T cell phenotypes in women with Chlamydia trachomatis infection and influence of treatment on phenotype distributions

Chlamydia trachomatis and the HLA involvement in the development of infection and disease: a narrative review

Introduction

CT (Chlamydia trachomatis) is among the most common pathogens leading to sexually transmitted diseases. Considering the uncertain mechanism by which HLA polymorphisms influence the CT infection, reinfection, comorbidities or evolution and because there is no consensus regarding the alleles involved in the pathogenesis of the infection, we considered necessary to perform a review to summarize the current knowledge of HLA related to CT.

Methods

Pubmed was researched using key terms. Out of the 198 results found, we analyzed articles of all types which describe how the MHC, through HLA alleles, participates in the different stages of CT penetration in the body, including studies about cells or other molecules involved in the process.

Results

Almost 40% of the variation in the clinical course of CT infection depends on host genetic factors. There are haplotypes that influence the infection susceptibility/resistance, haplotypes that are involved in the recurrence of the infection, haplotypes that are related to tubal infertility, pelvic inflammatory disease development or trachoma. Antibody to Chsp60 (influenced by MHC genes) has been observed to correlate with late tissue-damaging sequelae. Toll-like receptors were found to increase the susceptibility to CT. The association of HLA-B27 creates susceptibility of reactive arthritis in the organisms infected by CT, but does not influence the carriage of CT.

Conclusion

We identified HLA haplotypes belonging both to MHC class l and ll, which influence different stages of CT infection. Genetic risk factors still need research, especially on Caucasians. Studies are moving towards designing a safe and effective vaccine.

Maraviroc, celastrol and azelastine alter Chlamydia trachomatis development in HeLa cells

Introduction . Chlamydia trachomatis (Ct) is an obligate intracellular bacterium, causing a range of diseases in humans. Interactions between chlamydiae and antibiotics have been extensively studied in the past.Hypothesis/Gap statement: Chlamydial interactions with non-antibiotic drugs have received less attention and warrant further investigations. We hypothesized that selected cytokine inhibitors would alter Ct growth characteristics in HeLa cells.Aim. To investigate potential interactions between selected cytokine inhibitors and Ct development in vitro.Methodology. The CCR5 receptor antagonist maraviroc (Mara; clinically used as HIV treatment), the triterpenoid celastrol (Cel; used in traditional Chinese medicine) and the histamine H1 receptor antagonist azelastine (Az; clinically used to treat allergic rhinitis and conjunctivitis) were used in a genital in vitro model of Ct serovar E infecting human adenocarcinoma cells (HeLa).Results. Initial analyses revealed no cytotoxicity of Mara up to 20 µM, Cel up to 1 µM and Az up to 20 µM. Mara exposure (1, 5, 10 and 20 µM) elicited a reduction of chlamydial inclusion numbers, while 10 µM reduced chlamydial infectivity. Cel 1 µM, as well as 10 and 20 µM Az, reduced chlamydial inclusion size, number and infectivity. Morphological immunofluorescence and ultrastructural analysis indicated that exposure to 20 µM Az disrupted chlamydial inclusion structure. Immunofluorescence evaluation of Cel-incubated inclusions showed reduced inclusion sizes whilst Mara incubation had no effect on inclusion morphology. Recovery assays demonstrated incomplete recovery of chlamydial infectivity and formation of structures resembling typical chlamydial inclusions upon Az removal.Conclusion. These observations indicate that distinct mechanisms might be involved in potential interactions of the drugs evaluated herein and highlight the need for continued investigation of the interaction of commonly used drugs with Chlamydia and its host.