Pathogenesis of Chlamydia induced pelvic inflammatory disease

Innovative approach for the clinical development of a Chlamydia trachomatis vaccine through a human challenge model in women

Chlamydia trachomatis remains the most common sexually transmitted bacterial infection worldwide. Recent phase I trials of the C. trachomatis vaccine candidate CTH522 in women and men have shown that the adjuvanted and non-adjuvanted formulations are safe and elicit systemic (immunoglobulin G) and mucosal (immunoglobulin A) antibodies, as well as vaccine-specific cell-mediated immunity. In advance of a standard phase II randomized controlled trial to determine the vaccine's efficacy, this perspective advocates for a carefully and ethically designed human challenge model as an innovative approach to assess a vaccine's ability to prevent infection and its impact on tubal immunopathogenesis in breakthrough infections. Such models could accelerate vaccine development by providing critical insights, making it essential for stakeholders to consider this approach and expedite the long-awaited chlamydia vaccine.

The possible pathogenic mechanisms of microorganisms in infertility: a narrative review

Infertility can harm a patient in physical, psychological, spiritual, and medical ways. This illness is unusual because it affects the patient's companion and the patient individually. Infertility is a multifactorial disease, and various etiological factors like infection are known to develop this disorder. Recently published studies reported that different bacteria, such as Chlamydia trachomatis, Mycoplasma spp., Ureaplasma urealyticum, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa, can lead to infertility by immunopathological effects, oxidative stress, and adverse effects on sperm concentration, motility, morphology, and DNA condensation. Among viruses, Human papillomavirus and Herpes simplex virus reduce sperm progressive motility and sperm concentration. The viruses can lead to the atrophy of the germinal epithelium and degenerative changes in the testes. Candida albicans also harm sperm quality, motility, and chromatin integrity and induce apoptosis in sperm cells. Finally, Trichomonas vaginalis leads to distorted heads, broken necks, and acrosomes exocytosis in sperms. This parasite decreases sperm viability and functional integrity. Noteworthy, oxidative stress could have a role in many pathological changes in the reproductive system. Recent findings show that microorganisms can increase reactive oxygen species concentration inside the host cells, leading to oxidative stress and sperm distress and dysfunction. Therefore, this article explores the potential significance of critical bacteria linked to infertility and their pathogenic mechanisms that can affect sperm function and the female reproductive system.

Characterization of beta2-adrenergic receptor knockout mouse model during Chlamydia muridarum genital infection

Chlamydia genital infection caused by Chlamydia trachomatis is the most common bacterial sexually transmitted disease worldwide. A mouse model has been developed in our laboratory to better understand the effect of cold-induced stress on chlamydia genital infection and immune response. However, the stress mechanism affecting the host response to Chlamydia muridarum genital infection remains unclear. Here, we demonstrate a role for the beta2-adrenergic receptor (β2-AR), which binds noradrenaline and modulates the immune response against chlamydia genital infection in a mouse model. A successful β2-AR homozygous knockout (KO) mouse model was used to study the infection and analyze the immune response. Our data show that stressed mice lacking the β2-AR are less susceptible to C. muridarum genital infection than controls. A correlation was obtained between lower organ load and higher interferon-gamma production by CD4+ and CD8+ cells of the KO mice. Furthermore, exposure of CD4+ T cells to noradrenaline alters the production of cytokines in mice during C. muridarum genital infection. This study suggests that the blockade of β2-AR signaling could be used to increase resistance to chlamydia genital infection. We value the β2-AR KO as a viable model that can provide reproducible results in investigating medical research, including chlamydia genital infection.

Association of Chlamydia and Mycoplasma infections with susceptibility to ovarian cancer: A systematic review and meta-analysis

BACKGROUND

Ovarian cancer is one of the most prevalent cancers with a high mortality rate in women. Published studies indicate that inflammation, DNA damage, and pelvic inflammatory disease (PID) are the most important risk factors for ovarian cancer and this could be induced and exacerbated by infectious agents such as Chlamydia trachomatis and Mycoplasma genitalium. The aim of this study was to determine the association between Chlamydia and Mycoplasma infections and the risk of ovarian cancer.

METHODS

We carried out a comprehensive search of PubMed, Scopus, Web of Science, Embase, and Google Scholar without limitation on publication date. All relevant studies which investigatived probable potential connection between Chlamydia and Mycoplasma infection and development of ovarian cancer were included.

RESULTS

Eighteen studies comprising a total of 8207 patients were evaluated in the study and this showed that the frequency of infection with Chlamydia and Mycoplasma among ovarian cancer patients was 32.6 % and 23 %, respectively. The results suggested that Chlamydia trachomatis infection increased the overall risk for ovarian cancer by 1.344 fold (OR: 1.344; 95 %CI: 1.19-1.50). Moreover, infection with Mycoplasma infections showed a week but not significant increased risk of ovarian cancer (OR: 1.12; 95 %CI: 0.86-1.44). However, the test for heterogeneity was significant among these studies.

CONCLUSION

This study confirmed the clinical relevance of Chlamydia and Mycoplasma infection and development of the ovarian cancer risk, although the significance was marginal and study heterogeneity was significant. This highlights the need for further studies in this area.

Human genital antibody-mediated inhibition of Chlamydia trachomatis infection and evidence for ompA genotype-specific neutralization

The endocervix, the primary site of Chlamydia trachomatis (Ct) infection in women, has a unique repertoire of locally synthesized IgG and secretory IgA (SIgA) with contributions from serum IgG. Here, we assessed the ability of genital and serum-derived IgG and IgA from women with a recent positive Ct test to neutralize Ct elementary bodies (EBs) and inhibit inclusion formation in vitro in human endocervical epithelial cells. We also determined if neutralization was influenced by the major outer membrane protein (MOMP) of the infecting strain, as indicated by ompA gene sequencing and genotyping. At equivalent low concentrations of Ct EB (D/UW-3/Cx + E/UW-5/Cx)-specific antibody, genital-derived IgG and IgA and serum IgA, but not serum IgG, significantly inhibited inclusion formation, with genital IgA being most effective, followed by genital IgG, then serum IgA. The well-characterized Ct genotype D strain, D/UW-3/Cx, was neutralized by serum-derived IgG from patients infected with genotype D strains, genital IgG from patients infected with genotype D or E strains, and by genital IgA from patients infected with genotype D, E, or F strains. Additionally, inhibition of D/UW-3/Cx infection by whole serum, rather than purified immunoglobulin, was associated with levels of serum EB-specific IgG rather than the genotype of infecting strain. In contrast, a Ct genotype Ia clinical isolate, Ia/LSU-56/Cx, was neutralized by whole serum in a genotype and genogroup-specific manner, and inhibition also correlated with EB-specific IgG concentrations in serum. Taken together, these data suggest that (i) genital IgA most effectively inhibits Ct infection in vitro, (ii) human antibody-mediated inhibition of Ct infection is significantly influenced by the ompA genotype of the infecting strain, (iii) the genital antibody repertoire develops or matures differently compared to systemic antibody, and (iv) ompA genotype-specificity of inhibition of infection by whole serum can be overcome by high concentrations of Ct-specific IgG.

