Chlamydia induces anchorage independence in 3T3 cells and detrimental cytological defects in an infection model

When Bacteria and Viruses Collide: A Tale of Chlamydia trachomatis and Sexually Transmitted Viruses

The global incidence of sexually transmitted infections (STIs) remains high, with the World Health Organization (WHO) estimating that over 1 million people acquire STIs daily. STIs can lead to infertility, pregnancy complications, and cancers. Co-infections with multiple pathogens are prevalent among individuals with an STI and can lead to heightened infectivity and more severe clinical manifestations. Chlamydia trachomatis (CT) is the most reported bacterial STI worldwide in both men and women, and several studies have demonstrated co-infection of CT with viral and other bacterial STIs. CT is a gram-negative bacterium with a unique biphasic developmental cycle including infectious extracellular elementary bodies (EBs) and metabolically active intracellular reticulate bodies (RBs). The intracellular form of this organism, RBs, has evolved mechanisms to persist for long periods within host epithelial cells in a viable but non-cultivable state. The co-infections of CT with the most frequently reported sexually transmitted viruses: human immunodeficiency virus (HIV), human papillomavirus (HPV), and herpes simplex virus (HSV) have been investigated through in vitro and in vivo studies. These research studies have made significant strides in unraveling the intricate interactions between CT, these viral STIs, and their eukaryotic host. In this review, we present an overview of the epidemiology of these co-infections, while specifically delineating the underlying mechanisms by which CT influences the transmission and infection dynamics of HIV and HSV. Furthermore, we explore the intricate relationship between CT and HPV infection, with a particular emphasis on the heightened risk of cervical cancer. By consolidating the current body of knowledge, we provide valuable insights into the complex dynamics and implications of co-infection involving CT and sexually transmitted viruses.

The Chlamydia trachomatis type III-secreted effector protein CteG induces centrosome amplification through interactions with centrin-2

The centrosome is the main microtubule organizing center of the cell and is crucial for mitotic spindle assembly, chromosome segregation, and cell division. Centrosome duplication is tightly controlled, yet several pathogens, most notably oncogenic viruses, perturb this process leading to increased centrosome numbers. Infection by the obligate intracellular bacterium Chlamydia trachomatis (C.t.) correlates with blocked cytokinesis, supernumerary centrosomes, and multipolar spindles; however, the mechanisms behind how C.t. induces these cellular abnormalities remain largely unknown. Here we show that the secreted effector protein, CteG, binds to centrin-2 (CETN2), a key structural component of centrosomes and regulator of centriole duplication. Our data indicate that both CteG and CETN2 are necessary for infection-induced centrosome amplification, in a manner that requires the C-terminus of CteG. Strikingly, CteG is important for in vivo infection and growth in primary cervical cells but is dispensable for growth in immortalized cells, highlighting the importance of this effector protein to chlamydial infection. These findings begin to provide mechanistic insight into how C.t. induces cellular abnormalities during infection, but also indicate that obligate intracellular bacteria may contribute to cellular transformation events. Centrosome amplification mediated by CteG-CETN2 interactions may explain why chlamydial infection leads to an increased risk of cervical or ovarian cancer.

In Search of a Mechanistic Link between Chlamydia trachomatis-Induced Cellular Pathophysiology and Oncogenesis

Centrosome duplication and cell cycle progression are essential cellular processes that must be tightly controlled to ensure cellular integrity. Despite their complex regulatory mechanisms, microbial pathogens have evolved sophisticated strategies to co-opt these processes to promote infection. While misregulation of these processes can greatly benefit the pathogen, the consequences to the host cell can be devastating. During infection, the obligate intracellular pathogen Chlamydia trachomatis induces gross cellular abnormalities, including supernumerary centrosomes, multipolar spindles, and defects in cytokinesis. While these observations were made over 15 years ago, identification of the bacterial factors responsible has been elusive due to the genetic intractability of Chlamydia. Recent advances in techniques of genetic manipulation now allows for the direct linking of bacterial virulence factors to manipulation of centrosome duplication and cell cycle progression. In this review, we discuss the impact, both immediate and downstream, of C. trachomatis infection on the host cell cycle regulatory apparatus and centrosome replication. We highlight links between C. trachomatis infection and cervical and ovarian cancers and speculate whether perturbations of the cell cycle and centrosome are sufficient to initiate cellular transformation. We also explore the biological mechanisms employed by Inc proteins and other secreted effector proteins implicated in the perturbation of these host cell pathways. Future work is needed to better understand the nuances of each effector's mechanism and their collective impact on Chlamydia's ability to induce host cellular abnormalities.

