TY - JOUR
T1 - Pyruvate protects pathogenic spirochetes from H2O2 killing
AU - Troxel, Bryan
AU - Zhang, Jun Jie
AU - Bourret, Travis J.
AU - Zeng, Melody Yue
AU - Blum, Janice
AU - Gherardini, Frank
AU - Hassan, Hosni M.
AU - Yang, X. Frank
PY - 2014/1/2
Y1 - 2014/1/2
N2 - Pathogenic spirochetes cause clinically relevant diseases in humans and animals, such as Lyme disease and leptospirosis. The causative agent of Lyme disease, Borrelia burgdorferi, and the causative agent of leptospirosis, Leptospria interrogans, encounter reactive oxygen species (ROS) during their enzootic cycles. This report demonstrated that physiologically relevant concentrations of pyruvate, a potent H2O2 scavenger, and provided passive protection to B. burgdorferi and L. interrogans against H 2O2. When extracellular pyruvate was absent, both spirochetes were sensitive to a low dose of H2O2 (≈0.6 mM per h) generated by glucose oxidase (GOX). Despite encoding a functional catalase, L. interrogans was more sensitive than B. burgdorferi to H 2O2 generated by GOX, which may be due to the inherent resistance of B. burgdorferi because of the virtual absence of intracellular iron. In B. burgdorferi, the nucleotide excision repair (NER) and the DNA mismatch repair (MMR) pathways were important for survival during H 2O2 challenge since deletion of the uvrB or the mutS genes enhanced its sensitivity to H2O2 killing; however, the presence of pyruvate fully protected ΔuvrB and ΔmutS from H 2O2 killing further demonstrating the importance of pyruvate in protection. These findings demonstrated that pyruvate, in addition to its classical role in central carbon metabolism, serves as an important H2O2 scavenger for pathogenic spirochetes. Furthermore, pyruvate reduced ROS generated by human neutrophils in response to the Toll-like receptor 2 (TLR2) agonist zymosan. In addition, pyruvate reduced neutrophil-derived ROS in response to B. burgdorferi , which also activates host expression through TLR2 signaling. Thus, pathogenic spirochetes may exploit the metabolite pyruvate, present in blood and tissues, to survive H 2O2 generated by the host antibacterial response generated during infection.
AB - Pathogenic spirochetes cause clinically relevant diseases in humans and animals, such as Lyme disease and leptospirosis. The causative agent of Lyme disease, Borrelia burgdorferi, and the causative agent of leptospirosis, Leptospria interrogans, encounter reactive oxygen species (ROS) during their enzootic cycles. This report demonstrated that physiologically relevant concentrations of pyruvate, a potent H2O2 scavenger, and provided passive protection to B. burgdorferi and L. interrogans against H 2O2. When extracellular pyruvate was absent, both spirochetes were sensitive to a low dose of H2O2 (≈0.6 mM per h) generated by glucose oxidase (GOX). Despite encoding a functional catalase, L. interrogans was more sensitive than B. burgdorferi to H 2O2 generated by GOX, which may be due to the inherent resistance of B. burgdorferi because of the virtual absence of intracellular iron. In B. burgdorferi, the nucleotide excision repair (NER) and the DNA mismatch repair (MMR) pathways were important for survival during H 2O2 challenge since deletion of the uvrB or the mutS genes enhanced its sensitivity to H2O2 killing; however, the presence of pyruvate fully protected ΔuvrB and ΔmutS from H 2O2 killing further demonstrating the importance of pyruvate in protection. These findings demonstrated that pyruvate, in addition to its classical role in central carbon metabolism, serves as an important H2O2 scavenger for pathogenic spirochetes. Furthermore, pyruvate reduced ROS generated by human neutrophils in response to the Toll-like receptor 2 (TLR2) agonist zymosan. In addition, pyruvate reduced neutrophil-derived ROS in response to B. burgdorferi , which also activates host expression through TLR2 signaling. Thus, pathogenic spirochetes may exploit the metabolite pyruvate, present in blood and tissues, to survive H 2O2 generated by the host antibacterial response generated during infection.
UR - http://www.scopus.com/inward/record.url?scp=84894237428&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84894237428&partnerID=8YFLogxK
U2 - 10.1371/journal.pone.0084625
DO - 10.1371/journal.pone.0084625
M3 - Article
C2 - 24392147
AN - SCOPUS:84894237428
VL - 9
JO - PLoS One
JF - PLoS One
SN - 1932-6203
IS - 1
M1 - e84625
ER -