Lactate oxidation facilitates growth of Mycobacterium tuberculosis in human macrophages

Abstract Mycobacterium tuberculosis (Mtb) uses alveolar macrophages as primary host cells during infection. In response to an infection, macrophages switch from pyruvate oxidation to reduction of pyruvate into lactate. Lactate might present an additional carbon substrate for Mtb. Here, we demonstrat...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Sandra Billig, Marie Schneefeld, Claudia Huber, Guntram A. Grassl, Wolfgang Eisenreich, Franz-Christoph Bange
Formato: article
Lenguaje:EN
Publicado: Nature Portfolio 2017
Materias:
R
Q
Acceso en línea:https://doaj.org/article/5a9ddd76b9534aa68d725bfbe922215f
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
Descripción
Sumario:Abstract Mycobacterium tuberculosis (Mtb) uses alveolar macrophages as primary host cells during infection. In response to an infection, macrophages switch from pyruvate oxidation to reduction of pyruvate into lactate. Lactate might present an additional carbon substrate for Mtb. Here, we demonstrate that Mtb can utilize L-lactate as sole carbon source for in vitro growth. Lactate conversion is strictly dependent on one of two potential L-lactate dehydrogenases. A knock-out mutant lacking lldD2 (Rv1872c) was unable to utilize L-lactate. In contrast, the lldD1 (Rv0694) knock-out strain was not affected in growth on lactate and retained full enzymatic activity. On the basis of labelling experiments using [U-13C3]-L-lactate as a tracer the efficient uptake of lactate by Mtb and its conversion into pyruvate could be demonstrated. Moreover, carbon flux from lactate into the TCA cycle, and through gluconeogenesis was observed. Gluconeogenesis during lactate consumption depended on the phosphoenolpyruvate carboxykinase, a key enzyme for intracellular survival, showing that lactate utilization requires essential metabolic pathways. We observed that the ΔlldD2 mutant was impaired in replication in human macrophages, indicating a critical role for lactate oxidation during intracellular growth.