Aryl Trehalose Derivatives as Vaccine Adjuvants for <i>Mycobacterium tuberculosis</i>

Abstract

<i>Mycobacterium tuberculosis</i> (<i>Mtb</i>) continues to be a major health threat worldwide, and the development of <i>Mtb</i> vaccines could play a pivotal role in the prevention and control of this devastating epidemic. Th17-mediated immunity has been implicated in disease protection correlates of immune protection against <i>Mtb</i>. Currently, there are no approved adjuvants capable of driving a Th17 response in a vaccine setting. Recent clinical trial results using trehalose dibehenate have demonstrated a formulation-dependant proof of concept adjuvant system CAF01 capable of inducing long-lived protection. We have discovered a new class of Th17-inducing vaccine adjuvants based on the natural product Brartemicin. We synthesized and evaluated the capacity of a library of aryl trehalose derivatives to drive immunostimulatory reresponses and evaluated the structure-activity relationships in terms of the ability to engage the Mincle receptor and induce production of innate cytokines from human and murine cells. We elaborated on the structure-activity relationship of the new scaffold and demonstrated the ability of the lead entity to induce a pro-Th17 cytokine profile from primary human peripheral blood mononuclear cells and demonstrated efficacy in generating antibodies in combination with tuberculosis antigen M72 in a mouse model.