OBJECTIVE: The asymptomatic nature of tuberculosis (TB) during its latent phase, combined with limitations in current diagnostic methods, makes accurate diagnosis challenging. This study aims to identify TB diagnostic bi...OBJECTIVE: The asymptomatic nature of tuberculosis (TB) during its latent phase, combined with limitations in current diagnostic methods, makes accurate diagnosis challenging. This study aims to identify TB diagnostic biomarkers by integrating gene expression screening with machine learning, evaluating their diagnostic potential and correlation with immune cell infiltration. METHODS: We analyzed GSE19435, GSE19444, and GSE54992 datasets to identify differentially expressed genes (DEGs). GO and KEGG enrichment characterized gene functions. Three machine learning algorithms identified potential biomarkers, validated with GSE83456, GSE62525, and RT-qPCR on clinical samples. Immune cell infiltration was analyzed and verified with blood data. RESULTS: 249 DEGs were identified, with PDE7A and DOK3 emerging as potential biomarkers. RT-qPCR confirmed their expression, showing AUCs above 0.75 and a combined AUC of 0.926 for TB diagnosis. Immune infiltration analysis revealed strong correlations between PDE7A, DOK3, and immune cells. CONCLUSION: PDE7A and DOK3 show strong diagnostic potential for TB, closely linked to immune cell infiltration, and may serve as promising biomarkers and therapeutic targets.
Mycobacterium tuberculosis is a deadly pathogen that claims millions of lives every year. Current research focuses on finding new anti-tuberculosis drugs that are safe and effective, with lesser side effects and toxicity...Mycobacterium tuberculosis is a deadly pathogen that claims millions of lives every year. Current research focuses on finding new anti-tuberculosis drugs that are safe and effective, with lesser side effects and toxicity. One important approach is to identify bio-enhancers that can improve the effectiveness of anti-tuberculosis drugs, resulting in reduced doses and shortened treatment times. The present study investigates the use of C-4 modified isotetrones as bio-enhancers. A series of studies suggest an isotetrone, labeled as C11, inhibits growth, improves MIC, MBC and enhances the killing of M. tuberculosis H37Rv strain when used in combination with the first line and injectable anti-TB drugs in a dose-dependent manner. The combination of C11 and rifampicin also reduces the generation of spontaneous mutants against rifampicin and reaches a mutation prevention concentration (MPC) with moderate rifampicin concentrations. The identified compounds are effective against the MDR strain of M. tuberculosis and non-cytotoxic in HepG2 cells. We find that C11 induces the generation of reactive oxygen species (ROS) inside macrophages and within bacteria, resulting in better efficacy.
Bijker EM, Smith JP, Mchembere W
… +6 more, McCarthy KD, Oord H, Gerritsen JW, Click ES, Cain K, Song R
Tuberculosis (Edinb)
· 2024 Dec · PMID 39332067
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The diagnosis of paediatric pulmonary tuberculosis is difficult, especially in young infants who cannot expectorate sputum spontaneously. Breath testing has shown promise in diagnosing respiratory tract infections, but d...The diagnosis of paediatric pulmonary tuberculosis is difficult, especially in young infants who cannot expectorate sputum spontaneously. Breath testing has shown promise in diagnosing respiratory tract infections, but data on paediatric tuberculosis are limited. We performed a prospective cross-sectional study in Kenya in children younger than five years with symptoms of tuberculosis. We analysed exhaled breath with a hand-held battery-powered nose device. For data analysis, machine learning was applied using samples classified as positive (microbiologically confirmed) or negative (unlikely tuberculosis) to assess diagnostic accuracy. Breath analysis was performed in 118 children. The area under the curve of the optimal model was 0.73. At a sensitivity of 86 % (CI 62-96 %), this resulted in a specificity of 42 % (95 % CI 30-55 %). Exhaled breath analysis shows promise as a triage test for TB in young children, although the WHO target product characteristics were not met.
