Phosphonamidate Prodrugs of a Butyrophilin Ligand Display Plasma Stability and Potent V?9 V?2 T Cell Stimulation.

ABSTRACT: Small organophosphorus compounds stimulate V?9 V?2 T cells if they serve as ligands of butyrophilin 3A1. Because the most potent natural ligand is ( E)-4-hydroxy-3-methyl-but-2-enyl diphosphate (HMBPP), which is the last intermediate in bacterial biosynthesis of isoprenoids that is not found in mammalian metabolism, activation of these T cells represents an important component of the immune response to bacterial infections. To identify butyrophilin ligands that may have greater plasma stability, and clinical potential, we have prepared a set of aryl phosphonamidate derivatives (9a-i) of the natural ligand. Testing of these new compounds in assays of T cell response has revealed that this strategy can provide compounds with high potency for expansion of V?9 V?2 T cells (9f, EC50 = 340 pM) and interferon ? production in response to loaded K562 cells (9e, EC50 = 62 nM). Importantly, all compounds of this class display extended plasma stability ( t1/2 > 24 h). These findings increase our understanding of metabolism of butyrophilin ligands and the structure-activity relationships of phosphonamidate prodrugs.

SUBMITTER: Lentini NA 

PROVIDER: S-EPMC6703555 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature