Characterization of genital chlamydia trachomatis infection among women attending infertility and gynecology clinics in Hunan, China.

BACKGROUND: Genital infection with Chlamydia trachomatis (C. trachomatis) is a major public health issue worldwide. It can lead to cervicitis, urethritis, and infertility. This study was conducted to determine the characteristics of genital C. trachomatis infection among women attending to the infertility and gynecology clinics. METHODS: Endocervical swabs were collected from 8,221 women for C. trachomatis nucleotide screening and genotyping, while serum samples were collected for C. trachomatis pgp3 antibody determination using luciferase immunosorbent assays. RESULTS: High C. trachomatis DNA prevalence (3.76%) and seroprevalence (47.46%) rates were found, with genotype E (27.5%) being the most prevalent. C. trachomatis omp1 sense mutation was associated with cervical intraepithelial neoplasia (CIN) (odds ratio [OR] = 6.033, 95% confidence interval [CI] = 1.219-39.185, p = 0.045). No significant differences in C. trachomatis seroprevalence rates were observed between women with detectable C. trachomatis DNA in the infertility and routine physical examination groups (86.67% vs. 95%, p > 0.05); however, among women with negative C. trachomatis DNA, the former group had a markedly higher seroprevalence than the latter group (56.74% vs. 20.17%, p < 0.001). C. trachomatis DNA, but not pgp3 antibody, was significantly associated with CIN (OR = 4.087, 95% CI = 2.284-7.315, p < 0.001). CONCLUSION: Our results revealed a high prevalence, particularly seroprevalence, of C. trachomatis among women with infertility. Furthermore, we found an association between C. trachomatis omp1 sense mutations and CIN. Therefore, C. trachomatis serves as a risk factor for CIN.

The role of tryptophan in Chlamydia trachomatis persistence.

Chlamydia trachomatis (C. trachomatis) is the most common etiological agent of bacterial sexually transmitted infections (STIs) and a worldwide public health issue. The natural course with C. trachomatis infection varies widely between individuals. Some infections clear spontaneously, others can last for several months or some individuals can become reinfected, leading to severe pathological damage. Importantly, the underlying mechanisms of C. trachomatis infection are not fully understood. C. trachomatis has the ability to adapt to immune response and persist within host epithelial cells. Indoleamine-2,3-dioxygenase (IDO) induced by interferon-gamma (IFN-γ) degrades the intracellular tryptophan pool, to which C. trachomatis can respond by converting to a non-replicating but viable state. C. trachomatis expresses and encodes for the tryptophan synthase (TS) genes (trpA and trpB) and tryptophan repressor gene (trpR). Multiple genes interact to regulate tryptophan synthesis from exogenous indole, and persistent C. trachomatis can recover its infectivity by converting indole into tryptophan. In this review, we discuss the characteristics of chlamydial infections, biosynthesis and regulation of tryptophan, the relationship between tryptophan and C. trachomatis, and finally, the links between the tryptophan/IFN-γ axis and C. trachomatis persistence.

Development of an immune-related prognostic index associated with osteosarcoma.

Tumor immunity is closely associated with the prognosis of tumors, including osteosarcoma (OS). The aim of the present study was to construct an immune-related prognostic index (PI) to predict the prognosis of OS. Herein, OS expression data were sourced from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database. We divided the OS patients into nonmetastatic and metastatic groups, allowing differentially immune-related genes (DIRGs) to be selected. After DIRGs were further investigated by enrichment analysis, four keys prognostic IRGs (CD79A, CSF3R, MTNR1B and NPPC) were identified using a Cox proportional hazards model. Then, an immune-related prognostic index was constructed. Finally, gene set enrichment analysis (GSEA) was employed to further explore the underlying mechanisms. The difference in tumor-infiltrating immune cell (TIIC) abundance was also discussed. In our study, eight upregulated genes and 30 downregulated genes were identified. Several Gene Ontology (GO) terms and the most significantly enriched KEGG pathways were immune-associated functions and pathways. Four genes, including CD79A, CSF3R, MTNR1B and NPPC, were used to establish a risk assessment model for evaluating OS prognosis. GSEA revealed that the risk score was related to cytokine receptor interaction and to the chemokine and B cell receptor signaling pathways. Furthermore, high risk markedly related to the infiltration of several immune cell types, including M2 macrophages, naïve CD4 T cells, and CD8 T cells. In sum, we developed a survival model for OS. The underlying molecular mechanisms of the high-risk group may affect immune-related biological processes and TIICs.Abbreviations TARGET: Therapeutically Applicable Research To Generate Effective Treatments; PI: Prognostic index; OS: Osteosarcoma; DIRGs: Differentially immune-related genes; GSEA: Gene set enrichment analysis; TIIC: Tumor-infiltrating immune cell.