Chlamydia Trachomatis Protein Research Articles

Exploring Bioinformatics-Driven Approaches for Enhanced Diagnosis of Chlamydia trachomatis Infections: Analysis of Target Proteins

Chlamydia trachomatis, a major cause of sexually transmitted infection, poses a range of symptoms including genital discharge, pain during urination, and abdominal pains in women, and can lead to serious health complications such as pelvic inflammatory diseases, infertility, and ectopic pregnancy if left untreated. The need for rapid and accurate detection is imperative so prompt treatment and control of the disease can be achieved. This study conducted an immunoinformatic analysis of proteins of Chlamydia trachomatis (incA, hctA, ompA, omcB, rpoB, and HSP60) for the development of a lateral flow assay-based diagnostic test. Detailed in silico evaluation of selected proteins from publicly available genomic databases was conducted to evaluate their suitability as targets for lateral flow assay-based detection. The series of tests included antigenicity, toxicity, solubility, physicochemical characteristics and molecular docking of the derived constructs, and protein sequence. Chimeric construct was derived from the prediction of linear B cell epitopes, helper T cell major histocompatibility complex II binding epitopes, and IL4 and IL10 inducers using bioinformatic tools at standard thresholds. With a Ramachandra’s score of 95.4% and Z-score of -5.1, results indicate that the construct efficacy is high in potential to provide extreme specificity and sensitivity for the detection of Chlamydia trachomatis in clinical samples as compared to traditional culture-based methods using nucleic acid amplification, hereby providing a quicker and more accurate diagnostic tool for Chlamydia trachomatis infection. Findings offer valuable data for the development of a rapid and reliable diagnostic point-of-care test kit for Chlamydia trachomatis that allows for drastic reduction in clinical wait time and treatment.

Exploring Bioinformatics-Driven Approaches for Enhanced Diagnosis of Chlamydia trachomatis Infections: Analysis of Target Proteins

Chlamydia trachomatis, a major cause of sexually transmitted infection, poses a range of symptoms including genital discharge, pain during urination, and abdominal pains in women, and can lead to serious health complications such as pelvic inflammatory diseases, infertility, and ectopic pregnancy if left untreated. The need for rapid and accurate detection is imperative so prompt treatment and control of the disease can be achieved. This study conducted an immunoinformatic analysis of proteins of Chlamydia trachomatis (incA, hctA, ompA, omcB, rpoB, and HSP60) for the development of a lateral flow assay-based diagnostic test. Detailed in silico evaluation of selected proteins from publicly available genomic databases was conducted to evaluate their suitability as targets for lateral flow assay-based detection. The series of tests included antigenicity, toxicity, solubility, physicochemical characteristics and molecular docking of the derived constructs, and protein sequence. Chimeric construct was derived from the prediction of linear B cell epitopes, helper T cell major histocompatibility complex II binding epitopes, and IL4 and IL10 inducers using bioinformatic tools at standard thresholds. With a Ramachandra’s score of 95.4% and Z-score of -5.1, results indicate that the construct efficacy is high in potential to provide extreme specificity and sensitivity for the detection of Chlamydia trachomatis in clinical samples as compared to traditional culture-based methods using nucleic acid amplification, hereby providing a quicker and more accurate diagnostic tool for Chlamydia trachomatis infection. Findings offer valuable data for the development of a rapid and reliable diagnostic point-of-care test kit for Chlamydia trachomatis that allows for drastic reduction in clinical wait time and treatment.

Proteomic analysis of HeLa cells after stable transfection with the Chlamydia trachomatis CT143 gene

