Identification of novel B-lineage cells in human fetal bone marrow that coexpress CD7.
In the present study we used multiparameter flow cytometry and cell sorting to evaluate fetal bone marrow, a rich source of cells early in lymphoid development. We found CD7 to be expressed on a subset of CD19+ cells, including some that had matured to cytoplasmic mu+ (pre-B) and surface mu+ (B) cells. In addition, a less mature CD7+19+ population was characterized as mu- and CD34+/-. The CD7+19+ population was clearly distinct from the mature T cells. The CD7+19+ cells were negative for nuclear TdT in contrast to CD7-19+ cells, which frequently contained TdT. CD10, which is coexpressed on the cell surface of more than 90% of CD19+ lymphocytes, was detected in a minority of CD7+19+ lymphocytes. The CD7+19+34+ cell population may be B-lineage committed, or may represent uncommitted lymphoid precursors. The biologic role of the expression of CD7 on immature and mature cells, including those of the B lineage, may indicate (1) the presence of CD7+19+ lymphoid precursor cells and/or (2) an alternate pathway of B-cell development, in which cells coexpress CD7 with other B-lineage markers.
Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis 55455.
E R
ER
Grümayer
F
F
Griesinger
D S
DS
Hummell
R D
RD
Brunning
J H
JH
Kersey
D015703:Antigens, CD / Q000032:analysis*; D018941:Antigens, CD19; D019011:Antigens, CD7; D000943:Antigens, Differentiation / Q000032:analysis; D000944:Antigens, Differentiation, B-Lymphocyte / Q000032:analysis; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis*; D000951:Antigens, Neoplasm / Q000032:analysis; D001402:B-Lymphocytes / Q000276:immunology*; D001853:Bone Marrow / Q000276:immunology*; D005333:Fetus / Q000276:immunology*; D005434:Flow Cytometry; D005865:Gestational Age; D006801:Humans; D015260:Neprilysin
D015703:Antigens, CD; D018941:Antigens, CD19; D019011:Antigens, CD7; D000943:Antigens, Differentiation; D000944:Antigens, Differentiation, B-Lymphocyte; D000945:Antigens, Differentiation, T-Lymphocyte; D000951:Antigens, Neoplasm; D015260:Neprilysin