Tumor necrosis factor-alpha response to infection with Chlamydia trachomatis in human fallopian tube organ culture

IL-17C is a driver of damaging inflammation during Neisseria gonorrhoeae infection of human Fallopian tube

The human pathogen Neisseria gonorrhoeae ascends into the upper female reproductive tract to cause damaging inflammation within the Fallopian tubes and pelvic inflammatory disease (PID), increasing the risk of infertility and ectopic pregnancy. The loss of ciliated cells from the epithelium is thought to be both a consequence of inflammation and a cause of adverse sequelae. However, the links between infection, inflammation, and ciliated cell extrusion remain unresolved. With the use of ex vivo cultures of human Fallopian tube paired with RNA sequencing we defined the tissue response to gonococcal challenge, identifying cytokine, chemokine, cell adhesion, and apoptosis related transcripts not previously recognized as potentiators of gonococcal PID. Unexpectedly, IL-17C was one of the most highly induced genes. Yet, this cytokine has no previous association with gonococcal infection nor pelvic inflammatory disease and thus it was selected for further characterization. We show that human Fallopian tubes express the IL-17C receptor on the epithelial surface and that treatment with purified IL-17C induces pro-inflammatory cytokine secretion in addition to sloughing of the epithelium and generalized tissue damage. These results demonstrate a previously unrecognized but critical role of IL-17C in the damaging inflammation induced by gonococci in a human explant model of PID.

Ovarian sex steroid and epithelial control of immune responses in the uterus and oviduct: human and animal models†

The female reproductive tract (FRT), including the uterus and oviduct (Fallopian tube), is responsible for maintaining an optimal microenvironment for reproductive processes, such as gamete activation and transportation, sperm capacitation, fertilization, and early embryonic and fetal development. The mucosal surface of the FRT may be exposed to pathogens and sexually transmitted microorganisms due to the opening of the cervix during mating. Pathogens and endotoxins may also reach the oviduct through the peritoneal fluid. To maintain an optimum reproductive environment while recognizing and killing pathogenic bacterial and viral agents, the oviduct and uterus should be equipped with an efficient and rigorously controlled immune system. Ovarian sex steroids can affect epithelial cells and underlying stromal cells, which have been shown to mediate innate and adaptive immune responses. This, in turn, protects against potential infections while maintaining an optimal milieu for reproductive events, highlighting the homeostatic involvement of ovarian sex steroids and reproductive epithelial cells. This article will discuss how ovarian sex steroids affect the immune reactions elicited by the epithelial cells of the non-pregnant uterus and oviduct in the bovine, murine, and human species. Finally, we propose that there are regional and species-specific differences in the immune responses in FRT.

Shift work influences the outcomes of Chlamydia infection and pathogenesis

Shift work, performed by approximately 21 million Americans, is irregular or unusual work schedule hours occurring after 6:00 pm. Shift work has been shown to disrupt circadian rhythms and is associated with several adverse health outcomes and chronic diseases such as cancer, gastrointestinal and psychiatric diseases and disorders. It is unclear if shift work influences the complications associated with certain infectious agents, such as pelvic inflammatory disease, ectopic pregnancy and tubal factor infertility resulting from genital chlamydial infection. We used an Environmental circadian disruption (ECD) model mimicking circadian disruption occurring during shift work, where mice had a 6-h advance in the normal light/dark cycle (LD) every week for a month. Control group mice were housed under normal 12/12 LD cycle. Our hypothesis was that compared to controls, mice that had their circadian rhythms disrupted in this ECD model will have a higher Chlamydia load, more pathology and decreased fertility rate following Chlamydia infection. Results showed that, compared to controls, mice that had their circadian rhythms disrupted (ECD) had higher Chlamydia loads, more tissue alterations or lesions, and lower fertility rate associated with chlamydial infection. Also, infected ECD mice elicited higher proinflammatory cytokines compared to mice under normal 12/12 LD cycle. These results imply that there might be an association between shift work and the increased likelihood of developing more severe disease from Chlamydia infection.