BackgroundThe CT143 protein of Chlamydia trachomatis (Ct) is a key immunodominant antigen and candidate type-III secretion substrate. Although CT143 expression has not been detected in the cytosol of infected cells, it is known to interfere with the physiological behavior of HeLa cells. This study aims to investigate how the CT143 protein affects the protein expression profile of HeLa cells, providing a basis for further research into Ct’s pathogenic mechanisms. MethodsWe constructed a stably transfected HeLa cell line, pCD513B-1-CT143-HeLa, and a control cell line, pCD513B-1-HeLa. Protein expression profiles of these cell lines were determined using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Differentially expressed proteins were identified, constructed into a database, and verified using parallel reaction monitoring (PRM). Bioinformatics software facilitated the preliminary analysis of the biological functions of these differential proteins. ResultsA total of 221 host proteins were differentially expressed, with 68 upregulated and 153 downregulated. These variations influence the regulation of peptidase activity and are crucial in biological processes such as cell secretion and protease activity. Significant changes were noted in protein processing, alcohol dehydrogenase activity, Aldo-Keto reductase activity, and peptidase regulator activity. Furthermore, alterations were observed in cellular components like the plasma membrane and cell periphery. Pathways involving the hematopoietic system, glycosaminoglycan degradation, retinol metabolism, and cytochrome P450-mediated exogenous drug metabolism were notably affected. Indirect interactions among differentially expressed proteins included three key nodal proteins: C3, IFIT3, and IFIT1. ConclusionThe successful construction of a host differential protein expression profile was achieved through stable transfection of HeLa cells with the CT143 gene. The differential proteins identified are implicated in regulating various biological processes such as intracellular signal transduction, cell secretion, protein processing, hydrolysis, and enzyme activity. These findings suggest that the CT143 protein may influence the host cell’s biological behavior by altering host protein expression, potentially hindering Ct growth and development.

Pgp3 protein of Chlamydia trachomatis inhibits apoptosis via HO-1 upregulation mediated by PI3K/Akt activation

As an obligate intracellular pathogen, Chlamydia trachomatis assumes various strategies to inhibit host cells apoptosis, thereby providing a suitable intracellular environment to ensure completion of the development cycle. In the current study, we revealed that Pgp3 protein, one of eight plasmid proteins of C. trachomatis that has been illustrated as the key virulence factor, increased HO-1 expression to suppress apoptosis, and downregulation of HO-1 with siRNA–HO–1 failed to exert anti-apoptosis activity of Pgp3 protein. Moreover, treatment of PI3K/Akt pathway inhibitor and Nrf2 inhibitor evidently reduced HO-1 expression and Nrf2 nuclear translocation was blocked by PI3K/Akt pathway inhibitor. These findings highlight that induction of HO-1 expression by Pgp3 protein is probably due to regulation of Nrf2 nuclear translocation activated by PI3K/Akt pathway, which provide clues on how C. trachomatis adjusts apoptosis.

Serum antibodies to surface proteins of Chlamydia trachomatis as candidate biomarkers of disease: results from the Baltimore Chlamydia Adolescent/Young Adult Reproductive Management (CHARM) cohort.

We previously observed that the nine-member family of autotransported polymorphic membrane proteins (Pmps) of Chlamydia trachomatis is variably expressed in cell culture. Additionally, C. trachomatis-infected patients display variable Pmp-specific serum antibody profiles indirectly suggesting expression of unique Pmp profiles is an adaptive response to host-specific stimuli during infection. Here, we propose that the host response to Pmps and other outer surface proteins may correlate with disease severity. This study tests this hypothesis using an ELISA that measures serum IgG antibodies specific for the nine C. trachomatis Pmp subtypes and four immunodominant antigens (MOMP, OmcB, Hsp60, ClpP) in 265 participants of the Chlamydia Adolescent/Young Adult Reproductive Management (CHARM) cohort. More C. trachomatis-infected females displayed high Pmp-specific antibody levels (cut-off Indexes) than males (35.9%-40.7% of females vs. 24.2%-30.0% of males), with statistical significance for PmpC, F and H (P < 0.05). Differences in Pmp-specific antibody profiles were not observed between C. trachomatis-infected females with a clinical diagnosis of pelvic inflammatory disease (PID) and those without. However, a statistically significant association between high levels of OmcB-specific antibody and a PID diagnosis (P< 0.05) was observed. Using antibody levels as an indirect measure of antigen expression, our results suggest that gender- and/or site-specific (cervix in females vs. urethra in males) stimuli may control pmp expression in infected patients. They also support the possible existence of immune biomarkers of chlamydial infection associated with disease and underline the need for high resolution screening in human serum.

Reduced Endometrial Ascension and Enhanced Reinfection Associated With Immunoglobulin G Antibodies to Specific Chlamydia trachomatis Proteins in Women at Risk for Chlamydia.

