Growth kinetics of Chlamydia trachomatis in primary human Sertoli cells

Deciphering the Puzzle: Literature Insights on Chlamydia trachomatis-Mediated Tumorigenesis, Paving the Way for Future Research

Some infectious agents have the potential to cause specific modifications in the cellular microenvironment that could be propitious to the carcinogenesis process. Currently, there are specific viruses and bacteria, such as human papillomavirus (HPV) and Helicobacter pylori, that are well established as risk factors for neoplasia. Chlamydia trachomatis (CT) infections are one of the most common bacterial sexually transmitted infections worldwide, and recent European data confirmed a continuous rise across Europe. The infection is often asymptomatic in both sexes, requiring a screening program for early detection. Notwithstanding, not all countries in Europe have it. Chlamydia trachomatis can cause chronic and persistent infections, resulting in inflammation, and there are plausible biological mechanisms that link the genital infection with tumorigenesis. Herein, we aimed to understand the epidemiological and biological plausibility of CT genital infections causing endometrial, ovarian, and cervical tumors. Also, we covered some of the best suitable in vitro techniques that could be used to study this potential association. In addition, we defend the point of view of a personalized medicine strategy to treat those patients through the discovery of some biomarkers that could allow it. This review supports the need for the development of further fundamental studies in this area, in order to investigate and establish the role of chlamydial genital infections in oncogenesis.

Leukocytospermia and/or Bacteriospermia: Impact on Male Infertility

Infertility is a globally underestimated public health concern affecting almost 190 million people, i.e., about 17.5% of people during their lifetime, while the prevalence of male factor infertility is about 7%. Among numerous other causes, the prevalence of male genital tract infections reportedly ranges between 10% and 35%. Leukocytospermia is found in 30% of infertile men and up to 20% in fertile men. Bacterial infections cause an inflammatory response attracting leukocytes, which produce reactive oxygen species (ROS) and release cytokines, both of which can cause damage to sperm, rendering them dysfunctional. Although leukocytospermia and bacteriospermia are both clinical conditions that can negatively affect male fertility, there is still debate about their impact on assisted reproduction outcomes and management. According to World Health Organization (WHO) guidelines, leukocytes should be determined by means of the Endtz test or with monoclonal antibodies against CD15, CD68 or CD22. The cut-off value proposed by the WHO is 1 × 106 peroxidase-positive cells/mL. For bacteria, Gram staining and semen culture are regarded as the "gold standard", while modern techniques such as PCR and next-generation sequencing (NGS) are allowing clinicians to detect a wider range of pathogens. Whereas the WHO manual does not specify a specific value as a cut-off for bacterial contamination, several studies consider semen samples with more than 103 colony-forming units (cfu)/mL as bacteriospermic. The pathogenic mechanisms leading to sperm dysfunction include direct interaction of bacteria with the male germ cells, bacterial release of spermatotoxic substances, induction of pro-inflammatory cytokines and ROS, all of which lead to oxidative stress. Clinically, bacterial infections, including "silent" infections, are treatable, with antibiotics being the treatment of choice. Yet, non-steroidal antiphlogistics or antioxidants should also be considered to alleviate inflammatory lesions and improve semen quality. In an assisted reproduction set up, sperm separation techniques significantly reduce the bacterial load in the semen. Nonetheless, contamination of the semen sample with skin commensals should be prevented by applying relevant hygiene techniques. In patients where leukocytospermia is detected, the causes (e.g. infection, inflammation, varicocele, smoking, etc.) of the leukocyte infiltration have to be identified and addressed with antibiotics, anti-inflammatories or antioxidants in cases where high oxidative stress levels are detected. However, no specific strategy is available for the management of leukocytospermia. Therefore, the relationship between bacteriospermia and leukocytospermia as well as their specific impact on functional sperm parameters and reproductive outcome variables such as fertilization or clinical pregnancy must be further investigated. The aim of this narrative review is to provide an update on the current knowledge on leukocytospermia and bacteriospermia and their impact on male fertility.

