Fluorinated trehalose analogues for cell surface engineering and imaging ofMycobacterium tuberculosis

Abstract

AbstractThe sensitive, rapid and accurate diagnosis ofMycobacterium tuberculosis(Mtb) infection is a central challenge in controlling the global tuberculosis (TB) pandemic. Yet the detection of mycobacteria is often made difficult by the low sensitivity of current diagnostic tools, with over 3.6 million TB cases missed each year. To overcome these limitations there is an urgent need for next-generation TB diagnostic technologies. Here we report the use of a discrete panel of native19F-trehalose (F-Tre) analogues to label and directly visualiseMtbby exploiting the uptake of fluorine-modified trehalose analoguesviathe mycobacterial trehalose LpqY-SugABC ATP-binding cassette (ABC) importer. We discovered the extent of modified F-Tre uptake correlates with LpqY substrate recognition and characterisation of the interacting sites by saturation transfer difference NMR coupled with molecular dynamics provides a unique glimpse into the molecular basis of fluorine-modified trehalose import inMtb. Lipid profiling demonstrated that F-Tre analogues modified at positions 2, 3 and 6 are incorporated into mycobacterial cell-surface trehalose-containing glycolipids. This rapid one-step labelling approach facilitates the direct visualisation of F-Tre-labelledMtbby focused ion beam (FIB) secondary ion mass spectrometry (SIMS), enabling pathogen specific detection. Collectively, our findings highlight that F-Tre analogues have potential as tools to probe and unravelMtbbiology and can be exploited to detect and image TB.