Previous research revealed antibodies targeting Chlamydia trachomatis elementary bodies was not associated with reduced endometrial or incident infection in C. trachomatis-exposed women. However, data on the role of C. trachomatis protein-specific antibodies in protection are limited. A whole-proteome C. trachomatis array screening serum pools from C. trachomatis-exposed women identified 121 immunoprevalent proteins. Individual serum samples were probed using a focused array. Immunoglobulin (Ig) G antibody frequencies and endometrial or incident infection relationships were examined using Wilcoxon rank sum test. The impact of the breadth and magnitude of protein-specific IgGs on ascension and incident infection were examined using multivariable stepwise logistic regression. Complementary RNA sequencing quantified C. trachomatis gene transcripts in cervical swab samples from infected women. IgG to pGP3 and CT_005 were associated with reduced endometrial infection; anti-CT_443, anti-CT_486, and anti-CT_123 were associated with increased incident infection. Increased breadth of protein recognition did not however predict protection from endometrial or incident infection. Messenger RNAs for immunoprevalent C. trachomatis proteins were highly abundant in the cervix. Protein-specific C. trachomatis antibodies are not sufficient to protect against ascending or incident infection. However, cervical C. trachomatis gene transcript abundance positively correlates with C. trachomatis protein immunogenicity. These abundant and broadly recognized antigens are viable vaccine candidates.

A PROSPECTIVE STUDY TO ANALYZE THE SPECIFICITY OF CHLAMYDIAL HEAT SHOCK PROTEIN (CHSP60) ANTIBODIES TO DIAGNOSE TUBAL INFERTILITY

The aim: To investigate the utility of testing for chlamydial heat shock protein 60 (CHSP60) antibodies in the diagnosis of tubal infertility. Materials and methods: All the collected samples were assayed for IgM and IgG antibodies to chlamydia trachomatis and chlamydial heat shock protein 60 (CHSP60) by using immunofluorescence and enzyme-linked immunosorbent assay (ELISA) techniques, respectively. Results: There were no substantial differences between antibodies to C. trachomatis in females with tubal infertility (67%) and non-tubal infertility (48%). However, women with tubal infertility (45%) have more anti-CHSP60 antibodies than non-tubal infertility (9%). Antibody screening for C. trachomatis has only (63%) sensitivity and (54%) specificity for detecting tubal infertility. On the other hand, the CHSP60 antibody testing has (44%) sensitivity and 92% specificity for diagnosing tubal infertility. A positive microimmunofluorescence (MIF) titer was observed in 12 of 18 (67%) females with the tubal problem, 31 of 64 (48%) with non-tubal infertility (P=0.3, OR=2.2, 95% CI=0.71 to 8.01). The CHSP60 antibodies were found in 8 of 18 (45%) females with tubal problem & 6 of 64 (9%) women with non-tubal infertility, power factor alpha α P=0.004, OR=9.3, 95% CI=2.1 to 43.2, power= 1.002 for n= 0.05). Incorporating CHSP60 and C. trachomatis antibodies testing gives an excellent positive probability proportion of 10 to diagnose C. trachomatis associated tubal infertility. Conclusions: CHSP60 antibody testing is a more specific evaluation than antibody testing for C. trachomatis for predicting chlamydia-associated tubal infertility. Using these tests at the first infertility examination may help the immediate diagnosis for non-interceptive tubal infertility.

The expression and purification of LpxA of Chlamydia trachomatis and preparation of its polyclonal antibody.

The purpose of this study is to purify the LpxA protein of Chlamydia trachomatis (Ct) and prepare the polyclonal antibody against LpxA protein, so as to lay a foundation for studying the function of LpxA protein. The LpxA gene was amplified by PCR. The expression plasmid pET28a-LpxA was constructed by using pET28a as the vector. The fusion protein containing 6 histidine tag was induced by IPTG and purified by Ni2+ chromatography gel. The purified His-LpxA protein was used as an immunogen to immunize New Zealand rabbits subcutaneously through the back to prepare polyclonal antibody. Immunoblotting was used to detect the reaction between the antibody and His-LpxA. The determination of polyclonal antibody titer was detected by ELISA. The relative molecular weight of His-LpxA was 32.8 kDa, and it could be expressed in Escherichia coli. The purity of the purified protein was about 95%. After immunizing New Zealand rabbits, the antiserum was able to recognize the recombinant His-LpxA protein with a titer greater than 1:10240. In this study, LpxA protein was successfully purified and antiserum was prepared, which provided an experimental basis for studying the function of LpxA protein.

