Photopharmacological control of TRPC3/6 channels in T-cells

Changes in calcium within the cell are known to be essential for the proper function of all cells, including immune cells. Calcium channels are a particularly well-suited molecular target for influencing the immune system therapeutically. The clinical benefit of modulation of immune system by targeting ion channels depends on the cell specificity as well as the spatial and temporal precision of the pharmacological intervention. Calcium channels called TRPC (transient receptor potential canonical) are present on the cell surface in special immune cells and in certain disease processes. Recently, in our lab we developed a series of molecules which can activate/inactivate TRPC channels type 3 and 6. These molecules, known as Optobenzimidazole (OptoBI) photoswitches, can be switched on by UV light and switched off by blue light. This results in the possibility of a previously unattained precision of the pharmacological modulation in terms of temporal and spatial limitation. Having this new generation of TRPC activating/inhibiting molecules at hand, we now aim to utilize this novel approach to investigate the function of TRPC3/6 channels in mouse lymphocytes. In the work package 1 we plan to, on the basis of these new photoswitchable molecules, develop a new therapeutic concept. For this purpose, the possibilities for controlling the function of lymphocytes via photopharmacological influencing of TRPC3/6 channels in a mouse model will be investigated. The newly available TRPC3 / 6 activators/inhibitors will be then tested with regard to their possible therapeutic benefit and their application will be further developed. Our second aim (work package 2) is to, by using the tools developed in the first package, pinpoint specific lymphocyte populations in which TRPC3/6 channels play significant role. Cells will be isolated from the spleen of mice which are genetically engineered to express different levels of TRPC channels. Calcium signals related to TRPC channels will be analyzed in detail. The third aim of this proposal (work package 3) is to test TRPC3/6 photoswitches in vivo in a murine psoriasis model of skin inflammation. In the end of this project, we expect to better understand calcium signals within the highly complex immunological network. Identification of so far not known signaling pathways in lymphocytes by using photoswitchable molecules could provide new therapeutic targets and drug candidates in immune diseases.