Probing Isosteric Replacement for Immunoadjuvant Design: Bis-Aryl Triazole Trehalolipids are Mincle Agonists.

Herein, we report the modular synthesis and immunological activity of seven bis-aryl triazole trehalolipids (-) as Brartemicin analogs. The compounds comprised one or two octyloxy (C8) alkyl chains and were synthesized using the venerable CuAAc reaction between the respective aryl acetylenes and a trehalose diazide. A Mincle reporter cell assay revealed that all lipidated analogs activated Mincle. Two compounds, and , produced strong Mincle-dependent immune responses . The activity was dependent on the degree of alkylation and regiochemistry, with and showing significantly increased IL-1β production compared to monoalkylated compounds and dialkylated compounds lacking substitution. Molecular docking of positioned the triazole in proximity to Arg-183, which may offer additional interactions that could explain the binding affinity for this class of ligand. These findings demonstrate the capability of triazole-linked Brartemicin analogs as Mincle-mediated Th1/Th17 vaccine adjuvants.