Chlamydia trachomatis Growth and Cytokine mRNA Response in a Prostate Cancer Cell Line.

In the present paper, we report that C. trachomatis can be efficiently propagated and affect mRNA expression for two major cytokines, relevant to tumor progression, in CWR-R1 cells, a malignant prostate cell line. CWR-R1 and McCoy cells, a classic cell line for chlamydial research, were grown and infected with C. trachomatis under similar conditions. Cell monolayers were harvested for RNA analysis and immunostaining with major outer membrane protein (MOMP) antibody at 24, 48, and 72 hours of the postinfection (hpi) period. It was shown that the infectious cycle of chlamydial pathogen in CWR-R1 cells resembles the progression of C. trachomatis infection in McCoy cells but with a few important differences. First of all, the initial stage of C. trachomatis propagation in CWR-R1 cells (24 hpi) was characterized by larger inclusion bodies and more intense, specific immunofluorescent staining of infected cells as compared with McCoy cells. Moreover, there was a corresponding increase in infective progeny formation in CWR-R1 cells along with mRNA for EUO, a crucial gene controlling the early phase of the chlamydial development cycle (24 hpi). These changes were more minimal and became statistically insignificant at a later time point in the infectious cycle (48 hpi). Altogether, these data suggest that the early phase of C. trachomatis infection in CWR-R1 cells is accompanied by more efficient propagation of the pathogen as compared with the growth of C. trachomatis in McCoy cells. Furthermore, propagation of C. trachomatis in CWR-R1 cells leads to enhanced transcription of interleukin-6 and fibroblast growth factor-2, genes encoding two important proinflammatory cytokines implicated in the molecular mechanisms of chemoresistance of prostate cancer and its ability to metastasize. The possible roles of reactive oxygen species and impaired mitochondrial oxidation in the prostate cancer cell line are discussed as factors promoting the early stages of C. trachomatis growth in CWR-R1 cells.

Small Molecule Inhibitor of Type Three Secretion System Belonging to a Class 2,4-disubstituted-4H-[1,3,4]-thiadiazine-5-ones Improves Survival and Decreases Bacterial Loads in an Airway Pseudomonas aeruginosa Infection in Mice.

Pseudomonas aeruginosa is a cause of high mortality in burn, immunocompromised, and surgery patients. High incidence of antibiotic resistance in this pathogen makes the existent therapy inefficient. Type three secretion system (T3SS) is a leading virulence system of P. aeruginosa that actively suppresses host resistance and enhances the severity of infection. Innovative therapeutic strategies aiming at inhibition of type three secretion system of P. aeruginosa are highly attractive, as they may reduce the severity of clinical manifestations and improve antibacterial immune responses. They may also represent an attractive therapy for antibiotic-resistant bacteria. Recently our laboratory developed a new small molecule inhibitor belonging to a class 2,4-disubstituted-4H-[1,3, 4]-thiadiazine-5-ones, Fluorothiazinon (FT), that effectively suppressed T3SS in chlamydia and salmonella in vitro and in vivo. In this study, we evaluate the activity of FT towards antibiotic-resistant clinical isolates of P. aeruginosa expressing T3SS effectors ExoU and ExoS in an airway infection model. We found that FT reduced mortality and bacterial loads and decrease lung pathology and systemic inflammation. In addition, we show that FT inhibits the secretion of ExoT and ExoY, reduced bacteria cytotoxicity, and increased bacteria internalization in vitro. Overall, FT shows a strong potential as an antibacterial therapy of antibiotic-resistant P. aeruginosa infection.

Non-Invasive Immunofluorescence Assessment of Lycopene Supplementation Status in Skin Smears.

