@article{mbs:/content/journal/jmm/10.1099/jmm.0.000672, author = "Du, Kun and Zhou, Ming and Li, Qi and Liu, Xue-zheng", title = "Chlamydia trachomatis inhibits the production of pro-inflammatory cytokines in human PBMCs through induction of IL-10", journal= "Journal of Medical Microbiology", year = "2018", volume = "67", number = "2", pages = "240-248", doi = "https://doi.org/10.1099/jmm.0.000672", url = "https://www.microbiologyresearch.org/content/journal/jmm/10.1099/jmm.0.000672", publisher = "Microbiology Society", issn = "1473-5644", type = "Journal Article", keywords = "IL-10", keywords = "PBMCs", keywords = "pro-inflammatory cytokine", keywords = "Chlamydia trachomatis", abstract = " Purpose. Previous research demonstrated that IL-10 was up-regulated in Chlamydia trachomatis-infected cells and that exogenous IL-10 was able to inhibit the secretion of pro-inflammatory cytokines by infected cells. However, the mechanisms are not well understood. The aim of this study was to investigate the mechanisms for up-regulation of IL-10 and inhibition of pro-inflammatory cytokine secretion in C. trachomatis-stimulated peripheral blood mononuclear cells (PBMCs). Methodology. Human PBMCs were isolated from the blood of healthy human donors by standard Ficoll–Hypaque density gradient centrifugation. Cells were exposed to C. trachomatis in the presence or absence of MEK inhibitor U0126, the p38 inhibitor SB203580, the STAT3 inhibitor Ruxolitinib or anti-human IL-10 antibody. Cytokines were measured from culture supernatants using ELISA kits. Cells were harvested for real-time quantitative PCR to determine IL-10 mRNA levels and for Western blot assay to detect the expression of ERK1/2, p-ERK1/2, p38, p-p38, STAT3 and p-STAT3. Results. Both mRNA and protein levels of IL-10 were up-regulated in stimulated cells, and the production of IL-10 was reduced when cells were treated with U0126 or SB203580. The expression of cytokines IL-6, IL-8 and TNF-α was enhanced in stimulated cells treated with anti-human IL-10 antibody. Moreover, neutralization of IL-10 resulted in a significant decrease of phosphorylated STAT3 in stimulated cells. Ruxolitinib caused a significant increase in the production of IL-6, IL-8 and TNF-α in stimulated cells. Conclusion. IL-10 is up-regulated in an ERK- and p38-dependent fashion in stimulated human PBMCs. IL-10 inhibits the production of pro-inflammatory cytokines by activating the JAK/STAT signalling pathway.", }