Reproductive system infections in women: upper genital tract, fetal, neonatal and infant syndromes

Lower genital tract infection and bloodborne spread of infection are the two principal modes for infection of the upper genital tract or for infection of the fetus, neonate or infant. Treponema pallidum and human immunodeficiency virus (HIV) are the two most common bloodborne pathogens that infect the fetus, neonate or infant. Most infections of the upper genital tract, however, spread along epithelial surfaces from the vagina or cervix to the upper genital tract or chorioamnion, fetus, neonate or infant. These infections are caused by either pathogens associated with a dysbiotic vaginal microbiome or those that are sexually transmitted. The clinical syndromes that these pathogens produce in the lower genital tract were discussed in part one of this review. We now discuss the syndromes and pathogens that affect the upper genital tract of both non-pregnant and pregnant women as well as fetus, neonate and infant.

Chlamydia abortus in Pregnant Woman with Acute Respiratory Distress Syndrome

We describe a case of Chlamydia abortus in a woman in rural France who was pregnant, developed severe generalized infection, and suffered fetal loss. The case stresses the need for healthcare personnel to perform thorough anamnesis in pregnant women in farming areas and to advise them to avoid contact with small ruminants.

Endocervical miRNA Expression Profiles in Women Positive for Chlamydia trachomatis with Clinical Signs and/or Symptoms Are Distinct from Those in Women Positive for Chlamydia trachomatis without Signs and Symptoms

Chlamydia trachomatis is the leading cause of sexually transmitted infections that may progress to pelvic inflammatory disease and infertility. No effective vaccine exists for Chlamydia, nor are there biomarkers available that readily predict disease progression. In this cross-sectional pilot study, we recruited symptomatic and asymptomatic women with C. trachomatis (CT) infection and asymptomatic, uninfected control women from an urban sexually transmitted disease clinic to determine if there were differences in microRNA (miRNA) expression. Infected women with signs and/or symptoms (CTSS) have distinct miRNA profiles compared to asymptomatic infected women (CTNS). In the CTSS group, miR-142 and -147 showed 2.2- to 6.9-fold increases in expression. In the CTNS group, miR-449c, -6779, -519d, -449a, and -2467 showed 3.9- to 9.0-fold increases in expression. In the CTNS group, cyclins and cell cycle regulation and IL-17 pathways were likely downregulated, while the same signaling pathways were upregulated in the CTSS group. In addition, in the CTSS group, additional inflammatory pathways associated with TNFR1 and IL-8 appear to be upregulated. The miRNA expression patterns differ between CT-infected symptomatic and asymptomatic women, and these differences may warrant further study.

Moxibustion for treating chronic pelvic inflammatory disease: A protocol for systematic review and meta-analysis

BACKGROUND

Chronic pelvic inflammatory disease (CPID) is a difficult-to-treat gynaecological disorder, which has complex etiologies, among married women. In recent years, moxibustion has gradually shown its clinical advantages and been more and more widely used In China. The protocol is try to synthesize and assess the effectiveness and safety of moxibustion for patients with CPID.

METHODS

Seven databases as following: PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, WangFang Database, Chinese Scientific Journal Database, Chinese Biomedical Literatures Database will be searched from their inception to May 2020. No restrictions about language and status. Study selection, data collection, and quality assessment will be respectively conducted by 2 researchers. Based on the heterogeneity test results, the fixed-effects or random-effects model will be selected to synthesize data. The effective rate, Pelvic inflammatory mass diameter and Pelvic fluid depth will be the primary outcomes. Patient reported outcome scale, visual analog scale, C-reactive protein, transforming growth factor β1 =  transforming growth factor β, incidence of any adverse events will be the secondary outcomes. Revman 5.4 software will be implemented for data synthesis. Dichotomous data will be represented by risk ratio for efficacy and safety of CPID treated with moxibustion, while continuous data will be represented by mean difference with a 95% confidence interval.

RESULTS

The results of this study will be published in a peer-reviewed journal. This study will provide a comprehensive review of the available evidence for the treatment of moxibustion with CPID.

CONCLUSIONS

This study expects to provide high-quality, evidence-based recommendations on further treatment for clinical guidance of CPID.

TRIAL REGISTRATION NUMBER

CRD42020158744 in PROSPERO 2020.

Modulation of T helper 1 and T helper 2 immune balance in a murine stress model during Chlamydia muridarum genital infection

A murine model to study the effect of cold-induced stress (CIS) on Chlamydia muridarum genital infection and immune response has been developed in our laboratory. Previous results in the lab show that CIS increases the intensity of chlamydia genital infection, but little is known about the effects and mechanisms of CIS on the differentiation and activities of CD4+ T cell subpopulations and bone marrow-derived dendritic cells (BMDCs). The factors that regulate the production of T helper 1 (Th1) or T helper 2 (Th2) cytokines are not well defined. In this study, we examined whether CIS modulates the expressions of beta-adrenergic receptor (β-AR), transcription factors, hallmark cytokines of Th1 and Th2, and differentiation of BMDCs during C. muridarum genital infection in the murine model. Our results show that the mRNA level of the beta2-adrenergic receptor (β2-AR) compared to β1-AR and β3-AR was high in the mixed populations of CD4+ T cells and BMDCs. Furthermore, we observed decreased expression of T-bet, low level of Interferon-gamma (IFN-γ) production, increased expression of GATA-3, and Interleukin-4 (IL-4) production in CD4+ T cells of stressed mice. Exposure of BMDCs to Fenoterol, β2-AR agonist, or ICI118,551, β2-AR antagonist, revealed significant β2-AR stimulation or inhibition, respectively, in stressed mice. Moreover, co-culturing of mature BMDCs and naïve CD4+ T cells increased the production of IL-4, IL-10, L-17, and IL-23 cytokines, suggesting that stimulation of β2-AR leads to the increased production of Th2 cytokines. Overall, our results show for the first time that CIS promotes the switching from a Th1 to Th2 cytokine environment. This was evidenced in the murine stress model by the overexpression of GATA-3 concurrent with elevated IL-4 production, reduced T-bet expression, and IFN-γ secretion.

Future of human Chlamydia vaccine: potential of self-adjuvanting biodegradable nanoparticles as safe vaccine delivery vehicles

INTRODUCTION

There is a persisting global burden and considerable public health challenge by the plethora of ocular, genital and respiratory diseases caused by members of the Gram-negative bacteria of the genus Chlamydia. The major diseases are conjunctivitis and blinding trachoma, non-gonococcal urethritis, cervicitis, pelvic inflammatory disease, ectopic pregnancy, tubal factor infertility, and interstitial pneumonia. The failures in screening and other prevention programs led to the current medical opinion that an efficacious prophylactic vaccine is the best approach to protect humans from chlamydial infections. Unfortunately, there is no human Chlamydia vaccine despite successful veterinary vaccines. A major challenge has been the effective delivery of vaccine antigens to induce safe and effective immune effectors to confer long-term protective immunity. The dawn of the era of biodegradable polymeric nanoparticles and the adjuvanted derivatives may accelerate the realization of the dream of human vaccine in the foreseeable future.

AREAS COVERED

This review focuses on the current status of human chlamydial vaccine research, specifically the potential of biodegradable polymeric nanovaccines to provide efficacious Chlamydia vaccines in the near future.

EXPERT COMMENTARY

The safety of biodegradable polymeric nanoparticles-based experimental vaccines with or without adjuvants and the array of available chlamydial vaccine candidates would suggest that clinical trials in humans may be imminent. Also, the promising results from vaccine testing in animal models could lead to human vaccines against trachoma and reproductive diseases simultaneously.

