96 research outputs found
Effects of water-filtered infrared A and visible light (wIRA/VIS) radiation on heat- and stress-responsive proteins in the retina and cornea of guinea pigs
Water-filtered infrared A and visible light (wIRA/VIS), shown to reduce chlamydial infections in vitro and in vivo, might represent an innovative therapeutic approach against trachoma, a neglected tropical disease caused by ocular infection with the bacterium C. trachomatis. In this in vivo study, we assessed the impact of wIRA radiation in combination with VIS (wavelength range 595–1400 nm, intensity 2100 W/m2) on the retina and cornea in a guinea pig animal model of inclusion conjunctivitis. We investigated the effects 19 days after wIRA/VIS irradiation by comparing a single and double wIRA/VIS treatment with a sham control. By immunolabeling and western blot analyses of critical heat- and stress-responsive proteins, we could not detect wIRA/VIS-induced changes in their expression pattern. Also, immunolabeling of specific retinal marker proteins revealed no changes in their expression pattern caused by the treatment. Our preclinical study suggests wIRA/VIS as a promising and safe therapeutic tool to treat ocular chlamydial infections
Effects of iota-carrageenan on ocular Chlamydia trachomatis infection in vitro and in vivo
Ocular chlamydial infections with the ocular serovars A, B, Ba, and C of Chlamydia trachomatis represent the world's leading cause of infectious blindness. Carrageenans are naturally occurring, sulfated polysaccharides generally considered safe for food and topical applications. Carrageenans can inhibit infection caused by a variety of viruses and bacteria. To investigate whether iota-carrageenan (I-C) isolated from the red alga Chondrus crispus could prevent ocular chlamydial infection, we assessed if targeted treatment of the conjunctival mucosa with I-C affects chlamydial attachment, entry, and replication in the host cell. Immortalized human conjunctival epithelial cells were treated with I-C prior to C. trachomatis infection and analyzed by flow cytometry and immunofluorescence microscopy. In vivo effects were evaluated in an ocular guinea pig inclusion conjunctivitis model. Ocular pathology was graded daily, and chlamydial clearance was investigated. Our study showed that I-C reduces the infectivity of C. trachomatis in vitro. In vivo results showed a slight reduced ocular pathology and significantly less shedding of infectious elementary bodies by infected animals. Our results indicate that I-C could be a promising agent to reduce the transmission of ocular chlamydial infection and opens perspectives to develop prophylactic approaches to block C. trachomatis entry into the host cell
Cross-Reactive Effects of Vaccines: Heterologous Immunity between Tetanus and Chlamydia
Vaccines can have heterologous effects on the immune system, i.e., effects other than triggering an immune response against the disease targeted by the vaccine. We investigated whether monoclonal antibodies (mAbs) specific for tetanus could cross-react with Chlamydia and confer heterologous protection against chlamydial infection. The capability of two tetanus-specific mAbs, namely mAb26 and mAb51, to prevent chlamydial infection has been assessed: (i) in vitro, by performing a neutralization assay using human conjunctival epithelial (HCjE) cells infected with Chlamydia trachomatis serovar B, and (ii) in vivo, by using a guinea pig model of Chlamydia caviae-induced inclusion conjunctivitis. The mAb26 has been superior in comparison with mAb51 in the prevention of chlamydial infection in HCjE cells. The mAb26 has conferred approximate to 40% inhibition of the infection, compared to less than 5% inhibition in the presence of the mAb51. In vivo, mAb26 significantly diminished ocular pathology intensity in guinea pigs infected with C. caviae compared to either the mAb51-treated or sham-treated guinea pigs. Our data provide insights that tetanus immunization generates antibodies which induce heterologous chlamydial immunity and promote protection beyond the intended target pathogen
Chlamydia trachomatis Infection Is Associated with E-Cadherin Promoter Methylation, Downregulation of E-Cadherin Expression, and Increased Expression of Fibronectin and α-SMA—Implications for Epithelial-Mesenchymal Transition