Indonesia has the third highest number of tuberculosis (TB) patients infected with Mycobacterium tuberculosis (MTB) Lineage 1 (L1). Most of these MTB L1 cases can be found in Indonesia's remote easternmost province of Pa...Indonesia has the third highest number of tuberculosis (TB) patients infected with Mycobacterium tuberculosis (MTB) Lineage 1 (L1). Most of these MTB L1 cases can be found in Indonesia's remote easternmost province of Papua, one of Indonesia's most underdeveloped provinces with a particularly high burden for TB. In this study, we sequenced and described 42 MTB L1 isolates from a well-characterized cohort of patients. We found a genetically diverse MTB L1 population with no association between pathogen genetic relatedness and place of residence or pathogen genetic relatedness and patient ethnicity, which could reflect mixing between different locales and ethnicities or our low sampling fraction. Only a small number showed genetic variants associated with drug resistance (5/42, 11.9 %), probably due to a lack of effective treatment programs. The Papuan isolates showed similarities to other Island Southeast Asian Countries due to the high proportion of L1.2.1.2.1 (30/42, 71.4 %), especially East Timor and the Philippines. This study fills a research gap of MTB L1 in Indonesian Papua and should serve as a stepping stone for further research in the region.
Tuberculosis is a global threat and is still a leading cause of death due to an infectious agent. The infection is spread through inhalation of M. tb containing aerosol droplets. Bacteria after reaching the lung alveoli...Tuberculosis is a global threat and is still a leading cause of death due to an infectious agent. The infection is spread through inhalation of M. tb containing aerosol droplets. Bacteria after reaching the lung alveoli are engulfed by alveolar macrophages, leading to an immune response. Then, pro-inflammatory cytokines are released by these macrophages, recruiting other antigen-presenting cells like dendritic cells. These cells phagocytose the bacteria and present mycobacterial antigens to naïve T cells. After activation by DCs, T cells differentiate into various T cells subsets, viz. CD4, CD8, Th17, Treg, Tfh cells and others display enormous diversification in their characteristics and functions. This review comprises a comprehensive literature on conventional and unconventional T cells, highlighting the polyfunctional T cells as well, their role in controlling TB infection, and their implications in the spectrum of TB infection. While some subsets such as CD4 T cells are extensively studied, some T cell subsets such as gamma delta T cells and Tfh cells remain poorly understood in the pathophysiology of tuberculosis, despite having significant potential implications. The goal of TB eradication can be assisted by development of better vaccines against TB, which can effectively induce a robust and long-term T cells memory. The same has been discussed in the latter part of this review. BCG being the standalone commercialised TB vaccine so far has its limitations. Strategies for the enhancement of BCG along with novel studies in vaccine development, has also been discussed in great detail. Lastly, T cells display a complex interplay of an adaptive immune response against TB, with activation and enhancement of the innate immune responses. Therefore, it is critical to fully understand the role of various T cells subsets in pathophysiology of tuberculosis to provide better therapeutic inventions and improve patient care.
There is an increasingly urgent need to improve our ability to accurately forecast and control zoonotic diseases in wildlife reservoirs. We are confronted, however, with the continued challenge of accurately determining...There is an increasingly urgent need to improve our ability to accurately forecast and control zoonotic diseases in wildlife reservoirs. We are confronted, however, with the continued challenge of accurately determining host infection status across space and time. This dilemma is epitomized with the Mycobacterium tuberculosis Complex (MTBC) pathogens and particularly in free-ranging wildlife, a critical global challenge for both human and animal health. In humans, transcriptional markers have been increasingly identified as a robust tool for diagnosing Mycobacterium tuberculosis (MTB) infection status but have rarely been utilized for diagnosing TB in free-ranging wildlife populations. Here, we report the first use of transcriptional markers to evaluate TB infection status in a free-ranging wildlife species, banded mongoose (Mungos mungo), infected with the MTBC pathogen, Mycobacterium mungi. In this study, we found that GBP5 and DUSP3 were significantly upregulated in free-ranging banded mongoose infected with M. mungi. These results provide the first step in developing an antemortem diagnostic tool for use in free-ranging wildlife species. Our results highlight the potential of transcriptional marker-based assays to advance our ability to detect and manage TB in free-ranging wildlife, especially in field studies and other scenarios when conventional diagnostics are not feasible.
