Mycobacterium tuberculosis Host-Pathogen Interactions

Mycobacterium tuberculosis (Mtb) establishes infection by surviving uptake into alveolar macrophages and manipulating phagosomal maturation to prevent destruction. Key virulence determinants include the complex lipid-rich cell envelope and dedicated secretion systems such as ESX-1, which deliver effector proteins into host cytosol to modulate immune signalling. Within the granuloma, Mtb senses hypoxia, nutrient limitation and oxidative stress, reprogramming its transcriptional and translational machinery to enter non-replicating persistence. Concurrently, secreted effectors subvert host gene expression through epigenetic reprogramming and interference with cytokine networks, blunting antimicrobial responses and delaying adaptive immunity. Host cells respond by producing interferon-gamma and other cytokines, by inducing epigenetic “trained immunity” and by alternative splicing of key transcripts, all of which shape the outcome of infection. Understanding this dynamic interplay is critical for development of new diagnostics, host-directed therapies and vaccines with improved efficacy against drug-resistant strains.

Research from Nature Portfolio

Recent studies have revealed that transcriptional pausing is a prominent feature of the Mtb transcriptome. High-resolution mapping of RNA 5′ and 3′ ends shows that most transcripts are truncated within a few hundred nucleotides of their start site, reflecting frequent early pausing by RNA polymerase. This checkpoint can be relieved by translating ribosomes, suggesting that transcription–translation coupling is an adaptive mechanism to balance gene expression under stress and may provide novel targets for antimicrobial intervention.

Work on a secreted Mtb methyltransferase has uncovered a non-canonical epigenetic mechanism by which the bacterium directly alters host chromatin. The enzyme localises to the host nucleus and specifically dimethylates histone H3 at arginine 42, silencing genes involved in the first line of defence. Deletion of this factor reduces bacterial survival in vivo, highlighting its potential as a virulence target.

Evidence is emerging that vaccination with BCG can induce stable epigenetic changes in innate immune cells. Analysis of DNA methylation patterns in peripheral blood mononuclear cells from vaccinated individuals identifies a subset of responders whose macrophages exhibit enhanced control of Mtb replication. These epigenetic signatures correlate with upregulated promoters in immune pathways and may inform strategies to boost vaccine-induced trained immunity.

Research from all publishers

Profiling of host alternative splicing in tuberculosis patients has identified specific exon-skipping events in immune genes as potential diagnostic biomarkers. Long-read sequencing across large cohorts reveals stable splicing patterns in genes such as UBE2B that are modulated by mycobacterial stimulation and classify disease status with high accuracy, offering a novel approach to TB detection.

Investigations into non-coding RNAs within Mtb demonstrate an abundant repertoire of small RNAs that accumulate during chronic infection in mouse lungs. These intergenic and antisense transcripts are upregulated in stationary phase and may contribute to pathogen persistence by fine-tuning stress responses and host interactions, pointing to new layers of post-transcriptional regulation in vivo.

Reviews of interferon-gamma biology emphasise its central role in orchestrating host defence against intracellular pathogens. IFN-γ enhances antigen presentation, promotes macrophage activation and interfaces with pattern recognition receptor pathways. Dysregulation of IFN-γ signalling is implicated in TB susceptibility and informs host-directed therapy development.

Mycobacterium tuberculosis Host-Pathogen Interactions publication trend

The graph below shows the total number of articles in mycobacterium tuberculosis host-pathogen interactions across all publications each year (not limited to Nature Index journals).

Technical terms

Transcriptional pausing: A temporary halt of RNA polymerase shortly after initiation, influencing transcript length and gene regulation.

Transcription–translation coupling: The spatial and temporal coordination of RNA synthesis and protein synthesis in bacteria.

Epigenetic reprogramming: Stable modification of host chromatin (e.g. DNA methylation, histone methylation) that alters gene expression without changing DNA sequence.

Alternative splicing: The process by which a single gene gives rise to multiple mRNA variants through differential exon inclusion.

Non-coding RNA (ncRNA): RNA molecules that do not encode proteins but regulate gene expression at transcriptional and post-transcriptional levels.

References

1. Incomplete transcripts dominate the Mycobacterium tuberculosis transcriptome. Nature (2024).
2. Mycobacteria modulate host epigenetic machinery by Rv1988 methylation of a non-tail arginine of histone H3. Nature Communications (2015).
3. Anti-mycobacterial activity correlates with altered DNA methylation pattern in immune cells from BCG-vaccinated subjects. Scientific Reports (2017).
4. From tuberculosis bedside to bench: UBE2B splicing as a potential biomarker and its regulatory mechanism. Signal Transduction and Targeted Therapy (2023).
5. Sequence-Based Analysis Uncovers an Abundance of Non-Coding RNA in the Total Transcriptome of Mycobacterium tuberculosis. PLOS Pathogens (2011).
6. Interferon-gamma (IFN-γ): Exploring its implications in infectious diseases. BioMolecular Concepts (2018).