Project description:Introduction Chlamydia trachomatis (C. trachomatis) is a Gram-negative bacterium and a common human pathogen. The World Health Organization (WHO) estimates that over 130 million people are infected with C. trachomatis globally each year and with increasing incidence. C. trachomatis causes long-lasting and recurrent infections that over time induce severe tissue damage in the female genital tract that can lead to ectopic pregnancy and infertility. Thus, the human immune system fails to control and eradicate C. trachomatis during primary infection and fails to develop protective immunity against secondary infections. In vivo infection models, using complement knock out mice, suggest that the complement system is critically involved in both anti-chlamydial immunity and infection-induced pathology. To increase our understanding of complement-mediated immunity against C. trachomatis we analyzed global complement deposition on serum-incubated C. trachomatis by mass spectrometry. Methods Purified C. trachomatis was incubated in seronegative normal human serum (NHS) or heat-inactivated normal human serum (HI-NHS) for 30 min, thoroughly washed, and processed for mass spectrometry. All samples were lysed, reduced and alkylated and digested with trypsin. Some samples were chemically modified to acetylate free amino groups (N-terminal and lysine amino groups) before trypsin digestion. Peptides were analyzed on a UltimateTM 3500 RSLCnano coupled to a Q Exactive HF-X mass spectrometer. Raw data files were searched against the Uniprot human reference proteome using MaxQuant. Results We demonstrate that C. trachomatis elicits potent complement activation demonstrated by deposition of both early and late complement factors together with several complement regulators. We further demonstrate proteolytically processing of complement C3b to “inactive” C3 cleavage fragments. Conclusion We demonstrate the deposition of several novel complement-associated proteins and -cleavage fragments on the surface of C. trachomatis.
Project description:To determine the role that GrgA plays in chlamydial physiology, we constructed a Chlamydia trachomatis mutant that we term L/cgad-peig, in which the chromosomal grgA (ctl0766 or ct504) has been disrupted by Targetron mutagenesis, and the plasmid carries an inducible grgA under the control of anhydrotetracycline (ATC). RNA-Seq analysis was performed for L2/cgad-peig grown with and without ATC.
Project description:The aim of this study was to perform a microarray analysis of the response pattern of EEC from both large and small bowel to infection in vitro, using Chlamydia trachomatis infection as a model. Two human EEC lines: LCC-18, derived from a neuroendocrine colonic tumour, and CNDT-2, derived from a small intestinal carcinoid, were infected with C. trachomatis serovar LGV II strain 434 (ATCC VR-902B). Penicillin G was used to induce persistent infection. Gene expression levels in infected and persistently infected EEC cells were investigated by microarray analysis
Project description:The aim of this study was to perform a microarray analysis of the response pattern of EEC from both large and small bowel to infection in vitro, using Chlamydia trachomatis infection as a model.
Project description:Chlamydia trachomatis is the most common sexually transmitted infection and the bacterial agent of trachoma globally. C. trachomatis undergoes a biphasic developmental cycle involving an infectious elementary body and a replicative reticulate body. Little is currently known about the expression of host cell mRNAs, lncRNAs, and miRNAs at different stages of C. trachomatis development. Here, we performed RNA-seq and miR-seq on HeLa cells infected with C. trachomatis serovar E at 20 hpi and 44 hpi with or without IFN-γ treatment. Our study identified and validated differentially expressed host cell mRNAs, lncRNAs, and miRNAs during infection. Infection at 20 hpi showed the most differential upregulation of both coding and non-coding genes while infection at 44 hpi in the presence of IFN-γ resulted in a dramatic downregulation of a large proportion of genes. Using RT-qPCR, we validated the top 5 stage-specific upregulated mRNAs and miRNAs. One of the commonly expressed miRNAs at all three stages, miR-193b-5p, showed significant expression in clinical serum samples of C. trachomatis-infected patients as compared to sera from healthy controls and HIV-1-infected patients. Furthermore, at 20 hpi we observed significant upregulation of antigen processing and presentation, and T helper cell differentiation pathways whereas T cell receptor, mTOR, and Rap1 pathways were modulated at 44 hpi. Treatment with IFN-γ at 44 hpi showed the regulation of cytokine-cytokine receptor interaction, FoxO signaling, and Ras signaling pathways. Our study documents a role for the stage-specific transcriptional manipulation of the host cell genome and important signaling pathways that are necessary for the survival of pathogen and could serve as potential biomarkers in the diagnosis and management of the disease.
Project description:Chlamydia trachomatis causes chronic inflammatory diseases of the eye and genital tract of global medical importance. The chlamydial plasmid plays an important role in the pathophysiology of these diseases as plasmid-deficient organisms are highly attenuated. The plasmid encodes both noncoding RNAs and eight conserved ORFs of undefined function. To understand plasmid gene function we generated plasmid shuttle vectors with deletions in each of the eight ORFs. The individual deletion mutants were used to transform chlamydiae and the transformants were characterized in terms of plasmid biology and transcriptional profiling. We show that pgp1-2, -6 and -8 are essential for plasmid maintenance while the other ORFs can be deleted and the plasmid stably maintained. We further show that a pgp4 knockout mutant exhibits an in vitro phenotype similar to its isogenic plasmid-less strain in terms of abnormal inclusion morphology and lack of glycogen accumulation. Microarray and qRT-PCR analysis revealed that pgp4 is involved in transcriptional regulation of multiple chromosomal genes; including the glycogen synthase gene glgA. Based on our results, we propose that Pgp1 is a plasmid replicative helicase, Pgp2 is a plasmid replication protein, Pgp4 is a transcriptional regulator of virulence associated chromosomal genes, and Pgp6-8 are plasmid partitioning proteins. These findings have important implications for understanding the plasmidM-bM-^@M-^Ys role in chlamydial pathogenesis and the development of novel antigenically multivalent live-attenuated chlamydial vaccines. Chlamydia trachomatis wild type vs. two deletion mutants, and mock
Project description:Chlamydia trachomatis is an obligate intracellular Gram-negative bacterium that frequently causes an asymptomatic genital tract infection, gradually cleared by host immunity Transcriptome profiles were made of endometrial tissue from women with or without genital tract C. trachomatis infection, to characterize host responses to infection. Profiles showed that infection polarized host defense toward Type 2 immune responses. Responses included fibrin deposition, enhanced wound repair, and tissue remodeling. Trans-cervical endometrial biopsy specimens were collected from 10 women with no identified upper or lower genital tract infection and 12 women with C. trachomatis endometrial infection.
Project description:In this project we examined the in-vitro effect of female sex hormones (estradiol and progesterone at average physiological concentrations) during a infection mediated by Chlamydia trachomatis serovar D, on the gene expression of human endometrial cell line ECC-1 The effects of the female sex hormones progesterone and oestradiol while infected by Chlamydia trachomatis were examined at two timepoints.