Effect of cold water-induced stress on immune response, pathology and fertility in mice during Chlamydia muridarum genital infection

Genital infection by Chlamydia trachomatis is the most common bacterial sexually transmitted disease worldwide. It causes serious reproductive health complications, including pelvic inflammatory disease and infertility. Stress is implicated as a risk factor for various infections; however, its effect on chlamydia genital infection is unknown. We previously showed that repeated exposure of mice to cold water results in increased severity of chlamydia genital infection. In this study, cold water-induced stress resulted in (i) elevated levels of norepinephrine (NE) and epinephrine in the spleen and genital tract of stressed mice; (ii) elevated IL-1β, TNF-α, IL-6 and nitric oxide production in macrophage-rich peritoneal cells of mice; (iii) supplement of NE in vitro exerts an immunosuppressive effect on splenic T-cell production of cytokines; (iv) decreased C. muridarum shedding in the genital tract of β1Adr/β2Adr receptor KO mice; and (v) a higher rate of infertility in infected mice. These results suggest that cold water stress induces the production of catecholamines, which may play a critical role in the modulation of the immune system leading to increased intensity of C. muridarum genital infection.

Clinical characteristics of genital chlamydia infection in pelvic inflammatory disease

BACKGROUND

Chlamydia infection in acute pelvic inflammatory disease (PID) is associated with serious complications including ectopic pregnancy, tubal infertility, Fitz-Hugh-Curtis syndrome and tubo-ovarian abscess (TOA). This study compared clinical and laboratory data between PID with and without chlamydia infection.

METHODS

The medical records of 497 women who were admitted with PID between 2002 and 2011 were reviewed. The patients were divided into two groups (PID with and without chlamydia infection), which were compared in terms of the patients' characteristics, clinical presentation, and laboratory findings, including inflammatory markers.

RESULTS

The chlamydia and non-chlamydia groups comprised 175 and 322 women, respectively. The patients in the chlamydia group were younger and had a higher rate of TOA, a longer mean hospital stay, and had undergone more surgeries than the patients in the non- chlamydia group. The erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and CA-125 level were higher in the chlamydia group than in the non-chlamydia group, but there was no significant difference in the white blood cell count between the two groups. The CA-125 level was the strongest predictor of chlamydia infection, followed by the ESR and CRP level. The area under the receiving operating curve for CA-125, ESR, and CRP was 0.804, 0.755, and 0.663, respectively.

CONCLUSIONS

Chlamydia infection in acute PID is associated with increased level of inflammatory markers, such as CA-125, ESR and CRP, incidence of TOA, operation risk, and longer hospitalization.

Prevalence of plasmid-bearing and plasmid-free Chlamydia trachomatis infection among women who visited obstetrics and gynecology clinics in Malaysia

Background

The 7.5 kb cryptic plasmid of Chlamydia trachomatis has been shown to be a virulence factor in animal models, but its significance in humans still remains unknown. The aim of this study was to investigate the prevalence and potential involvement of the C. trachomatis cryptic plasmid in causing various clinical manifestations; including infertility, reproductive tract disintegrity, menstrual disorder, and polycystic ovarian syndrome (PCOS) among genital C. trachomatis–infected patients.

Results

A total of 180 female patients of child bearing age (mean 30.9 years old, IQR:27–35) with gynecological complications and subfertility issues, who visited Obstetrics and Gynecology clinics in Kuala Lumpur, Malaysia were recruited for the study. Prevalence of genital chlamydial infection among these patients was alarmingly high at 51.1 % (92/180). Of the 92 chlamydia-infected patients, 93.5 % (86/92) were infected with plasmid-bearing (+) C. trachomatis while the remaining 6.5 % (6/92) were caused by the plasmid-free (−) variant. Our data showed that genital C. trachomatis infection was associated with infertility issues, inflammation in the reproductive tract (mucopurulent cervicitis or endometriosis), irregular menstrual cycles and polycystic ovarian syndrome (PCOS). However, no statistical significance was detected among patients with plasmid (+) versus plasmid (−) C. trachomatis infection. Interestingly, plasmid (+) C. trachomatis was detected in all patients with PCOS, and the plasmid copy numbers were significantly higher among PCOS patients, relative to non-PCOS patients.

Conclusion

Our findings show a high incidence of C. trachomatis infection among women with infertility or gynecological problems in Malaysia. However, due to the low number of plasmid (−) C. trachomatis cases, a significant role of the plasmid in causing virulence in human requires further investigation of a larger cohort.

Performance evaluation of the PelvoCheck CT/NG test kit for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae

OBJECTIVE

Assessment of the performance of the PelvoCheck CT/NG test (Greiner-Bio-One GmbH) to detect Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) in first-void urine (FVU) of females.

DESIGN

A cross-sectional study to compare the PelvoCheck CT/NG with COBAS TaqMan CT Test V.2.0 (Roche) for the detection of CT and with an in-house porA-based PCR for the detection of NG in FVU specimens. In addition, pools of 5 FVU specimens containing only CT-negative or 1 CT-positive and 4 CT-negative samples were tested. Abbott RealTime CT/NG was used as an additional test to resolve discordant results.

SETTING

Samples sent from six laboratories were tested at the University Medical Center Hamburg.

PARTICIPANTS

Urine samples were from 1622 female patients attending gynaecological practices for chlamydia screening, another 120 urine samples were from patients pretested for NG at Synlab, Medical Service Center, Weiden GmbH. In addition, 50 urine samples spiked with various concentrations of reference material were used.

RESULTS

For the detection of CT and NG, the sensitivity and specificity of the PelvoCheck CT/NG test were 98.8% and 100%, and 98.3% and 98.2%, respectively. The data obtained with the PelvoCheck CT/NG for pooled urine specimens resulted in a positive agreement of 90.9% and a negative agreement of 100%.

CONCLUSIONS

The PelvoCheck CT/NG assay is a suitable test method for the detection of CT and NG in female FVU samples, with sensitivity and specificity comparable with other Food and Drug Administration approved CT/NG nucleic acid amplification tests. To the best of our knowledge, this is the first commercial test system validated for the analysis of pooled urine specimens. No false-positive or invalid result was observed in 55 analysed pools. Nevertheless, 5 samples were false negative due to a target concentration below the limit of detection of the PelvoCheck CT/NG test as a consequence of pooling-associated dilution.

Potential protective effect of a G>A SNP in the 3'UTR of HLA-A for Chlamydia trachomatis symptomatology and severity of infection

The interindividual differences in response to Chlamydia trachomatis (CT) infections are for an important part based on the differences in our host genetic make-up. In the past, several genes and pathways have been identified and linked to protection against or risk for CT infection (i.e. susceptibility), and/or the severity of infection, with a major emphasis on the development of tubal pathology, one of the main causes of female infertility. In the current study, we analyzed in Dutch Caucasian women whether the carriage of HLA-A G>A SNP (rs1655900) was related to the susceptibility of CT infection in a STD cohort (n = 329) and to the severity of infection in a subfertility cohort (n = 482). We also investigated if this A-allele was linked to increase in severity of symptoms, from mild symptoms (lower genital infection) to lower abdominal pain (upper genital tract infection) to the most severe late complication of tubal pathology, including double-sided tubal pathology. We showed that the carriage of HLA-A SNP rs1655900 studied is not associated with the susceptibility to CT infection based on the data from the STD cohort, but might be protective to the development of late complications (p = 0.0349), especially tubal pathology could be relevant.

