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Reactivation of Latent Epstein-Barr Virus: A Comparison after Exposure to Gamma, Proton, Carbon, and Iron Radiation

Authors :
Satish K. Mehta
David C. Bloom
Ianik Plante
Raymond Stowe
Alan H. Feiveson
Ashlie Renner
Adit Dhummakupt
Dhruv Markan
Ye Zhang
Honglu Wu
Blaire Scoles
Jeffrey I. Cohen
Brian Crucian
Duane L. Pierson
Source :
International Journal of Molecular Sciences, Vol 19, Iss 10, p 2961 (2018)
Publication Year :
2018
Publisher :
MDPI AG, 2018.

Abstract

Among the many stressors astronauts are exposed to during spaceflight, cosmic radiation may lead to various serious health effects. Specifically, space radiation may contribute to decreased immunity, which has been documented in astronauts during short- and long-duration missions, as evidenced by several changes in cellular immunity and plasma cytokine levels. Reactivation of latent herpes viruses, either directly from radiation of latently infected cells and/or from perturbation of the immune system, may result in disease in astronauts. Epstein‒Barr virus (EBV) is one of the eight human herpes viruses known to infect more than 90% of human adults and persists for the life of the host without normally causing adverse effects. Reactivation of several latent viruses in astronauts is well documented, although the mechanism of reactivation is not well understood. We studied the effect of four different types of radiation, (1) 137Cs gamma rays, (2) 150-MeV protons, (3) 600 MeV/n carbon ions, and (4) 600 MeV/n iron ions on the activation of lytic gene transcription and of reactivation of EBV in a latently infected cell line (Akata) at doses of 0.1, 0.5, 1.0, and 2.0 Gy. The data showed that for all doses used in this study, lytic gene transcription was induced and median viral loads were significantly higher for all types of radiation than in corresponding control samples, with the increases detected as early as four days post-exposure and generally tapering off at later time points. The viability and size of EBV-infected Akata cells were highly variable and exhibited approximately the same trend in time for all radiation types at 0.1, 0.5, 1.0, and 2.0 Gy. This work shows that reactivation of viruses can occur due to the effect of different types of radiation on latently infected cells in the absence of changes or cytokines produced in the immune system. In general, gamma rays are more effective than protons, carbon ions, and iron ions in inducing latent virus reactivation, though these high-energy particles did induce more sustained and later reactivation of EBV lytic gene transcription. These findings also challenge the common relative biological effectiveness concept that is often used in radiobiology for other end points.

Details

Language :
English
ISSN :
14220067
Volume :
19
Issue :
10
Database :
Directory of Open Access Journals
Journal :
International Journal of Molecular Sciences
Publication Type :
Academic Journal
Accession number :
edsdoj.f3f2b3eb63234ef698b4fa4968262e8e
Document Type :
article
Full Text :
https://doi.org/10.3390/ijms19102961