A Chlamydia trachomatis Strain Expressing Ovalbumin Stimulates an Antigen-Specific CD4+ T Cell Response in Mice.

Antigen-specific CD4+ T cells against Chlamydia are crucial for driving bacterial clearance and mediating protection against reinfection. Although the Chlamydia trachomatis protein Cta1 has been identified to be a dominant murine CD4+ T cell antigen, its level of expression during the bacterial developmental cycle and precise localization within the host cell are unknown. Newly developed tools for Chlamydia genetic manipulation have allowed us to generate a C. trachomatis strain expressing a heterologous CD4+ T cell epitope from ovalbumin (OVA) consisting of OVA residues 323 to 339 (OVA323-339). By tagging proteins expressed in C. trachomatis with OVA323-339, we can begin to understand how protein expression, developmental regulation, and subcellular compartmentalization affect the potential of those proteins to serve as antigens. When OVA323-339 was expressed as a fusion with green fluorescent protein, we found that we were able to elicit an OT-II T cell response in an antigen-dependent manner, but surprisingly, these T cells were unable to reduce bacterial burden in mice. These data suggest that the subcellular localization of antigen, the level of antigen expression, or the timing of expression within the developmental cycle of Chlamydia may play a crucial role in eliciting a protective CD4+ T cell response.

Effects of cationic adjuvant formulation particle type, fluidity and immunomodulators on delivery and immunogenicity of saRNA

Self-amplifying RNA (saRNA) is well suited as a vaccine platform against chlamydia, as it is relatively affordable and scalable, has been shown to induce immunity against multivalent antigens, and can result in protein expression for up to 60 days. Cationic adjuvant formulations (CAFs) have been previously investigated as an adjuvant for protein subunit vaccines; here we optimize the CAFs for delivery of saRNA in vivo and observe the immunogenicity profile in the context of both cellular and humoral immunity against the major outer membrane protein (MOMP) of Chlamydia trachomatis. We tested both liposomal and emulsion based CAFs with solid and fluid phase lipids, with or without the TLR agonists R848 and 3M-052, for in vitro transfection efficiency and cytotoxicity. We then optimized the RNA/delivery system ratio for in vivo delivery using saRNA coding for firefly luciferase (fLuc) as a reporter protein in vivo. We observed that while the fluid phase liposome formulations showed the highest in vitro transfection efficiency, the fluid and solid phase liposomes had equivalent luciferase expression in vivo. Incorporation of R848 or 3M-052 into the formulation was not observed to affect the delivery efficiency of saRNA either in vitro or in vivo. MOMP-encoding saRNA complexed with CAFs resulted in both MOMP-specific cellular and humoral immunity, and while there was a slight enhancement of IFN-γ+ T-cell responses when R848 was incorporated into the formulation, the self-adjuvanting effects of RNA appeared to dominate the immune response. These studies establish that CAFs are efficient delivery vehicles for saRNA both for in vitro transfections and in vivo immunogenicity and generate cellular and humoral responses that are proportionate to protein expression.

Obtaining an ELISA test based on a recombinant protein of Chlamydia trachomatis.

Chlamydia trachomatis is considered as a public health problem due to its high prevalence and increased rates of gynecological disorders. The major outer membrane protein (MOMP) of this bacterium is the most abundant protein in its membrane and has been evaluated not only as a vaccine development candidate but also is used in many diagnostic tests. The MOMP weighs 69kDa and contains four variable segments (VS 1-4) separated by constant regions. Several research groups have developed recombinant single-variable segments of MOMP expressed in Escherichia coli cytoplasm. But, all variable segments have been used minimally for the diagnosis of a chlamydial infection. In this experiment, the authors obtained the recombinant MOMP of C. trachomatis (rMOMP) in E. coli rMOMP and extracted, purified, and partially characterized it. This was later used to identify anti-Chlamydia trachomatis antibodies in sera of infertile patients by immunodetection assays, enzyme-linked immunosorbent assay (ELISA), and indirect immunofluorescence tests. The ELISA test showed high sensitivity and low specificity of 100 and 58.3%, respectively. The above results obtained were linked to the cross-reactivity of antibodies against C. pneumoniae or C. psittaci. Hence, an evaluation was performed to obtain an optimized test for the diagnosis of C. trachomatis infection.

