The Cording Phenotype of Mycobacterium tuberculosis Induces the Formation of Extracellular Traps in Human Macrophages

Frontiers in Cellular and Infection Microbiology

Raffetseder, Johanna²  Kalsum, Sadaf²  Lerm, Maria²  Braian, Clara³  Lindroth, Margaretha³  van Crevel, Reinout⁴  Koeken, Valerie A. C. M.⁴ 

[1] Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, Netherlands;Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden

关键词: Mycobacterium tuberculosis;    Macrophage Extracellular Traps;    Cording;    Tween 80;    Virulence;    early secreted antigenic target 6 (ESAT-6);   

DOI  :  10.3389/fcimb.2017.00278

学科分类：生物科学（综合）

来源: Frontiers

【 摘 要 】

The causative agent of tuberculosis, Mycobacterium tuberculosis, shares several characteristics with organisms that produce biofilms during infections. One of these is the ability to form tight bundles also known as cords. However, little is known of the physiological relevance of the cording phenotype. In this study, we investigated whether cord-forming M. tuberculosis induce the formation of macrophage extracellular traps (METs) in human monocyte-derived macrophages. Macrophages have previously been shown to produce extracellular traps in response to various stimuli. We optimized bacterial culturing conditions that favored the formation of the cord-forming phenotype as verified by scanning electron microscopy. Microscopy analysis of METs formation during experimental infection of macrophages with M. tuberculosis revealed that cord-forming M. tuberculosis induced significantly more METs compared to the non-cording phenotype. Deletion of early secreted antigenic target-6 which is an important virulence factor of M. tuberculosis, abrogated the ability of the bacteria to induce METs. The release of extracellular DNA from host cells during infection may represent a defense mechanism against pathogens that are difficult to internalize, including cord-forming M. tuberculosis.

【 授权许可】

CC BY