Laboratory of Integrated Physiology, Department of Health and Human Performance, University of Houston, Houston, TX, USA.
JesTech, NASA Johnson Space Center, Houston, TX, USA.
FASEB J. 2020 Feb;34(2):2869-2881. doi: 10.1096/fj.201902327R. Epub 2020 Jan 3.
Latent viral reactivation is a commonly reported manifestation of immune system dysregulation during spaceflight. As physical fitness and exercise training have been shown to benefit multiple arms of the immune system, we hypothesized that higher levels of preflight physical fitness and/or maintaining fitness during a mission would protect astronauts from latent viral reactivation. Standardized tests of maximal strength, muscular endurance, flexibility, and cardiorespiratory fitness (CRF) were performed in 22 international space station (ISS) crewmembers before and after a ~6-month mission. Reactivation of cytomegalovirus (CMV), Epstein-Barr virus (EBV), and varicella zoster virus (VZV) was determined in crewmembers and ground-based controls before, during, and after spaceflight. Crewmembers with higher CRF before spaceflight had a 29% reduced risk of latent viral reactivation compared to crew with lower CRF. Higher preflight upper body muscular endurance was associated with a 39% reduced risk of viral reactivation, a longer time to viral reactivation, and lower peak viral DNA concentrations, particularly for EBV and VZV. Latent viral reactivation rates were highest in crew with lower preflight CRF and higher levels of CRF deconditioning on return to Earth. We conclude that physical fitness may protect astronauts from latent viral reactivation during long duration spaceflight missions.
潜伏性病毒激活是航天飞行期间免疫系统失调的一种常见表现。由于身体适应性和锻炼训练已被证明对免疫系统的多个分支有益,我们假设更高水平的飞行前身体适应性和/或在任务期间保持适应性将保护宇航员免受潜伏性病毒激活。在 22 名国际空间站(ISS)机组人员执行约 6 个月的任务前后,对他们进行了最大力量、肌肉耐力、柔韧性和心肺适应性(CRF)的标准化测试。在航天飞行前、期间和之后,在机组人员和地面对照组中确定了巨细胞病毒(CMV)、爱泼斯坦-巴尔病毒(EBV)和水痘带状疱疹病毒(VZV)的激活情况。与 CRF 较低的机组人员相比,飞行前 CRF 较高的机组人员潜伏性病毒激活的风险降低了 29%。较高的飞行前上身肌肉耐力与病毒激活风险降低 39%、病毒激活时间延长和峰值病毒 DNA 浓度降低有关,特别是 EBV 和 VZV。在返回地球时 CRF 较低且适应性降低程度较高的机组人员中,潜伏性病毒激活率最高。我们的结论是,身体适应性可能会保护宇航员免受长期太空飞行任务中潜伏性病毒激活的影响。