Understanding the hidden relations between pro- and anti-inflammatory cytokine genes in bovine oviduct epithelium using a multilayer response surface method

An understanding gene-gene interaction helps users to design the next experiments efficiently and (if applicable) to make a better decision of drugs application based on the different biological conditions of the patients. This study aimed to identify changes in the hidden relationships between pro- and anti-inflammatory cytokine genes in the bovine oviduct epithelial cells (BOECs) under various experimental conditions using a multilayer response surface method. It was noted that under physiological conditions (BOECs with sperm or sex hormones, such as ovarian sex steroids and LH), the mRNA expressions of IL10, IL1B, TNFA, TLR4, and TNFA were associated with IL1B, TNFA, TLR4, IL4, and IL10, respectively. Under pathophysiological + physiological conditions (BOECs with lipopolysaccharide + hormones, alpha-1-acid glycoprotein + hormones, zearalenone + hormones, or urea + hormones), the relationship among genes was changed. For example, the expression of IL10 and TNFA was associated with (IL1B, TNFA, or IL4) and TLR4 expression, respectively. Furthermore, under physiological conditions, the co-expression of IL10 + TNFA, TLR4 + IL4, TNFA + IL4, TNFA + IL4, or IL10 + IL1B and under pathophysiological + physiological conditions, the co-expression of IL10 + IL4, IL4 + IL10, TNFA + IL10, TNFA + TLR4, or IL10 + IL1B were associated with IL1B, TNFA, TLR4, IL10, or IL4 expression, respectively. Collectively, the relationships between pro- and anti-inflammatory cytokine genes can be changed with respect to the presence/absence of toxins, sex hormones, sperm, and co-expression of other gene pairs in BOECs, suggesting that considerable cautions are needed in interpreting the results obtained from such narrowly focused in vitro studies.

Up-regulated mRNA expression of some anti-inflammatory mediators in bovine oviduct epithelial cells by urea in vitro: Cellular pathways by Reactome analysis

Increased urea concentration is a major cause of low fertility in dairy cows fed high-protein diets. A strong correlation exists between the urea concentration in the blood and oviduct fluid of dairy cows. In this study, bovine oviduct epithelial cells (BOECs) were incubated with varying concentrations of urea (0, 20, 40, and 80 mg/dL) in the absence of ovarian sex steroids (estradiol and progesterone) and luteinizing hormone. The 80 mg/dL urea reduced the cell viability, and thus was excluded in further analysis. Compared to the control (U0), the 20 mg/dL urea (U20) increased the mRNA expression of Toll-like receptor (TLR) 4, interleukin (IL) 10, IL4, and prostaglandin (PG) E synthase (mPGES) but decreased the mRNA expression of tumor necrosis factor α (TNFA). Compared to U0, the 40 mg/dL urea (U40) decreased the mRNA expression of TNFA and increased alpha-1-acid glycoprotein (AGP). U40 also increased TLR2, IL10, and IL4 mRNA expression compared to U0. In addition, compared to U20, the U40 decreased the mRNA expression of TLR4 and IL1B but increased that of AGP and TLR2. Subsequently, the mRNA expression data were then projected into the Reactome database. The Reactome analysis showed that pathways, including cytokine signaling in the immune system (i.e., TNFs bind their physiological receptors) and death receptor signaling (i.e., TNF signaling), were down-regulated in the presence of urea compared to the U0 group. These in vitro data implied that high urea level can alter the balance between pro- and anti-inflammatory responses in BOECs, thus providing a suboptimal environment for the early reproductive events or a weakened innate immune system, predisposing the oviduct to infections.

Immunity, immunopathology, and human vaccine development against sexually transmitted Chlamydia trachomatis

This review examines the immunity, immunopathology, and contemporary problems of vaccine development against sexually transmitted Chlamydia trachomatis. Despite improved surveillance and treatment initiatives, the incidence of C. trachomatis infection has increased dramatically over the past 30 years in both the developed and developing world. Studies in animal models have shown that protective immunity to C. trachomatis is largely mediated by Th1 T cells producing IFN-γ which is needed to prevent dissemination of infection. Similar protection appears to develop in humans but in contrast to mice, immunity in humans may take years to develop. Animal studies and evidence from human infection indicate that immunity to C. trachomatis is accompanied by significant pathology in the upper genital tract. Although no credible evidence is currently available to indicate that autoimmunity plays a role, nevertheless, this underscores the necessity to design vaccines strictly based on chlamydial-specific antigens and to avoid those displaying even minimal sequence homologies with host molecules. Current advances in C. trachomatis vaccine development as well as alternatives for designing new vaccines for this disease are discussed. A novel approach for chlamydia vaccine development, based on targeting endogenous dendritic cells, is described.

