New concepts in Chlamydia induced inflammasome responses

Autophagy: the misty lands of Chlamydia trachomatis infection

Chlamydia are Gram-negative, obligate intracellular bacterial pathogens that infect eukaryotic cells and reside within a host-derived vacuole known as the inclusion. To facilitate intracellular replication, these bacteria must engage in host-pathogen interactions to obtain nutrients and membranes required for the growth of the inclusion, thereby sustaining prolonged bacterial colonization. Autophagy is a highly conserved process that delivers cytoplasmic substrates to the lysosome for degradation. Pathogens have developed strategies to manipulate and/or exploit autophagy to promote their replication and persistence. This review delineates recent advances in elucidating the interplay between Chlamydia trachomatis infection and autophagy in recent years, emphasizing the intricate strategies employed by both the Chlamydia pathogens and host cells. Gaining a deeper understanding of these interactions could unveil novel strategies for the prevention and treatment of Chlamydia infection.

Association Between Self-Reported Infections and Seropositivity Among Pregnant Women With Gastroschisis: A Case Control Study, With Emphasis on Chlamydia trachomatis

BACKGROUND

Gastroschisis is a birth defect with the greatest risk among women <20 years of age.

METHODS

Pregnant women attending the University of Utah's Maternal-Fetal Medicine Diagnostic Center between 2011 and 2017 for either their routine diagnostic ultrasound or referral were recruited (cases: pregnant women with fetal gastroschisis, n = 53 participated/57, 93%; controls: pregnant women without fetal abnormalities, n = 102 participated/120, 85%). A clinic coordinator consented and interviewed women and obtained a blood sample and prenatal medical records. We evaluated self-reported maternal characteristics, risk factors, and infections. To assess pathogen seropositivity we used Serimmune's Serum Epitope Repertoire Analysis validated 35 pathogen panels and Chlamydia trachomatis and compared seropositivity to self-report and prenatal medical record screening to assess sensitivity.

RESULTS

Cases were more likely to report a younger age at sexual debut (p = <0.01), more sexual partners (p = 0.02), being unmarried (p < 0.01), changing partners between pregnancies (p = <0.01), smoking cigarettes (<0.01), and a recent sexually transmitted infection (STI) (p = 0.02). No differences were observed for self-report of illicit drug use or periconceptional urinary tract infections. Cases had a higher seropositivity for cytomegalovirus (p = 0.01). No differences were observed for herpes simplex I, II, or Epstein-Barr. Though based on small numbers, C. trachomatis seropositivity was highest in cases (17%) compared to controls (8.8%) with the highest proportion observed in case women <20 years of age (cases 33%; controls 0%). Any STI (self-report or seropositivity) was also highest among cases <20 years of age (cases 47%; controls 0%). Among C. trachomatis seropositive women, self-report and prenatal medical record sensitivity was 27.8% and 3%, respectively.

CONCLUSIONS

Cases were more likely to engage in behaviors that can increase their risk of exposure to sexually transmitted pathogens. Case women <20 years of age had the highest proportion of C. trachomatis seropositivity and any STI. Prenatal medical records and self-report were inadequate to identify a recent chlamydial infection whereas, the SERA assay is a novel approach for evaluating subclinical infections that may impact the developing embryo.

In Silico Identification and Validation of Pyroptosis-Related Genes in Chlamydia Respiratory Infection

