Dual-lipid metabolomics revealed the communication of MTB or MB with Bovine alveolar macrophages in lipid metabolisms

Abstract

M. tuberculosis(MTB) and M. bovis(MB) of the Mycobacterium tuberculosis complex (MTBC) are the causative agents of the notorious infectious disease tuberculosis(TB) in a range of mammals, including cattle and human. The lipid composition of MTB/MB performed imperative function as invading host macrophage. In the present study, a dual-lipid metabolomics were used to elucidate the differences in lipid composition of MTB and MB and the different responses in lipid metabolisms of bovine alveolar macrophage challenged by MTB/MB. The lipid metabolomics of MTB and MB indicated that there were significant differences in lipid composition of both bacteria that the level of various lipids belonged to Glycerophospholipids, Sterol Lipids, Fatty Acyls and Polyketides exhibited differences between MTB and MB. Meanwhile, both MTB and MB with different lipid composition could invoked different responses in lipid metabolisms of the host macrophage. MTB infection mainly induced the increase in content of Polyketides and Glycerophospholipids in macrophages, whereas MB infection induced the level of Glycerophospholipids and Sterol Lipids of macrophages. Furthermore, we identified TAG 13:0-18:5-18:5 of MTB and PC(16:1(9E)/0:0), PI(20:2(11Z,14Z)/22:6(4Z,7Z,10Z,13Z,16Z,19Z)), 4,6-Decadiyn-1-ol isovalerate and LacCer(d18:1/24:1(15Z)) of MB caused the different variations in lipid metabolisms of macrophage following MTB/MB attacks, respectively. Finally, we proposed MTB and MB with different lipid compositions could successfully colonize in macrophage by different mechanisms that MTB could promote the formation of foam cells of macrophage for its colonization and development, while MB mainly through suppressing the macrophage autophagy to escape the immune responses of host. ImportanceThe differences in lipid composition of MTB and MB and the different responses in lipid metabolisms of bovine alveolar macrophage challenged by MTB/MB were elucidated in this study. The lipid composition of MTB and MB exhibited significantly different patterns, which could induced different responses of the host macrophage during the infection process of MTB or MB, respectively. MTB infection mainly induced the increase in content of Polyketides and Glycerophospholipids in macrophages, whereas MB infection induced the level of Glycerophospholipids and Sterol Lipids of macrophages.The results presented here thus provides a comprehensively dual-lipid metabolomics profile in MTB/MB and MTB/MB-attacked macrophages, which deepened our understanding of the interaction between host and pathogens in lipid metabolisms.