The expression of IL-20 and IL-24 and their shared receptors are increased in rheumatoid arthritis and spondyloarthropathy.
The purpose of this study was to analyze the expression of the two proinflammatory cytokines IL-20 and IL-24 and their shared receptors in rheumatoid arthritis and spondyloarthropathy. IL-20 was increased in plasma of rheumatoid arthritis patients compared with osteoarthritis patients and IL-24 was increased in synovial fluid and plasma of rheumatoid arthritis and spondyloarthropathy patients compared with osteoarthritis patients. IL-20 and IL-24 mRNA was only present at low levels in the synovium. In the synovial membrane, IL-20 protein was present in mononuclear cells and neutrophil granulocytes whereas IL-24 protein was observed in endothelial cells and mononuclear cells. IL-20 receptor type 1 and IL-22 receptor were expressed by granulocytes in the synovial fluid. In synovial fluid mononuclear cell cultures, stimulation with recombinant human IL-20 or recombinant human IL-24 induced monocyte chemoattractant protein 1 (CCL2/MCP-1) secretion, but not tumour necrosis factor alpha mRNA synthesis or IL-6 secretion. Both IL-20 and IL-24 showed correlations to CCL2/MCP-1 in plasma from rheumatoid arthritis and spondyloarthropathy patients. This study associates IL-20 and IL-24 to the synovium of rheumatoid arthritis and spondyloarthropathy and results indicate that the two cytokines contribute to disease pathogenesis through recruitment of neutrophil granulocytes and induction of CCL2/MCP-1.
Institute of Medical Microbiology and Immunology, Aarhus University, Building 240, Wilhelm Meyers Allé, DK-8000 Aarhus C, Denmark. tue@immunology.au.dk
Tue Wenzel
TW
Kragstrup
Kristian
K
Otkjaer
Christian
C
Holm
Annette
A
Jørgensen
Marianne
M
Hokland
Lars
L
Iversen
Bent
B
Deleuran
D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000378:metabolism* / Q000473:pathology; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000096:biosynthesis; D042783:Endothelial Cells / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D007378:Interleukins / Q000096:biosynthesis* / Q000494:pharmacology; D007963:Leukocytes, Mononuclear / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000378:metabolism / Q000473:pathology; D010003:Osteoarthritis / Q000378:metabolism / Q000473:pathology; D018123:Receptors, Interleukin / Q000096:biosynthesis*; D025242:Spondylarthropathies / Q000378:metabolism* / Q000473:pathology; D013582:Synovial Fluid / Q000378:metabolism*; D000099180:Interleukin-24
D018932:Chemokine CCL2; D007378:Interleukins; D018123:Receptors, Interleukin; D000099180:Interleukin-24; C111835:CCL2 protein, human; C492510:interleukin-20 receptor; C422042:interleukin 20