Diversity of Cervicovaginal Cytokine Response to Incident Chlamydia trachomatis Infection Among a Prospective Cohort of Young Women

PROBLEM

Animal, in vitro, and ex vivo studies have identified several cytokines involved in host immunity to genital Chlamydia trachomatis (CT) infection. However, in vivo cytokine responses are not well described. Our objectives were to document cervicovaginal cytokine levels and intrawoman cytokine changes during incident CT in a prospective cohort.

METHODS

From our prospective cohort, 62 women had incident CT, comprising a CT-negative visit followed by a CT-positive visit. At these visits, cytokine protein levels (IL-6, IL-8, IL-1α, IL-1β, MIP-1α, RANTES, IFN-γ) were measured using cervicovaginal lavages and the MILLIPLEX(™) /Luminex(®) multiplex assay. Quartiles were defined for each cytokine from all 124 visits.

RESULTS

At the group level, RANTES was higher (P < 0.01) at the CT-positive visit than at baseline, but the other cytokines did not significantly differ. For intrawoman cytokine changes, women with a cytokine level that increased at least one quartile higher (going from baseline to the CT-positive visit) ranged between 26 and 53%. Women with a cytokine level staying in the same quartile ranged between 32 and 48%. Women with a cytokine level that decreased at least one quartile lower ranged between 15 and 37%.

CONCLUSION

Intrawoman cervicovaginal cytokine changes during incident CT appear heterogeneous and may reflect differences in natural host immunity.

Regulation of innate immune function in bovine oviduct epithelial cells in culture: the homeostatic role of epithelial cells in balancing Th1/Th2 response

This study aimed to investigate the role of epithelial cells in regulating innate immunity in bovine oviduct epithelial cell (BOEC) culture. We studied the effect of Escherichia coli lipopolysaccharide (LPS) and its interaction with ovarian steroids, estradiol (E2) and progesterone (P4), and luteinizing hormone (LH) at concentrations observed during the preovulatory period on immune responses in BOEC culture. Immunohistochemistry of oviduct tissue showed intensive expression of Toll-like receptor-4 (TLR-4) and TLR-2 in epithelial cells. A dose of 10 ng/ml LPS stimulated TLR-4, cyclooxygenase-2 (COX-2), nuclear factor kappa B inhibitor A (NFKBIA), interleukin 1β (IL-1β) and tumor necrosis factor α (TNF-α) expression, indicating an early pro-inflammatory response. A dose of 100 ng/ml LPS did not induce expression of these genes but stimulated TLR-2, IL-10,IL-4 and microsomal prostaglandin E synthase-1 (mPGES-1) expression and PGE2 secretion, indicating an anti-inflammatory response. Ovarian steroids and LH completely block LPS (10 ng/ml)-induced TLR-4, IL-1β and TNF-α expression as well as LPS (100 ng/ml)-induced TLR-2 expression. Taken together, this study suggests the existence of an early signaling system to respond to infection in the BOEC. In addition, ovarian steroids and LH may play a critical role in inducing homeostasis and in controlling hyperactive pro-inflammatory responses detrimental to epithelial cells, sperm and the embryo.

Differing effects of azithromycin and doxycycline on cytokines in cells from Chlamydia trachomatis-infected women

