Fractalkine, a CX3C-chemokine, functions predominantly as an adhesion molecule in monocytic cell line THP-1.
A newly identified CX3C-chemokine, fractalkine, expressed on activated endothelial cells plays an important role in leucocyte adhesion and migration. Co-immobilized fractalkine with fibronectin or intercellular adhesion molecule-1 enhanced adhesion of THP-1 cells, which express the fractalkine receptor (CX3CR1), compared with that observed for each alone. That adherence was fractalkine-dependent and was confirmed in blocking studies. However, soluble fractalkine induced little chemotaxis in THP-1 cells in comparison to monocyte chemotactic protein-1 (MCP-1), which induced a strong chemotactic response. Moreover, the membrane form of fractalkine expressed on ECV304 cells reduced MCP-1 mediated chemotaxis of THP-1 cells. These results indicate that fractalkine may function as an adhesion molecule between monocytes and endothelial cells rather than as a chemotactic factor.
Umehara
H
H
Department of Internal Medicine, Osaka Dental University, Osaka, Kan Research Institute, Kyoto, Japan. umehara@cc.osaka-dent.ac.jp
Goda
S
S
Imai
T
T
Nagano
Y
Y
Minami
Y
Y
Tanaka
Y
Y
Okazaki
T
T
Bloom
E T
ET
Domae
N
N
D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology*; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002460:Cell Line; D054428:Chemokine CX3CL1; D020523:Chemokines, CX3C / Q000378:metabolism* / Q000494:pharmacology; D002633:Chemotaxis / Q000187:drug effects; D004727:Endothelium / Q000166:cytology / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism* / Q000494:pharmacology; D009000:Monocytes / Q000187:drug effects / Q000502:physiology*
C515538:CX3CL1 protein, human; D015815:Cell Adhesion Molecules; D054428:Chemokine CX3CL1; D020523:Chemokines, CX3C; D005353:Fibronectins; D008565:Membrane Proteins; D018799:Intercellular Adhesion Molecule-1