Current progresses and challenges for microbiome research in human health: a perspective

It is becoming increasingly clear that the human microbiota, also known as "the hidden organ", possesses a pivotal role in numerous processes involved in maintaining the physiological functions of the host, such as nutrient extraction, biosynthesis of bioactive molecules, interplay with the immune, endocrine, and nervous systems, as well as resistance to the colonization of potential invading pathogens. In the last decade, the development of metagenomic approaches based on the sequencing of the bacterial 16s rRNA gene via Next Generation Sequencing, followed by whole genome sequencing via third generation sequencing technologies, has been one of the great advances in molecular biology, allowing a better profiling of the human microbiota composition and, hence, a deeper understanding of the importance of microbiota in the etiopathogenesis of different pathologies. In this scenario, it is of the utmost importance to comprehensively characterize the human microbiota in relation to disease pathogenesis, in order to develop novel potential treatment or preventive strategies by manipulating the microbiota. Therefore, this perspective will focus on the progress, challenges, and promises of the current and future technological approaches for microbiome profiling and analysis.

Extra Virgin Olive Oil-Based Formulations: A "Green" Strategy against Chlamydia trachomatis

In recent decades, antibiotic misuse has emerged as an important risk factor for the appearance of multi-drug-resistant bacteria, and, recently, antimicrobial resistance has also been described in Chlamydia trachomatis as the leading cause of bacterial sexually transmitted diseases worldwide. Herein, we investigated, for the first time, the antibacterial activity against C. trachomatis of a polyphenolic extract of extra virgin olive oil (EVOO), alongside purified oleocanthal and oleacein, two of its main components, in natural deep eutectic solvent (NaDES), a biocompatible solvent. The anti-chlamydial activity of olive-oil polyphenols (OOPs) was tested in the different phases of chlamydial developmental cycle by using an in vitro infection model. Transmission and scanning electron microscopy analysis were performed for investigating potential alterations of adhesion and invasion, as well as morphology, of chlamydial elementary bodies (EBs) to host cells. The main result of our study is the anti-bacterial activity of OOPs towards C. trachomatis EBs down to a total polyphenol concentration of 1.7 μg/mL, as shown by a statistically significant decrease (93.53%) of the total number of chlamydial-inclusion-forming units (p < 0.0001). Transmission and scanning electron microscopy analysis supported its anti-chlamydial effect, suggesting that OOP might damage the chlamydial outer layers, impairing their structural integrity and hindering EB capability to infect the host cell. In conclusion, OOPs may represent an interesting alternative therapeutic option toward C. trachomatis, although further studies are necessary for exploring its clinical applications.

Probing the Potential Mechanism of Quercetin and Kaempferol against Heat Stress-Induced Sertoli Cell Injury: Through Integrating Network Pharmacology and Experimental Validation

Quercetin and kaempferol are flavonoids widely present in fruits, vegetables, and medicinal plants. They have attracted much attention due to their antioxidant, anti-inflammatory, anticancer, antibacterial, and neuroprotective properties. As the guarantee cells in direct contact with germ cells, Sertoli cells exert the role of support, nutrition, and protection in spermatogenesis. In the current study, network pharmacology was used to explore the targets and signaling pathways of quercetin and kaempferol in treating spermatogenic disorders. In vitro experiments were integrated to verify the results of quercetin and kaempferol against heat stress-induced Sertoli cell injury. The online platform was used to analyze the GO biological pathway and KEGG pathway. The results of the network pharmacology showed that quercetin and kaempferol intervention in spermatogenesis disorders were mostly targeting the oxidative response to oxidative stress, the ROS metabolic process and the NFκB pathway. The results of the cell experiment showed that Quercetin and kaempferol can prevent the decline of cell viability induced by heat stress, reduce the expression levels of HSP70 and ROS in Sertoli cells, reduce p-NF-κB-p65 and p-IκB levels, up-regulate the expression of occludin, vimentin and F-actin in Sertoli cells, and protect cell structure. Our research is the first to demonstrate that quercetin and kaempferol may exert effects in resisting the injury of cell viability and structure under heat stress.

Identification of Chlamydia trachomatis genotypes in Mexican men with infertile women as sexual partners

BACKGROUND

Chlamydia trachomatis is considered a public health problem due to the high prevalence in sexually active women and men. The distribution of genital Chlamydia genotypes among Mexican men is unknown.

OBJECTIVE

To assess the prevalence of Chlamydia genotypes in men with infertile women as sexual partners.

