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␤, 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 MTVinduced monocytes to synthesize IL-8 suggests that these cells can contribute to the induction of the acute inflammatory response seen in T. vaginalis infection.

Immunological Aspects of Trichomonas vaginalis Infection in Women Attending Maternity Teaching Hospital and Some Public Health Centers in Erbil Governorate, Northern Iraq

“…Controversial studies have been published concerning cytokines profile that may be induced in response to T. vaginalis infection. Some previous studies in vitro revealed that exposure to T. vaginalis stimulated IL-8 secretion in human monocytes, [21] neutrophils, [22] and vaginal epithelial cells. [23] It was further demonstrated that the cytokines IL-2 and IFN-γ were secreted by murine lymphocytes infected with T. vaginalis.…”

Cleavage/Alteration of Interleukin-8 by Matrix Metalloproteinase-9 in the Female Lower Genital Tract

“…The chemokine Interleukin-8 (IL-8, CXCL8) is a member of the CXC chemokine family that plays a number of important roles in immunity including activation and attraction of neutrophils [ 1 , 2 ]. In vitro, IL-8 is produced by neutrophils, macrophages, monocytes and epithelial cells when exposed to either microbial products derived from commensal bacteria or organisms that cause sexually transmitted infections (STI) [ 3 – 5 ]. IL-8 levels in lower genital tract secretions are increased in women with STIs [ 5 – 7 ] and also increased in response to non-STI alterations in lower genital tract microbiota [ 7 – 11 ].…”

The proteins secreted by Trichomonas vaginalis and vaginal epithelial cell response to secreted and episomally expressed AP65

“…While overall immune responses during trichomonosis are largely unknown, high levels of interleukin‐8 (IL‐8) and leukotreine B4 (LTB4) have been found in the vaginal secretions from symptomatic patients with trichomonosis (Shaio et al ., 1994; 1995; Shaio and Lin, 1995). There are also reports of IL‐8 produced in response to T. vaginalis stimulation by human neutrophils (Ryu et al ., 2004) and human monocytes (Shaio et al ., 1995). Further, in vitro studies have revealed that IL‐8 production is regulated through NF‐κB and MAP kinase signalling pathways.…”