Chlamydial plasmid-encoded protein pORF5 induces production of IL-1β and IL-18 via NALP3 inflammasome activation and p38 MAPK pathway

The pathogenesis of Chlamydia-induced inflammation is poorly understood. pORF5 is the only secreted protein encoded by Chlamydial plasmid. This study aims to investigate the effects of pORF5 on the production of interleukin-1β (IL-1β) and interleukin-18 (IL-18) and the underlying mechanisms of these effects. THP-1 (a human acute monocytic leukemia cell line) cells were stimulated by pORF5 with or without pretreatment with Natch domain, Leucine-rich repeat and PYD-containing protein 3 (NALP3) siRNA, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) siRNA, cysteine aspartate-specific protease-1 (caspase-1) specific inhibitor and p38 mitogen-activated protein kinase (p38 MAPK) inhibitor. IL-1β, IL-18 and caspase-1 expression was detected through both ELISA and qRT-PCR. NALP3 and ASC expression was detected by qRT-PCR. The expression of caspase-1 and phosphorylated-p38 MAPK was detected by western blot analysis. pORF5 induced IL-1β, IL-18, caspase-1 and NALP3 inflammasome expression in THP-1 cells. Caspase-1 inhibitor significantly reduced pORF5-induced IL-1β and IL-18 expression. The siRNAs for NALP3 inflammasome significantly reduced pORF5-induced IL-1β, IL-18 and caspase-1 expression. Furthermore, p38 MAPK inhibitor significantly reduced pORF5-induced IL-1β, IL-18, caspase-1 and NALP3 inflammasome expression. pORF5 could induce production of IL-1β and IL-18 via NALP3 inflammasome activation and p38MAPK pathway. pORF5 protein might play an important role in Chlamydia pathogenesis. This study provides a new insight into the molecular pathogenesis of Chlamydial diseases.

An Excess of the Proinflammatory Cytokines IFN-γ and IL-12 Impairs the Development of the Memory CD8+ T Cell Response to Chlamydia trachomatis

The obligate intracellular bacterium Chlamydia trachomatis is the most common cause of bacterial sexually transmitted disease in the United States and the leading cause of preventable blindness worldwide. Transfer of cultured Chlamydia-specific CD8(+) T cells or vaccination with recombinant virus expressing an MHC I-restricted Chlamydia Ag confers protection, yet surprisingly a protective CD8(+) T cell response is not stimulated following natural infection. In this study, we demonstrate that the presence of excess IL-12 and IFN-γ contributes to poor memory CD8(+) T cell development during C. trachomatis infection of mice. IL-12 is required for CD8(+) T cell expansion but drives effector CD8(+) T cells into a short-lived fate, whereas IFN-γ signaling impairs the development of effector memory cells. We show that transient blockade of IL-12 and IFN-γ during priming promotes the development of memory precursor effector CD8(+) T cells and increases the number of memory T cells that participate in the recall protection against subsequent infection. Overall, this study identifies key factors shaping memory development of Chlamydia-specific CD8(+) T cells that will inform future vaccine development against this and other pathogens.

Protective immunity against Chlamydia trachomatis can engage both CD4+ and CD8+ T cells and bridge the respiratory and genital mucosae

Understanding the cellular populations and mechanisms responsible for overcoming immune compartmentalization is valuable for designing vaccination strategies targeting distal mucosae. In this study, we show that the human pathogen Chlamydia trachomatis infects the murine respiratory and genital mucosae and that T cells, but not Abs, elicited through intranasal immunization can protect against a subsequent transcervical challenge. Unlike the genital infection where CD8(+) T cells are primed, yet fail to confer protection, we found that intranasal priming engages both CD4(+) and CD8(+) T cells, allowing for protection against genital infection with C. trachomatis. The protection is largely dependent on IFN-γ secretion by T cells. Moreover, different chemokine receptors are critical for C. trachomatis-specific CD4(+) T cells to home to the lung, rather than the CXCR3- and CCR5-dependent migration observed during genital infection. Overall, this study demonstrates that the cross-mucosa protective immunity against genital C. trachomatis infection following intranasal immunization is not dependent on Ab response but is mediated by not only CD4(+) T cells but also by CD8(+) T cells. This study provides insights for the development of vaccines against mucosal pathogens that threaten reproductive health worldwide.

Lactobacilli inactivate Chlamydia trachomatis through lactic acid but not H2O2

Lactobacillus species dominate the microbiome in the lower genital tract of most reproductive-age women. Producing lactic acid and H2O2, lactobacilli are believed to play an important role in prevention of colonization by and growth of pathogens. However, to date, there have been no reported studies characterizing how lactobacilli interact with Chlamydia trachomatis, a leading sexually transmitted bacterium. In this report, we demonstrate inactivation of C. trachomatis infectivity by culture media conditioned by Lactobacillus crispatus, L. gasseri and L. jensenii, known to be dominating organisms in the human vaginal microbiome. Lactobacillus still cultures produced lactic acid, leading to time- and concentration-dependent killing of C. trachomatis. Neutralization of the acidic media completely reversed chlamydia killing. Addition of lactic acid into Lactobacillus-unconditioned growth medium recapitulated the chlamydiacidal activity of conditioned media. The H2O2 concentrations in the still cultures were found to be comparable to those reported for the cervicovaginal fluid, but insufficient to inactivate chlamydiae. Aeration of Lactobacillus cultures by shaking markedly induced H2O2 production, but strongly inhibited Lactobacillus growth and lactic acid production, and thus severely affected acidification, leading to significantly reduced chlamydiacidal efficiency. These observations indicate lactobacilli inactivate chlamydiae primarily through maintaining acidity in a relatively hypoxic environment in the vaginal lumen with limited H2O2, which is consistent with the notion that women with higher vaginal pH are more prone to sexually transmitted C. trachomatis infection. In addition to lactic acid, formic acid and acetic acid also exhibited potent chlamydiacidal activities. Taken together, our findings imply that lowering the vaginal pH through engineering of the vaginal microbiome and other means will make women less susceptible to C. trachomatis infection.

Morphologic and molecular evaluation of Chlamydia trachomatis growth in human endocervix reveals distinct growth patterns

In vitro models of Chlamydia trachomatis growth have long been studied to predict growth in vivo. Alternative or persistent growth modes in vitro have been shown to occur under the influence of numerous stressors but have not been studied in vivo. Here, we report the development of methods for sampling human infections from the endocervix in a manner that permits a multifaceted analysis of the bacteria, host and the endocervical environment. Our approach permits evaluating total bacterial load, transcriptional patterns, morphology by immunofluorescence and electron microscopy, and levels of cytokines and nutrients in the infection microenvironment. By applying this approach to two pilot patients with disparate infections, we have determined that their contrasting growth patterns correlate with strikingly distinct transcriptional biomarkers, and are associated with differences in local levels of IFNγ. Our multifaceted approach will be useful to dissect infections in the human host and be useful in identifying patients at risk for chronic disease. Importantly, the molecular and morphological analyses described here indicate that persistent growth forms can be isolated from the human endocervix when the infection microenvironment resembles the in vitro model of IFNγ-induced persistence.