Deregulation of the cyclin-dependent kinase inhibitor p27 as a putative candidate for transformation in Chlamydia trachomatis infected mesenchymal stem cells

Purpose

Several pathological conditions might cause the degradation of the cyclin-dependent kinase inhibitor (CKI) p27 and cell cycle arrest at the G1 phase, including cancers and infections. Chlamydia trachomatis (Ctr), as an obligatory intracellular pathogen, has been found to alter the fate of the cell from different aspects. In this study, we aimed to investigate the effect of Ctr infection on the expression of the important cell cycle regularity protein p27 in mesenchymal stem cells (MSCs).

Methods

Isolation of MSCs from healthy human fallopian tube was confirmed by detection of the stemness markers Sox2, Nanog and Oct4 and the surface markers CD44, CD73 and CD90 by Western blotting and fluorescence-activated cell sorting analysis. The expression of p27 was downregulated at the protein level upon Ctr D infection measured by Real-Time Quantitative Reverse Transcription PCR (qRT-PCR), IF and Western blotting. Recovery of p27 in Ctr D-infected MSCs was achieved by treatment with difluoromethylornithine (DFMO). Ctr D infected MSCs were able to produce colonies in anchorage-independent soft agar assay.

Conclusion

Ctr D infection was able to downregulate the expression of the important cell cycle regulator protein p27, which will be considered a putative candidate for transformation in Ctr D infected MSCs.

Chlamydia and HPV induce centrosome amplification in the host cell through additive mechanisms

Based on epidemiology studies, Chlamydia trachomatis has been proposed as a co-factor for human papillomavirus (HPV) in the development of cervical cancer. These two intracellular pathogens have been independently reported to induce the production of extra centrosomes, or centrosome amplification, which is a hallmark of cancer cells. We developed a cell culture model to systematically measure the individual and combined effects of Chlamydia and HPV on the centrosome in the same host cell. We found that C. trachomatis caused centrosome amplification in a greater proportion of cells than HPV and that the effects of the two pathogens on the centrosome were additive. Furthermore, centrosome amplification induced by Chlamydia, but not by HPV, strongly correlated with multinucleation and required progression through mitosis. Our results suggest that C. trachomatis and HPV induce centrosome amplification through different mechanisms, with the chlamydial effect being largely due to a failure in cytokinesis that also results in multinucleation. Our findings provide support for C. trachomatis as a co-factor for HPV in carcinogenesis and offer mechanistic insights into how two infectious agents may cooperate to promote cancer. TAKE AWAYS: • Chlamydia and HPV induce centrosome amplification in an additive manner. • Chlamydia-induced centrosome amplification is linked to host cell multinucleation. • Chlamydia-induced centrosome amplification requires cell cycle progression. • Chlamydia and HPV cause centrosome amplification through different mechanisms. • This study supports Chlamydia as a co-factor for HPV in carcinogenesis.

