Gene expression of lipid binding protein transferred the ability of specific attachment of hemopoietic cells to non-supportive stromal cell line, MS-K.
In order to identify the cDNAs responsible for hemopoietic supportive activity, expression of mRNAs in hemopoietic supportive bone marrow stromal cells (MS-5) and non-supportive stromal cells (MS-K) were compared by the cDNA subtraction method. A subtracted MS-5-cDNA library, which contains cDNA clones corresponding to mRNAs present in MS-5 cells but not in MS-K cells, was constructed. Screening of subtracted MS-5-cDNA library resulted in the isolation of some clones. Two of them, lipid binding protein (LBP) and haptoglobin (Hp), were expressed specifically in MS-5 cells but not in MS-K cells. The genes of LBP and Hp were subcloned into mammalian expression vector and transfected into hemopoietic non-supportive stromal cells line, MS-K. Then LBP-expressing stable transformants (MS-K-LBP) and Hp-expressing transformants (MS-K-Hp) were cloned. A rosette formation assay was carried out to investigate whether or not the LBP and Hp cause MS-K cells to adhere to hemopoietic cells. MS-K-LBP formed rosettes with hemopoietic cells as MS-5 cells, although the MS-K-Hp and normal MS-K cells did not form rosettes. These data indicate that LBP expressed in hemopoietic supportive stromal cells is partly responsible for the adhesion of hemopoietic stem cells to stromal cells.
Takashita
E
E
Department of Cell Science, Faculty of Graduate School of Science and Technology, Niigata University, Japan.
Sugimoto
K
K
Jiang
H
H
Tohma
M
M
Urano
E
E
Yokoyama
H
H
Mori
K J
KJ
D000209:Acute-Phase Proteins; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D002448:Cell Adhesion / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D018076:DNA, Complementary; D015870:Gene Expression; D006242:Haptoglobins / Q000235:genetics; D006412:Hematopoietic Stem Cells / Q000737:chemistry / Q000166:cytology / Q000502:physiology*; D050356:Lipid Metabolism; D008070:Lipopolysaccharides / Q000378:metabolism; D008562:Membrane Glycoproteins; D051379:Mice; D012333:RNA, Messenger / Q000032:analysis; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017154:Stromal Cells / Q000737:chemistry / Q000166:cytology / Q000502:physiology*; D000099231:Lipopolysaccharide-Binding Protein
D000209:Acute-Phase Proteins; D002352:Carrier Proteins; D018076:DNA, Complementary; D006242:Haptoglobins; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D000099231:Lipopolysaccharide-Binding Protein