Integrin α4β1 is necessary for CD4+ T cell-mediated protection against genital Chlamydia trachomatis infection

Chlamydia trachomatis infection is the most common sexually transmitted bacterial infection in the United States and a significant health burden worldwide. Protection from Chlamydia infection in the genital mucosa is dependent on IFN-γ derived from CD4(+) Th1 cells. These CD4(+) T cells must home successfully to the genital tract to exert their effector function and decrease C. trachomatis burden. Although adhesion receptors expressed by CD4(+) T cells in the genital tract have been characterized, the integrin receptor required for Chlamydia-specific CD4(+) T cell-mediated protection has not been explored. In this study, we demonstrate that C. trachomatis infection of the upper genital tract results in recruitment of Chlamydia-specific CD4(+) T cells robustly expressing the integrin α4β1. Interfering with α4β1, but not α4β7, function resulted in defective CD4(+) T cell trafficking to the uterus and high bacterial load. We conclude that integrin α4β1 is necessary for CD4(+) T cell-mediated protection against C. trachomatis infection in the genital mucosa. By identifying homing molecules required for successful CD4(+) T cell trafficking to C. trachomatis-infected tissues, we will be better equipped to design vaccines that elicit sterilizing, long-lasting immunity without inducing immune pathologies in the upper genital tract.

Reorganization of the host cytoskeleton by the intracellular pathogen Chlamydia trachomatis

Chlamydiae are obligate intracellular pathogens that cause a wide range of human diseases. Chlamydia resides in a membrane bound vacuole ("inclusion") that expands to accommodate replicating bacteria. We recently reported that Chlamydia remodels and recruit two major cytoskeletal components of the host cell- F-actin and Intermediate filaments-to form a dynamic scaffold that provides structural stability to the inclusion. As the inclusion expands, a secreted chlamydial protease progressively modifies the intermediate filaments scaffold, presumably to increase the inclusion's flexibility and accommodate the increased bacterial load. This represents a unique mechanism employed by an intracellular pathogen to support its intracellular niche and may be linked to immune evasion by this pathogen. Here, we discuss the potential consequences of Chlamydia-mediated alteration of host cytoskeletal dynamics on the pathogenesis of chlamydial infections.

Fluorometric high-throughput assay for measuring chlamydial neutralizing antibody

Chlamydia trachomatis is an obligate intracellular mucosotropic pathogen that causes human infections of global importance. C. trachomatis causes trachoma, the leading cause of preventable blindness worldwide, and is the most common cause of bacterial sexually transmitted disease. Although oculogenital infections are treatable with antibiotics, a vaccine is needed to control C. trachomatis infection. Ideally, a vaccine would provide coverage against most, if not all, naturally occurring antigenically distinct serovariants. The development of a subunit vaccine to prevent oculogenital disease could be advanced by identifying chlamydial antigens that elicit pan-neutralizing antibodies, particularly among infected human populations of known risk factors. There is currently no objective high-throughput in vitro assay to screen human sera for neutralization to aid in identification of these antigens. This report describes an objective, high-throughput in vitro assay that measures C. trachomatis-neutralizing antibodies. Antibody-mediated neutralization of chlamydial infection was performed in a 96-well microtiter format, and neutralization was quantified by immunostaining fixed cells followed by automated fluorometric analysis. This report shows that fluorometric analysis of C. trachomatis infection directly correlates to labor-intensive manual inclusion counts. Furthermore, this report shows that fluorometry can be used to identify C. trachomatis serovar- and serocomplex-specific neutralization. This objective, high-throughput analysis of serum neutralization is amenable to epidemiological studies of human chlamydial infection, human clinical vaccine trials, and preclinical animal model experiments of Chlamydia infection.

Cold-induced stress increases the intensity of Chlamydia genital infection in mice

BACKGROUND/PURPOSE(S)

Genital infection by Chlamydia trachomatis (CT) is the most common bacterial sexually transmitted disease worldwide. The infection can cause serious reproductive health complications including pelvic inflammatory disease and infertility. Stress is implicated as a risk factor for various infections; however, its effect on Chlamydia genital infection and complications are unknown.

METHODS

We investigated the effect of cold-stress on resistance to Chlamydia genital infection, stress hormone production, and the functions of immune cells in a mouse model. Mice were infected intravaginally with CT after a 24-day cold-stress application. The course of infection was monitored by cervicovaginal swabbing for isolation of live Chlamydia in tissue culture. The production of stress hormones and cytokines in genital tracts, spleen or blood were assessed.

RESULTS

Exposure of mice to 24-day stress resulted in: (a) increased susceptibility to Chlamydia genital infection and greater intensity of infection, (b) increased plasma or tissue noradrenaline and adrenaline levels, and (c) decreased mRNA and protein levels of major cytokines and chemokines in the spleen and genital tract.

CONCLUSION

These results suggest that cold-induced stress induces the production of catecholamines, which may play a critical role in the modulation of the immune system leading to increased susceptibility and greater intensity of Chlamydia genital infection that could promote the development of complications.

An automated image-based method for rapid analysis of Chlamydia infection as a tool for screening antichlamydial agents

A major limitation in the identification of novel antichlamydial compounds is the paucity of effective methods for large-scale compound screening. The immunofluorescence assay is the preferred approach for accurate quantification of the intracellular growth of Chlamydia. In this study, an immunofluorescence image-based method (termed image-based automated chlamydial identification and enumeration [iBAChIE]) was customized for fully automated quantification of Chlamydia infection using the freely available open-source image analysis software program CellProfiler and the complementary data exploration software program CellProfiler Analyst. The method yielded enumeration of different species and strains of Chlamydia highly comparably to the conventional manual methods while drastically reducing the analysis time. The inhibitory capability of established antichlamydial activity was also evaluated. Overall, these data support that iBAChIE is a highly effective tool for automated quantification of Chlamydia infection and assessment of antichlamydial activities of molecules. Furthermore, iBAChIE is expected to be amenable to high-throughput screening studies for inhibitory compounds and fluorescently labeled molecules to study host-pathogen interactions.

Chlamydia vaccines: recent developments and the role of adjuvants in future formulations

Bacteria of the genus Chlamydia cause a plethora of ocular, genital and respiratory diseases that continue to pose a considerable public health challenge worldwide. The major diseases are conjunctivitis and blinding trachoma, non-gonococcal urethritis, cervicitis, pelvic inflammatory disease, ectopic pregnancy, tubal factor infertility and interstitial pneumonia. The rampart asymptomatic infections prevent timely and effective antibiotic treatments, and quite often clinical presentation of sequelae is the first evidence of an infection. Besides, significant broad coverage in population screening and treatment is economically and logistically impractical, and mass education for public awareness has been ineffective. The current medical opinion is that an efficacious prophylactic vaccine is the best approach to protect humans from chlamydial infections. Unfortunately, a human vaccine has yet to be realized despite successful veterinary vaccines. Fortunately, recent advances in chlamydial immunobiology, cell biology, molecular pathogenesis, genomics, antigen discovery and animal models of infections are hastening progress toward an efficacious vaccine. Thus, it is established that Chlamydia immunity is mediated by T cells and a complementary antibody response, and several potential vaccine candidates have been identified. However, further advances are needed in effective vaccine delivery systems and safe potent adjuvants to boost and sustain immune responses for long-lasting protective immunity. This article focuses on the current status of human chlamydial vaccine research, specifically how application of new delivery systems and human compatible adjuvants could lead to a timely achievement of efficacious Chlamydia vaccines. The ranking of the candidate vaccine antigens for human vaccine development will await the availability of results from studies in which the antigens are tested by comparable experimental standards, such as antigen-adjuvant combination, route of delivery and possible toxicity.