Chlamydial infection of the lower genital tract usually spreads to the upper genital tract and is then responsible for more serious consequences, such as infertility, ectopic pregnancy, pelvic pain, and pelvic inflammatory disease. Genital infection with Chlamydia trachomatis and the resulting cytokine response largely determines the outcome of infection and disease. To date, studies showing comparative effects of azithromycin and doxycycline treatment for C. trachomatis infection in women with reproductive sequelae like infertility and their effect on immune molecules like cytokines are lacking. Hence, our objective was to study the effect of azithromycin and doxycycline in vitro on cytokines in cells from C. trachomatis-positive fertile and infertile women as well as their efficacy in C. trachomatis infection. Fertile and infertile women with primary and recurrent C. trachomatis infection attending the gynecology outpatient department of Safdarjung Hospital, New Delhi, India, were enrolled. Enzyme-linked immunosorbent assay and real-time reverse transcription-polymerase chain reaction was performed for evaluating cytokines in cells stimulated with chlamydial elementary bodies (EBs) in the presence and absence of antibiotics (azithromycin and doxycycline). C. trachomatis-infected women were also followed up to assess the efficacy of azithromycin and doxycycline. We observed inhibition of cytokines (interleukin [IL]-1beta (β), IL-6, IL-8, IL-10, and tumor necrosis factor-alpha) in the presence of azithromycin in EB-stimulated cells from both fertile and infertile women with primary and recurrent C. trachomatis infection. However, in presence of doxycycline, inhibition of cytokines (IL-1β and IL-6) was only observed in stimulated cells from fertile women with primary C. trachomatis infection. The clinical efficacy of azithromycin was also better than doxycycline in recurrent C. trachomatis infection in women with complications such as infertility. Overall, this study suggests that azithromycin treatment with broader immunomodulatory effects may be preferable to doxycycline for the treatment of recurrent C. trachomatis infection associated with infertility.

A comparison of the effects of a chlamydial vaccine administered during or after a C. muridarum urogenital infection of female mice

Research into an efficacious Chlamydia trachomatis vaccine is ongoing, however, there has been no examination into the timing of vaccine administration to either asymptomatically or previously infected individuals. Using the female Chlamydia muridarum genital tract mouse model, we examined this aspect of vaccine development. Our results show timing of vaccination affected the production of systemic antibodies, but had minimal effects on mucosal antibody production. Vaccination during an active infection or after a resolved infection did not provide protection against re-exposure to Chlamydia, and did not exacerbate the development of pathological sequelae in infected mice. This demonstrates that vaccination may not be protective in individuals who are seropositive for an acute or previous chlamydial infection.

Nitric oxide synthases and tubal ectopic pregnancies induced by Chlamydia infection: basic and clinical insights

Human ectopic pregnancy (EP) remains a common cause of pregnancy-related first trimester death. Nitric oxide (NO) is synthesized from L-arginine by three NO synthases (NOS) in different tissues, including the Fallopian tube. Studies of knockout mouse models have improved our understanding of the function of NOS isoforms in reproduction, but their roles and specific mechanisms in infection-induced tubal dysfunction have not been fully elucidated. Here, we provide an overview of the expression, regulation and possible function of NOS isoforms in the Fallopian tube, highlighting the effects of infection-induced changes in the tubal cellular microenvironment (imbalance of NO production) on tubal dysfunction and the potential involvement of NOS isoforms in tubal EP after Chlamydia trachomatis genital infection. The non-equivalent regulation of tubal NOS isoforms during the menstrual cycle suggests that endogenous ovarian steroid hormones regulate NOS in an isoform-specific manner. The current literature suggests that infection with C. trachomatis induces an inflammatory response that eventually leads to tubal epithelial destruction and functional impairment, caused by a high NO output mediated by inducible NOS (iNOS). Therefore, tissue-specific therapeutic approaches to suppress iNOS expression may help to prevent ectopic implantation in patients with prior C. trachomatis infection of the Fallopian tube.