Chlamydia trachomatis (Ct) can induce scarring disease of the ocular mucosa, known as trachoma, the most common infectious cause of blindness worldwide. We hypothesized that epithelial-mesenchymal transition (EMT) contributes to the fibrotic process in trachomatous scarring. Infection of human conjunctival epithelial cells (HCjE) with Ct activated signaling pathways involved in EMT induction, which was correlated with decreased expression of E-cadherin, guardian of the epithelial phenotype. In addition, Ct infection was associated with increased expression of two mesenchymal cell markers: fibronectin and α-SMA. The DNA methylation statuses of selected regions of E-cadherin, fibronectin, and α-SMA genes revealed that Ct infection was accompanied with changes in DNA methylation of the E-cadherin promoter, while the expression of the two mesenchymal markers was not related with this epigenetic event. Our data suggest that Ct infection of conjunctival epithelial cells induces EMT-like changes that go along with modification of the methylation profile of the E-cadherin promoter and could, as one of the earliest events, contribute to processes triggering conjunctival scarring.Frontiers in Cellular and Infection Microbiology (2017), 7(JUN): 25
Supplementary data for the article: Spasojević, D.; Zmejkoski, D.; Glamočlija, J.; Nikolić, M.; Soković, M.; Milošević, V.; Jarić, I.; Stojanović, M.; Marinković, E.; Barisani-Asenbauer, T.; et al. Lignin Model Compound in Alginate Hydrogel: A Strong Antimicrobial Agent with High Potential in Wound Treatment. International Journal of Antimicrobial Agents 2016, 48 (6), 732–735. https://doi.org/10.1016/j.ijantimicag.2016.08.014
Supplementary material for: [https://doi.org/10.1016/j.ijantimicag.2016.08.014]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2364
Chlamydia trachomatis infection and development of epithelial mesenchymal transition in conjunctiva : possible epigenetic mechanisms unveiled
Introduction: Trachoma is the most common cause of infectious blindness worldwide, initiated by repeated infection of the conjunctiva with Chlamydia trachomatis (Ct). The resulting chronic inflammation and formation of fibrotic tissue eventually lead to corneal damage. Based on the facts that epithelial to mesenchymal transition (EMT) plays an important role in the development of fibrosis and that EMT is epigenetically regulated process, the aims of this study were to reveal the capacity of Ct to induce EMT in vitro and to unveil potential underlying epigenetic mechanisms. Methods: Human conjunctival epithelial (HCjE) cells were infected with 107 IFU of Ct for 72 h. EMT-inducing signaling pathways, as well as mRNA and protein expression of EMT markers (E-cadherin, fibronectin and α-SMA) were evaluated by RT-qPCR, Immunoblotting and Immunocytochemistry. DNA methylation patterns of selected regions of E-cadherin, fibronectin and α-SMA genes were examined by Methylation-Specific PCR, High Resolution Melting analysis and Bisulfite Sequencing. Results: Infection with Ct was accompanied with the activation of EMT-inducing signaling pathways, downregulation of epithelial marker E-cadherin and upregulation of mesenchymal markers fibronectin and α-SMA. While DNA methylation status of E-cadherin gene promoter correlated with its expression, methylation status of fibronectin and α-SMA genes couldn’t be related to their expression levels. Conclusion: Ct infection of HCjE cells triggers EMT that goes along with changes in the methylation profile of the E-cadherin promoter. Sequence of events described herein could contribute to scarring process in trachoma and open up possibilities for development of new therapeutic strategies in trachoma treatment.Brajušković G, Đorđević A, editors. CoMBoS. 1st Congress of Molecular Biologists of Serbia; 2017 Sep 20-22; Belgrade, Serbia. Belgrade: University of Belgrade, Faculty of Biology; 2017. p. 70
Chlamydia trachomatis infection and development of epithelial mesenchymal transition in conjunctiva : possible epigenetic mechanisms unveiled
Introduction: Trachoma is the most common cause of infectious blindness worldwide, initiated by repeated infection of the conjunctiva with Chlamydia trachomatis (Ct). The resulting chronic inflammation and formation of fibrotic tissue eventually lead to corneal damage. Based on the facts that epithelial to mesenchymal transition (EMT) plays an important role in the development of fibrosis and that EMT is epigenetically regulated process, the aims of this study were to reveal the capacity of Ct to induce EMT in vitro and to unveil potential underlying epigenetic mechanisms. Methods: Human conjunctival epithelial (HCjE) cells were infected with 107 IFU of Ct for 72 h. EMT-inducing signaling pathways, as well as mRNA and protein expression of EMT markers (E-cadherin, fibronectin and α-SMA) were evaluated by RT-qPCR, Immunoblotting and Immunocytochemistry. DNA methylation patterns of selected regions of E-cadherin, fibronectin and α-SMA genes were examined by Methylation-Specific PCR, High Resolution Melting analysis and Bisulfite Sequencing. Results: Infection with Ct was accompanied with the activation of EMT-inducing signaling pathways, downregulation of epithelial marker E-cadherin and upregulation of mesenchymal markers fibronectin and α-SMA. While DNA methylation status of E-cadherin gene promoter correlated with its expression, methylation status of fibronectin and α-SMA genes couldn’t be related to their expression levels. Conclusion: Ct infection of HCjE cells triggers EMT that goes along with changes in the methylation profile of the E-cadherin promoter. Sequence of events described herein could contribute to scarring process in trachoma and open up possibilities for development of new therapeutic strategies in trachoma treatment.Brajušković G, Đorđević A, editors. CoMBoS. 