Approach to discover T- and B-cell antigens of intracellular pathogens applied to the design of Chlamydia trachomatis vaccines

Natural immunity against obligate and/or facultative intracellular pathogens is usually mediated by both humoral and cellular immunity. The identification of those antigens stimulating both arms of the immune system is instrumental for vaccine discovery. Although high-throughput technologies have been applied for the discovery of antibody-inducing antigens, few examples of their application for T-cell antigens have been reported. We describe how the compilation of the immunome, here defined as the pool of immunogenic antigens inducing T- and B-cell responses in vivo, can lead to vaccine candidates against Chlamydia trachomatis. We selected 120 C. trachomatis proteins and assessed their immunogenicity using two parallel high-throughput approaches. Protein arrays were generated and screened with sera from C. trachomatis-infected patients to identify antibody-inducing antigens. Splenocytes from C. trachomatis-infected mice were stimulated with 79 proteins, and the frequency of antigen-specific CD4(+)/IFN-γ(+) T cells was analyzed by flow cytometry. We identified 21 antibody-inducing antigens, 16 CD4(+)/IFN-γ(+)-inducing antigens, and five antigens eliciting both types of responses. Assessment of their protective activity in a mouse model of Chlamydia muridarum lung infection led to the identification of seven antigens conferring partial protection when administered with LTK63/CpG adjuvant. Protection was largely the result of cellular immunity as assessed by CD4(+) T-cell depletion. The seven antigens provided robust additive protection when combined in four-antigen combinations. This study paves the way for the development of an effective anti-Chlamydia vaccine and provides a general approach for the discovery of vaccines against other intracellular pathogens.

Chlamydia trachomatis infection causes mitotic spindle pole defects independently from its effects on centrosome amplification

Chlamydiae are Gram negative, obligate intracellular bacteria, and Chlamydia trachomatis is the etiologic agent of the most commonly reported sexually transmitted disease in the United States. Chlamydiae undergo a biphasic life cycle that takes place inside a parasitophorous vacuole termed an inclusion. Chlamydial infections have been epidemiologically linked to cervical cancer in patients previously infected by human papillomavirus (HPV). The inclusion associates very closely with host cell centrosomes, and this association is dependent upon the host motor protein dynein. We have previously reported that this interaction induces supernumerary centrosomes in infected cells, leading to multipolar mitotic spindles and inhibiting accurate chromosome segregation. Our findings demonstrate that chlamydial infection causes mitotic spindle defects independently of its effects on centrosome amplification. We show that chlamydial infection increases centrosome spread and inhibits the spindle assembly checkpoint delay to disrupt centrosome clustering. These data suggest that chlamydial infection exacerbates the consequences of centrosome amplification by inhibiting the cells' ability to suppress the effects of these defects on mitotic spindle organization. We hypothesize that these combined effects on mitotic spindle architecture identifies a possible mechanism for Chlamydia as a cofactor in cervical cancer formation.

Diagnosis and follow-up of genital chlamydial infection by direct methods and by detection of serum IgG, IgA and secretory IgA

PURPOSE

To determine the prevalence of Chlamydia trachomatis infection in a high-risk population by direct and indirect methods and to evaluate the diagnosis of secretory immunoglobulin A (sIgA).

PATIENTS AND METHODS

Urethral or endocervical specimens from 78 patients (48 females and 30 males) were examined by cell culture, direct fluorescence assay, PCR Cobas Amplicor (Roche Molecular Diagnostics), and sIgA was detected by the recombinant lipopolysaccharide (LPS)-enzyme-linked immunoassay (rELISA). Serum from each patient was also obtained and analysed for the presence of IgG and IgA antibody by in-house microimmunofluorescence (MIF) and by the rELISA method (Medac, Hamburg, Germany).

RESULTS

The overall C. trachomatis prevalence determined by direct methods was 28%. The detection of sIgA antibodies was significantly higher in the group of patients with a positive direct detection (50%) than in the group of negative direct detection (10.7%). The Chlamydia-specific IgA antibodies were detected by the rELISA in 40.9 and 53.6% of group I (positive direct detection) and group II patients (negative direct detection), respectively. The species-specific IgA antibodies were detected by the MIF method in 18.2 and 16.1% of group I and II patients, respectively. Chlamydia genus-specific IgG antibodies were detected by the rELISA in 86.4 and 83.9% of group I and group II patients and, C. trachomatis specific IgG were present in 81.8 and 73.2% of group I and group II patients, respectively, as assessed by the MIF test.

CONCLUSION

Combining the positive direct methods and/or positive sIgA antibody results from cervical or urethral specimens had an indication of current C. trachomatis infection.

Efficacy of the therapy of non-complicated mixed infections of the urogenital tract with Safocid (a combined drug)

The author presents data from the current scientific literature related to etiology of inflammatory diseases of the urogenital system. The author also presents the results of a complex clinical, laboratory and instrumental study of 32 patients with non-complicated mixed infections of the urogenital tract and assessment of the efficacy of their therapy with the use of Safocid (a combined drug).

Pelvic inflammatory disease among privately insured women, United States, 2001-2005

BACKGROUND

We explored the utility of using insurance claims data for surveillance of pelvic inflammatory disease (PID). PID rates are an important indicator of population level trends in reproductive morbidity; however, data available to monitor PID trends are limited. National survey data are currently used to estimate PID rates in the United States, but a declining number of cases threaten their future usefulness.

METHODS

We performed a retrospective analysis of PID diagnosis rates using administrative claims data from 2001 to 2005. Diagnostic codes were used to identify women aged 15 to 44 in the study population that were diagnosed with acute PID as inpatients, in emergency departments, and in outpatient ambulatory settings.

RESULTS

Rates of PID diagnoses among privately insured women declined significantly from 2001 to 2005 among all age groups examined and within all geographic regions. Annual PID diagnosis rates decreased from 317.0 to 236.0 per 100,000 enrollees, representing a 25.5% decline over the study period. The highest rates of PID were among 25- to 29-year-olds (352.8 per 100,000 in 2005) and among those residing in the South (314.3 per 100,000 in 2005). Most women (70.1%) received PID care through physician offices and other outpatient facilities; of these women, approximately 40% were treated by an obstetrician/gynecologist.

CONCLUSIONS

The decline in PID diagnoses corresponds with previous reports from national surveys. Claims data offer a much needed new data source that will allow for continued monitoring of PID among a broad population in both inpatient and outpatient clinical settings.

Development and evaluation of an ompA quantitative real-time PCR assay for Chlamydia trachomatis serovar determination

Knowledge of circulating Chlamydia trachomatis serovars can be beneficial for sexual network surveillance, monitoring treatment success, and associating specific clinical manifestations. Typically, C. trachomatis serovars are predicted by nucleotide sequencing of four variable domains within the ompA gene. However, sequencing procedures can be labor-intensive, are not readily available, and can lack the capacity to identify multiple serovars. This study describes the development and evaluation of a quantitative real-time PCR (qPCR) test algorithm for the rapid prediction of C. trachomatis serovars, including ocular (A to C) and anogenital (D to L3) strains. This test comprises a primary qPCR to confirm C. trachomatis positivity and the phylogenetic group(s) present and a secondary set of qPCRs to determine specific serovars. Cell culture isolates from 15 prototypic C. trachomatis serovars were correctly identified using this assay, with no cross-reactivity observed among serovars or with other common pathogenic microorganisms. Five hundred clinical specimens (previously diagnosed as being C. trachomatis positive) were evaluated by qPCR, with their results compared to results obtained by conventional sequencing. The qPCR identified 88.9% (423/476) complete matches (95% confidence interval [CI], 86 to 92%) of serovars compared to the results obtained using the sequence-based approach. Among the anogenital specimens, 2.4% (12/494) (95% CI, 1.3 to 4.2%) contained multiple serovars, categorized as single-serovar infections by conventional sequencing. Overall, this test exhibited high discriminatory success for predicting C. trachomatis serovars, particularly among anogenital infections. This is the first report of a qPCR typing assay offering differentiation of C. trachomatis serovars associated with both anogenital and ocular diseases.