Pathogenesis of genital tract disease due to Chlamydia trachomatis

Although the pathologic consequences of C. trachomatis genital infection are well-established, the mechanism(s)that result in chlamydia-induced tissue damage are not fully understood. We reviewed in vitro, animal, and human data related to the pathogenesis of chlamydial disease to better understand how reproductive sequelae result from C. trachomatis infection. Abundant in vitro data suggest that the inflammatory response to chlamydiae is initiated and sustained by actively infected nonimmune host epithelial cells. The mouse model indicates a critical role for chlamydia activation of the innate immune receptor, Toll-like receptor 2, and subsequent inflammatory cell influx and activation, which contributes to the development of chronic genital tract tissue damage. Data from recent vaccine studies in the murine model and from human immunoepidemiologic studies support a role for chlamydia-specific CD4 Th1-interferon-g-producing cells in protection from infection and disease. However, limited evidence obtained using animal models of repeated infection indicates that, although the adaptive T cell response is a key mechanism involved in controlling or eliminating infection, it may have a double-edged nature and contribute to tissue damage. Important immunologic questions include whether anamnestic CD4 T cell responses drive disease rather than protect against disease and the role of specific immune cells and inflammatory mediators in the induction of tissue damage with primary and repeated infections. Continued study of the complex molecular and cellular interactions between chlamydiae and their host and large-scale prospective immunoepidemiologic and immunopathologic studies are needed to address gaps in our understanding of pathogenesis that thwart development of optimally effective control programs, including vaccine development.

Modulation of cytokines and transcription factors (T-Bet and GATA3) in CD4 enriched cervical cells of Chlamydia trachomatis infected fertile and infertile women upon stimulation with chlamydial inclusion membrane proteins B and C

BACKGROUND

Chlamydial Inclusion membrane proteins (Incs), are involved in biochemical interactions with host cells and infecting Chlamydiae. We have previously reported the role of two Chlamydia trachomatis (CT) Incs, namely IncB and IncC in generating host immunity in CT infected women. Emerging data shows involvement of Inc stimulated CD4 positive T cells in aiding host immunity in infected fertile and infertile women through the secretion of interferon gamma. However the lack of data on the intra-cytokine interplay to these Incs in infected cell milieu prompted us to investigate further.

METHODS

A total of 14 CT-positive fertile, 18 CT-positive infertile women and 25 uninfected controls were enrolled in this study. CD8 depleted, CD4 enriched cervical cells were isolated and upon stimulation with IncB and IncC, modulation of cytokines (Interleukin (IL)-1 Beta, IL-4, IL-5, IL-6, IL-10, Interferon-gamma, IL-12, IL-23, Tumor Necrosis Factor-alpha and Granulocyte macrophage colony-stimulating factor (GM-CSF) and T cell lineage regulating transcription factors T-Bet and GATA3 was determined by real-time reverse-transcriptase (RT)-PCR and ELISA.

RESULTS

Significant higher expression (P < 0.05) of Interferon-gamma, IL-12, IL-23 and GM-CSF were found in Inc-stimulated CD4 enriched cervical cells of CT-positive fertile women and contrastingly high IL-1 Beta, IL-4, IL-5, IL-6 and IL-10 levels were found in CT-positive infertile women. Positive correlation (P < 0.05) was found between Interferon-gamma and T-Bet levels in CT-positive fertile women and IL-4 mRNA and GATA3 levels in CT-positive infertile patients upon IncB and IncC stimulation.

CONCLUSION

Overall our data shows that CT IncB and IncC are able to upregulate expression of cytokines, namely interferon-gamma, IL-12, IL-23 and GM-CSF in CT-positive fertile women while expression of IL-1 Beta, IL-4, IL-5, IL-6 and IL-10 were upregulated in CT-positive infertile women. Our study also suggests that Incs are able to modulate expression of T cell lineage determinants indicating their involvement in regulation of immune cells.

Human oviductal stromal fibroblasts, but not oviductal epithelial cells, express Toll-like receptor 4: the site-specific mucosal immunity of the human fallopian tube against bacterial infection

PROBLEM

To evaluate the site-specific immunoregulatory mechanisms against bacterial infection in the human fallopian tubes.

METHOD OF STUDY

We investigated the effects of lipopolysaccharide (LPS) on the production of CXC chemokines by cultured oviductal epithelial cells (OEC) and oviductal stromal fibroblasts (OSF). The expression of Toll-like receptor (TLR) 4 and CD14 protein in OEC and OSF were evaluated. The phosphorylation of the inhibitor kappaB-alpha (IkappaB-alpha) protein after LPS stimulation was also examined.

RESULTS

Lipopolysaccharide stimulated the secretion of granulocyte chemotactic protein-2, growth-regulated oncogene-alpha, and epithelial neutrophil activating peptide-78 by OSF, but not by OEC. The phosphorylation of the IkappaB-alpha protein was not detected in OEC after stimulation by LPS, whereas IkappaB-alpha phosphorylation was observed in OSF after stimulation by LPS. The expression of the TLR4 protein and mRNA was detected only in OSF but not in OEC. The expression of CD14 was not detected in either OEC or OSF.

