Tuberculosis最新文献

The PhoPR system is a master regulator in Mycobacterium tuberculosis. A key difference between M. tuberculosis and Mycobacterium bovis is a G71I substitution in the M. bovis PhoR orthologue. Functional studies of the M. bovis PhoPR system have generated conflicting findings, with some research suggesting that the M. bovis PhoPR is defective while others indicate it is functional.

We sought to revisit the functionality of the M. bovis PhoPR system. To address this, we constructed a phoPR mutant in the reference strain M. bovis AF2122/97. We employed a combination of growth assays and transcriptomics analyses to assess the phenotype of the mutant vs wild type and complemented strains. We found that the M. bovis AF2122/97 ΔphoPR mutant showed a growth defect on solid and liquid media compared to the wild type and complemented strains. The transcriptome of the M. bovis AF2122/97 ΔphoPR mutant was also altered as compared to wild type, including differential expression of genes involved in lipid metabolism and secretion. Our work provides further insight into the activity of PhoPR in M. bovis and underlines the importance of the PhoPR system as a master regulator of gene expression in the Mycobacterium tuberculosis complex.

Tuberculosis (TB) is the leading cause of human death worldwide due to Mycobacterium tuberculosis (Mtb) infection. Multiple lines of evidences have illuminated the emerging role of NLRP3 inflammasome-mediated pyroptosis in the clearance of pathogenic infection. In the current study, we sought to investigate the functional role and feasible potential mechanism of BRD4 in Mtb-infected macrophages. We observed that BRD4 was distinctly ascended in THP-1 macrophages upon Mtb infection. Functionally, intervention of BRD4 or pretreated with JQ1 obviously restricted Mtb-triggered cell pyroptosis, as evidenced by declination of protein level of the specific pyroptosis markers including Cleaved Caspase 1, gasdermin D (GSDMD-N) and Cleaved-IL-1β. In the meanwhile, disruption of BRD4 or JQ1 application remarkably prohibited excessive inflammatory responses as characterized by reduce the production of the inflammatory factors such as IL-1β and IL-18. Concomitantly, disruption of BRD4 or administrated with JQ1 manifestly repressed Mtb-aroused Nod-like receptor family pyrindomain-containing 3 (NLRP3) inflammasome activation, as witnessed by attenuation of protein levels of NLRP3, Pro-Caspase1 and apoptosis-associated speck-like protein (ASC). The above findings clearly demonstrated that suppression of BRD4 exerted great influence on regulating Mtb-elicited inflammatory response by coordinating NLRP3 inflammasome-mediated pyroptosis. More importantly, perturbation of BRD4 or JQ1 employment notably restrained endoplasmic reticulum (ER) stress triggered by Mtb-infection, as reflected by noticeably lessened the levels of GRP78, CHOP and ATF6. In terms of mechanism, ER stress agonist tunicamycin profoundly abrogated the favorable effects of BRD4 inhibition on Mtb-triggered pyroptosis, inflammation reaction and inflammasome activation. Collectively, these preceding outcomes strongly illuminated that inhibition of BRD4 targeted ER stress to retard NLRP3 inflammasome activation and subsequent cell pyroptosis and prevention of inflammatory response in Mtb-infected macrophages, highlighting that blocking BRD4 might serve as a promising candidate for protection against Mtb-triggered inflammatory injury.

The process of whole genome sequencing of the Mycobacterium tuberculosis complex is dependent on complete the inactivation of the strain and subsequent DNA extraction. The objective of this study was to optimise the two steps.

