The influence of S17 stromal cells and interleukin 7 on B cell development.
A clonal assay was used to study different stimuli involved in the progression of fetal liver B cell precursors to mature B lymphocytes. In this report we replaced fetal liver heterogenous feeder cells by a recombinant growth factor, interleukin 7 (IL 7), and a clonal stromal cell line, S17. Under those conditions we could clone 1 in 10 B220+ B cell precursors from fetal liver and the cells could differentiate to a mitogen-responsive, immunoglobulin-secreting stage. We found that IL 7 stimulates proliferation of B220+ precursors but is not sufficient to support maturation of those precursors to a stage of mitogen responsiveness. We show further that the cell line S17 does not produce IL 7 at functionally detectable level but provides support for B cell maturation. We conclude that this cell line supplies an exogenous stimulus required by B cell precursors to become mature lymphocytes. We describe therefore two stages in pre-B cell development: (a) IL 7-dependent proliferation and (b) S17-dependent maturation to mitogen reactivity. Further studies demonstrate that S17 has a profound effect on B cells by increasing the clonal efficiency of lipopolysaccharide-responsive cells to nearly 1:1 B cell in the spleen of adult C57BL/6 mice.
Cumano
A
A
Immunex Corporation, Seattle.
Dorshkind
K
K
Gillis
S
S
Paige
C J
CJ
D000362:Agar / Q000494:pharmacology; D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology* / Q000187:drug effects; D001854:Bone Marrow Cells; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D005333:Fetus; D006412:Hematopoietic Stem Cells / Q000187:drug effects; D015851:Interleukin-7 / Q000502:physiology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008099:Liver / Q000166:cytology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D011994:Recombinant Proteins
D015851:Interleukin-7; D008070:Lipopolysaccharides; D011994:Recombinant Proteins; D000362:Agar