Chlamydia Trachomatis Infection: Their potential implication in the Etiology of Cervical Cancer

Pathogenic bacterial strains can alter the normal function of cells and induce different levels of inflammatory responses that are connected to the development of different diseases, such as tuberculosis, diarrhea, cancer etc. Chlamydia trachomatis (C. trachomatis) is an intracellular obligate gram-negative bacterium which has been connected with the cervical cancer etiology. Nevertheless, establishment of causality and the underlying mechanisms of carcinogenesis of cervical cancer associated with C. trachomatis remain unclear. Studies reveal the existence of C. trachomatis in cervical cancer patients. The DNA repair pathways including mismatch repair, nucleotide excision, and base excision are vital in the abatement of accumulated mutations that can direct to the process of carcinogenesis. C. trachomatis recruits DDR proteins away from sites of DNA damage and, in this way, impedes the DDR. Therefore, by disturbing host cell-cycle control, chromatin and DDR repair, C. trachomatis makes a situation favorable for malignant transformation. Inflammation originated due to infection directs over production of reactive oxygen species (ROS) and consequent oxidative DNA damage. This review may aid our current understanding of the etiology of cervical cancer in C. trachomatis-infected patients.

Infection With Chlamydia trachomatis Increases the Risk of High-grade Anal Intraepithelial Neoplasia in People Living With Human Immunodeficiency Virus

BACKGROUND

We aimed to assess the relationship between sexually transmitted infections (STIs)-including a large panel of human papillomavirus (HPV) genotypes-and high-grade anal intraepithelial neoplasia (HGAIN) in men who have sex with men (MSM) who were living with human immunodeficiency virus (HIV).

METHODS

In a prospective study in an HIV cohort, participants underwent high-resolution anoscopy (HRA) for anorectal swabs collection to investigate STIs and for anal biopsy. Multiplex real-time polymerase chain reactions were performed, detecting several STIs and 28 HPV genotypes. Univariate and multivariate generalized linear models were used to analyze the relationships of variables of interest with HGAIN.

RESULTS

There were 145 participants included; in 49, 2 HRAs were performed. Ureaplasma urealyticum (UU) was detected in 25 (17.2%) participants, Chlamydia trachomatis (CT) in 13 (9.0%), Mycoplasma genitalium (MG) in 4 (2.8%), HPV16 in 38 (26.2%), HPV52 in 29 (20%), and HPV53 and HPV42 in 28 (19.3%) participants each. There were 35 (24.1%) subjects diagnosed with HGAIN. In the univariate analysis, HGAIN was associated with CT, UU, MG, HPV16, HPV53, HPV68, and HPV70, and significant interactions were found between CT and HPV16 (odds ratio [OR] 31.0 95% confidence interval [CI] 4.3-221.7) and between UU and HPV16 (OR 8.8, 95% CI 2.1-37.5). In the adjusted model, CT, HPV16, HPV53, HPV70, the CD4+/CD8+ ratio, and the interaction between CT and HPV16 remained independent predictors of HGAIN. HPV16, HPV53, and HPV70 persisted in the second HRA in all the participants with recurrent HGAIN.

CONCLUSIONS

Coinfection with CT may potentiate the oncogenic capability of HPV16 and increase the risk of HGAIN in people with HIV. HPV53 and HPV70 should be considered among the genotypes associated with HGAIN.

Sulforaphane promotes chlamydial infection by suppressing mitochondrial protein oxidation and activation of complement C3

Sulforaphane (SFN), a phytochemical found in broccoli and other cruciferous vegetables, is a potent antioxidant and anti-inflammatory agent with reported effects in cancer chemoprevention and suppression of infection with intracellular pathogens. Here we report on the impact of SFN on infection with Chlamydia trachomatis (Ct), a common sexually transmitted pathogen responsible for 131 million new cases annually worldwide. Astoundingly, we find that SFN as well as broccoli sprouts extract (BSE) promote Ct infection of human host cells. Both the number and size of Ct inclusions were increased when host cells were pretreated with SFN or BSE. The initial investigations presented here point to both the antioxidant and thiol alkylating properties of SFN as regulators of Ct infection. SFN decreased mitochondrial protein sulfenylation and promoted Ct development, which were both reversed by treatment with mitochondria-targeted paraquat (MitoPQ). Inhibition of the complement component 3 (complement C3) by SFN was also identified as a mechanism by which SFN promotes Ct infections. Mass spectrometry analysis found alkylation of cysteine 1010 (Cys1010) in complement C3 by SFN. The studies reported here raise awareness of the Ct infection promoting activity of SFN, and also identify potential mechanisms underlying this activity.

