title: Suppressive effect of interleukin-4 (IL-4) on IL-6 production by adherent rheumatoid synovial cells.
abstract: Interleukin-6 (IL-6) has recently been characterized as a mediator of multiple inflammatory responses. Excessive production of this cytokine has been demonstrated in the joints of patients with rheumatoid arthritis (RA). On the other hand, anti-inflammatory effects of IL-4 have recently been demonstrated. We therefore investigated the suppressive effect of IL-4 on IL-6 production by synovial cells in patients with RA. Freshly prepared adherent rheumatoid synovial cells expressed IL-6 mRNA and spontaneously produced a large amount of IL-6 in culture. This spontaneous production of IL-6 was significantly suppressed by IL-4. The suppressive effect of IL-4 on IL-6 production was demonstrated in all patients with RA tested in this study. On the other hand, IL-6 mRNA levels already expressed in adherent synovial cells were not reduced by IL-4 in 24 hr of culture. The suppressive effect of IL-4 on IL-6 production suggests that IL-4 is an important physiological regulator of IL-6 production in synovial cells.
authors.affiliation: First Department of Internal Medicine, Toyama Medical and Pharmaceutical University, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Suzuki
authors.forename: E
authors.initials: E
authors.lastname: Sugiyama
authors.forename: I S
authors.initials: IS
authors.lastname: Tunru
authors.forename: N
authors.initials: N
authors.lastname: Yamashita
authors.forename: H
authors.initials: H
authors.lastname: Matsuno
authors.forename: T
authors.initials: T
authors.lastname: Hamazaki
authors.forename: M
authors.initials: M
authors.lastname: Kobayashi
mesh_terms: D000328:Adult; D000906:Antibodies / Q000276:immunology; D001172:Arthritis, Rheumatoid / Q000378:metabolism / Q000473:pathology*; D015152:Blotting, Northern; D002448:Cell Adhesion; D005260:Female; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D015847:Interleukin-4 / Q000276:immunology / Q000494:pharmacology* / Q000502:physiology; D015850:Interleukin-6 / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009500:Neutralization Tests; D012333:RNA, Messenger / Q000302:isolation & purification; D013583:Synovial Membrane / Q000378:metabolism* / Q000473:pathology*; D000093242:Interleukin-6 Inhibitors
chemical_list: D000906:Antibodies; D007375:Interleukin-1; D015847:Interleukin-4; D015850:Interleukin-6; D012333:RNA, Messenger; D000093242:Interleukin-6 Inhibitors