Trichomonas vaginalis induces IL-1ß production in a human prostate epithelial cell line by activating the NLRP3 inflammasome via reactive oxygen species and potassium ion efflux.

BACKGROUND: Trichomonas vaginalis is a sexually transmitted protozoan parasite that causes vaginitis in women, and urethritis and prostatitis in men. IL-1ß is synthesized as immature pro-IL-1ß, which is cleaved by activated caspase-1. Caspase-1 is, in turn, activated by a multi-protein complex known as an inflammasome. In this study, we investigated the inflammatory response of a prostate epithelial cell line (RWPE-1) to T. vaginalis and, specifically, the capacity of T. vaginalis to activate the NLRP3 inflammasome. METHODS: RWPE-1 cells were stimulated by live T. vaginalis, and subsequent expression of pro-IL-1ß, IL-1ß, NLRP3, ASC and caspase-1 was determined by real-time PCR and Western blotting. IL-1ß and caspase-1 production was also measured by ELISA. To evaluate the effects of NLRP3 and caspase-1 on IL-1ß production, the activated RWPE-1 cells were transfected with small interfering RNAs to silence the NLRP3 and caspase-1 genes. Activation of the NLRP3 inflammasome was observed by fluorescence microscopy. Intracellular reactive oxygen species (ROS) were evaluated by spectrofluorometry. RESULTS: When RWPE-1 cells were stimulated with live T. vaginalis, the mRNA and protein expression of IL-1ß, NLRP3, ASC, and caspase-1 increased. Moreover, silencing of NLRP3 and caspase-1 attenuated T. vaginalis-induced IL-1ß secretion. The NADPH oxidase inhibitor DPI and high extracellular potassium ion suppressed the production of IL-1ß, caspase-1, and the expression of NLRP3 and ASC proteins. The specific NF-κB inhibitor, Bay 11-7082, inhibited IL-1ß production, and also inhibited the production of caspase-1, ASC and NLRP3 proteins. CONCLUSIONS: T. vaginalis induces the formation of the NLRP3 inflammasome in human prostate epithelial cells via ROS and potassium ion efflux, and this results in IL-1ß production. This is the first evidence for activation of the NLRP3 inflammasome in the inflammatory response by prostate epithelial cells infected with T. vaginalis. Prostate 76:885-896, 2016. © 2016 Wiley Periodicals, Inc.

Prevalence of Trichomoniasis by PCR in Women Attending Health Screening in Korea.

Trichomoniasis is the most common curable sexually-transmitted infection (STI) worldwide. There are few reports on the prevalence of Trichomonas vaginalis in Korea. The purpose of this study was to examine the prevalence of trichomoniasis by PCR in Guri city, Korea. All adult women who visited Hanyang University Guri Hospital for health screening within the National Health Care Service were invited to participate in the study, and 424 women were enrolled between March and June 2011. PCR was used to detect Trichomonas vaginalis using primers based on a repetitive sequence cloned from T. vaginalis (TV-E650). Fourteen women (3.3%) were found to have T. vaginalis. All were over 50, and they were significantly older on average than the 410 Trichomonas-negative women (mean ages 63.4 vs 55.3 years). It seems that T. vaginalis infection is not rare in women receiving health screening, especially among those over 50.

Corneal lymphangiogenesis facilitates ocular surface inflammation and cell trafficking in dry eye disease.

PURPOSE: While the normal cornea has limited innervation by the lymphatic system, chronic immune-inflammatory disorders such as dry eye (DE) can induce lymphangiogenesis in the ocular surface. Using a conditional knock-down murine model, Lyve-1Cre;VEGFR2flox mice, this study investigated the role of lymphangiogenesis in the pathophysiology of DE. METHODS: DE was induced in both wild type (WT) B6 and Lyve-1Cre;VEGFR2flox mice. Tissue immunostaining and volumetric gross measurements were used to assess changes in the ocular surface, skin, and lymph nodes (LNs). The expression of lymphangiogenic factors (TNF-α, IL-6/-8/-12/-17, VEGF-C/-D, IFN-γ, VEGFR-2/-3, Lyve-1, and podoplanin) and the frequency of immune cells (CD4, CD11b, and CD207) on the ocular surface and lacrimal glands were quantified by real-time polymerase chain reaction and flow cytometry. RESULTS: Compared to WT mice, there were fewer lymphatic vessels and a reduction in lymphangiogenic markers in the ocular surface and skin of Lyve-1Cre;VEGFR2flox mice. After DE induction, mRNA levels of TNF-α, IL-8, and IFN-γ were significantly reduced in Lyve-1Cre;VEGFR2flox mice compared to WT mice (p < .01). Surprisingly, the LNs from Lyve-1Cre;VEGFR2flox mice with DE were significantly smaller and populated by fewer dendritic cells and effector T cells than those from WT mice (p < .001). Furthermore, immunostaining showed corneal nerves in the DE-induced Lyve-1Cre;VEGFR2flox mice were notably intact like in the naïve condition. CONCLUSIONS: Inhibition of lymphangiogenesis in the cornea effectively attenuates not only the inflammatory response including trafficking of immune cells but also preserves corneal nerves under desiccating stress. Corneal lymphangiogenesis might be a contributing factor in deterioration on the ocular surface homeostasis.

Langerhans cells prevent subbasal nerve damage and upregulate neurotrophic factors in dry eye disease.

The functional role of Langerhans cells (LCs) in ocular surface inflammation and nerve damage in dry eye (DE) disease has yet to be determined. This study was performed to investigate this relationship through both clinical study on DE patients and in vivo mouse models with induced DE disease. In a cross-sectional case-control study (54 eyes of DE patients; 34 eyes of control patients), average cell density, area, and process length of LCs were measured using confocal microscopy. Data were analyzed to determine whether changes in LCs are correlated with subbasal nerve plexus (SNP) parameters (nerve density, beading, and tortuosity). In DE patients, SNP density marginally decreased and nerve beading and tortuosity were significantly increased compared to the control group. The total number of LCs significantly increased in DE patients, and some LCs with elongated processes were found to be attached to nerve fibers. Interestingly, nerve loss and deformation were correlated with inactivation of LCs. In an in vivo experiment to elucidate the role of LCs in ocular surface inflammation and corneal nerve loss, we used a genetically modified mouse model (CD207-DTR) that reduced the population of CD207 (Langerin) expressing cells by injection of diphtheria toxin. In CD207-depleted mice with DE disease (CD207-dDTR+DE), corneal nerves in the central region were significantly decreased, an effect that was not observed in wild-type (WT)+DE mice. In CD207-dDTR+DE mice, infiltration of CD4+, CD19+, CD45+, and CD11b+ cells into the ocular surface was increased, as confirmed by flow cytometry. Increased IL-17 and IFN-γ mRNA levels, and decreased expression of neurotrophic factors and neurotransmitters, were also found in the CD207-dDTR+DE mice. These data support a functional role for LCs in negatively regulating ocular surface inflammation and exhibiting a neuroprotective function in DE disease.