Expression of autocrine motility-like factor in rheumatoid synovial fluid.
OBJECTIVE
To examine whether a cytokine, autocrine motility factor (AMF), plays a role in rheumatoid arthritis (RA).


METHODS
We investigated the chemokinetic activity of synovial fluids (SF) obtained from patients using a unique protein-free culture fibrosarcoma Gc-4 PF, the motility of which is specifically dependent on the cytokine.


RESULTS
Treatment of the cells with the SF stimulated their phagokinetic motility by 1.4, 1.8, and 2.1-fold at protein concentrations of 100, 250 and 500 micrograms/ml, respectively. This dose dependent response was observed in all 3 patients with classical or definite RA. In contrast with Gc-4 PF cells, the SF did not stimulate the motility of Gc-4 SD cells that have little response to AMF. The ability of this chemokinetic activity to block binding of the monoclonal antibody to the receptor for AMF was demonstrated on immunoblots.


CONCLUSIONS
Based on these results, it is suggested that the motile activity may be AMF. The possible role of the cytokine in the pathogenesis of RA is discussed.
Watanabe
H
H
Department of Orthopedic Surgery, Gunma University School of Medicine, Japan.
Takeuchi
K
K
Chigira
M
M
D001172:Arthritis, Rheumatoid / Q000378:metabolism*; D002465:Cell Movement / Q000502:physiology; D005956:Glucose-6-Phosphate Isomerase / Q000378:metabolism*; D006801:Humans; D060285:Receptors, Autocrine Motility Factor; D018121:Receptors, Cytokine / Q000378:metabolism; D013582:Synovial Fluid / Q000378:metabolism* / Q000502:physiology; D014407:Tumor Cells, Cultured; D044767:Ubiquitin-Protein Ligases
D018121:Receptors, Cytokine; C555000:AMFR protein, human; D060285:Receptors, Autocrine Motility Factor; D044767:Ubiquitin-Protein Ligases; D005956:Glucose-6-Phosphate Isomerase