Circulating lycopene level is negatively associated with the prevalence of cardiovascular disease, cancers (prostate and breast), type 2 diabetes mellitus, and aging. Traditionally, lycopene is measured in biological specimens by a combination of high-performance liquid chromatography (HPLC) and mass spectrometry methods. Moreover, as we recently reported, tissue/cell lycopene depositions can be observed by the immunohistochemistry method with a newly developed monoclonal antibody (mAb) against lycopene. A main objective of this study is to evaluate the performance of a new noninvasive immunofluorescence (IF) lycopene quantification skin test with mAbs against lycopene versus HPLC lycopene assay of serum lycopene in volunteers subjected to lycopene supplementation which represents a novel approach to lycopene measurement methodology. For this purpose, 32 healthy volunteers, 30-40 years old, were supplemented with lycopene (n = 15) or placebo (n = 17) for a period of 4 weeks. It was found that lycopene supplementation leads to a significant increase in serum lycopene concentration after 2 and 4 weeks by 2.6- and 3.4-fold over control, respectively. This was accompanied by a concordant step-wise rise in IF staining of skin corneocytes and sebum, quantifiable by arbitrary IF scores. Placebo supplementation did not affect serum lycopene values or intensity of IF staining of the skin samples. There was 86.6% agreement in paired HPLC/IF variants for the intermediate time point and 80.0% agreement at the end of the study in the lycopene group. Intraclass correlation between paired values in this group was +0.49 for the 2-week time point and +0.63 for the end point. These results indicate that the new antibody-based skin assay can be used for rapid detection of lycopene deficiencies. Moreover, the noninvasive nature of the skin swab test would allow using it to monitor, optimize, and personalize lycopene supplementation protocol of risk groups in the general population.

Identification of chlamydial T3SS inhibitors through virtual screening against T3SS ATPase.

Chlamydia trachomatis is a widespread sexually transmitted pathogen that resides within a special vacuole inside host cells. Although acute infection can be treated with antibiotics, chlamydia can enter persistent state, leading to chronic infection that is difficult to cure. Thus, novel anti-chlamydial compounds active against persistent chlamydia are required. Chlamydiae rely upon type III secretion system (T3SS) to inject effector proteins into host cell cytoplasm, and T3SS inhibitors are viewed as promising compounds for treatment of chlamydial infections. C. trachomatis ATPase SctN is an important T3SS component and has not been targeted before. We thus used virtual screening against homology modeled SctN structure to search for SctN inhibitors. Selected compounds were tested for their ability to inhibit chlamydial survival and development within eukaryotic cells, and for the ability to suppress normal T3SS functioning. We identified two compounds that were able to block normal protein translocation through T3SS and inhibit chlamydial survival within eukaryotic cells in 50-100 µm concentrations. These two novel T3SS inhibitors also possessed relatively low toxicity toward eukaryotic cells. A small series of derivatives was further synthesized for the most active of two inhibitors to probe SAR properties.

Chlamydial Type III Secretion System Needle Protein Induces Protective Immunity against Chlamydia muridarum Intravaginal Infection.

Chlamydia trachomatis imposes serious health problems and causes infertility. Because of asymptomatic onset, it often escapes antibiotic treatment. Therefore, vaccines offer a better option for the prevention of unwanted inflammatory sequelae. The existence of serologically distinct serovars of C. trachomatis suggests that a vaccine will need to provide protection against multiple serovars. Chlamydia spp. use a highly conserved type III secretion system (T3SS) composed of structural and effector proteins which is an essential virulence factor. In this study, we expressed the T3SS needle protein of Chlamydia muridarum, TC_0037, an ortholog of C. trachomatis CdsF, in a replication-defective adenoviral vector (AdTC_0037) and evaluated its protective efficacy in an intravaginal Chlamydia muridarum model. For better immune responses, we employed a heterologous prime-boost immunization protocol in which mice were intranasally primed with AdTC_0037 and subcutaneously boosted with recombinant TC_0037 and Toll-like receptor 4 agonist monophosphoryl lipid A mixed in a squalene nanoscale emulsion. We found that immunization with TC_0037 antigen induced specific humoral and T cell responses, decreased Chlamydia loads in the genital tract, and abrogated pathology of upper genital organs. Together, our results suggest that TC_0037, a highly conserved chlamydial T3SS protein, is a good candidate for inclusion in a Chlamydia vaccine.