title: Imaging cytosolic translocation of Mycobacteria with two-photon fluorescence resonance energy transfer microscopy.
abstract: Transition from latency to active tuberculosis requires Mycobacterium tuberculosis (Mtb) to penetrate the phagosomal membrane and translocate to the cytosol of the host macrophage. Quantitative two-photon fluorescence resonance energy transfer (FRET) microscopy is developed to measure cytosolic translocation using Mycobacterium marinum (Mm) as a model organism for Mtb. Macrophages were infected with Mm or non-pathogenic Mycobacterium smegmatis (Ms) as a control, then loaded with a FRET substrate. Once translocation occurs, mycobacterium-bearing β-lactamase cleaves the substrate, resulting in decrease of FRET signal. Quantification of this FRET signal change revealed that Mm, but not Ms, is capable of translocating to the cytosol.
authors.affiliation: Department of Physics, The University of Texas at El Paso, 500 W. University Ave., El Paso, Texas 79968, USA ; These authors contribute equally.
authors.forename: Yassel
authors.initials: Y
authors.lastname: Acosta
authors.affiliation: Department of Biological Sciences, The University of Texas at El Paso, 500 W. University Ave., El Paso, Texas 79968, USA ; These authors contribute equally.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Physics, The University of Texas at El Paso, 500 W. University Ave., El Paso, Texas 79968, USA.
authors.forename: Arifur
authors.initials: A
authors.lastname: Rahaman
authors.affiliation: Department of Biological Sciences, The University of Texas at El Paso, 500 W. University Ave., El Paso, Texas 79968, USA.
authors.forename: Hugues
authors.initials: H
authors.lastname: Ouellet
authors.affiliation: Department of Chemistry, The University of Texas at El Paso, 500 W. University Ave., El Paso, Texas 79968, USA.
authors.forename: Chuan
authors.initials: C
authors.lastname: Xiao
authors.affiliation: Department of Biological Sciences, The University of Texas at El Paso, 500 W. University Ave., El Paso, Texas 79968, USA ; jsun@utep.edu.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Sun
authors.affiliation: Department of Physics, The University of Texas at El Paso, 500 W. University Ave., El Paso, Texas 79968, USA.
authors.forename: Chunqiang
authors.initials: C
authors.lastname: Li
keywords: (170.1530) Cell analysis; (170.2520) Fluorescence microscopy