Firstly, the efficacy of Triton X-100 as a solvent for the inactivation step was evaluated. This solvent has been demonstrated to be effective in killing bacteria and is less toxic than the previously employed chloroform. For the extraction step, two lysis methods were evaluated: enzymatic (B1 protocol) and mechanical (B2 protocol). For whole genome sequencing, the Nextera XT DNA library preparation protocol was performed for both the B1 and B2 protocols. Subsequently, each library was subjected to whole-genome sequencing. The results demonstrated that heat lysis inactivation with Triton was effective, with no bacteria remaining viable following this treatment. The enzymatic and mechanical extraction protocols yielded comparable results in terms of DNA quantity and quality. The sequencing results showed that there was no significant difference in read depths between the two protocols. In conclusion, for MTBC strains, we recommend the use of our Triton inactivation method, which meets biosafety expectations.

A new, more effective vaccine against tuberculosis (TB) is urgently needed to curtail the current TB problem. The only licensed vaccine, BCG, has been shown to have highly variable protective efficacy in several clinical trials ranging from zero to 80 % against TB disease. We have previously reported that BCG formulated in dimethyl dioctadecyl-ammonium bromide (DDA) with D-(+)-Trehalose 6,6′-Dibehenate (TDB) adjuvant (BCG + Adj) is significantly more protective than BCG alone following murine aerosol Mycobacterium tuberculosis infection. Here we investigate the immunological basis for this improved efficacy by examining expression of different immune markers and cytokines in the lungs of vaccinated mice after M. tuberculosis aerosol challenge. We found significantly greater numbers of pulmonary IL-17A-expressing CD4⁺ T cells in mice immunized with BCG+Adj as compared to nonvaccinated and BCG-immunized mice at one-month post-challenge and that the enhanced protection was abrogated in IL-17A-deficient mice. Furthermore, we found significantly higher levels of IL-17A, IL-12p40 and IL-33 expression in the lungs of BCG + Adj immunized animals relative to nonvaccinated mice after M. tuberculosis challenge. These results demonstrate that the DDA/TDB adjuvant increases expression of IL-17A in response to the BCG vaccine and that these augmented IL-17A levels enhance control of M. tuberculosis infection.

Bovine tuberculosis (bTB), primarily caused by Mycobacterium bovis (M. bovis), is a globally zoonotic disease with significant economic impacts. Plasma exosomes have been extensively used for investigating disease processes and exploring biomarkers. While mass spectrometry (MS)-based proteomic analysis of plasma exosomes has been employed for human tuberculosis (TB) studies, it has not yet been applied to bTB. Therefore, a comprehensive proteomic overview of plasma exosomes from M. bovis-infected cows is essential. In this study, we presented an extensive proteomic analysis of plasma exosomes from 89 M. bovis-infected cows across three farms, using data dependent acquisition (DDA) mode. Our analysis encompasses 239,894 spectra, 6,011 peptides and 835 proteins. The proteomic overview revealed both consistencies and differences among individual cows, supplements 595 proteins to the bovine exosome library, and enriches tuberculosis and related pathways. Additionally, six pathways were validated as immune response pathways, and three proteins (CATHL1, H1-1, and LCN2) were identified as potential indicators of bTB. This study is the first to investigate the exosome proteome of plasma from cows infected with M. bovis, providing a valuable dataset for exploring candidate bTB markers and understanding the mechanisms of host defense against M. bovis.

Tuberculosis (TB) is a serious public health issue in India. Numerous molecular mechanisms and immunological responses play significant roles in the pathogenesis of tuberculosis. This study aimed to identify host immune-related biomarkers that are significantly differentially expressed in active TB and that play a vital role in disease progression. The methodology employed in this study included data collection, pre-processing, analysis, and interpretation of the results. Six microarray datasets were used to identify differentially expressed genes (DEGs), and only the common DEGs were used for further downstream analysis, such as hub gene identification, gene ontology, pathway enrichment analysis, and drug-gene interaction analysis. The study identified 1728 DEGs, including 906 upregulated and 822 downregulated genes. Five hub genes were identified that were: STAT1, GBP5, GBP1, FCGR1A, and BATF2. Gene ontology and pathway enrichment revealed that most of the genes were involved in interferon-gamma signaling. In addition, through drug-gene interactions, known drugs have been identified for STAT1, FCGR1A and GBP1. The findings of this study may contribute to early detection and treatment of active TB.

