title: Water-filtered infrared A reduces chlamydial infectivity in vitro without causing ex vivo eye damage in pig and mouse models.
abstract: Repeated ocular infections with Chlamydia trachomatis trigger the development of trachoma, the most common cause of infectious blindness worldwide. Water-filtered infrared A (wIRA) has shown positive effects on cultured cells and human skin. Our aim was to evaluate the potential of wIRA as a possible non-chemical treatment for trachoma patients. We both modeled ocular chlamydial infections using C. trachomatis B to infect human conjunctival epithelial cells (HCjE) and studied the effects of wIRA on non-infected ocular structures with two ex vivo eye models. We focused on the temperature development during wIRA irradiation in cell culture and perfused pig eyes to exclude potentially harmful side effects. Furthermore, cell viability of HCjE and cytotoxicity in mouse retina explants was analyzed. We demonstrated a significant wIRA-dependent reduction of chlamydial infectivity in HCjE cells. Moreover, we observed that wIRA treatment of HCjE prior to infection was sufficient to inhibit chlamydial infectivity and that visible light enhances the effect of wIRA. Irradiation did not reduce cell viability and there was no indication of retinal damage post treatment. Additionally, temperatures during wIRA exposure did not markedly exceed physiological eye temperatures, suggesting that hyperthermia-related lesions are unlikely. For clinical applications, further exploration of wIRA as a non-chemical treatment device in an experimental animal model is essential.
authors.affiliation: Institute of Veterinary Pathology, University of Zurich, Vetsuisse Faculty, Winterthurerstrasse 268, 8057 Zurich, Switzerland. Electronic address: carolin.rahn@uzh.ch.
authors.forename: Carolin
authors.initials: C
authors.lastname: Rahn
authors.affiliation: Institute of Veterinary Pathology, University of Zurich, Vetsuisse Faculty, Winterthurerstrasse 268, 8057 Zurich, Switzerland. Electronic address: hanna.marti@uzh.ch.
authors.forename: Hanna
authors.initials: H
authors.lastname: Marti
authors.affiliation: Technical University of Darmstadt, Schnittspahnstraße 10, 64287 Darmstadt, Germany. Electronic address: antonia.frohns@gmail.com.
authors.forename: Antonia
authors.initials: A
authors.lastname: Frohns
authors.affiliation: Technical University of Darmstadt, Schnittspahnstraße 10, 64287 Darmstadt, Germany. Electronic address: frohns@bio.tu-darmstadt.de.
authors.forename: Florian
authors.initials: F
authors.lastname: Frohns
authors.affiliation: Institute of Veterinary Pathology, University of Zurich, Vetsuisse Faculty, Winterthurerstrasse 268, 8057 Zurich, Switzerland. Electronic address: christian.blenn@mgb.ch.
authors.forename: Christian
authors.initials: C
authors.lastname: Blenn
authors.affiliation: Institute of Veterinary Pathology, University of Zurich, Vetsuisse Faculty, Winterthurerstrasse 268, 8057 Zurich, Switzerland. Electronic address: coryann.leonard@uzh.ch.
authors.forename: Cory Ann
authors.initials: CA
authors.lastname: Leonard
authors.affiliation: Medical University of Vienna, Sensengasse 2a, 1090 Vienna, Austria. Electronic address: talin.barisani@meduniwien.ac.at.
authors.forename: Talin
authors.initials: T
authors.lastname: Barisani-Asenbauer
authors.affiliation: Medical University of Vienna, Sensengasse 2a, 1090 Vienna, Austria. Electronic address: elisabeth.stein@meduni.ac.at.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Stein
authors.affiliation: Institute of Veterinary Pathology, University of Zurich, Vetsuisse Faculty, Winterthurerstrasse 268, 8057 Zurich, Switzerland. Electronic address: n.borel@access.uzh.ch.
authors.forename: Nicole
authors.initials: N
authors.lastname: Borel
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D007259:Infrared Rays / Q000627:therapeutic use*; D051379:Mice; D013552:Swine; D014141:Trachoma / Q000517:prevention & control*; D014867:Water
chemical_list: D014867:Water
keywords: Chlamydiaceae; Cytotoxicity; Retina; Temperature; Vitreous body