title: Generation of interleukin-8 from human monocytes in response to Trichomonas vaginalis stimulation.
abstract: Neutrophils are the predominant inflammatory cells found in the vaginal discharges of patients with Trichomonas vaginalis infection. We have investigated the possible role of interleukin-8 (IL-8) in the inflammatory response elicited by T. vaginalis infection. This study has shown that T. vaginalis induces blood monocytes to produce large amounts of bioactive IL-8, mainly by membrane components of T. vaginalis (MTV). Monocyte-derived IL-8 induced by MTV was dose and time dependent. The peak level of IL-8 was 102 +/- 11 ng/ml of conditioned media (mean +/- standard error; n = 5) obtained from MTV-stimulated monocytes (MTVCM) at 36 h of cultivation. With a multichamber chemotactic assay, we found an optimal neutrophil chemotaxis (177 +/- 14 migrated cells) induced by MTVCM collected at 16 h of cultivation when the level of IL-8 was 42 +/- 8 ng/ml. A neutralizing monoclonal antibody directed against IL-8, but not the irrelevant antibodies, significantly blocked the neutrophil chemotactic activity (decreased from 153 +/- 6 to 23 +/- 3 migrated cells; n = 3 [P < 0.001]) induced by MTVCM. Moreover, the maximum increase of the IL-8 mRNA level from MTV-treated monocytes was observed after a 5-h cultivation and decreased thereafter. Monocytes cocultured with MTV in the presence of a neutralizing monoclonal antibody directed against tumor necrosis factor alpha, but not against IL-1 beta, decreased IL-8 production by 25% (P < 0.05), indicating that the release of IL-8 in MTV-stimulated monocytes is partially dependent on tumor necrosis factor alpha. The capacity of MTV-induced monocytes to synthesize IL-8 suggests that these cells can contribute to the induction of the acute inflammatory response seen in T. vaginalis infection.
authors.affiliation: Department of Parasitology and Tropical Medicine, National Defense Medical Center, Taipei, Taiwan, Republic of China.
authors.forename: M F
authors.initials: MF
authors.lastname: Shaio
authors.forename: P R
authors.initials: PR
authors.lastname: Lin
authors.forename: J Y
authors.initials: JY
authors.lastname: Liu
authors.forename: K D
authors.initials: KD
authors.lastname: Yang
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D002478:Cells, Cultured; D002634:Chemotaxis, Leukocyte; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis* / Q000235:genetics; D009000:Monocytes / Q000378:metabolism*; D009504:Neutrophils / Q000276:immunology; D014245:Trichomonas Infections / Q000209:etiology; D014246:Trichomonas vaginalis / Q000502:physiology*
chemical_list: D000911:Antibodies, Monoclonal; D016209:Interleukin-8