The incidence of Chlamydia trachomatis respiratory infection is increasing, and its pathogenesis is still unclear. Pyroptosis, as a mode of inflammatory cell death, plays a vital role in the occurrence and development of Chlamydia trachomatis respiratory infection. In this study, the potential pyroptosis-related genes involved in Chlamydia trachomatis respiratory infection were identified by constructing a mouse model of C. muridarum infection combined with bioinformatics analysis. Through in-depth analysis of the RNA sequencing data, 13 differentially expressed pyroptosis-related genes were screened, including 1 downregulated gene and 12 upregulated genes. Gene ontology (GO) analysis showed that these genes mainly regulate inflammatory responses and produce IL-1β. Protein-protein interaction network analysis identified eight hub genes of interest: Tnf, Tlr2, Il1b, Nlrp3, Tlr9, Mefv, Zbp1 and Tnfaip3. Through quantitative real-time PCR (qPCR) analysis, we found that the expression of these genes in the lungs of C. muridarum-infected mice was significantly reduced, consistent with the bioinformatics results. At the same time, we detected elevated levels of caspase-3, gasdermin D and gasdermin E proteins in the lungs of C. muridarum-infected mice, demonstrating that Chlamydia trachomatis infection does induce pyroptosis. We then predicted nine miRNAs targeting these hub genes and constructed a key competitive endogenous RNA (ceRNA) network. In summary, we identified six key pyroptosis-related genes involved in Chlamydia trachomatis respiratory infection and constructed a ceRNA network associated with these genes. These findings will improve understanding of the molecular mechanisms underlying pyroptosis in Chlamydia trachomatis respiratory infections.

A systematic review of toll-like receptors in endometriosis

INTRODUCTION

The pathogen-associated molecular patterns and the danger-associated molecular patterns are possibly responsible for the activation of the inflammatory process in endometriosis through the activation of toll-like receptors (TLRs).

OBJECTIVE

The aim of this systematic review was to critically analyze the findings of published articles on TLRs in endometriosis.

METHODS

The keywords used were "endometriosis" and "toll-like" and the search was performed in Pubmed, Scielo and Lilacs databases. This study followed the PRISMA guidelines and the risk of bias of articles was conducted by Newcastle-Ottawa scale (NOS).

RESULTS

Overall, the studies analyzed in this review point toward an increased expression of TLRs two, four and nine in women with endometriosis. Among all TLRs, TLR4 was the most cited receptor.

CONCLUSION

Despite the evidence demonstrating elevated TLR levels in endometriosis, the relationship with the disease is still unclear and needs to be clarified in further studies about innate immune response.

Microbiome Profile of Deep Endometriosis Patients: Comparison of Vaginal Fluid, Endometrium and Lesion

This work aimed to identify and compare the bacterial patterns present in endometriotic lesions, eutopic endometrium and vaginal fluid from endometriosis patients with those found in the vaginal fluid and eutopic endometrium of control patients. Vaginal fluid, eutopic endometrium and endometriotic lesions were collected. DNA was extracted and the samples were analyzed to identify microbiome by high-throughput DNA sequencing of the 16S rRNA marker gene. Amplicon sequencing from vaginal fluid, eutopic endometrium and endometriotic lesion resulted in similar profiles of microorganisms, composed most abundantly by the genus Lactobacillus, Gardnerella, Streptococcus and Prevotella. No significant differences were found in the diversity analysis of microbiome profiles between control and endometriotic patients; however deep endometriotic lesions seems to present different bacterial composition, less predominant of Lactobacillus and with more abundant Alishewanella, Enterococcus and Pseudomonas.

Clear Victory for Chlamydia: The Subversion of Host Innate Immunity

As obligate intracellular bacterial pathogens, members of the Chlamydia genera are the pivotal triggers for a wide range of infections, which can lead to blinding trachoma, pelvic inflammation, and respiratory diseases. Because of their restricted parasitism inside eukaryotic cells, the pathogens have to develop multiple strategies for adaptation with the hostile intracellular environment—intrinsically present in all host cells—to survive. The strategies that are brought into play at different stages of chlamydial development mainly involve interfering with diverse innate immune responses, such as innate immune recognition, inflammation, apoptosis, autophagy, as well as the manipulation of innate immune cells to serve as potential niches for chlamydial replication. This review will focus on the innate immune responses against chlamydial infection, highlighting the underlying molecular mechanisms used by the Chlamydia spp. to counteract host innate immune defenses. Insights into these subtle pathogenic mechanisms not only provide a rationale for the augmentation of immune responses against chlamydial infection but also open avenues for further investigation of the molecular mechanisms driving the survival of these clinically important pathogens in host innate immunity.