Increasing Human Th17 Differentiation through Activation of Orphan Nuclear Receptor Retinoid Acid-Related Orphan Receptor γ (RORγ) by a Class of Aryl Amide Compounds

Abstract

In a screen for small-molecule inhibitors of retinoid acid-related orphan receptor ␥ (ROR␥), we fortuitously discovered that a class of aryl amide compounds behaved as functional activators of the interleukin 17 (IL-17) reporter in Jurkat cells. Three of these compounds were selected for further analysis and found to activate the IL-17 reporter with potencies of ϳ0.1 M measured by EC 50 . These compounds were shown to directly bind to ROR␥ by circular dichroism-based thermal stability experiments. Furthermore, they can enhance an in vitro Th17 differentiation process in human primary T cells. As ROR␥ remains an orphan nuclear receptor, discovery of these aryl amide compounds as functional agonists will now provide pharmacological tools for us to dissect functions of ROR␥ and facilitate drug discovery efforts for immune-modulating therapies.

Discovery of N -(4-aryl-5-aryloxy-thiazol-2-yl)-amides as potent RORγt inverse agonists

“…The representative compounds in the series were selected for evaluation in the mouse Th17 cell differentiation assay. 27,29 Most of the compounds showed reasonable Th17 cellular activity ( Table 2). Compound 3m showed a pIC 50 of 6.8 in Th17 assay.…”

“…27,28 RORt potency (pXC 50 ) and maximum response (%max) were measured in both FRET and dual FRET assays. 29,30 While the FRET assay is useful to identify antagonists, the dual FRET assay in which a surrogate agonist is not added allows the detection of both agonists and inverse agonists based on the changes in the basal level of RORt activity. 30 As we observed before, 27 addition of small alkyl groups such as Me (2a) and Et (2b) at 5-position of the thiazole ring did not change much of RORt activity in both FRET and dual FRET assays.…”

The cytokine networks of adaptive immunity in fish

“…The up-regulation of RORgt involves STAT3, IRF4, c-Rel, and upstream stimulatory factors [141]. Although the native ligand is unknown, the recent identification of small molecule inhibitors and activators of RORg that impair or enhance Th17 development further support its role in Th17 development [142].…”

“…The dissociation of expression of trout RORg and IL-17A/F2 poses a question as to whether RORg can control IL-17A/F expression in fish. The question might be answered by applying the recently developed small molecular modulators of mammalian RORg to conditions where fish IL-17A/F can be expressed and modulated [142].…”

Discovery of Biaryl Amides as Potent, Orally Bioavailable, and CNS Penetrant RORγt Inhibitors

“…Among the five-membered ring analogues, 2,4-substituted thiophene 4c showed the best RORγt potency in the FRET assay. 32,34 The heteroatom such as oxygen and nitrogen on the ring decreased (4a) and even abolished (4d, 4f, 4h) RORγt activities. For the six-membered ring analogues, para-substituted aryl amide (4i) showed better RORγt potency than the meta-substituted one (4g).…”