Plasmacytoid dendritic cells modulate nonprotective T-cell responses to genital infection by Chlamydia muridarum

Given their immune-modulating capacity, regulatory T cells (Treg) cells may be important players in the induction of the protective T-cell response (Th1) to genital chlamydial infection. Recent work has demonstrated that plasmacytoid dendritic cells (pDC) respond to genital chlamydial infection, and that pDC may be uniquely positioned for the induction of Treg cells during this infection. Here, we present the first data demonstrating that Treg influx into the draining lymph node and the site of infection during genital chlamydial infection. We found that pDC depletion altered the numbers of Treg and nonprotective inflammatory cells [interferongamma-(IFNgamma)-producing CD8+ T and IFNgamma-producing natural killer T cells] in the spleens of mice genitally infected with Chlamydia muridarum. Furthermore, pDC depletion did not alter Th1 cell numbers, indicating that pDC modulate cells that could inhibit and promote nonprotective inflammation during genital chlamydial infection. Finally, we demonstrate that depletion of pDC results in less severe dilation and collagen deposition in the oviduct following resolution of infection, implicating pDC activity in the formation of sequelae following genital C. muridarum infection.

A pilot qualitative analysis of the psychosocial factors which drive young people to decline chlamydia testing in the UK: implications for health promotion and screening

The main objectives of this study are to investigate the psychosocial issues for young people who decline chlamydia testing as part of the national chlamydia screening programme in the UK and to consider the implications for future opportunistic screening. Transcripts of qualitative semi-structured interviews were analysed using interpretative phenomenological analysis to identify themes. The study involved 14 young people aged 16–24 years who declined chlamydia tests in non-health-care settings as part of the chlamydia screening programme. The study was conducted in educational settings where chlamydia screening is available. Four interlinked themes were identified: stigmatization of young people with chlamydia and who take a test, the feeling of embarrassment, their perception of risk and their beliefs of what the test involves. These beliefs and feelings were pervasive and negatively affected their personal decisions of having a test. In conclusion, understanding psychosocial cultural phenomena in the context of screening programmes for sexually transmitted infections (STIs) in young people are important for their success. Chlamydia and STIs remain stigmatized; testing is poorly understood and embarrassing for young people, which impacts the poor uptake for opportunistic screening. Strategies are needed to normalize and de-stigmatize chlamydia and the chlamydia test.

Chlamydia trachomatis, a hidden epidemic: effects on female reproduction and options for treatment

The number of genital tract Chlamydia trachomatis infections is steadily increasing worldwide, with approximately 50-70% of infections asymptomatic. There is currently no uniform screening practice, current antibiotic treatment has failed to prevent the increased incidence, and there is no vaccine available. We examined studies on the epidemiology of C. trachomatis infections, the effects infections have on the female reproductive tract and subsequent reproductive health and what measures are being taken to reduce these problems. Undetected or multiple infections in women can lead to the development of severe reproductive sequelae, including pelvic inflammatory disease and tubal infertility. There are two possible paradigms of chlamydial pathogenesis, the cellular and immunological paradigms. While many vaccine candidates are being extensively tested in animal models, they are still years from clinical trials. With no vaccine available and antibiotic treatment unable to halt the increased incidence, infection rates will continue to increase and cause a significant burden on health care systems.

Role of T lymphocytes in the pathogenesis of Chlamydia disease

Vaccines are needed to prevent the oculogenital diseases of Chlamydia trachomatis. Infected hosts develop immunity, although temporary, and experimental vaccines have yielded significant protective immunity in animal models, fueling the impetus for a vaccine. Because infections cause sequelae, the functional relationship between infection- and vaccine-induced immunity is unclear. We hypothesized that infection- and vaccine-induced immunity are functionally distinct, particularly in the ability to prevent sequelae. Chlamydia-immune mice, with immunity generated by either a previous infection or vaccination, exhibited a significant degree of protective immunity, marked by a lower-intensity, abbreviated course of infection. However, vaccinated mice were protected from infertility, whereas preinfected mice were not. Thus, infection-induced immunity does not prevent the pathologic process leading to infertility. Furthermore, T cell subsets, especially CD8 T cells, play a major role in Chlamydia-induced infertility. The results have important implications for the immunopathogenesis of chlamydial disease and new vaccine strategies.

Chlamydia trachomatis evokes a relative anti-inflammatory response in a free Ca2+ dependent manner in human macrophages

Chlamydia trachomatis infections manifest as unique, chronic inflammatory diseases, indicating a relative compromise in the capacity of early immune responders such as macrophages to resolve the infection. We decided to investigate whether or not the chronic inflammatory manifestations are influenced by a disturbance in the pattern of inflammatory:anti-inflammatory cytokine elaboration early in the infection cycle in macrophages and assess the possible modulatory role of Ca(2+) signals in the process. Although the basal and functional levels of IL-12 and IL-10 are not identical in concentration, chlamydia initiated a significant decline in IL-12. This led to a difference in the ratio of time-course decline in IL-12 compared with IL-10 in a Ca(2+)-poor medium, while there was significant increase in IL-10 in a Ca(2+)-rich medium. Also, when macrophages were infected after treatment with drugs that either facilitated Ca(2+) influx into cells or inhibited efflux from intracellular stores into cytosol, there was a significant enhancement of the elaboration of IL-10 compared with IL-12. The immobilization of cytosolic Ca(2+) by BAPTA-AM resulted in the decline of macrophage IL-12 and IL-10 in both infected and uninfected cases. There was evidence that infectivity and status of chlamydial elementary bodies harvested from macrophages during these experiments were consistent with chronic forms as assessed by HSP-60:MOMP ratio. The implication of these findings is that chlamydia infection of macrophages, together with its capacity to moderate macrophage intracellular Ca(2+) levels, may evoke a net anti-inflammatory response that presumably favors chronic chlamydia infections.

Inflammasome-dependent caspase-1 activation in cervical epithelial cells stimulates growth of the intracellular pathogen Chlamydia trachomatis

Inflammasomes have been extensively characterized in monocytes and macrophages, but not in epithelial cells, which are the preferred host cells for many pathogens. Here we show that cervical epithelial cells express a functional inflammasome. Infection of the cells by Chlamydia trachomatis leads to activation of caspase-1, through a process requiring the NOD-like receptor family member NLRP3 and the inflammasome adaptor protein ASC. Secretion of newly synthesized virulence proteins from the chlamydial vacuole through a type III secretion apparatus results in efflux of K(+) through glibenclamide-sensitive K(+) channels, which in turn stimulates production of reactive oxygen species. Elevated levels of reactive oxygen species are responsible for NLRP3-dependent caspase-1 activation in the infected cells. In monocytes and macrophages, caspase-1 is involved in processing and secretion of pro-inflammatory cytokines such as interleukin-1beta. However, in epithelial cells, which are not known to secrete large quantities of interleukin-1beta, caspase-1 has been shown previously to enhance lipid metabolism. Here we show that, in cervical epithelial cells, caspase-1 activation is required for optimal growth of the intracellular chlamydiae.

