Deciphering Mycobacterium tuberculosis glycan epitopes through clustering of human polyclonal and isolating novel monoclonal antibodies II

The immunomodulatory mycobacterial surface antigen lipoarabinomannan (LAM) with its immunogenic glycan component arabinomannan (AM) facilitates Mycobacterium tuberculosis’ (Mtb) escape from the host’s immune response. Some but not all antibodies against AM can protect against TB. To better understand which of AM’s structures to target, we must first identify the spectrum of its epitopes. Through isolating and characterizing a panel of novel human mAbs with binding to distinct AM OS motifs, we further defined the glycan epitope structures, identified a new epitope, and determined their differences among mycobacterial strains. Monoclonal antibodies at 5 ug/ml were tested for direct binding to 30 synthetic oligosaccharides