a reproducible culture system that supports differentiation. Fluorescence-activated cell sorting and magnetic bead depletion were used to purify fetal bone marrow CD10+/surface mu- cells, which contain 60-70% cytoplasmic mu+ pre-B cells. CD10+/surface mu- cells cultured for 2 d were observed to differentiate into surface mu+ cells. Analysis by Southern blotting provided direct evidence that rearrangement of kappa light chain genes occurs in culture, and flow cytometric analysis revealed the appearance of surface Ig+ B cells expressing mu/kappa or mu/lambda. Unexpectedly, the kappa/lambda ratio in differentiated cells was the inverse of what is normally observed in adult peripheral blood. Differentiation occurs in the absence of exogenous growth factors or cytokines, suggesting that a stimulus-independent differentiative inertia might characterize pre-B cells in vivo. Future use of this model will facilitate our understanding of normal and abnormal human pre-B cell differentiation.
Villablanca
J G
JG
Department of Pediatrics, University of Minnesota Medical School, Minneapolis 55455.
Anderson
J M
JM
Moseley
M
M
Law
C L
CL
Elstrom
R L
RL
LeBien
T W
TW
D000943:Antigens, Differentiation / Q000276:immunology; D000951:Antigens, Neoplasm / Q000276:immunology; D000954:Antigens, Surface / Q000276:immunology; D001402:B-Lymphocytes / Q000166:cytology*; D015139:Blotting, Southern; D001854:Bone Marrow Cells; D002453:Cell Cycle; D002454:Cell Differentiation / Q000235:genetics; D002478:Cells, Cultured; D005333:Fetus; D005434:Flow Cytometry; D015870:Gene Expression / Q000276:immunology; D015321:Gene Rearrangement / Q000235:genetics; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D007145:Immunoglobulin kappa-Chains / Q000235:genetics; D066298:In Vitro Techniques; D015260:Neprilysin
D000943:Antigens, Differentiation; D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D007145:Immunoglobulin kappa-Chains; D015260:Neprilysin