TY - JOUR
T1 - Mycobacteria entry and trafficking into endothelial cells
AU - Baltierra-Uribe, Shantal Lizbeth
AU - de García-Vásquez, Manuel Jesús
AU - Castrejón-Jiménez, Nayeli Shantal
AU - Estrella-Piñón, Mayra Patricia
AU - Luna-Herrera, Julieta
AU - García-Pérez, Blanca Estela
N1 - Publisher Copyright:
© 2014, NRC Research Press. All rights reserved.
PY - 2014/7/1
Y1 - 2014/7/1
N2 - Endothelial cells are susceptible to infection by mycobacteria, but the endocytic mechanisms that mycobacteria exploit to enter host cells and their mechanisms of intracellular transport are completely unknown. Using pharmacological inhibitors, we determined that the internalization of Mycobacterium tuberculosis (MTB), Mycobacterium smegmatis (MSM), and Mycobacterium abscessus (MAB) is dependent on the cytoskeleton and is differentially inhibited by cytochalasin D, nocodazole, cycloheximide, wortmannin, and amiloride. Using confocal microscopy, we investigated their endosomal trafficking by analyzing Rab5, Rab7, LAMP-1, and cathepsin D. Our results suggest that MSM exploits macropinocytosis to enter endothelial cells and that the vacuoles containing these bacteria fuse with lysosomes. Conversely, the entry of MTB seems to depend on more than one endocytic route, and the observation that only a subset of the intracellular bacilli was associated with phagolysosomes suggests that these bacteria are able to inhibit endosomal maturation to persist intracellularly. The route of entry for MAB depends mainly on microtubules, which suggests that MAB uses a different trafficking pathway. However, MAB is also able to inhibit endosomal maturation and can replicate intracellularly. Together, these findings provide the first evidence that mycobacteria modulate proteins of host endothelial cells to enter and persist within these cells.
AB - Endothelial cells are susceptible to infection by mycobacteria, but the endocytic mechanisms that mycobacteria exploit to enter host cells and their mechanisms of intracellular transport are completely unknown. Using pharmacological inhibitors, we determined that the internalization of Mycobacterium tuberculosis (MTB), Mycobacterium smegmatis (MSM), and Mycobacterium abscessus (MAB) is dependent on the cytoskeleton and is differentially inhibited by cytochalasin D, nocodazole, cycloheximide, wortmannin, and amiloride. Using confocal microscopy, we investigated their endosomal trafficking by analyzing Rab5, Rab7, LAMP-1, and cathepsin D. Our results suggest that MSM exploits macropinocytosis to enter endothelial cells and that the vacuoles containing these bacteria fuse with lysosomes. Conversely, the entry of MTB seems to depend on more than one endocytic route, and the observation that only a subset of the intracellular bacilli was associated with phagolysosomes suggests that these bacteria are able to inhibit endosomal maturation to persist intracellularly. The route of entry for MAB depends mainly on microtubules, which suggests that MAB uses a different trafficking pathway. However, MAB is also able to inhibit endosomal maturation and can replicate intracellularly. Together, these findings provide the first evidence that mycobacteria modulate proteins of host endothelial cells to enter and persist within these cells.
KW - Endothelial cells
KW - Macropinocytosis
KW - Mycobacterium abscessus
KW - Mycobacterium tuberculosis
KW - Rab proteins
UR - http://www.scopus.com/inward/record.url?scp=84906957767&partnerID=8YFLogxK
U2 - 10.1139/cjm-2014-0087
DO - 10.1139/cjm-2014-0087
M3 - Artículo
SN - 0008-4166
VL - 60
SP - 569
EP - 577
JO - Canadian Journal of Microbiology
JF - Canadian Journal of Microbiology
IS - 9
ER -