The human body contains approximately 48 genes encoding nuclear receptors. Given their crucial role in pathologies, these proteins are preferred targets for drug discovery and development. Nuclear receptors are the target for approximately 13 percent of all available pharmaceuticals — from prostate cancer treatments to oral contraceptives. These drugs all work using the same mechanism: they bind to a receptor at the same site as its natural ligand and thereby influence its behavior.
The published research focuses specifically on the RORγt receptor, which plays an important role in auto-immune diseases like rheumatism and Crohn’s disease. The researchers have discovered that a particular class of molecules binds to a previously unknown site on RORγt and potently antagonizes this nuclear receptor’s function. The main advantage of this new mode of action is that it uses a kind of back door of the nuclear receptor that endogenous ligands do not access. This suggests that any compensatory mechanism the human body may make in ligand production would be less likely to induce resistance and decrease efficacy.
For the first time in fifty years, research has identified an effective means for drugs to bind to a novel site on a nuclear receptor and thus inhibit it, explains Luc Brunsveld, TU/e professor of Chemical Biology. This opens the way for new drugs for auto-immune diseases. But the impact could go beyond this. Perhaps some of the other 47 known receptors can be blocked in the same way. This could enable a new class of drugs that function differently, and potentially better, than current medications. “This news is going to have a major effect on the field of drug development,” Brunsveld expects. “I anticipate a flow of further research geared to investigating the potential of this concept.”