“Vaginal epithelial cells (VECs) are thought to function as immune-responsive cells in trichomoniasis, and mast cells have been detected in vaginal smears and the vaginal wall in trichomoniasis. It therefore seemed possible that the VEC-trichomonad reaction might affect the activity of mast cells present in the lamina propria of the vaginal mucosa. In this study, we tested whether culture supernatants of VEC incubated with Trichomonas vaginalis (TCM) could stimulate mast cells. When VECs (MS74) were incubated with live trichomonads, IL-8, IL-6 and MCP-1 expressions increased in the TCM, and mast cells
EGFR inhibitor (HMC-1) and human neutrophils migrated more actively towards the TCM. Also, when the TCM was added to mast cells, β-hexosaminidase and cytokines (IL-8 and TNF-α) expressions were increased. Moreover, the culture supernatant of mast cells incubated with TCM (M-TCM) had more increased chemotactic activity for neutrophils than that of TCM. We conclude that inflammatory mediators made by VECs in response to activation by T. vaginalis activate and attract mast cells and
then stimulate them to induce neutrophil migration. Our results indicate, for the first time, that VECs play a role in the infiltration of mast cells and neutrophils early in T. vaginalis infection. Trichomonas vaginalis is the most common curable sexually transmitted infection (STI) worldwide. Despite a number of serious health consequences including facilitation of HIV transmission, pelvic inflammatory disease and adverse outcomes of pregnancy, X-396 research buy it remains an under-recognized condition (1). The pathogenesis of trichomoniasis in humans is not yet clearly understood, although T. vaginalis is known to be a noninvasive microorganism that recruits inflammatory cells to the site of infection following attachment
to the surface of the genital tract (2,3). Infection typically elicits aggressive local cellular immune responses with inflammation of the vaginal epithelium 6-phosphogluconolactonase and exocervix in women and urethra in men (4). In fact, many neutrophils have been observed in the vaginal discharge of women with trichomoniasis (5). In addition, an increased frequency of mast cells is commonly found in the vaginal smears and vaginal walls of infected women (6,7). The adhesion of T. vaginalis to vaginal epithelial cells (VECs) plays an important role in the pathogenesis of trichomoniasis (8). It results in upregulation of two major proinflammatory cytokines IL-8 and MCP-1 (9) in the VECs, and molecules produced by the vaginal epithelium as a result of stimulation by T. vaginalis may be expected to have an effect on mast cells prevalent in the lamina propria. Mast cells have evolutionarily conserved functions in pathogen surveillance.