CONCLUSION

These results suggest that epithelial cells and fibroblasts in the human fallopian tube have evolved a unique, site-specific mechanism for recognizing Gram-negative pathogens. The lack of TLR4 in OEC may be important for avoiding a state of unnecessary inflammation that could disrupt the epithelial barrier and cause irreversible tubal scarring.

The reproductive significance of human Fallopian tube cilia

Effective tubal transport of ova, sperm and embryos is a prerequisite for successful spontaneous pregnancy. Although there is much yet to be discovered about the mechanisms involved, it is evident that tubal transit is a far more complicated process than initially thought. Propulsion of gametes and embryos is achieved by complex interaction between muscle contractions, ciliary activity and the flow of tubal secretions. Evidence is accumulating of the important and possibly pre-eminent role of ciliary motion in this process; and this review describes current knowledge about ciliary activity and its physiological regulation. There is also a description of the effects on ciliary function of cigarette smoking and various pathological states, including endometriosis and microbial infection, with consideration given as to how altered ciliary activity may impact upon fertility.

Murine oviduct epithelial cell cytokine responses to Chlamydia muridarum infection include interleukin-12-p70 secretion

Epithelial cells play an important role in host defense as sentinels for invading microbial pathogens. Chlamydia trachomatis is an intracellular bacterial pathogen that replicates in reproductive tract epithelium. Epithelial cells lining the reproductive tract likely play a key role in triggering inflammation and adaptive immunity during Chlamydia infections. For this report a murine oviduct epithelial cell line was derived in order to determine how epithelial cells influence innate and adaptive immune responses during Chlamydia infections. As expected, oviduct epithelial cells infected by Chlamydia muridarum produced a broad spectrum of chemokines, including CXCL16, and regulators of the acute-phase response, including interleukin-1alpha (IL-1alpha), IL-6, and tumor necrosis factor alpha. In addition, infected epithelial cells expressed cytokines that augment gamma interferon (IFN) production, including IFN-alpha/beta and IL-12-p70. To my knowledge this is the first report of a non-myeloid/lymphoid cell type making IL-12-p70 in response to an infection. Equally interesting, infected epithelial cells significantly upregulated transforming growth factor alpha precursor expression, suggesting a mechanism by which they might play a direct role in the pathological scarring seen as a consequence of Chlamydia infections. Data from these in vitro studies predict that infected oviduct epithelium contributes significantly to host innate and adaptive defenses but may also participate in the immunopathology seen with Chlamydia infections.

Immunopathogenesis of chlamydia trachomatis infections in women

OBJECTIVE

To develop a model of pathogenesis by which Chlamydia trachomatis progresses from acute to chronic infection, and finally serious disease (salpingitis, tubal occlusion).

DESIGN

Review of current literature located through web-based Medline searches using key words: Chlamydia trachomatis, immunology, cytokines, heat shock protein, infertility.

RESULT(S)

Cell-mediated immune mechanisms appear to be critical in determining whether acute infection is resolved or progresses into chronicity with pathological outcome. What determines the particular immune pathway depends on a range of determinants-HLA subtype and human genetics, cytokine profile, infectious load, route of infection, and endocrinology. A clearer picture of the natural history of chlamydial pathology may assist in providing better predictors of those women who may go on to develop significant sequelae after infection.

CONCLUSION(S)

Predicting those who may develop serious disease, including infertility, may contribute to improved management of such persons during earlier stages of infection and assist in prevention.

Expression and regulation of interleukin-8 in human fallopian tubal cells

OBJECTIVE

The human fallopian tube creates the microenvironment for fertilization and early embryogenesis. Salpingitis may result in infertility and ectopic pregnancy by causing tubal blockage and hydrosalpinx. To better understand the relationship between infectious inflammation and tubal damage, we investigated the expression and regulation of interleukin-8 in human tubal epithelial and stromal cells in culture.