The Bioinformatics Analyses Reveal Novel Antigen Epitopes in Major Outer Membrane Protein of Chlamydia trachomatis

Purpose: The aim of this study was to predict the T-cell and B-cell epitopes in major outer membrane protein (MOMP) of Chlamydia trachomatis (CT) by using online software and also to analyse the secondary structure of MOMP through bioinformatics tools. Materials and Methods: The predictions of secondary structure of MOMP protein were carried out using SOPMA software, and the prediction of B-cell epitopes in MOMP protein was carried out using IEDB and LEPS software, while the T-cell epitopes were predicted by the software of IEBD and SYFPEITHI. The predictions from the software were combined with MOMP protein characteristics, including surface features, hydrophilicity, flexibility, accessibility and plasticity, to analyse the common epitope areas’ response by T-cells and B-cells. Results: In the secondary structure of CT MOMP, the alpha-helices accounted for 41.62% of total amino acid, while the beta sheets and random coil accounted for 19.80% and 32.49%, respectively. Predictions combined with MOMP protein surface features, hydrophilicity, flexibility, accessibility and plasticity were further characterised, and three high-score B-cell epitope areas were found as located in 24–31, 307–311 and 318–327 amino acids of MOMP protein, respectively; in the meanwhile, three high-score T-cell epitope areas were found in 234–236, 323–329 and 338–343 amino acids of MOMP using major histocompatibility complex (MHC) class I HLA-A 0201 restrictive T-cell epitope analyser. Conclusion: We established the methods by using the biological information network technologies for looking the T-cell antigen epitopes and B-cell antigen epitopes in MOMP of CT, and three novel T-cell epitopes as well as three novel B-cell epitopes were identified in the current study. It provides important information for further studying the antigenicity of CT MOMP protein and also provides useful information for developing highly efficient subunit vaccines for CT.

Modulation of Inflammation Induced by Recombinant MOMP of Chlamydia in Mouse Macrophages by IL-10 is Mediated by Skewing M1 to an M2 Polarizing Macrophage Phenotype

Abstract The major outer membrane protein (MOMP) of Chlamydia trachomatis (CT) is a very desirable vaccine candidate against CT because it stimulates robust T- and B-cell protective responses. Conversely, we showed that MOMP contributes to CT inflammation by stimulating macrophages to secrete pro-inflammatory cytokines that play pivotal roles in the pathogenesis of chlamydial diseases, and whose secretion levels are modulated by IL-10. We also showed that MOMP induced marked expression of the Socs3 gene in macrophages, correlating with its induction of pro-inflammatory cytokines, and its triggering of an M1 macrophage phenotype. Our goal in this study is to understand the inflammatory nature of MOMP by focusing on key chemokines (CCL5 and CXCL10), NO and Nod1/2 receptors, which are implicated in CT inflammation. We also evaluated their inhibition by IL-10 and its effect on M1 and M2 macrophage phenotypes. Mouse J774 macrophages were stimulated with recombinant MOMP (0.01–10 ug/mL) with/without exogenously added IL-10 (10 ng/mL); supernatants and RNA were collected for cytokine ELISAs, NO production and TaqMan gene expression analyses. Our results showed that rMOMP induced expression of CCL5, CXCL10, NO and Nod1/2 receptors that recognize and activate key inflammatory pathways, which were all modulated by IL-10. Characterization of macrophages revealed that rMOMP increased Nos2 expression, an M1 phenotypic marker, which was modulated by IL-10, suggesting skewing of the M1 phenotype whereas IL-10 upregulated M2 markers including, Arg 1 (and its isoform Arg 2) and Mrc1. Overall, our data helps in understanding the inflammatory nature of MOMP and the potential role played by M1 and M2 phenotypes in mediating IL-10 regulation of CT inflammation.

