Characterizing the effects of lunar dust simulants on T-cell viability and activation

With the Artemis Program, humans are returning to the Moon for the first time in 50 years. During precedent Apollo missions, astronauts got into contact with lunar dust, and reported visual obstruction, nose and throat irritation, skin irritation, dust pollution and psychological effects which could be the result of lunar dust exposure (Cain, 2010; Cernan et al., 1973; Park et al., 2008; Stubbs et al., 2007; Taylor et al., 2005). Lunar dust has been thoroughly examined to describe its chemical and morphological characteristics and behaviour. Due to these descriptions, lunar dust simulants (LDS) were developed to be able to perform research of lunar dust (and LDS) on the human body. Prominent research has revealed the many adverse effects lunar dust might have on the immune system, lungs, cardiovascular system, skin, eyes, neurons and machinery. These studies are important to characterise these effects and for the development of biological countermeasures as well as avoidance by technical countermeasures. In this study, the effects of Lunar Highland Simulant (LHS-1) and Lunar Mare Simulant (LMS-1), were examined on the viability and cytokine release in Jurkat cells. By performing MTS assays and IL-2 ELISA assay. These assays encountered several methodological issues and were first optimised to retain reliable results. LHS-1 and LMS-1, induce cell death in Jurkat cells, up to 50%, independent of the LDS concentration. Exposure to LMS-1 leads to an increased IL-2 release in Jurkat cells. When exposed to LHS-1, the IL-2 concentration is inversely proportional to the LHS-1 dose. This might be the result of cell death caused by LHS-1 or the interaction of LHS-1 with IL-2. In addition, the LDS were visualised with a scanning electron microscope (SEM) as well as the LDS exposed Jurkat cells. It could be noticed how LDS particles cover the cell’s surface, indicating that the dust likely could interfere with the cellular processes and mechanisms. LHS-1 and LMS-1 were characterised by an SEM to test their compatibility with lunar dust. The LDS lack nanophase iron and the vesicular surface of lunar dust which might play a critical role in its toxicity. Further research is needed to test the effects of lunar dust, and in combination with other space stressors, on the immune system further.