Sirenomelia and maternal chlamydia trachomatis infection: a case report and review

Background: Sirenomelia is a lethal congenital anomaly, presenting with fusion of lower extremities and malformed perineum. The pathogenesis is unclear, and "defective blastogenesis" is the proposed mechanism. Chlamydia trachomatis (CT) is an obligate intracellular pathogen which reportedly invades placenta and may result in fetal demise. It has documented cytopathogenic effects, specifically, cellular disruption, tissue dysgenesis, and genomic instability.Case report: An infant with sirenomelia was born as a product of 30 weeks of pregnancy, which was normal except for a persistent maternal CT infection. The infant expired shortly after birth.Conclusion: Fetal invasion by CT, conceivably, may induce structural anomalies, such as sirenomelia by virtue of its cytopathic effects. We intend to draw attention to such a possibility by reporting this case. This association, however, is speculative and more cases of sirenomelia with CT positive mothers need to be described in order to make definite conclusions about such a relationship.

Chlamydia trachomatis infection in primary fallopian tube and high-grade serous ovarian cancers: a pilot study

Background

The aim of this study was to evaluate the association of Chlamydia trachomatis (CT) infection with primary tubal and high-grade serous ovarian cancers.

Methods

This is a cross-sectional, retrospective study conducted at Ain Shams University Maternity Hospital, Egypt, from February 2008 to October 2017. Sixty-seven paraffin archival blocks specimens were retrieved from cases who underwent staging laparotomy due to high-grade serous ovarian cancer (30 cases), primary tubal serous cancer (25 cases), and control specimens of (12) tubal specimens from cases of benign gynecological conditions. All samples were examined for CT DNA using semiquantitative qRT-PCR.

Results

CT DNA was detected in 84% of high-grade tubal serous cancer, 16.7% of high-grade serous ovarian cancer, and 13.3% in controls (P<0.0005). Mean CT DNA relative quantity was significantly high (256) in tubal carcinoma, in comparison to that in high-grade serous ovarian cancer and controls (13.5 and 0.28, respectively; P<0.0005).

Conclusion

To the best of our knowledge, this is the first report on relation of CT to the tubal serous cancer, so the responsibility of CT tubal infection in the pathogenesis of primary tubal cancer needs to be considered.

Characterization of the Growth of Chlamydia trachomatis in In Vitro-Generated Stratified Epithelium

Chlamydia infection targets the mucosal epithelium, where squamous and columnar epithelia can be found. Research on Chlamydia-epithelia interaction has predominantly focused on columnar epithelia, with very little known on how Chlamydia interacts with the squamous epithelium. The stratification and differentiation processes found in the squamous epithelium might influence chlamydial growth and infection dissemination. For this reason, three-dimensional (3D) organotypic stratified squamous epithelial cultures were adapted to mimic the stratified squamous epithelium and chlamydial infection was characterized. Chlamydia trachomatis infection in monolayers and 3D cultures were monitored by immunofluorescence and transmission electron microscopy to evaluate inclusion growth and chlamydial interconversion between elementary and reticulate body. We observed that the stratified epithelium varied in susceptibility to C. trachomatis serovars L2 and D infection. The undifferentiated basal cells were susceptible to infection by both serovars, while the terminally differentiated upper layers were resistant. The differentiating suprabasal cells exhibited different susceptibilities to serovars L2 and D, with the latter unable to establish a successful infection in this layer. Mature elementary body-containing inclusions were much more prevalent in these permissive basal layers, while the uppermost differentiated layers consistently harbored very few reticulate bodies with no elementary bodies, indicative of severely limited bacterial replication and development. For serovar D, the differentiation state of the host cell was a determining factor, as calcium-induced differentiation of cells in a monolayer negatively affected growth of this serovar, in contrast to serovar L2. The apparent completion of the developmental cycle in the basal layers of the 3D cultures correlated with the greater degree of dissemination within and the level of disruption of the stratified epithelium. Our studies indicate that the squamous epithelium is a suboptimal environment for growth, and thus potentially contributing to the protection of the lower genital tract from infection. The relatively more fastidious serovar D exhibited more limited growth than the faster-growing and more invasive L2 strain. However, if given access to the more hospitable basal cell layer, both strains were able to produce mature inclusions, replicate, and complete their developmental cycle.