[Chlamydia trachomatis infections in neonates--overview of current laboratory diagnostics]

Based on recent literature and their own laboratory experiences the author summarizes the clinical manifestations, diagnostic possibilities and the tools of prevention of neonatal Chlamydia trachomatis infection, where a potential or a verified role of this pathogen is present. Definitive diagnosis is complicated by the common phenomenon of asymptomatic, undiagnosed maternal infection, as well as by the need for adequate sample-collection and targetted screening techniques. There are only estimated data regarding the incidence of neonatal Chlamydia trachomatis infection; however we do have the diagnostic tests to identify the affected neonates, who may have generally only a mild-moderate manifestation of infection in case of an early treatment. Focussed screening efforts should be made to reduce the number of infected pregnant women and thereby the vertical rate of transmission.

Chlamydia trachomatis serology in women with and without ovarian cancer

Pelvic inflammation has been implicated in the genesis of ovarian cancer. We conducted serologic measurements of Chlamydia trachomatis antibodies as a surrogate marker of chlamydial pelvic inflammatory disease. Women with ovarian cancer (n = 521) and population-based controls (n = 766) were tested. IgG antibodies to serovar D of chlamydia elementary bodies (EBs) were detected using an ELISA assay. The odds of having ovarian cancer among women with the highest titers (>or=0.40 OD units) were 0.6 (95% CI 0.4-0.9). These data do not support our earlier finding of elevated titers for antibodies to C. trachomatis among women with ovarian cancer.

Chlamydia trachomatis-specific heat shock proteins 60 antibodies can serve as prognostic marker in secondary infertile women

BACKGROUND

The magnitude of reproductive morbidity associated with sexually transmitted Chlamydia trachomatis infection is enormous. A predictive serological test for upper genital tract infection would be a desirable diagnostic tool as C. trachomatis infection may lead to various immunopathological sequelae such as infertility, or ectopic pregnancy.

MATERIALS AND METHODS

Female patients (n = 198) attending gynecology outpatient department of Safdarjung hospital were enrolled for the study and clinically characterized into four groups on the basis of their symptoms; discharge, chronic cervicitis, primary and secondary infertility. Serological detection of C. trachomatis was done by ELISA using specific peptide sequences of major outer membrane protein (MOMP), Chlamydia heat shock protein (cHSP60 and 10).

RESULTS

Significant high seropositivity to chlamydial anti-cHSP60 antibodies were detected in patients with secondary infertility. A significant percent of chlamydial reinfection was observed in patients having secondary infertility (82.6%; p < 0.01) and chronic cervicitis (64.28%; p < 0.05). Considering IgG MOMP ELISA as a test standard, anti-cHSP60 antibodies showed higher sensitivity (90.91%) and specificity (89.47%) than cHSP10 ELISA (75.6% and 73.87%) in the secondary infertile group. Further anti-cHSP60 antibodies' detection had a sensitivity of 67.33% and a specificity of 90.67% in secondary infertile women when compared with DFA and PCR.

CONCLUSIONS

Our data suggest that detection of anti-cHSP60 antibodies would help in early prognosis of immunopathological sequelae in C. trachomatis-infected women and thereby in instituting appropriate therapy for controlling C. trachomatis infection at an early stage.

Chlamydia antibodies, chlamydia heat shock protein, and adverse sequelae after pelvic inflammatory disease: the PID Evaluation and Clinical Health (PEACH) Study

BACKGROUND

Among women with pelvic inflammatory disease (PID), we assessed the associations among antibodies to Chlamydia trachomatis elementary bodies (EB), antibodies to chlamydia heat shock protein (Chsp60), rates of pregnancy, and PID recurrence.

METHODS

Four hundred forty-three women with clinical signs and symptoms of mild to moderate PID enrolled in the PID Evaluation and Clinical Health Study were followed for a mean of 84 months for outcomes of time-to-pregnancy and time-to-PID recurrence. Antibodies to EB and Chsp60 were assessed in relation to these long-term sequelae of PID.

RESULTS

Rates of pregnancy were significantly lower (adj. hazard ratio 0.47, 95% confidence interval 0.28-0.79) and PID recurrence higher (adj. hazard ratio 2.48, 95% confidence interval 1.00-6.27) after adjusting for confounding factors among women whose antibody titers to chlamydia EB measured in the final year of follow-up were in the highest tertile.

CONCLUSION

Among women with mild to moderate PID, antibodies to C. trachomatis were independently associated with reduced rates of pregnancy and elevated rates of recurrent PID.

Intracellular interleukin-1alpha mediates interleukin-8 production induced by Chlamydia trachomatis infection via a mechanism independent of type I interleukin-1 receptor

Chlamydia trachomatis infection induces a wide array of inflammatory cytokines and chemokines, which may contribute to chlamydia-induced pathologies. However, the precise mechanisms by which Chlamydia induces cytokines remain unclear. Here we demonstrate that the proinflammatory cytokine interleukin-1alpha (IL-1alpha) plays an essential role in chlamydial induction of the chemokine IL-8. Cells deficient in IL-1alpha expression or IL-1alpha-competent cells treated with IL-1alpha-specific small interfering RNA failed to produce IL-8 in response to chlamydial infection. However, neutralization of extracellular IL-1alpha or blockade of or deficiency in type I IL-1 receptor (IL-1RI) signaling did not affect chlamydial induction of IL-8 in cells capable of producing IL-1alpha. These results suggest that IL-1alpha can mediate the chlamydial induction of IL-8 via an intracellular mechanism independent of IL-1RI, especially during the early stage of the infection cycle. This conclusion is further supported by the observations that expression of a transgene-encoded full-length IL-1alpha fusion protein in the nuclei enhanced IL-8 production and that nuclear localization of chlamydia-induced precursor IL-1alpha correlated with chlamydial induction of IL-8. Thus, we have identified a novel mechanism for chlamydial induction of the chemokine IL-8.

Caspase-1 contributes to Chlamydia trachomatis-induced upper urogenital tract inflammatory pathologies without affecting the course of infection

Chlamydia trachomatis infection induces inflammatory pathologies in the upper genital tract, potentially leading to ectopic pregnancy and infertility in the affected women. Caspase-1 is required for processing and release of the inflammatory cytokines interleukin-1beta (IL-1beta), IL-18, and possibly IL-33. In the present study, we evaluated the role of caspase-1 in chlamydial infection and pathogenesis. Although chlamydial infection induced caspase-1 activation and processing of IL-1beta, mice competent and mice deficient in caspase-1 experienced similar courses of chlamydial infection in their urogenital tracts, suggesting that Chlamydia-activated caspase-1 did not play a significant role in resolution of chlamydial infection. However, when genital tract tissue pathologies were examined, the caspase-1-deficient mice displayed much reduced inflammatory damage. The reduction in inflammation was most obvious in the fallopian tube tissue. These observations demonstrated that although caspase-1 is not required for controlling chlamydial infection, caspase-1-mediated responses can exacerbate the Chlamydia-induced inflammatory pathologies in the upper genital tract, suggesting that the host caspase-1 may be targeted for selectively attenuating chlamydial pathogenicity without affecting the host defense against chlamydial infection.