Mouse femur LC-MSMS upon weightlessness

Bone loss and immune dysregulation are among the main adverse outcomes of spaceflight challenging astronaut’s health and safety. However, consequences on B cell development and responses are still under-investigated. Up to now, most studies addressing these questions were performed using an amphibian species. Consequently, we used advanced proteomics analysis of femur bone and marrow of mice flown for one month on board the BION-M1 biosatellite, to determine whether extreme conditions encountered during a real spaceflight affect B cell development in mice and to examine reversibility of the effects upon return to Earth. Our data revealed that adverse effects on B lymphopoiesis were more marked one week after landing and that this phenomenon was associated with a 41% reduction of B cells in the spleen. Thus, the effects of spaceflight persisted during at least one week after landing. These reductions may contribute to explain increased susceptibility to infection even if we confirmed that animals were able to mount a humoral immune response.

骨质流失与免疫失调是航天飞行引发的主要不良事件，严重威胁航天员的健康与安全。然而，航天飞行对B细胞发育及免疫应答的影响仍未得到充分研究。迄今为止，针对该问题的多数研究均采用两栖类动物作为实验模型。为此，本研究对在BION-M1生物卫星上在轨飞行1个月的小鼠股骨及骨髓开展先进蛋白质组学（proteomics）分析，以探究真实航天飞行中遭遇的极端环境是否会影响小鼠的B细胞发育，并考察返回地球后相关影响的可逆性。本研究数据显示，着陆后1周时，对B淋巴细胞生成的不良影响更为显著，且该现象与脾脏内B细胞数量减少41%相关。由此可见，航天飞行带来的影响至少在着陆后1周内仍持续存在。即便本研究已证实实验动物仍可启动体液免疫应答，但上述B细胞数量的减少或可解释感染易感性升高的现象。