METHODS

A total of 659 urine samples were collected from men whose sexual partners were infertile women; the identifying Chlamydia infection was by means of a real-time nucleic acid amplification test (qPCR). OmpA gene PCR-RFLP and sequencing were used to confirm the genotypes of C. trachomatis. The association of genotypes with age, spermatic parameters and gynecological data of sexual partners was further analyzed.

RESULTS

Forty-nine urine samples were positive infection (7.4%). The Chlamydia infection was significantly associated with teratozoospermia, azoospermia, hypospermia, and oligozoospermia. Five genotypes (F 51%; 12.2% to D; 12.2% to E; 6.1% to L2 and 4.1% Ia) were correctly identified. None genotypes identified in this comparative study were positively associated with changes in some of the spermatic values because all of them typically produce some considerable damage to these cells.

CONCLUSIONS

The F genotype was the most frequent genotype identified in infertile men from Mexico City and all genotypes play an important role in the seminal alteration of Mexican men whose female partners are infertile.

Better In Vitro Tools for Exploring Chlamydia trachomatis Pathogenesis

Currently, Chlamydia trachomatis still possesses a significant impact on public health, with more than 130 million new cases each year, alongside a high prevalence of asymptomatic infections (approximately 80% in women and 50% in men). C. trachomatis infection involves a wide range of different cell types, from cervical epithelial cells, testicular Sertoli cells to Synovial cells, leading to a broad spectrum of pathologies of varying severity both in women and in men. Several two-dimensional in vitro cellular models have been employed for investigating C. trachomatis host–cell interaction, although they present several limitations, such as the inability to mimic the complex and dynamically changing structure of in vivo human host-tissues. Here, we present a brief overview of the most cutting-edge three-dimensional cell-culture models that mimic the pathophysiology of in vivo human tissues and organs for better translating experimental findings into a clinical setting. Future perspectives in the field of C. trachomatis research are also provided.

Sertoli Cell Immune Regulation: A Double-Edged Sword

The testis must create and maintain an immune privileged environment to protect maturing germ cells from autoimmune destruction. The establishment of this protective environment is due, at least in part, to Sertoli cells. Sertoli cells line the seminiferous tubules and form the blood-testis barrier (BTB), a barrier between advanced germ cells and the immune system. The BTB compartmentalizes the germ cells and facilitates the appropriate microenvironment necessary for spermatogenesis. Further, Sertoli cells modulate innate and adaptive immune processes through production of immunoregulatory compounds. Sertoli cells, when transplanted ectopically (outside the testis), can also protect transplanted tissue from the recipient’s immune system and reduce immune complications in autoimmune diseases primarily by immune regulation. These properties make Sertoli cells an attractive candidate for inflammatory disease treatments and cell-based therapies. Conversely, the same properties that protect the germ cells also allow the testis to act as a reservoir site for infections. Interestingly, Sertoli cells also have the ability to mount an antimicrobial response, if necessary, as in the case of infections. This review aims to explore how Sertoli cells act as a double-edged sword to both protect germ cells from an autoimmune response and activate innate and adaptive immune responses to fight off infections.

In Vitro Modelling of Chlamydia trachomatis Infection in the Etiopathogenesis of Male Infertility and Reactive Arthritis

Chlamydia trachomatis is an obligate, intracellular bacterium responsible for a range of diseases of public health importance, since C. trachomatis infection is often asymptomatic and, hence, untreated, leading to chronic complications, including prostatitis, infertility, and reactive arthritis. The ample spectrum of diseases caused by C. trachomatis infection is reflected in its ability to infect and multiply within a wide range of different cell types. Cervical epithelial cells, to date, have been the most studied cellular infection model, highlighting the peculiar features of the host-cell inflammatory and immune responses to the infection. Herein, we provide the up-to-date evidence on the interaction between C. trachomatis and human prostate epithelial, Sertoli and synovial cells.