Chlamydia trachomatis induces an upregulation of molecular biomarkers podoplanin, Wilms' tumour gene 1, osteopontin and inflammatory cytokines in human mesothelial cells

Chlamydia trachomatis is the most prevalent infection of the genital tract in women worldwide. C. trachomatis has a tendency to cause persistent infection and induce a state of chronic inflammation, which has been reported to play a role in carcinogenesis. We report that persistent C. trachomatis infection increases the expression of inflammatory tumour cytokines and upregulates molecular biomarkers such as podoplanin, Wilms' tumour gene 1 and osteopontin in primary cultures of mesothelial cells (Mes1) and human mesothelioma cells (NCI). Infection experiments showed that Mes1 and NCI supported the growth of C. trachomatisin vitro, and at an m.o.i. of 4, the inclusion-forming units/cell showed many intracellular inclusion bodies after 3 days of infection. However, after 7 days of incubation, increased proliferative and invasive activity was also observed in Mes1 cells, which was more evident after 14 days of incubation. ELISA analysis revealed an increase in vascular endothelial growth factor, IL-6, IL-8, and TNF-α release in Mes1 cells infected for a longer period (14 days). Finally, real-time PCR analysis revealed a strong induction of podoplanin, Wilms' tumour gene 1 and osteopontin gene expression in infected Mes1 cells. The aim of the present study was to investigate the inflammatory response elicited by C. trachomatis persistent infection and the role played by inflammation in cell proliferation, secretion of proinflammatory cytokines and molecular biomarkers of cancer. The results of this study suggest that increased molecular biomarkers of cancer by persistent inflammation from C. trachomatis infection might support cellular transformation, thus increasing the risk of cancer.

Chlamydia trachomatis Inclusion Disrupts Host Cell Cytokinesis to Enhance Its Growth in Multinuclear Cells

Chlamydia trachomatis, the leading cause of bacterial sexually transmitted infections, disrupts cytokinesis and causes significant multinucleation in host cells. Here, we demonstrate that multinuclear cells that result from unsuccessful cell division contain significantly higher Golgi content, an important source of lipids for chlamydiae. Using immunofluorescence and fluorescent live cell imaging, we show that C. trachomatis in multinuclear cells indeed intercept Golgi-derived lipid faster than in mononuclear cells. Moreover, multinuclear cells enhance C. trachomatis inclusion growth and infectious particle formation. Together, these results indicate that C. trachomatis robustly position inclusions to the cell equator to disrupt host cell division in order to acquire host Golgi-derived lipids more quickly in multinucleated progeny cells.

Chlamydia trachomatis Genital Infections

Etiology, transmission and protection: Chlamydia trachomatis is the leading cause of bacterial sexually transmitted infection (STI) globally. However, C. trachomatis also causes trachoma in endemic areas, mostly Africa and the Middle East, and is a leading cause of preventable blindness worldwide. Epidemiology, incidence and prevalence: The World Health Organization estimates 131 million new cases of C. trachomatis genital infection occur annually. Globally, infection is most prevalent in young women and men (14-25 years), likely driven by asymptomatic infection, inadequate partner treatment and delayed development of protective immunity. Pathology/Symptomatology: C. trachomatis infects susceptible squamocolumnar or transitional epithelial cells, leading to cervicitis in women and urethritis in men. Symptoms are often mild or absent but ascending infection in some women may lead to Pelvic Inflammatory Disease (PID), resulting in reproductive sequelae such as ectopic pregnancy, infertility and chronic pelvic pain. Complications of infection in men include epididymitis and reactive arthritis. Molecular mechanisms of infection: Chlamydiae manipulate an array of host processes to support their obligate intracellular developmental cycle. This leads to activation of signaling pathways resulting in disproportionate influx of innate cells and the release of tissue damaging proteins and pro-inflammatory cytokines. Treatment and curability: Uncomplicated urogenital infection is treated with azithromycin (1 g, single dose) or doxycycline (100 mg twice daily x 7 days). However, antimicrobial treatment does not ameliorate established disease. Drug resistance is rare but treatment failures have been described. Development of an effective vaccine that protects against upper tract disease or that limits transmission remains an important goal.

