Differential regulation of rheumatoid synovial cell interleukin-12 production by tumor necrosis factor alpha and CD40 signals.
OBJECTIVE
To investigate the roles of tumor necrosis factor alpha(TNFalpha) and the CD40-CD154 interaction in interleukin-12 (IL-12) production by rheumatoid synovial cells (SC).


METHODS
Levels of IL-12 (p40 and p70) in synovial tissue and culture supernatants of SC from patients with rheumatoid arthritis (RA), osteoarthritis (OA), and ankylosing spondylitis (AS) were assayed by enzyme-linked immunosorbent assay. Effects of anti-CD154 and anti-TNFalpha antibody on spontaneous and lipopolysaccharide (LPS)-stimulated IL-12 production by SC were examined. Effects of immobilized anti-CD3 treatment and depletion of CD4+ T cells on IL-12 production were also tested. CD154 expression by synovial T cells and intracellular IL-12 production during culture were analyzed by flow cytometry.


RESULTS
IL-12 p40 and p70 levels in RA synovial tissue and spontaneous IL-12 p40 production by SC from RA patients were significantly higher than the levels in OA and AS patients. Spontaneous IL-12 production by SC from RA patients significantly decreased after depletion of CD4+ T cells from SC or after application of anti-CD154 antibody, but not by treatment with anti-TNFalpha antibody. Anti-CD3 antibody stimulation increased spontaneous IL-12 p40 production and CD154 expression by synovial T cells. The increment of IL-12 p40 production by anti-CD3 was abrogated by anti-CD154 antibody. IL-12 p40 production was also increased by LPS stimulation. LPS-stimulated IL-12 production was inhibited by anti-TNFalpha antibody, but not by T cell depletion and anti-CD154 antibody treatment. The TNFalpha inhibitor rolipram inhibited LPS-stimulated IL-12 p40 production by RA SC more strongly than spontaneous production. TNFalpha restored LPS-stimulated IL-12 production that had been inhibited by rolipram.


CONCLUSIONS
IL-12 production in RA is regulated by 2 different pathways. One pathway is T cell dependent, predominantly through a CD40-CD154 interaction, while the other is T cell independent, mediated through TNFalpha. Inhibition of IL-12 production by interference with CD40-CD154 interaction and TNFalpha production may be a potential therapeutic strategy for treating RA.
Kitagawa
M
M
Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan.
Mitsui
H
H
Nakamura
H
H
Yoshino
S
S
Miyakawa
S
S
Ochiai
N
N
Onobori
M
M
Suzuki
H
H
Sumida
T
T
D000276:Adjuvants, Immunologic / Q000096:biosynthesis / Q000502:physiology; D000906:Antibodies / Q000494:pharmacology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000494:pharmacology; D001172:Arthritis, Rheumatoid / Q000378:metabolism*; D019013:CD40 Antigens / Q000494:pharmacology*; D023201:CD40 Ligand; D003352:Corynebacterium; D015536:Down-Regulation; D006801:Humans; D018664:Interleukin-12 / Q000096:biosynthesis* / Q000502:physiology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008562:Membrane Glycoproteins / Q000276:immunology / Q000494:pharmacology; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D020889:Rolipram / Q000494:pharmacology; D015398:Signal Transduction; D013583:Synovial Membrane / Q000737:chemistry / Q000166:cytology*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D000276:Adjuvants, Immunologic; D000906:Antibodies; D000945:Antigens, Differentiation, T-Lymphocyte; D019013:CD40 Antigens; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D010726:Phosphodiesterase Inhibitors; D014409:Tumor Necrosis Factor-alpha; D023201:CD40 Ligand; D018664:Interleukin-12; D020889:Rolipram