STUDY DESIGN

Human fallopian tube epithelial and stromal cell cultures were used to measure interleukin-8 messenger RNA and interleukin-8 protein levels at basal conditions and after stimulation with interleukin-1alpha and tumor necrosis factor-alpha. Northern blot analysis and enzyme-linked immunosorbent assay were used to evaluate messenger RNA and protein levels, respectively.

RESULTS

Tubal epithelial cells expressed high levels of interleukin-8 messenger RNA and secreted significantly more immunoreactive interleukin-8 into culture medium than did tubal stromal cells (2065 +/- 153 pg/mg vs 530 +/- 56 pg/mg of total protein, P <.01). Interleukin-1alpha and TNF-alpha treatments induced a concentration-dependent increase in interleukin-8 messenger RNA expression in both epithelial and stromal cells. However, at the protein level, although interleukin-1alpha and tumor necrosis factor-alpha treatments increased the secretion of interleukin-8 from stromal cells significantly, similar treatments had no effect on interleukin-8 secretion from epithelial cells.

CONCLUSION

The expression of interleukin-8 in human tubal epithelial and stromal cells is different. Interleukin-8 expression of tubal epithelial and stromal cells in response to inflammatory cytokines such as interleukin-1alpha and tumor necrosis factor-alpha also varies. This may be important in the pathogenesis of salpingitis.

[Is extrauterine pregnancy a complication of chlamydial infection?]

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Chlamydia trachomatis enhances the expression of matrix metalloproteinases in an in vitro model of the human fallopian tube infection

OBJECTIVE

The sequelae of sexually transmitted Chlamydia trachomatis infection include fallopian tube scarring, which implies modification of the extracellular matrix. Our objective was to describe the production of two matrix metalloproteinases in response to chlamydial infection in vitro.

STUDY DESIGN

Human fallopian tube organ cultures were infected with Chlamydia, and the production of matrix metalloproteinases was assessed by gelatin zymography, antigen capture enzyme-linked immunosorbent assay, immunohistochemistry, and in situ zymography.

RESULTS

Significantly elevated levels of matrix metalloproteinase-2 and matrix metalloproteinase-9 were found in supernatants of infected segments. Immunohistochemistry and in situ zymography revealed that epithelial cells tended toward matrix metalloproteinase-2 production and that matrix metalloproteinase-9 exhibited a more diffuse stromal staining pattern.

CONCLUSION

Matrix metalloproteinase-2 and matrix metalloproteinase-9 are expressed in vitro in response to chlamydial infection. Enhanced matrix metalloproteinase production in some individuals in response to infection may lead to tubal scarring through the increased turnover and subsequent repair of the extracellular matrix.

Chlamydia trachomatis-induced apoptosis occurs in uninfected McCoy cells late in the developmental cycle and is regulated by the intracellular redox state

Infections with the obligate intracellular bacterium Chlamydia trachomatis are characterized by avoidance of fusion between chlamydia-containing endosomes and lysosomes, bacterial persistence and development of post-infectious sequelae. In this report we show that C. trachomatis induces apoptosis in McCoy and HeLa cells. Apoptosis was monitored by three different techniques; enzyme-linked immunoassay (EIA) of fragmented nucleosomes, terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) and flow cytometry of propidium iodide-stained cells. Apoptosis occurred in uninfected cells, was induced late in the chlamydial developmental cycle, beyond 24 h post-infection and was dependent on bacterial protein synthesis. Apoptosis was not significantly increased in infected, inclusion-containing cells. Treatment of cells with the antioxidants ascorbic acid (10 microM) and alpha-tocopherol (10 microM) reduced the degree of apoptosis. These results suggest that host cells infected with C. trachomatis generate proapoptotic stimuli that induce apoptosis in uninfected, neighbouring cells and that the redox state of the cell is a regulator in chlamydia-induced apoptosis.