Chlamydia cell biology and pathogenesis

Chlamydia spp. are important causes of human disease for which no effective vaccine exists. These obligate intracellular pathogens replicate in a specialized membrane compartment and use a large arsenal of secreted effectors to survive in the hostile intracellular environment of the host. In this Review, we summarize the progress in decoding the interactions between Chlamydia spp. and their hosts that has been made possible by recent technological advances in chlamydial proteomics and genetics. The field is now poised to decipher the molecular mechanisms that underlie the intimate interactions between Chlamydia spp. and their hosts, which will open up many exciting avenues of research for these medically important pathogens.

Chlamydia Trachomatis Infection-Associated Risk of Cervical Cancer: A Meta-Analysis

As whether Chlamydia trachomatis infection increases the risk of cervical cancer is controversial in the literature, we performed a meta-analysis.Based on a comprehensive search of publications in the Medline, Cochrane, and EMBASE databases, we identified and extracted data from all relevant articles examining C. trachomatis infection and the risk of cervical cancer. The quality of each included study was assessed according to the 9-star Newcastle-Ottawa scale. The strength of association between the C. trachomatis and risk of cervical cancer was estimated by odds ratio (OR) and 95% confidence intervals (CIs). This review was registered at PROSPERO with registration No. CRD42014015672. A total of 22 studies with 4291 cervical cancer cases and 7628 controls were identified. Overall, C. trachomatis was significantly linked to increased cervical cancer risk in prospective studies (OR = 2.21, 95% CI: 1.88-2.61, P < 0.001), as well as in retrospective studies (OR = 2.19, 95% CI: 1.74-2.74, P < 0.001). Additionally, with a multivariate logistic regression analysis adjusted for HPV and age, C. trachomatis infection was identified as an independent predictor of cervical cancer in 11 studies (OR = 1.76, 95% CI: 1.03-3.01, P = 0.04). Coinfection of human papilloma virus and C. trachomatis has a higher risk of cervical cancer (OR = 4.03, 95% CI: 3.15-5.16, P < 0.001). A subgroup analysis based on histological type indicated an elevated risk for both squamous cell carcinoma (OR = 2.21, 95% CI: 2.00-2.45, P < 0.001), and adenocarcinoma (OR = 1.61, 95% CI: 1.21-2.15, P = 0.001), in associated with C. trachomatis. Subgroup analysis by where C. trachomatis infection was detected showed a significantly higher risk of cervical cancer associated with C. trachomatis infection detected in serum (OR = 2.20, 95% CI: 2.01-2.42, P < 0.001), cervical tissue blocks (OR = 2.88, 95% CI: 1.21-6.83, P = 0.02), and cervical secretion (OR = 2.71, 95% CI: 1.41-5.20, P = 0.003), especially in serum with no obvious heterogeneity.In conclusion, our novel data demonstrate that individuals infected with C. trachomatis have a higher risk of cervical cancer. Therefore, it is necessary to expand C. trachomatis infection screening and treat women with C. trachomatis promptly, particularly those with human papilloma virus infections. This approach will not only protect against pelvic inflammatory disease and infertility, but may also prevent cervical cancer.

