Revisiting the role of phospholipases C in virulence and the lifecycle of Mycobacterium tuberculosis.
Sci Rep 2015;
5:16918. [PMID:
26603639 PMCID:
PMC4658479 DOI:
10.1038/srep16918]
[Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 10/22/2015] [Indexed: 12/02/2022] Open
Abstract
Mycobacterium tuberculosis, the agent of human tuberculosis has developed
different virulence mechanisms and virulence-associated tools during its evolution
to survive and multiply inside the host. Based on previous reports and by analogy
with other bacteria, phospholipases C (PLC) of M. tuberculosis were thought
to be among these tools. To get deeper insights into the function of PLCs, we
investigated their putative involvement in the intracellular lifestyle of M.
tuberculosis, with emphasis on phagosomal rupture and virulence, thereby
re-visiting a research theme of longstanding interest. Through the construction and
use of an M. tuberculosis H37Rv PLC-null mutant (ΔPLC) and
control strains, we found that PLCs of M. tuberculosis were not required for
induction of phagosomal rupture and only showed marginal, if any, impact on
virulence of M. tuberculosis in the cellular and mouse infection models used
in this study. In contrast, we found that PLC-encoding genes were strongly
upregulated under phosphate starvation and that PLC-proficient M.
tuberculosis strains survived better than ΔPLC mutants under
conditions where phosphatidylcholine served as sole phosphate source, opening new
perspectives for studies on the role of PLCs in the lifecycle of M.
tuberculosis.
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