CysLT receptor-mediated NOX2 activation is required for IL-8 production in HMC-1 cells induced by Trichomonas vaginalis-derived secretory products

Trichomoniasis is caused by a sexually transmitted flagellate protozoan parasite Trichomonas vaginalis. . T. vaginalis-derived secretory products (TvSP) contain lipid mediators such as leukotriene B4 4 (LTB4) 4 ) and various cysteinyl leukotrienes (CysLTs) which included LTC4, 4 , LTD4, 4 , and LTE4. 4 . However, the signaling mechanisms by which T. vaginalis-induced CysLTs stimulate interleukin (IL)-8 production in human mast cells remain unclear. In this study, we investigated these mechanisms in human mast cells (HMC-1). Stimulation with TvSP resulted in increased intracellular reactive oxygen species (ROS) generation and NADPH oxidase 2 (NOX2) activation compared to unstimulated cells. Pre-treatment with NOX2 inhibitors such as diphenyleneiodonium chloride (DPI) or apocynin significantly reduced ROS production in TvSP-stimulated HMC-1 cells. Additionally, TvSP stimulation increased NOX2 protein expression and the translocation of p47 phox from the cytosol to the membrane. Pretreatment of HMC-1 cells with PI3K or PKC inhibitors reduced TvSP-induced p47 phox translocation and ROS generation. Furthermore, NOX2 inhibitors or NOX2 siRNA prevented CREB phosphorylation and IL-8 gene expression or protein secretion induced by TvSP. Pretreatment with a CysLTR antagonist significantly inhibited TvSP-induced ROS production, CREB phosphorylation, and IL-8 production. These results indicate that CysLT-mediated activation of NOX2 plays a crucial role in ROS-dependent IL-8 production in human mast cells stimulated by T. vaginalis-secreted CysLTs. These findings enhance our understanding of the inflammatory response in trichomoniasis and may inform the development of targeted therapies to mitigate this response.