Comparison of the nine polymorphic membrane proteins of Chlamydia trachomatis for their ability to induce protective immune responses in mice against a C. muridarum challenge

ObjectivesTo test vaccines, formulated with novel antigens, to protect mice against Chlamydia infections. MethodsTo determine the ability of polymorphic membrane proteins (Pmps) to induce cross-species protective immune responses, recombinant fragments from all nine C. trachomatis serovar E Pmps were used to vaccinate BALB/c mice utilizing CpG-1826 and Montanide ISA 720 as adjuvants. C. muridarum recombinant MOMP and PBS, formulated with the same adjuvants, were used as positive and negative controls, respectively. Mice were challenged intranasally with 104 inclusion-forming units (IFU) of C. muridarum. Animals were weighed daily and at 10days post-challenge, they were euthanized, their lungs harvested, weighed and the number of chlamydial IFU counted. ResultsFollowing vaccination the nine Pmps elicited immune responses. Based on body weight changes, or number of IFU recovered from lungs, mice vaccinated with Pmp C, G or H were the best protected. For example, over the 10-day period, the negative control group vaccinated with PBS lost significantly more body weight than mice immunized with PmpC or G (P<0.05). C. muridarum MOMP vaccinated mice were better protected against body weight losses than any group immunized with Pmps. Also, the median number of IFU recovered from the lungs of mice vaccinated with PmpC (72×106) or PmpH (61×106) was significantly less than from mice immunized with PBS (620×106; P<0.05). As determined by the number of IFU, all Pmps elicited less protection than C. muridarum MOMP (0.078×106 IFU; P<0.05). ConclusionsThis is the first time PmpC has been shown to elicit cross-species protection against a respiratory challenge. Additional work with Pmps C, G and H is recommended to determine their ability to protect animal models against genital and ocular challenges.

Antibody to Chlamydia trachomatis proteins, TroA and HtrA, as a biomarker for Chlamydia trachomatis infection.

Recombinant proteins C. trachomatis TroA and HtrA were used as antigens in enzyme immunoassay (EIA). Both IgG and IgA antibody responses were studied. IgG or IgA antibody to either protein was infrequently detected in sera from healthy blood donors or virgin girls. Patients attending the STI Clinic and patients with perihepatitis had often IgG antibody against TroA (25 and 50% respectively) and HtrA (21 and 38% respectively). Especially in sera from patients with chlamydial perihepatitis, the A450nm values with TroA were high (mean 1.591). A positive correlation between C. trachomatis MIF antibody and TroA (r = 0.7) as well as HtrA (r =0.5) antibody was observed in sera from STI clinic patients and perihepatitis patients. Individuals with C. trachomatis infection and positive serology already when seeking medical attention had higher A450nm values for TroA (0.638) and HtrA (0.836) than patients with no marker of previous exposure or with no infection (0.208 and 0.234 respectively). Diagnosis of genital C. trachomatis infection is often NAAT-based, whereas serology has little value in testing for uncomplicated genital C. trachomatis infection. TroA and HtrA antibodies are potential biomarkers for evaluation of ascending and repeated C. trachomatis infection.

Control of Trachoma from Achham District, Nepal: A Cross-Sectional Study from the Nepal National Trachoma Program

