Secretion of cytokines by human synoviocytes during in vitro infection with Chlamydia trachomatis.

Abstract

Since Chlamydia-induced reactive arthritis is associated with the presence of viable chlamydiae in the synovial membrane, we studied the ability of Chlamydia trachomatis to stimulate a cytokine response by fibroblast-like synoviocytes in culture. Fibroblast-like cells derived from biopsies of the synovial membrane were infected with Chlamydia trachomatis serotype E. Interleukin-6 (IL-6), transforming growth factor-beta (TGF-beta) and tumor necrosis factor-alpha (TNF-alpha) were determined using bio-assays. Granulocyte macrophage colony stimulating factor (GMCSF) was quantified by ELISA. Fibroblast-like synovial cells were capable of supporting chlamydial growth in vitro. Chlamydia trachomatis stimulated synoviocytes to produce IL-6, TGF-beta, and GMCSF. IL-1beta increased the production of IL-6 and GMCSF by mock-infected and infected cells. Treatment of synoviocytes with interferon-gamma resulted in the release of TNF-alpha in response to chlamydial infection. Chlamydia-induced cytokine release from synovial fibroblasts may contribute to alterations in the synovial membrane promoting the development of joint inflammation.