RESUMO
AIM: Develop in vitro model for studying production of cytokines by monocyte cells infected with Chlamydia trachomatis mediated by type III secretion system (TTSS). MATERIALS AND METHODS: Strain C. trachomatis L2/434/Bu was used in the experiments, culture of human monocytes U-937 was infected by this strain. Level of inflammatory cytokines was measured on flow analyzer Bio-Plex 200 (Bio-Rad Laboratories). Low molecular compound LHC-342 which belongs to the class of heterocyclic compounds was used as TTSS inhibitor. RESULTS: 24 hours after the infection with C. trachomatis culture 8 analyzed cytokines are induced in U-937 cells (IL-1beta, IL-4, IL-6, IL-8, IL-10, GM-CSF, IFN-gamma, TNFalpha). The most pronounced increase was observed for IL-8, GM-CSF and IFN-gamma. Introduction of TTSS inhibitor into the culture of infected cells suppressed chlamydia growth, but addition of FeSO4 restored the growth of chlamydiae. And activity associated with translocation of effector TTSS protein IncA to inclusion membrane was suppressed. Under the conditions of the obtained model of TTSS inhibition during intracellular development of C. trachomatis a significant decrease of 2 pro-inflammatory cytokines--IL-6 and IL-1beta--was observed. CONCLUSION: Cytokine response plays a key role in the protective immune response in chlamydia infection but at the same time induces immunopathologic conditions. The data obtained give reasons to assume role of C. trachomatis TTSS in the induction of this component of immune response that requires further detailed studies.
