Expression of B cell markers on SR-4987 cells derived from murine bone marrow stroma.
The murine cell line SR-4987 was originated in our laboratory from adherent cells of a long term bone marrow culture. SR-4987 cells do not express p21-ras and c-fms products on membrane whereas secrete M-CSF, evidence a fibroblast-like morphology and are vimentine positive. This line shows a very poor "in vitro" agar clonogenicity which is not modulated by the addition of different cytokines and growth factors (M-CSF, GM-CSF, G-CSF, IL-3, IL-7, alpha-TNF, PDGF, and EGF). On the contrary, a dramatic increase in clonogenicity is observed in the presence of bFGF. The RT-PCR investigation evidences the mRNA encoding for bFGF, IL-7, GM-CSF, and SCF (c-kit ligand). The analysis of CD antigen expression on SR-4987 cell membrane indicates a phenotype (CD5+, CD44+, 45R(B220)+, sIg+, 5'-nucleotidase+) that is consistent with a B cell feature. Our observations suggest that exogenous bFGF might represent an appropriate stimulus for inducing the SR-4987 cells proliferation also in the absence of cell-substrate anchorage. Further, they indicate that SR-4987 cells could represent a particular differentiation stage in which characters of "stromal cell" and "B cell" are coexpressed in agreement with the hypothesis of a common stromal-hematopoietic differentiation.
Pessina
A
A
Institute of Microbiology, University of Milan, Italy.
Neri
M G
MG
Mineo
E
E
Piccirillo
M
M
Gribaldo
L
L
Brambilla
P
P
Zaleskis
G
G
Ujházy
P
P
D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D000944:Antigens, Differentiation, B-Lymphocyte / Q000378:metabolism*; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D001854:Bone Marrow Cells; D002460:Cell Line; D016222:Fibroblast Growth Factor 2 / Q000235:genetics; D005434:Flow Cytometry; D015870:Gene Expression; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000235:genetics; D015851:Interleukin-7 / Q000235:genetics; D051379:Mice; D012333:RNA, Messenger / Q000235:genetics; D019089:Stem Cell Factor / Q000235:genetics
D015703:Antigens, CD; D000944:Antigens, Differentiation, B-Lymphocyte; D015851:Interleukin-7; D012333:RNA, Messenger; D019089:Stem Cell Factor; D016222:Fibroblast Growth Factor 2; D016178:Granulocyte-Macrophage Colony-Stimulating Factor