Expression of mucosal homing receptor alpha4beta7 is associated with enhanced migration to the Chlamydia-infected murine genital mucosa in vivo

The CD4 T helper cell type 1 (Th1) response is essential for the resolution of chlamydial genital infection in mice. However, not all Th1 clones are equally protective in eradicating the infection. Since oral immunization regimens produce protective immunity, we evaluated the role of the mucosa-associated homing receptor, alpha4beta7, in trafficking to the genital mucosa. Using a panel of CD4, Th1 cell lines and clones, we compared the lymphocyte homing patterns of a Chlamydia-specific, protective clone (P-MoPn), a nonprotective clone (N-MoPn), and a keyhole limpet hemocyanin (KLH)-specific cell line (KLH-1). T cells were labeled with the fluorescent dye PKH-26, adoptively transferred into Chlamydia-infected mice, and monitored at different time points throughout the course of a genital infection. We found that clones P-MoPn and N-MoPn migrated to similar extents to the genital tract and in significantly greater numbers than the KLH-specific T-cell line. Both clones and the KLH-1 line expressed similar levels of the adhesion molecules alpha4, beta1, CD44, and CD11a. However, clones P-MoPn and N-MoPn expressed higher levels of the mucosal homing receptor, alpha4beta7. Also, clones P-MoPn and N-MoPn but not the KLH-1 line migrated to the mesenteric lymph node, suggesting a mucosal recirculation pattern. Moreover, blocking alpha4beta7 adhesion interaction in vivo significantly reduced the recruitment of P-MoPn but not KLH-1 to the genital tract. These findings show that the mucosal homing receptor alpha4beta7 is utilized by a subset of CD4 cells during migration to the Chlamydia-infected genital tract.

Update on Chlamydia trachomatis

Chlamydia trachomatis is one the most important sexually transmitted diseases; it can cause serious sequelae despite the absence of symptoms in some people. It's estimated that about 25% of women who have acute salpingitis become infertile, and chlamydial infection is the commonest cause. The introduction of screening programs for its detection are still a topic of discussion. The literature shows that the total cost of examination and treatment of complications known to be associated with genital chlamydial infection (PID, chronic pelvic pain, tubal factor infertility) is generally higher than the total cost of a large-scale Chlamydia screening program. The selection of a diagnostic test for detection of chlamydial genital infection depends on availability, local expertise, and prevalence of Chlamydia trachomatis in the test population. Cell culture is too expensive in nonendemic regions, so the use of non-culture techniques is very attractive. PCR (polymerase chain reaction) and LCR (ligase chain reaction) are actually the two most commonly used alternatives to conventional methods for detecting STD agents. In fact, PCR and LCR have proved useful for detection of Chlamydia trachomatis in cervical and urethral samples both in symptomatic and asymptomatic women. Recently, testing of first-void urine (FVU) specimens with these techniques has shown that the amplification tests are as sensitive as tests with endocervical swab cultures.

Tumor necrosis factor in peritoneal fluid from asymptomatic infertile women

BACKGROUND

Tumor necrosis factor-alpha (TNF-alpha) is a cytokine that can be found in the peritoneal fluid (PF) of patients with endometriosis and pelvic inflammatory disease (PID) as a response to inflammatory disorders and infections. The cytotoxic effect of this cytokine could be a factor participating in the pathology of various gynecological diseases, and could also be accountable for the high immunological response and damage to the tubal epithelium. The objective of this study was to establish the presence of TNF-alpha in asymptomatic infertility and its association with various isolated bacteria.

METHODS

Ten milliliters of PF were collected from each of 73 patients by means of laparoscopy and cultured in synthetic medium and McCoy cells for the isolation of aerobic and anaerobic bacteria, as well as for Chlamydia trachomatis. The activity of TNF-alpha was determined by means of a bioassay using L-929 cells.

RESULTS

Forty-three percent of the PFs showed positive TNF-alpha activity, while the laparoscopic evaluation showed that 32 patients had Fallopian tube occlusion (FTO), 7 had endometriosis, 30 had PID, and 4 had myomas and adhesions. TNF-alpha activity was found to be high in FTO patients (p < 0.05). Positive cultures were found in 50.7% of patients; of these, 31.5% had PID (p < 0.05), and only 20.5% of positive cultures were TNF-alpha positive. Chlamydia trachomatis (16%) was the most frequently isolated bacteria in these patients.

CONCLUSIONS

The detection of TNF-alpha could be useful in the diagnosis of active infectious and inflammatory diseases in asymptomatic infertile patients.