Detection of Lipomannan in Cattle Infected with Bovine Tuberculosis

Abstract

Early and rapid detection of bovine tuberculosis (bTB) is critical to controlling the spread of this disease in cattle and other animals. In this study, we demonstrate the development of an immunoassay for the direct detection of the bovine bTB biomarker, lipomannan (LM) in serum using a waveguide-based optical biosensor. We apply an ultra-sensitive detection strategy developed by our team, termed lipoprotein capture, that exploits the pull-down of high-density lipoprotein (HDL) nanodiscs from cattle blood that allows for the recovery and detection of associated LM. We also profile the change in the expression of these TB biomarkers as a function of time from a small set of samples collected from studies of bovine TB-infected cattle. We demonstrate for the first time the direct detection of bovine LM in serum, and clearly show that the biomarker is expressed in detectable concentrations during the entire course of the infection.

Detection of Lipid and Amphiphilic Biomarkers for Disease Diagnostics

“…This system utilizes the interactions of these biomarkers with lipid bilayers and lipoproteins to capture them directly to the waveguide surface, followed by probing with labeled-antibodies excited by waveguide-coupled laser light ( Figure 2 ). This system has been demonstrated to effectively detect amphiphilic biomarkers associated with Mycobacterium tuberculosis [ 15 , 83 ], M. bovis [ 84 ], Escherichia coli [ 85 ], Salmonella Typhimurium [ 86 ], influenza [ 87 ], tumor markers [ 88 , 89 ] oftentimes directly in human serum, proving potential utility as a diagnostic tool [ 80 , 82 ]. These assays have been multiplexed for the simultaneous detection of several biomarkers [ 81 ].…”

“…LAM is readily detected in urine [ 88 , 89 ], but not in blood, likely because it associates with HDL in blood [ 15 ]. To this end, lipoprotein capture assays that utilize antibodies to target HDL have been used to pull down bound LAM in serum samples [ 15 , 83 , 84 ]. This method targets host pathogen interactions, and can be applied to other amphiphilic biomarkers in blood [ 83 ].…”

“…This method targets host pathogen interactions, and can be applied to other amphiphilic biomarkers in blood [ 83 ]. Pathogen biomarker based measurements can be used in both human and animal hosts [ 84 , 113 ]. However, the high cost of such technology, and biochemical nature of LAM are current challenges to the development of such assays [ 124 ].…”

Pediatric Tuberculosis: The Impact of “Omics” on Diagnostics Development

“…These studies show that LAM measurement is more reliable in immunocompromised children, and that measured concentrations of the antigen decrease with anti-TB treatment [ 136 ], which suggests potential for this biomarker to be used as a prognostic indicator. Longitudinal studies demonstrating antigen concentrations as a function of disease progression and treatment must be performed in order to validate this hypothesis, as previously demonstrated for the measurement of lipomannan in M. bovis infection [ 137 , 138 , 139 , 140 ].…”

Analytical System Using Lipid Bilayers to Immobilize Biofunctional Compounds

“…9 Vu et al developed a direct detection of the bovine bTB biomarker, lipomannan, in serum using a waveguide-based optical biosensor of which the surface was coated with lipid bilayers. 10 They indicated that the sensor was useful to detect lipomannan in the region of concentrations during the entire course of the infection. Similarly, self-assembled monolayer films on solid electrodes have been used to immobilize biofunctional compounds.…”