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: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.
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: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: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 plasmid’s role in chlamydial pathogenesis and the development of novel antigenically multivalent live-attenuated chlamydial vaccines.
Project description:Chlamydia trachomatis is the causative agent of sexually transmitted disease with the highest prevalence in the world today. Although, sensitive to antibiotic treatment, Ctr is also a major cause of infertility due to significant cell damage caused to the genital tract of affected women. Occlusion of Fallopian tubes is a frequent consequence of advanced ascending Ctr infection. So far the mechanisms of Ctr caused pathogensis are widely unclear. Here we show, by using an ex vivo infection model of human Fallopian tubes that Ctr causes changes in epithelial homeostasis within 2 days of inoculation, by disrupting cell adhesion and increasing cell proliferation. We demonstrate by imaging and expression analysis that tissue response to invading pathogen has also a paracrine component. We identify Wnt signalling activation as one of the hallmarks of Ctr infection which transmits effects of the infection beyond inclusion containing cells. Mechanisms of phenotypic changes involve up regulation of Epcam and Olfactomedin 4, biomarkers and regulators of cell adhesion and cell differentiation. Our findings bring focus to the pleiotropic effects of Ctr infection within epithelium and could be provide the basis for better understanding the pathological sequels in vivo. Microarray experiments were performed as dual-color hybridizations. To compensate for dye-specific effects, an independent dye-reversal color-swap was applied. Quality control and quantification of total RNA amount was assessed using an Agilent 2100 bioanalyzer (Agilent Technologies) and a NanoDrop 1000 spectrophotometer (Kisker).
Project description:Chlamydia trachomatis is an obligate intracellular pathogen that causes trachoma and sextually transmitted disease in human. During early stage of infection, Chlamydia secreted bacterial effector proteins into host cell cytoplasm to help its entry and estabilishment of early replicated niche. We identified a Chlamydia mutant that lack an early Effector. To address the function of this effector, we infected A2EN cells with this mutant (G1V) and its complemented counterpart (G1TEPP) to see what host gene transcriptions are affected by this effector. A2EN cells were mock infected, or infected with a Chlamydia mutant or its complemented counterpart for 4 hour post infection.