Ultrastructural Aspects of Photodynamic Inactivation of Highly Pathogenic Avian H5N8 Influenza Virus

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Viruses. 2019 Oct 16;11(10). pii: E955. doi: 10.3390/v11100955. Ultrastructural Aspects of Photodynamic Inactivation of Highly Pathogenic Avian H5N8 Influenza Virus.

Korneev D¹, Kurskaya O², Sharshov K³, Eastwood J⁴, Strakhovskaya M^5,6.
Author information

1 School of Biological Sciences, Monash University, 25 Rainforest Walk, Clayton, Victoria 3800, Australia. denis.korneev@monash.edu. 2 Federal Research Center of Fundamental and Translational Medicine (CFTM), 630117 Novosibirsk, Russia. kurskaya_og@mail.ru. 3 Federal Research Center of Fundamental and Translational Medicine (CFTM), 630117 Novosibirsk, Russia. sharshov@yandex.ru. 4 School of Biological Sciences, Monash University, 25 Rainforest Walk, Clayton, Victoria 3800, Australia. Justin.Eastwood@monash.edu. 5 Department of Biophysics, Faculty of Biology, M.V. Lomonosov Moscow State University, 119991 Moscow, Russia. maristra@yandex.ru. 6 Federal Research and Clinical Center of Specialized Medical Care and Medical Technologies, FMBA, 115682 Moscow, Russia. maristra@yandex.ru.

Abstract

Ultrastructural studies revealing morphological differences between intact and photodynamically inactivated virions can point to inactivation mechanisms and molecular targets. Using influenza as a model system, we show that photodynamic virus inactivation is possible without total virion destruction. Indeed, irradiation with a relatively low concentration of the photosensitizer (octacationic octakis(cholinyl) zinc phthalocyanine) inactivated viral particles (the virus titer was determined in Madin Darby Canine Kidney (MDCK) cells) but did not destroy them. Transmission electron microscopy (TEM) revealed that virion membranes kept structural integrity but lost their surface glycoproteins. Such structures are known as "bald" virions, which were first described as a result of protease treatment. At a higher photosensitizer concentration, the lipid membranes were also destroyed. Therefore, photodynamic inactivation of influenza virus initially results from surface protein removal, followed by complete virion destruction. This study suggests that photodynamic treatment can be used to manufacture "bald" virions for experimental purposes. Photodynamic inactivation is based on the production of reactive oxygen species which attack and destroy biomolecules. Thus, the results of this study can potentially apply to other enveloped viruses and sources of singlet oxygen.


KEYWORDS:

H5N8; influenza; photodynamic inactivation; photosensitizer; transmission electron microscopy

PMID: 31623281 DOI: 10.3390/v11100955
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