BackgroundThe WHO seeks to control trachoma as a public health problem in endemic areas. Achham District in western Nepal was found to have TF (trachoma follicular) above 20% in a 2006 government survey, triggering 3 annual mass drug administrations finishing in 2010. Here we assess the level of control that has been achieved using surveillance for clinical disease, ocular chlamydia trachomatis infection, and serology for antibodies against chlamydia trachomatis protein antigens.MethodsWe conducted a cross-sectional survey of children aged 1–9 years in communities in Achham District in early 2014 including clinical examination validated with photographs, conjunctival samples for Chlamydia trachomatis (Amplicor PCR), and serological testing for antibodies against chlamydia trachomatis protein antigens pgp3 and CT694 using the Luminex platform.FindingsIn 24 randomly selected communities, the prevalence of trachoma (TF and/or TI) in 1–9 year olds was 3/1124 (0.3%, 95% CI 0.1 to 0.8%), and the prevalence of ocular chlamydia trachomatis infection was 0/1124 (0%, 95% CI 0 to 0.3%). In 18 communities selected because they had the highest prevalence of trachoma in a previous survey, the prevalence of TF and/or TI was 7/716 (1.0%, 95% CI 0.4 to 2.0%) and the prevalence of ocular chlamydia trachomatis infection was 0/716 (0%, 95% CI 0 to 0.5%). In 3 communities selected for serological testing, the prevalence of trachoma was 0/68 (0%, 95% CI 0 to 5.3%), the prevalence of ocular chlamydia trachomatis infection was 0/68 (0%, 95% CI 0 to 0.5%), the prevalence of antibodies against chlamydia trachomatis protein antigen pgp3 was 1/68 (1.5%, 95% CI 0.04% to 7.9%), and the prevalence of antibodies against chlamydia trachomatis protein antigen CT694 was 0/68 (0%, 95% CI 0 to 5.3%).Conclusion/SignificanceThis previously highly endemic district in Nepal has little evidence of recent clinical disease, chlamydia trachomatis infection, or serological evidence of trachoma, suggesting that epidemiological control has been achieved.

Pharmacophore based virtual screening for identification of marine bioactive compounds as inhibitors against macrophage infectivity potentiator (Mip) protein of Chlamydia trachomatis

Macrophage infectivity potentiator (Mip) is the virulence factor fromChlamydia trachomatisthat is primarily responsible for causing sexually transmitted diseases (STDs) and blindness.

Computational modeling of TC0583 as a putative component of the Chlamydia muridarum V-type ATP synthase complex and assessment of its protective capabilities as a vaccine antigen

Numerous Chlamydia trachomatis proteins have been identified as potential subunit vaccines, of which the major outer-membrane protein (MOMP) has, so far, proven the most efficacious. Recently, subunit A of the V-type ATP synthase (ATPase; TC0582) complex was shown to elicit partial protection against infection. Computational modeling of a neighboring gene revealed a novel subunit of the V-type ATPase (TC0583). To determine if this newly identified subunit could induce protection and/or enhance the partial protection provided by subunit A alone, challenge studies were performed using a combination of these recombinant proteins. The TC0583 subunit alone and concurrently with TC0582, was used to vaccinate BALB/c mice utilizing CpG-1826 and Montanide ISA 720 VG as adjuvants. Vaccinated animals were challenged intranasally with Chlamydia muridarum and the course of the infection was followed. Mice immunized with individual antigens showed minimal alleviation of body weight reduction; however, mice immunized with TC0583 and TC0582 in combination, displayed weight loss levels close to those observed with MOMP. Importantly, immunization with a combination of recombinant subunit proteins reduced chlamydial inclusion forming units by approximately a log-fold. These protection levels support that, these highly conserved Chlamydia proteins, in combination with other antigens, may serve as potential vaccine candidates.

Design and preclinical characterization of a novel vaccine adjuvant formulation consisting of a synthetic TLR4 agonist in a thermoreversible squalene emulsion

We describe the development, analytical characterization, stability and preclinical efficacy of AF04, a combination adjuvant comprising the synthetic toll-like receptor 4 (TLR4) agonist, E6020, formulated in AF03, a thermoreversible squalene emulsion. By using AF04 with the recombinant major outer membrane protein of Chlamydia trachomatis (Ct-MOMP) and with the recombinant surface glycoprotein gB from human cytomegalovirus (CMV-gB) as model antigens, we show that AF03 and E6020 can synergize to augment specific antibody and Th-1 cellular immune responses in mice. In terms of formulation, we observe that the method used to incorporate E6020 into AF03 affects its partition between the oil and water phases of the emulsion which in turn has a significant impact on the tolerability (IV pyrogenicity test in rabbits) of this novel adjuvant combination.

In situ localization of Chlamydia trachomatis and Chlamydial Heat Shock Protein 60 in Endometrial Curettage Tissue of Recurrent Spontaneous Aborters

In situ localization of Chlamydia trachomatis and Chlamydial Heat Shock Protein 60 in Endometrial Curettage Tissue of Recurrent Spontaneous Aborters