biostudies-literatureStoop EJMedical Research CouncilWellcome Trust2093-108https://www.ebi.ac.uk/biostudies/studies/S-EPMC3963455biostudies-literatureUnknown15(12)The causative agent of tuberculosis (TB), Mycobacterium tuberculosis, remains an important worldwide health threat. Although TB is one of the oldest infectious diseases of man, a detailed understanding of the mycobacterial mechanisms underlying pathogenesis remains elusive. Here, we studied the role of the α(1→2) mannosyltransferase MptC in mycobacterial virulence, using the Mycobacterium marinum zebrafish infection model. Like its M. tuberculosis orthologue, disruption of M. marinum mptC (mmar_3225) results in defective elongation of mannose caps of lipoarabinomannan (LAM) and absence of α(1→2)mannose branches on the lipomannan (LM) and LAM mannan core, as determined by biochemical analysis (NMR and GC-MS) and immunoblotting. We found that the M. marinum mptC mutant is strongly attenuatedCellular microbiologyMannan core branching of lipo(arabino)mannan is required for mycobacterial virulence in the context of innate immunity.PMC3963455081569/Z/06/ZMR/K012118/1Mishra AKvan der Sar AMAppelmelk BJBouchier PVerboom Tvan Zon MGeurtsen JDriessen NNBitter WSparrius MRaadsen SAvan der Wel NNvan Stempvoort GStoop EJvan Leeuwen LMBesra GSfalseMannan core branching of lipo(arabino)mannan is required for mycobacterial virulence in the context of innate immunity.The causative agent of tuberculosis (TB), Mycobacterium tuberculosis, remains an important worldwide health threat. Although TB is one of the oldest infectious diseases of man, a detailed understanding of the mycobacterial mechanisms underlying pathogenesis remains elusive. Here, we studied the role of the α(1→2) mannosyltransferase MptC in mycobacterial virulence, using the Mycobacterium marinum zebrafish infection model. Like its M. tuberculosis orthologue, disruption of M. marinum mptC (mmar_3225) results in defective elongation of mannose caps of lipoarabinomannan (LAM) and absence of α(1→2)mannose branches on the lipomannan (LM) and LAM mannan core, as determined by biochemical analysis (NMR and GC-MS) and immunoblotting. We found that the M. marinum mptC mutant is strongly attenuated2013-01-01T00:00:00Z2013 Dec2026-05-07T10:26:14.045Z2026-04-29T03:07:49.446ZS-EPMC39634552390246410.1111/cmi.12175