Mitogenic effect of fibrinogen on hematopoietic cells: involvement of two distinct specific receptors, MFR and ICAM-1.
In addition to its well-known functions in blood clotting and cell adhesion, fibrinogen has been reported to be a mitogen for lymphoid cell lines and for human hematopoietic progenitors. Two specific receptors, the mitogenic fibrinogen receptor (MFR) and intercellular adhesion molecule-1 (ICAM-1/CD54), have been identified as possible candidates for the mediation of the mitogenic effect of fibrinogen. However, it has been questioned whether the MFR and ICAM-1 are truly distinct molecules. Using an antiserum specific for the MFR, we demonstrate that the MFR is a cell surface molecule clearly distinct from ICAM-1. Both receptors can be expressed separately or coexpressed on different cell types. Moreover, they are regulated differently: ICAM-1 is calcium-dependent whereas the MFR is not and the MFR is down-regulated by fibrinogen whereas ICAM-1 is not. The inhibition by an anti-MFR serum of the mitogenic effect of fibrinogen confirms the mitogenic function of the MFR.
Héron
A
A
Centre National de la Recherche Scientifique, UPR 9044, Villejuif, France.
Lévesque
J P
JP
Hatzfeld
A
A
Kisselev
S
S
Monier
M N
MN
Krief
P
P
Hatzfeld
J
J
D000906:Antibodies / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D005340:Fibrinogen / Q000378:metabolism / Q000494:pharmacology*; D006410:Hematopoiesis / Q000187:drug effects; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism*; D008934:Mitogens / Q000378:metabolism / Q000494:pharmacology*; D018000:Receptors, Peptide / Q000037:antagonists & inhibitors / Q000378:metabolism*
D000906:Antibodies; D008934:Mitogens; D018000:Receptors, Peptide; D018799:Intercellular Adhesion Molecule-1; D005340:Fibrinogen