Rheumatoid adherent synovial cells produce B cell differentiation factor activity neutralizable by antibody to B cell stimulatory factor-2/interleukin 6.
B cell differentiation factor (BCDF) activity assayed on SKW6-CL4 cells was found in adherent synovial cell (ASC) conditioned medium. ASC of patients with RA (n = 8) produced significantly larger amounts of BCDF than those of patients with osteoarthritis (n = 5) (219.0 +/- 212.1 vs 25.5 +/- 12.4 units/microgram.DNA, p less than 0.01). ASC clones, established by the limiting dilution technique, also produced this factor. Experiments with several neutralizing antibodies revealed that this BCDF is inhibited by anti-B cell stimulatory factor-2/interleukin 6 antibody (anti-BSF-2/IL-6 ab) up to 90%, but not by antiinterleukin 1, antiinterleukin 2 or antiinterferon-r antibodies. Our data suggest that ASC could participate in the B cell differentiation process in joint space by producing a molecule which has a similar active site to BSF-2/IL-6.
Harigai
M
M
1st Department of Medicine, National Defense Medical College, Saitama, Japan.
Kitani
A
A
Hara
M
M
Hirose
T
T
Norioka
K
K
Suzuki
K
K
Suzuki
M
M
Kawagoe
M
M
Shinmei
M
M
Nakamura
H
H
D000368:Aged; D000906:Antibodies / Q000276:immunology*; D001172:Arthritis, Rheumatoid / Q000378:metabolism*; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002461:Cell Line, Transformed; D002999:Clone Cells / Q000378:metabolism; D005260:Female; D006801:Humans; D015847:Interleukin-4; D015850:Interleukin-6; D007378:Interleukins / Q000096:biosynthesis* / Q000276:immunology* / Q000378:metabolism; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009500:Neutralization Tests; D010003:Osteoarthritis / Q000378:metabolism; D013582:Synovial Fluid / Q000276:immunology* / Q000378:metabolism
D000906:Antibodies; D015850:Interleukin-6; D007378:Interleukins; D015847:Interleukin-4