Fig. 6: Approaches to screen for immune-cell specific radioprotectors.

Various strategies can be employed to identify radioprotectors that specifically target immune cells. High-throughput screening of chemical libraries, genetic screens, and functional assays offer ways to discover agents that selectively shield immune cells from radiation damage. Depending on the type of ACT being studied, screens can be conducted in a range of immune-cell types, from easily manipulated cell lines to more clinically relevant, human-derived cells. Screening can be performed in vitro, which allows for more practical, controlled experiments, or in vivo, where complex biological interactions are better represented. Radiation is applied as needed, using tools like cabinet irradiators for in vitro cultures or small animal irradiators for in vivo studies. Readouts can vary depending on the specific goals of the screen, ranging from simple measurements of cell survival or function post-irradiation to more sophisticated next-generation sequencing (NGS) approaches that assess the selection of different perturbations after exposure. Analytical methods can involve straightforward ranking of top perturbations that improve immune-cell survival or function, as well as deeper molecular pathway analyses to gain mechanistic insight. Radioprotectors are also assessed for their ability to maintain immune-cell functionality, prevent apoptosis, or preserve immune-cell subsets during or after radiation. Validation of hits is critical to confirm radioprotective efficacy and ensure that identified candidates not only protect immune cells but also preserve their therapeutic potential. These methods hold promise for identifying radioprotectors that maintain immune competence in ACT, while ensuring therapeutic safety and efficacy.