1st Congress of Molecular Biologists of Serbia; 2017 Sep 20-22; Belgrade, Serbia. Belgrade: University of Belgrade, Faculty of Biology; 2017. p. 70
Guidance on Noncorticosteroid Systemic Immunomodulatory Therapy in Noninfectious Uveitis : Fundamentals Of Care for UveitiS (FOCUS) Initiative
Supplemental material available at www.aaojournal.org. Supported by AbbVie, Inc., and the Fundamentals of Care for Uveitis Initiative National Faculty. This manuscript was developed subsequent to an AbbVie-sponsored literature review of noninfectious, nonanterior uveitis. The meeting was conducted to understand the available literature regarding the management of patients with noninfectious, nonanterior uveitis. The program involved a total of 139 experts from 28 countries, who were selected for participation by AbbVie. However, AbbVie was not involved in the development of the manuscript. The authors maintained complete control over the content and this manuscript reflects the opinions of the authors. AbbVie selected the discussion participants and reviewed the final manuscript draft for scientific accuracy, but the authors determined the final content. All authors made substantial contributions to the article or critically revised it for important intellectual content and approved the final manuscript. AbbVie provided funding to invited participants, including honoraria for their attendance at the meetings. Travel to and from the meetings was reimbursed. No payments were made to the authors for the development of this manuscript. Dhinakaran Sambandan, PhD, and Shula Sarner, PhD, of Lucid Partners, Burleighfield House, Buckinghamshire, United Kingdom, provided medical writing and editorial support to the authors in the development of this manuscript; financial support for these services was provided by AbbVie. AbbVie reviewed the manuscript, but was not involved in the methodology, data collection and analysis, or completion of this manuscript.Peer reviewedPublisher PD
The Ocular Conjunctiva as a Mucosal Immunization Route: A Profile of the Immune Response to the Model Antigen Tetanus Toxoid
Background: In a quest for a needle-free vaccine administration strategy, we evaluated the ocular conjunctiva as an alternative mucosal immunization route by profiling and comparing the local and systemic immune responses to the subcutaneous or conjunctival administration of tetanus toxoid (TTd), a model antigen. Materials and methods: BALB/c and C57BL/6 mice were immunized either subcutaneously with TTd alone or via the conjunctiva with TTd alone, TTd mixed with 2% glycerol or TTd with merthiolate-inactivated whole-cell B. pertussis (wBP) as adjuvants. Mice were immunized on days 0, 7 and 14 via both routes, and an evaluation of the local and systemic immune responses was performed two weeks after the last immunization. Four weeks after the last immunization, the mice were challenged with a lethal dose (2 x LD50) of tetanus toxin. Results: The conjunctival application of TTd in BALB/c mice induced TTd-specific secretory IgA production and skewed the TTd-specific immune response toward a Th1/Th17 profile, as determined by the stimulation of IFN gamma and IL-17A secretion and/or the concurrent pronounced reduction of IL-4 secretion, irrespective of the adjuvant. In conjunctivaly immunized C57BL/6 mice, only TTd administered with wBP promoted the establishment of a mixed Th1/Th17 TTd-specific immune response, whereas TTd alone or TTd in conjunction with glycerol initiated a dominant Th1 response against TTd. Immunization via the conjunctiva with TTd plus wBP adjuvant resulted in a 33% survival rate of challenged mice compared to a 0% survival rate in non-immunized animals (p lt 0.05). Conclusion: Conjunctival immunization with TTd alone or with various adjuvants induced TTd-specific local and systemic immune responses, predominantly of the Th1 type. The strongest immune responses developed in mice that received TTd together with wBP, which implies that this alternative route might tailor the immune response to fight intracellular bacteria or viruses more effectively
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