title: Infection of human fibroblast-like synovial cells with Chlamydia trachomatis results in persistent infection and interleukin-6 production.
abstract: Recent studies have shown that the urogenital pathogen Chlamydia trachomatis to be a major bacterium triggering reactive arthritis (ReA), and is able to induce interleukin-6 (IL-6) production in human fibroblast-like synovial cells (FSC) in vitro. In the present study, we examined the correlation between IL-6 production and multiplication of chlamydia in FSC. All FSC from five patients secreted highly increased quantities of IL-6 in a dose-dependent and time-dependent fashion. Heat and UV inactivated chlamydia failed to enhance production of IL-6. When azithromycin was added to infected cultures of FSC at 0 or 48 h after infection, the level of IL-6 production was very low. Transmission electron microscopy of such infected cultures revealed many abnormal forms of chlamydia within the inclusions in FSC. From one step-growth curve experiments, it was suggested that C. trachomatis hardly multiplied in FSC. In contrast, in C. trachomatis infected HeLa 229 cells, chlamydia multiplied as usual, but little IL-6 production were found. These observations indicated that live chlamydia and the persistence of chlamydia may be essential for stimulating the synthesis of IL-6 in FSC.
authors.affiliation: Department of Microbiology, School of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Hanada
authors.forename: Yurika
authors.initials: Y
authors.lastname: Ikeda-Dantsuji
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Naito
authors.forename: Ariaki
authors.initials: A
authors.lastname: Nagayama
mesh_terms: D000328:Adult; D017963:Azithromycin / Q000494:pharmacology; D002690:Chlamydia Infections / Q000276:immunology; D002692:Chlamydia trachomatis / Q000254:growth & development / Q000502:physiology* / Q000528:radiation effects / Q000648:ultrastructure; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000382:microbiology*; D006367:HeLa Cells; D006358:Hot Temperature; D006801:Humans; D015850:Interleukin-6 / Q000032:analysis / Q000096:biosynthesis*; D008297:Male; D000091402:Prohibitins; D013583:Synovial Membrane / Q000166:cytology / Q000276:immunology / Q000382:microbiology*; D014466:Ultraviolet Rays
chemical_list: D015850:Interleukin-6; C000717331:PHB2 protein, human; D000091402:Prohibitins; D017963:Azithromycin