Evidence of the anti-inflammatory effect of silver-polyvinyl pyrrolidone nanoparticles (Ag-PVP) in Chlamydia trachomatis infected macrophages and HeLa cells

Chlamydia trachomatis infects macrophages and epithelial cells, which evoke TNF, IL-6, and IL-8 that are key protagonists of acute inflammation. These cytokines put the patient at risk for major health issues such as pelvic inflammation disease (PID) and infertility, if not controlled. Surface coated pure metal such as silver-polyvinyl pyrrolidone nanoparticle (Ag-PVP) has been studied extensively for its anti-inflammatory role. Here we explored the hypothesis that Ag-PVP will inhibit inflammatory cytokines that are produced during the early phase of a C. trachomatis infection. We used human epithelial cells and mouse J774 macrophages as target cells, and live C. trachomatis serovar L2 and its major outer membrane protein (MOMP) as stimulants. Ag-PVP added to 2 day C. trachomatis-infected cells down-regulated TNF, IL-6 and IL-8. When MOMP was used as the stimulant, Ag-PVP similarly down-regulated these cytokines. Results from the MTT cytotoxicity assay clearly show that the anti-inflammatory effect of Ag-PVP was not due to cell death. Our data imply that Ag-PVP maybe an important therapeutic agent to regulate inflammation during the early stage of a C. trachomatis infection.