Identification of very early lymphoid precursors in bone marrow and their regulation by estrogen.
Estrogen is a negative regulator of lymphopoiesis and provides an experimental tool for probing relationships between lymphocyte precursors and stem cells. We found that expression of lymphocyte-associated genes and immunoglobulin (Ig) gene rearrangement occurred before CD45R acquisition. Lymphoid-restricted progenitors that were Lin(-)IL-7R alpha(+)c-kit(lo)TdT(+) (lineage marker(-), interleukin receptor 7 alpha(+), c-kit(lo) and terminal deoxynucleotidyl transferase(+)) were selectively depleted in estrogen-treated mice; within a less differentiated Lin-c-kit(hi) fraction, functional precursors of B and T, but not myeloid, cells were also selectively depleted. TdT and an Ig heavy chain transgene were detected within a hormone-regulated Lin(-)c-kit(hi)Sca-1(+)CD27(+)Flk-2(+)IL-7R alpha(-) subset of this multipotential progenitor population. Identification of these extremely early lymphoid precursors should facilitate investigation of the molecular mechanisms that control lineage-fate decisions in hematopoiesis.
Medina
K L
KL
Immunobiology and Cancer Program, Oklahoma Medical Research Foundation, 825 N.E. 13th Street, Oklahoma City, OK 73104, USA.
Garrett
K P
KP
Thompson
L F
LF
Rossi
M I
MI
Payne
K J
KJ
Kincade
P W
PW
D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000502:physiology*; D019070:Cell Lineage / Q000276:immunology; D004967:Estrogens / Q000502:physiology*; D006410:Hematopoiesis / Q000502:physiology*; D008214:Lymphocytes / Q000166:cytology* / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL
D004967:Estrogens