Potential IFNγ Modulation of Inflammasome Pathway in Chlamydia trachomatis Infected Synovial Cells

Following a Chlamydia&nbsp;trachomatis infection, the host immune response is characterized by its recognition via Toll-like and Nod-like Receptors, and the subsequent activation of interferon (IFN)-γ-mediated signaling pathways. Recently, the inflammasome-mediated host cell response has emerged to play a role in the physiopathology of C. trachomatis infection. Here we investigated, for the first time, the interaction of IFN-γ and inflammasome in an in vitro model of C. trachomatis-infected primary human synovial cells. Chlamydial replication as well as the expression of caspase-1, IL-1β, as well as IL-18 and IL-6, were assayed. Our results demonstrated the inhibitory activity of IFN-γ by interfering with the inflammasome network through the downregulation of caspase-1 mRNA expression. In addition, the ability of C. trachomatis to hinder the inflammasome pathway favoring its intracellular survival within synovial cells, was observed. Overall, our data suggest a potential mechanism of immune evasion by C. trachomatis in synovial cells, that may be contested by IFN-γ.

Long-term consequences of sexually transmitted infections on men's sexual function: A systematic review

Objective: To systematically review the available literature on the long-term effects of sexually transmitted diseases (STIs) on male reproductive functions.

Methods: A PubMed search was conducted on 3 January 2021, and as a result, 952 articles were retrieved. Exclusion of irrelevant articles resulted in 36 articles, dating from 1998 to 2020, which were analysed.

Results: Only 52.8% of these articles described original research, while the rest were reviews. The majority (26) of the articles dealt with bacterial infections, of which 20 described Chlamydia trachomatis. There were 11 articles that described research on viruses, with five on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The analysis of the articles showed further that not much new knowledge on the long-term effects on male reproductive functions has been added. The existing knowledge that ascending infections can cause epididymo-orchitis, prostatitis or urethritis was confirmed. Due to epithelial inflammatory responses these infections can result in scarring with resulting infertility due to obstruction. These effects were described for Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium or Treponema pallidum, as well as for the Zika and SARS-CoV-2 viruses. Even trichomoniasis can lead to long-term compromised male fertility if not treated.

Conclusion: In conclusion, problem awareness needs to be raised and more research on this important topic needs to be conducted.

In-cell western assay as a high-throughput approach for Chlamydia trachomatis quantification and susceptibility testing to antimicrobials

Chlamydia trachomatis, the leading cause of bacterial sexually transmitted diseases in developed countries, with around 127 million new cases per year, is mainly responsible for urethritis and cervicitis in women, and urethritis and epididymitis in men. Most C. trachomatis infections remain asymptomatic (>50%) and, hence, untreated, leading to severe reproductive complications in both women and men, like infertility. Therefore, the detection of C. trachomatis as well as the antimicrobial susceptibility testing becomes a priority, and, along the years, several methods have been recommended, like cell culture and direct immunofluorescence (DFA) on cell cultures. Herein, we described the application of In-Cell Western assay (ICW) via Odyssey CLx as a fast, more accessible, and high-throughput platform for the quantification of C. trachomatis and the screening of anti-chlamydial drugs. As a first step, we set up a standard curve by infecting cell monolayers with 2-fold serial dilutions of C. trachomatis Elementary Body (EB) suspension. Then, different unknown C. trachomatis EB suspensions were quantified and the chlamydial susceptibility testing to erythromycin was performed, using the DFA as comparison. Our results showed a very high concordance between these two assays, as evidenced by the enumeration of chlamydial IFUs as well as the determination of erythromycin Minimum Inhibitory Concentration (MIC). In conclusion, the ICW assay may be a promising candidate as an accurate and accessible methodology for C. trachomatis antimicrobial susceptibility testing.

Therapeutic application of Sertoli cells for treatment of various diseases

Sertoli cells (SCs) are immune privileged cells found in the testis that function to immunologically protect maturing germ cells from immune destruction. This immune protection is due to the blood-testis-barrier, which prevents infiltration of cytotoxic immune cells and antibodies, and SC production of immunomodulatory factors, that favor a tolerogenic environment. The ability of SCs to create an immune privileged environment has led to the exploration of their potential use in the treatment of various diseases. SCs have been utilized to create a tolerogenic ectopic microenvironment, to protect co-grafted cells, and to deliver therapeutic proteins through gene therapy. To date, numerous studies have reported the potential use of SCs for the treatment of diabetes, neurodegenerative disorders, and restoration of spermatogenesis. Additionally, SCs have been investigated as a delivery vehicle for therapeutic products to treat other diseases like Laron syndrome, muscular dystrophy, and infections. This review will provide an overview of these therapeutic applications.

