Signal transduction in primary human T lymphocytes in altered gravity – results of the MASER-12 suborbital space flight mission

• Published in: Cell Communication and Signaling
• Main Authors: Tauber, Svantje, Hauschild, Swantje, Crescio, Claudia, Secchi, Christian, Paulsen, Katrin, Pantaleo, Antonella, Saba, Angela, Buttron, Isabell, Thiel, Cora Sandra, Cogoli, Augusto, Pippia, Proto, Ullrich, Oliver
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Science and Business Media LLC 2013
• Subjects: Cell Biology; Molecular Biology; Biochemistry; Kiruna; Esrange
• Online Access: http://dx.doi.org/10.1186/1478-811x-11-32; https://link.springer.com/content/pdf/10.1186/1478-811X-11-32.pdf

Abstract We investigated the influence of altered gravity on key proteins of T cell activation during the MASER-12 ballistic suborbital rocket mission of the European Space Agency (ESA) and the Swedish Space Cooperation (SSC) at ESRANGE Space Center (Kiruna, Sweden). We quantified components of the T cell receptor, the membrane proximal signaling, MAPK-signaling, IL-2R, histone modifications and the cytoskeleton in non-activated and in ConA/CD28-activated primary human T lymphocytes. The hypergravity phase during the launch resulted in a downregulation of the IL-2 and CD3 receptor and reduction of tyrosine phosphorylation, p44/42-MAPK phosphorylation and histone H3 acetylation, whereas LAT phosphorylation was increased. Compared to the baseline situation at the point of entry into the microgravity phase, CD3 and IL-2 receptor expression at the surface of non-activated T cells were reduced after 6 min microgravity. Importantly, p44/42-MAPK-phosphorylation was also reduced after 6 min microgravity compared to the 1g ground controls, but also in direct comparison between the in-flight μg and the 1g group. In activated T cells, the reduced CD3 and IL-2 receptor expression at the baseline situation recovered significantly during in-flight 1g conditions, but not during microgravity conditions. Beta-tubulin increased significantly after onset of microgravity until the end of the microgravity phase, but not in the in-flight 1g condition. This study suggests that key proteins of T cell signal modules are not severely disturbed in microgravity. Instead, it can be supposed that the strong T cell inhibiting signal occurs downstream from membrane proximal signaling, such as at the transcriptional level as described recently. However, the MASER-12 experiment could identify signal molecules, which are sensitive to altered gravity, and indicates that gravity is obviously not only a requirement for transcriptional processes as described before, but also for specific phosphorylation / dephosphorylation of signal molecules and surface receptor dynamics.