Interleukin-7 induces the proliferation of normal human B-cell precursors.
In the present study, we investigated the effects of human recombinant interleukin-7 (IL-7) on the proliferation of enriched hematopoietic cells isolated from human adult and fetal bone marrow (BM). In cultures of CD34+ cells, IL-7 was found to induce dose-dependent incorporation of 3H-thymidine (3H-TdR), but had no demonstrable effect on the development of myeloid colony-forming cells. Numbers of B-cell precursors (BCP), initially present within CD34+ populations and which included a CD34+CD20+ subset, were significantly increased when CD34+ BM cells were cultured in the presence of IL-7. This effect was most striking on CD20+ BCP, and resulted at least partly from higher numbers of cycling cells as indicated by Hoechst 33342 fluorescence (Calbiochem, Behring Diagnostics, La Jolla, CA). These results indicate that IL-7 promotes the growth of BCP within the CD34+ compartment. In line with the B-lineage affiliation of CD34+ target cells, committed BCP (CD10+ CD19+ surface IgM-) isolated from BM were also found to proliferate in response to IL-7. Interestingly, this effect of IL-7 was strongly potentiated by the addition of IL-3. Taken together, and in accordance with previous observations on murine cells, our data indicate that IL-7 acts as a growth factor during the ontogeny of human B lymphocytes.
Saeland
S
S
Schering-Plough, Laboratory for Immunological Research, Dardilly, France.
Duvert
V
V
Pandrau
D
D
Caux
C
C
Durand
I
I
Wrighton
N
N
Wideman
J
J
Lee
F
F
Banchereau
J
J
D000328:Adult; D015703:Antigens, CD / Q000032:analysis; D018952:Antigens, CD34; D001402:B-Lymphocytes / Q000166:cytology* / Q000276:immunology; D001483:Base Sequence; D001853:Bone Marrow / Q000196:embryology; D001854:Bone Marrow Cells; D002455:Cell Division; D002478:Cells, Cultured; D003001:Cloning, Molecular; D004247:DNA / Q000096:biosynthesis; D004357:Drug Synergism; D005434:Flow Cytometry; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000276:immunology; D006801:Humans; D007377:Interleukin-3 / Q000494:pharmacology; D015851:Interleukin-7 / Q000235:genetics / Q000494:pharmacology*; D008969:Molecular Sequence Data
D015703:Antigens, CD; D018952:Antigens, CD34; D007377:Interleukin-3; D015851:Interleukin-7; D004247:DNA