Identification of Chlamydia trachomatis genotypes in Mexican men with infertile women as sexual partners

BACKGROUND

Chlamydia trachomatis is considered a public health problem due to the high prevalence in sexually active women and men. The distribution of genital Chlamydia genotypes among Mexican men is unknown.

OBJECTIVE

To assess the prevalence of Chlamydia genotypes in men with infertile women as sexual partners.

METHODS

A total of 659 urine samples were collected from men whose sexual partners were infertile women; the identifying Chlamydia infection was by means of a real-time nucleic acid amplification test (qPCR). OmpA gene PCR-RFLP and sequencing were used to confirm the genotypes of C. trachomatis. The association of genotypes with age, spermatic parameters and gynecological data of sexual partners was further analyzed.

RESULTS

Forty-nine urine samples were positive infection (7.4%). The Chlamydia infection was significantly associated with teratozoospermia, azoospermia, hypospermia, and oligozoospermia. Five genotypes (F 51%; 12.2% to D; 12.2% to E; 6.1% to L2 and 4.1% Ia) were correctly identified. None genotypes identified in this comparative study were positively associated with changes in some of the spermatic values because all of them typically produce some considerable damage to these cells.

CONCLUSIONS

The F genotype was the most frequent genotype identified in infertile men from Mexico City and all genotypes play an important role in the seminal alteration of Mexican men whose female partners are infertile.

Prevalence, concordance and reproductive sequelae after Chlamydia trachomatis infection in Mexican infertile couples

There are few concordance studies on the Chlamydia trachomatis (infection among infertile couples. The objective of this research was to know the prevalence, concordance and reproductive sequelae that couples may develop when both partners show a C. trachomatis infection. A cross-sectional study among 688 infertile couples using the C. trachomatis detection by real-time PCR was performed. The infertility causes were obtained from their medical records. The prevalence of infection was 8.68%. The percentage of concordance was 22.4% (13 couples). A presence of tubal occlusion was only associated with infected-discordant women [RR = 3.46, 95% CI (1.54-7.74), p < .003]. Seminal values were not associated with discordant men. The concordant couples showed association with the infection and tubal occlusion [RR = 3.19, 95% CI (1.09-9.34), p < .05], and oligozoospermia [RR = 12.17, 95% CI (4.29-34.54), p < .001], hypospermia [RR = 14.13, 95% CI (4.78-41.84), p < .001]. An alteration in semen quality was shown particularly in men whose sexual partners show a tubal pathology. This could occur due to a C. trachomatis infection in the testis, which underlines the need to carry out effective and efficient strategies to identify and treat all sexual partners exposed to C. trachomatis.

Interferon-γ Possesses Anti-Microbial and Immunomodulatory Activity on a Chlamydia Trachomatis Infection Model of Primary Human Synovial Fibroblasts

Chlamydia trachomatis, an obligate intracellular pathogen, is the most common cause of bacterial sexually transmitted diseases, and it is potentially responsible for severe chronic sequelae, such as reactive arthritis. To date, details of the mechanisms by which Chlamydiae induce innate antimicrobial pathways in synovial fibroblasts, are not well characterized; therefore, herein, we investigated the effects of interferon (IFN)α, IFNβ, and IFNγ on the infection, and replication phases of the C. trachomatis developmental cycle, as well as on the induction of pattern recognition receptors (PRRs) and IFN-related pathways. To do so, we set up an in vitro chlamydial-infection model of primary human synovial cells treated with IFNs before or after the infection. We then determined the number of chlamydial inclusion forming units and inclusion size, as well as the expression of toll like receptor (TLR)2, TLR3, TLR4, cyclic GMP-AMP synthase (cGAS), stimulator of IFN gene (STING), IRF9, ISG56, and GBP1. The main result of our study is the significant inhibition of C. trachomatis infection and replication in human synovial cells following the treatment with IFNγ, whereas IFN-I proved to be ineffective. Furthermore, IFNγ greatly upregulated all the PRRs and ISGs examined. In conclusion, IFNγ exhibited a potent anti-Chlamydia activity in human synovial cells as well as the ability to induce a strong increase of innate immune pathways.