title: Cytokine response of human THP-1 macrophages to Trichomonas tenax.
abstract: Trichomonas tenax is a protozoan that inhabits the oral cavity of humans, most often those with poor oral hygiene. Although T. tenax is widely considered a commensal, recent studies have suggested a pathogenic role for the protozoan in persons with periodontitis. Here we investigated the capacity of T. tenax to induce pro-inflammatory cytokine secretion in human macrophages, with the idea that elicitation of inflammation may be one mechanism by which T. tenax contributes to oral pathology. Human THP-1 cells differentiated to the macrophage phenotype (dTHP-1) were incubated with live or sonicated T. tenax at trophozoite:dTHP-1 ratios of 1:5, 1:10, and 1:20. Culture media removed from the wells after 4, 8, and 16 h of stimulation were assayed by ELISA for tumor necrosis factor alpha, interleukin-1 beta, interleukin-8, and the immunoregulatory cytokine interleukin-10. Live T. tenax trophozoites failed to induce production of any of the cytokines tested, regardless of trophozoite:dTHP-1 cell ratio or length of co-incubation. T. tenax lysates stimulated interleukin-8 synthesis, but only after 16 h of incubation at the 1:5 trophozoite:dTHP-1 cell ratio. These results suggest that pro-inflammatory cytokine synthesis by human macrophages in direct response to T. tenax contributes little to oral pathology.
authors: Department of Microbiology/Immunology, A.T. Still University of Health Sciences, 800 W. Jefferson St., Kirksville, MO 63501, USA.
authors: Emily J
authors: EJ
authors: Govro
authors: Department of Microbiology/Immunology, A.T. Still University of Health Sciences, 800 W. Jefferson St., Kirksville, MO 63501, USA. Electronic address: mstuart@atsu.edu.
authors: Melissa K
authors: MK
authors: Stuart
mesh_terms: D000704:Analysis of Variance; D002460:Cell Line; D003470:Culture Media / Q000737:chemistry; D016207:Cytokines / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D016753:Interleukin-10 / Q000378:metabolism; D053583:Interleukin-1beta / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D008264:Macrophages / Q000276:immunology / Q000469:parasitology*; D009055:Mouth / Q000469:parasitology / Q000473:pathology; D014244:Trichomonas / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D003470:Culture Media; D016207:Cytokines; D053583:Interleukin-1beta; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10
keywords: Interleukin-1 beta; Interleukin-10; Interleukin-8; Oral trichomonads; Periodontitis; Tumor necrosis factor alpha