Background

Interferon-gamma release assay (IGRA) for tuberculosis (TB) remains limited in its ability to discriminate between active TB (ATB) and latent TB infection (LTBI). Activation markers on host T and NK cells are currently considered to be promising markers in the diagnosis of ATB.

Methods

This prospective observational study enrolled 213 participants and the participants were divided into ATB, LTBI, other lung-related diseases (ORD), and health control (HC) groups. CD69 and HLA-DR on T and NK cells were detected in QFT-TB assay, and a composite scoring system (TB-Flow) was created for the diagnosis of ATB.

Results

The expression of activation markers (CD69 and HLA-DR) were significantly increased in ATB. HLA-DR on NK cells, CD69 on T cells, and QFT-TB in the differential diagnosis of ATB and HC were all of good diagnostic value (AUC>0.90). In addition, the TB-Flow greatly improved the efficiency of differential diagnosis between ATB and LTBI (AUC=0.90, 95%CI: 0.84–0.96), with sensitivity and specificity of 79.17 % (95%CI: 64.60%–89.04 %) and 88.68 % (95%CI: 76.28%–95.31 %).

Conclusions

CD69 and HLA-DR on host T and NK cells are promising markers in distinguishing different TB infection status. Our blood-based TB-Flow scoring system can distinguish ATB from LTBI with good diagnostic efficacy.

Background

Isoniazid-induced pancreatitis is a potentially serious adverse drug reaction, however, the frequency of its occurrence is unknown. We conducted a systematic review to explore this adverse drug reaction comprehensively.

Methods

We performed an advanced search in PubMed, Web of Science, Scopus, Ovid, and Embase for studies that reported isoniazid-induced pancreatitis. From the extracted data of eligible cases, we performed a descriptive analysis and a methodological risk of bias assessment using a standardized tool.

Results

We included 16 case reports from eight countries comprising 16 patients in our systematic review. Most of the isoniazid-induced pancreatitis cases were extrapulmonary tuberculosis cases. We found the mean age across all case reports was 36.7 years. In all the cases, discontinuation of isoniazid resulted in the resolution of pancreatitis.

Conclusions

We found the latency period for isoniazid-induced pancreatitis to be ranged from 12 to 45 days after initiation of isoniazid therapy. A low threshold for screening of pancreatitis by measuring pancreatic enzymes in patients on isoniazid presenting with acute abdominal pain is recommended. This would facilitate an early diagnosis and discontinuation of isoniazid, thus reducing the severity of pancreatitis and preventing the complications of pancreatitis.

Host-directed therapy (HDT) with vitamin D in tuberculosis (TB) is beneficial only if the subject is deficient in vitamin D. We investigated pulmonary delivery of 1,25-dihydroxy vitamin D₃ (calcitriol) in mice infected with Mycobacterium tuberculosis (Mtb). We made two kinds of dry powder inhalations (DPI)— soluble particles or poly(lactide) (PLA) particles. We compared treatment outcomes when infected mice were dosed with a DPI alone or as an adjunct to standard oral anti-TB therapy (ATT). Mice infected on Day 0 were treated between Days 28–56 and followed up on Days 57, 71, and 85. Neither DPI significantly reduced Mtb colony forming units (CFU) in the lungs. Combining DPI with ATT did not significantly augment bactericidal activity in the lungs, but CFU were 2-log lower in the spleen. CFU showed a rising trend on stopping treatment, sharper in groups that did not receive calcitriol. Lung morphology and histology improved markedly in animals that received PLA DPI; with or without concomitant ATT. Groups receiving soluble DPI had high mortality. DPI elicited cathelicidin, interleukin (IL)-1 and induced autophagy on days 57, 71, and 85. Macrophage-targeted calcitriol is therefore bacteriostatic, evokes innate microbicidal mechanisms, and mitigates pathology arising from the host response to Mtb.