Genital tract infection with Chlamydia trachomatis in women attended at a cervical cancer screening program in Northeastern from Brazil

PURPOSE

This cross-sectional study aimed to estimate the prevalence of Chlamydia trachomatis (CT) infection alone and in combination with human papillomavirus (HPV). Furthermore, the study investigates whether the CT infection increases the risk of contracting HPV and whether the presence of both pathogens is associated with a higher prevalence of cervical lesions.

METHODS

Cervical samples of 1,134 asymptomatic women enrolled in a screening program for cervical cancer were analyzed. Two cervical specimens were collected from each patient, one for cytologic examination and the other for detection of CT by polymerase chain reaction (PCR), using a primer pair which amplifies a specific sequence of the DNA plasmid.

RESULTS

The overall prevalence rate infection was 10.9%, being 10% in the women with normal cytology, 13.8% in those with atypical squamous cells of undetermined significance (ASC-US), and 25% with low-grade squamous intraepithelial lesion (LSIL). The infection by CT did not increase the risk of acquiring HPV infection. The higher prevalence of LSIL in women co-infected with HPV and CT is possibly due to HPV.

CONCLUSION

CT infection was more prevalent in younger women aged up to 32 years, who had an early onset of reproductive activity and a history of having had multiple sexual partners lifelong may be at a greater risk of acquiring infection of the genital tract by C. trachomatis.

Multinucleation during C. trachomatis infections is caused by the contribution of two effector pathways

Chlamydia trachomatis is an obligate intracellular bacterial pathogen and the second leading cause of sexually transmitted infections in the US. Infections cause significant morbidity and can lead to serious reproductive sequelae, including an epidemiological link to increased rates of reproductive cancers. One of the overt changes that infected cells exhibit is the development of genomic instability leading to multinucleation. Here we demonstrate that the induction of multinucleation is not conserved equally across chlamydial species; C. trachomatis L2 caused high levels of multinucleation, C. muridarum intermediate levels, and C. caviae had very modest effects on multinucleation. Our data show that at least two effector pathways together cause genomic instability during infection leading to multinucleation. We find that the highly conserved chlamydial protease CPAF is a key effector for one of these pathways. CPAF secretion is required for the loss of centrosome duplication regulation as well as inducing early mitotic exit. The second effector pathway involves the induction of centrosome position errors. This function is not conserved in three chlamydial species tested. Together these two pathways contribute to the induction of high levels of genomic instability and multinucleation seen in C. trachomatis infections.

Chlamydia trachomatis and risk of cervical intraepithelial neoplasia grade 3 or worse in women with persistent human papillomavirus infection: a cohort study

OBJECTIVES

Some studies suggest that Chlamydia trachomatis (CT) enhances cervical carcinogenesis; however, a possible confounding effect of persistent human papillomavirus (HPV) infection was not addressed. We examined the potential role of CT infection in the development of subsequent cervical intraepithelial neoplasia grade 3 or worse (CIN3+) in women with prevalent HPV infection and in a subgroup of women with persistent HPV infection.

METHODS

Participants in this population-based cohort study underwent a structured interview, including history of CT infection, and subsequently cervical exfoliated cells were obtained for HPV DNA and CT DNA testing. Women with high-risk HPV DNA infection and no prevalent cervical disease constituted the overall study population (n=1390). A subgroup of women with persistent HPV infection (n=320) was also identified. All women were passively followed for development of cervical lesions in the national Pathology Data Bank. HRs and 95% CIs for CIN3+ during follow-up (up to 19 years) were estimated in an accelerated failure time model.

RESULTS

Women who reported more than one CT infection had a statistically significantly increased risk of CIN3+ (high-risk HPV-positive, HR=2.51, 95% CI 1.44 to 4.37) (persistent HPV infection, HR=3.65, 95% CI 1.53 to 8.70). We found no association between CT DNA and subsequent risk of CIN3+ among women who were HPV-positive or had a persistent HPV infection at baseline.

CONCLUSIONS

Repeated CT infections increased the risk of CIN3+ among women with prevalent as well as persistent high-risk HPV infection.