In vitro prevention of vaccinia and herpesvirus infection spread in explanted human corneas by N-chlorotaurine.
OBJECTIVE
Weak oxidants produced by activated human leukocytes are proven antimicrobial substances. We tested whether N-chlorotaurine (NCT, taurine chloramine), the chlorinated metabolite of the amino acid taurine, in addition to direct virucidal effects on viral suspensions, has the capability to prevent cell-to-cell spread of viruses in human corneal epithelium.


METHODS
Human corneal grafts were infected in vitro with poxvirus (vaccinia virus, VV) and herpesvirus. Different NCT dilutions were added to prevent viral spread within the corneal epithelium as detected by immune-staining and microscopy of cytopathic effects. Additionally, virus release was measured by cell culture.


RESULTS
Addition of NCT significantly reduced the number of VV-infected epithelial cells at concentrations as low as 0.01% in culture medium, which was far beyond cytotoxic concentrations in long-term cultures. The release of virus by the infected corneal grafts was reduced by 2-3 log(10 )as well. As expected, herpesvirus infection was also positively affected.


CONCLUSIONS
Smallpox has been known as a major cause of blindness in historical outbreaks. NCT could therefore provide an additional supportive means for treating orthopoxvirus-associated keratitis. Additionally, biocompatible local antiseptics like NCT could also serve as an experimental treatment in other keratitis of suspected viral origin.
Huemer
Hartwig P
HP
Department of Hygiene, Microbiology and Social Medicine, Innsbruck Medical University, Innsbruck, Austria.
Nagl
Markus
M
Irschick
Eveline U
EU
D000998:Antiviral Agents / Q000494:pharmacology*; D003315:Cornea / Q000821:virology*; D003588:Cytopathogenic Effect, Viral / Q000187:drug effects; D018259:Herpesvirus 1, Human / Q000472:pathogenicity*; D006801:Humans; D009924:Organ Culture Techniques; D013654:Taurine / Q000031:analogs & derivatives* / Q000494:pharmacology; D014616:Vaccinia virus / Q000472:pathogenicity*; D014774:Virulence / Q000187:drug effects
D000998:Antiviral Agents; D013654:Taurine; C043410:N-chlorotaurine