Several types of adherent cells elaborate a dialyzable lymphopoietic cofactor (Abelson Growth Promoter).
We have cloned a stromal cell from mouse bone marrow selected on the basis of its ability to promote the growth of an Abelson virus-transformed pre-B cell line. These stromal cells have smooth muscle features, and the ultrafiltrate of stromal cell-conditioned medium has proliferative effects on all feeder layer-responsive mouse pre-B cell lines tested, as well as on normal pre-B cells. One of these low MW substances is a protease-resistant factor with an MW of approximately 450 Da which we designate Abelson Growth Promoter (AGP). AGP was initially characterized as an activity which promotes the growth of Abelson virus-transformed mouse pre-B cells, but it also promotes the growth of a ras-transformed pre-B cell line as a single agent and in synergistic fashion with recombinant interleukin (IL) 7. AGP as a single agent has no effect on normal pre-B cells, which have a brisk response to IL-7. In contrast, transformed pre-B cells display a blunted response to IL-7. We propose that AGP plays a role in normal lymphopoiesis by expanding clones of pre-B cells which have been activated by other stromal cell-derived signals, such as IL-7, and directly promotes the growth of nascently transformed pre-B cells.
Muirhead
M
M
Veterans Administration Medical Center, Iowa City, Iowa.
Davis
R
R
Schwartz
R C
RC
Waldschmidt
T J
TJ
Ackermann
L
L
Palumbo
G
G
Smith
R G
RG
D000011:Abelson murine leukemia virus; D000199:Actins / Q000032:analysis; D000818:Animals; D001402:B-Lymphocytes / Q000187:drug effects*; D002448:Cell Adhesion / Q000502:physiology; D002460:Cell Line; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D002472:Cell Transformation, Viral; D003956:Dialysis; D005260:Female; D011905:Genes, ras / Q000235:genetics; D006133:Growth Substances / Q000032:analysis* / Q000494:pharmacology; D006412:Hematopoietic Stem Cells / Q000187:drug effects*; D015851:Interleukin-7 / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D008970:Molecular Weight; D009130:Muscle, Smooth / Q000737:chemistry / Q000166:cytology; D011994:Recombinant Proteins / Q000494:pharmacology
D000199:Actins; D006133:Growth Substances; D015851:Interleukin-7; D011994:Recombinant Proteins