How macrophage heterogeneity affects tuberculosis disease and therapy.

Macrophages are the primary host cell type for infection by Mycobacterium tuberculosis in vivo. Macrophages are also key immune effector cells that mediate the control of bacterial growth. However, the specific macrophage phenotypes that are required for optimal immune control of M.

The frequency of CD38 alveolar macrophages correlates with early control of M. tuberculosis in the murine lung.

Tuberculosis, caused by Mycobacterium tuberculosis, remains an enduring global health challenge due to the limited efficacy of existing treatments. Although much research has focused on immune failure, the role of host macrophage biology in controlling the disease remains underappreciated. Here we show, through multi-modal single-cell RNA sequencing in a murine model, that different alveolar macrophage subsets play distinct roles in either advancing or controlling the disease.

CD38+ Alveolar macrophages mediate early control of M. tuberculosis proliferation in the lung.

Tuberculosis, caused by (Mtb), remains an enduring global health challenge, especially given the limited efficacy of current therapeutic interventions. Much of existing research has focused on immune failure as a driver of tuberculosis. However, the crucial role of host macrophage biology in controlling the disease remains underappreciated.

Protocol for multi-modal single-cell RNA sequencing on M. tuberculosis-infected mouse lungs.

To elucidate how different immune cells contribute to control or progression of M. tuberculosis (Mtb) infection, we developed a technique to perform multi-modal single-cell RNA sequencing (scRNA-seq) from in vivo Mtb-infected lung macrophages. This protocol simultaneously acquires the transcriptome, surface marker expression, and bacterial phenotype of each infected cell.

Iron limitation in M. tuberculosis has broad impact on central carbon metabolism.

Mycobacterium tuberculosis (Mtb), the cause of the human pulmonary disease tuberculosis (TB), contributes to approximately 1.5 million deaths every year. Prior work has established that lipids are actively catabolized by Mtb in vivo and fulfill major roles in Mtb physiology and pathogenesis.

Single cell analysis of M. tuberculosis phenotype and macrophage lineages in the infected lung.

In this study, we detail a novel approach that combines bacterial fitness fluorescent reporter strains with scRNA-seq to simultaneously acquire the host transcriptome, surface marker expression, and bacterial phenotype for each infected cell. This approach facilitates the dissection of the functional heterogeneity of M. tuberculosis-infected alveolar (AMs) and interstitial macrophages (IMs) in vivo.

Dual RNA-Sequencing of -Infected Cells from a Murine Infection Model.

Dual RNA-sequencing is a powerful technique to assess both bacterial and host transcriptomes in an unbiased way. We developed a protocol to perform Dual RNA-seq on -derived macrophage populations infected with . Here, we provide a practical step-by-step guide to execute the protocol on Mtb-infected cells from a murine infection model.

Dual RNA-Seq of Mtb-Infected Macrophages In Vivo Reveals Ontologically Distinct Host-Pathogen Interactions.

Dissecting the in vivo host-pathogen interplay is crucial to understanding the molecular mechanisms governing control or progression of intracellular infections. In this work, we explore the in vivo molecular dynamics of Mtb infection by performing dual RNA-seq on Mycobacterium tuberculosis-infected, ontogenetically distinct macrophage lineages isolated directly from murine lungs. We first define an in vivo signature of 180 genes specifically upregulated by Mtb in mouse lung macrophages, then we uncover a divergent transcriptional response of the bacteria between alveolar macrophages that appear to sustain Mtb growth through increased access to iron and fatty acids and interstitial macrophages that restrict Mtb growth through iron sequestration and higher levels of nitric oxide.

The Deconstructed Granuloma: A Complex High-Throughput Drug Screening Platform for the Discovery of Host-Directed Therapeutics Against Tuberculosis.

(Mtb) continues to be a threat to Global Public Health, and its control will require an array of therapeutic strategies. It has been appreciated that high-throughput screens using cell-based assays to identify compounds targeting Mtb within macrophages represent a valuable tool for drug discovery. However, the host immune environment, in the form of lymphocytes and cytokines, is completely absent in a chemical screening platform based on infected macrophages alone.

The Alternative Sigma Factors SigE and SigB Are Involved in Tolerance and Persistence to Antitubercular Drugs.

The emergence and spread of drug-resistant strains possibly threaten our ability to treat this disease in the future. Even though two new antitubercular drugs have recently been introduced, there is still the need to design new molecules whose mechanisms of action could reduce the length of treatment. We show that two alternative sigma factors of (SigE and SigB) have a major role in determining the level of basal resistance to several drugs and the amount of persisters surviving long-duration drug treatment.

The ESX-3 secretion system is necessary for iron and zinc homeostasis in Mycobacterium tuberculosis.

ESX-3 is one of the five type VII secretion systems encoded by the Mycobacterium tuberculosis genome. We recently showed the essentiality of ESX-3 for M. tuberculosis viability and proposed its involvement in iron and zinc metabolism.