Genetic interference of distinctive Mycobacterium tuberculosis peptidoglycan modifications enhances β-lactam susceptibility and reveals expression-sensitive host immune dynamics
Silveiro, C.; Marques, M.; Olivenca, F.; Pires, D.; Anes, E.; Catalao, M. J.
Show abstract
The high mortality associated with tuberculosis (TB), alongside the lack of efficient therapeutics against emerging multidrug-resistant Mycobacterium tuberculosis (Mtb) strains, emphasizes the need to identify novel antitubercular targets. Mycobacterial peptidoglycan, displaying characteristic modifications comprising the amidation of D-iso-glutamate (D-iGlu) and the N-glycolylation of muramic acid, is a promising therapeutic target. The genes encoding the enzymes mediating these PG modifications (murT/gatD and namH) were silenced in Mtb using CRISPR interference (CRISPRi) to investigate their impact on {beta}-lactam susceptibility and host immune responses. First, qRT-PCR confirmed successful target mRNA knockdown, with variable repression efficiency based on the selected sgRNA, PAM strength, and target site. Phenotypic characterization through spotting dilution and growth curve assays corroborated the essentiality of D-iGlu amidation for mycobacterial survival, in contrast to the N-glycolylation of muramic acid. Moreover, susceptibility assays showed that both PG modifications contribute to {beta}-lactam resistance, with sgRNA2-mediated murT knockdown substantially increasing {beta}-lactam and isoniazid susceptibility. Furthermore, checkerboard assays showed reductions in the minimum fractional inhibitory concentration index (FICImin) value for AMX/MEM+CLA and EMB combinations following the depletion of both PG modifications, with significant differences observed upon namH knockdown. Additionally, D-iGlu amidation was uncovered as a determinant of Mtb survival within THP-1-derived macrophages at 6 days post-infection. Infection of THP-1-derived macrophages with MurT/GatD-depleted Mtb upregulated IL-1{beta} and downregulated IL-10, whereas NamH depletion caused upregulation of both IL-1{beta} and IL-10. Altogether, our findings unveiled the potential of targeting these PG modifications for the development of innovative therapeutic regimens against TB.
Matching journals
The top 3 journals account for 50% of the predicted probability mass.
Similar papers in this journal
- RNase HI depletion strongly potentiates cell killing by rifampicin in mycobacteria 96%
- Drug degradation caused by mce3R mutations confers contezolid (MRX-I) resistance in Mycobacterium tuberculosis 96%
- Developing synergistic drug combinations to restore antibiotic sensitivity in drug-resistant Mycobacterium tuberculosis 95%
Similar papers in this journal
- Evaluation of the role of whiB6 and kdpDE in the dominant multidrug resistant clone Mycobacterium tuberculosis B0/W148 96%
- Lsr2, a pleiotropic regulator at the core of the infectious strategy of Mycobacterium abscessus 95%
- Genetic determinants of intrinsic antibiotic tolerance in Mycobacterium avium 95%
Similar papers in this journal
- Ceragenins and antimicrobial peptides kill bacteria through distinct mechanisms 95%
- Cyclic di-AMP inhibits Listeria monocytogenes thymineless death during infection 95%
- Beyond self-resistance: ABCF ATPase LmrC is a signal-transducing component of an antibiotic-driven signaling cascade hastening the onset of lincomycin biosynthesis 94%
Similar papers in this journal
- PerSort facilitates characterization and elimination of persister subpopulation in mycobacteria 95%
- GplR1, an unusual TetR-like transcription factor in Mycobacterium abscessus, controls the production of cell wall glycopeptidolipids, colony morphology, and virulence 94%
- Nutrient Acquisition Drives Edwardsiella tarda Pathogenesis in Necrotizing Soft Tissue Infection 94%
Similar papers in this journal
- Loss of β-ketoacyl acyl carrier protein synthase III activity restores multidrug-resistant Escherichia coli sensitivity to previously ineffective antibiotics 94%
- A Novel Silver-Ruthenium-Based Antimicrobial Kills Gram-Negative Bacteria Through Oxidative Stress-Induced Macromolecular Damage 94%
- Transcription repressor protein ZBTB25 interacts with HDAC1 in macrophages infected with Mycobacterium tuberculosis, and its inhibition leads to autophagy and killing of the intracellular pathogen 93%
"Similar papers" are the closest papers from that journal in the model's embedding space. They show what the match is built on, but the ranking comes mostly from a classifier over the whole training set, not from these examples alone.