Buryatia is a multidrug-resistant tuberculosis (MDR-TB) high-burden region in the Russian Far East with ethnically diverse population (30 % Mongoloid Buryats and 65 % Russians). Two hundred M. tuberculosis strains from n...Buryatia is a multidrug-resistant tuberculosis (MDR-TB) high-burden region in the Russian Far East with ethnically diverse population (30 % Mongoloid Buryats and 65 % Russians). Two hundred M. tuberculosis strains from newly-diagnosed patients were subjected to phenotypic testing and genotyping. The Beijing genotype was more prevalent among Russians than Buryats (68 % vs 53 %; P = 0.055). European non-Beijing genotypes (LAM, Ural, Haarlem) were double more prevalent in Buryats vs Russians (39.2 % vs 20.5 %; P = 0.01). Higher prevalence of Beijing among former prison inmates (79 % vs 61 % in other patients, P = 0.1) suggests its increased transmissibility. The Russian epidemic cluster B0/W148 was in 9.5 %, double smaller than elsewhere in Siberia. The hypervirulent Beijing 14717-15-cluster was endemic in Buryatia but paradoxically enough, it was more frequently isolated from Russians than Buryats (9.1 % vs 3.9 %; P = 0.2). Beijing subtypes B0/W148, CAO, and 14717-15 were associated with poly/multi-drug resistance (P = 0.01-0.0001). HIV coinfection was more frequent in Russians than in Buryats: 35/141 (24.8 %) vs 5/51 (9.8 %), P = 0.03. To conclude, M. tuberculosis population structure in Buryatia retained its singularities compared to other parts of Russia and remains strikingly different from the neighboring Mongolia. A circulation of strongly MDR-associated Beijing subtypes and drug-resistant non-Beijing strains highlights a risk of their broader dissemination.
Our knowledge of how society viewed leprosy and treated its victims in the past is still scarce, especially in geographical regions and archaeological periods from where no written sources are available. To fill in some...Our knowledge of how society viewed leprosy and treated its victims in the past is still scarce, especially in geographical regions and archaeological periods from where no written sources are available. To fill in some research gaps, we provide the comparative analysis of five previously described, probable cases with leprosy from the Avar-period Trans-Tisza region (Hungary). The five skeletons were subject to a detailed macromorphological (re-)evaluation. Where possible, the biological and social consequences of having leprosy were reconstructed based on the observed bony changes and mortuary treatment, respectively. The retrospective, macromorphology-based diagnosis of leprosy could be established in three cases only. Based on the detected skeletal lesions, all of them suffered from near-lepromatous or lepromatous leprosy. The disease resulted in aesthetic repercussions and functional implications, which would have been disadvantageous for these individuals, and limited or changed their possibilities to participate in social situations. They could have even required heavy time investment from their respective communities. The analysis of the mortuary treatment of the confirmed leprosy cases revealed no evidence of a social stigma. These findings indicate that the afflicted have not been systematically expulsed or segregated, at least in death, in the Early Middle Ages of the Carpathian Basin.
Mesman AW, Calderon RI, Hauns L
… +4 more, Pollock NR, Mendoza M, Holmberg RC, Franke MF
Tuberculosis (Edinb)
· 2024 Sep · PMID 39098064
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Diagnosis of pulmonary tuberculosis (TB) relies on a sputum sample, which cannot be obtained from all symptomatic individuals. Mycobacterium tuberculosis (Mtb) transrenal DNA (trDNA) has been detected in urine, an easily...Diagnosis of pulmonary tuberculosis (TB) relies on a sputum sample, which cannot be obtained from all symptomatic individuals. Mycobacterium tuberculosis (Mtb) transrenal DNA (trDNA) has been detected in urine, an easily obtainable, noninvasive, alternative sample type. However, reported sensitivities have been variable and likely depend on collection and assay procedures and aspects of trDNA biology. We analyzed three serial urine samples from each of 75 adults with culture-confirmed pulmonary TB disease in Lima, Peru for detection of trDNA using short-fragment real-time PCR. Additionally, we examined host, urine, and sampling factors associated with detection. Overall per-sample sensitivity was 38 % (95 % Confidence Interval [CI] 30-45 %). On an individual level (i.e., any of the three samples positive), sensitivity was 73 % (95 % CI: 62-83 %). Sensitivity was highest among samples from patients with smear-positive TB, 92 % (95 % CI: 62-100 %). Specificity from a single sample from each of 10 healthy controls was 100 % (95 % CI: 69-100 %). Adjusting our assay positivity threshold increased individual-level sensitivity to 88 % (95 % CI: 78-94 %) overall without affecting the specificity. We did not find associations between Mtb trDNA detection and individual characteristics or urine sample characteristics. Overall, our results support the potential of trDNA detection for TB diagnosis.
Ayalew S, Wegayehu T, Wondale B
… +8 more, Kebede D, Osman M, Niway S, Tarekegn A, Tessema B, Berg S, Ashford RT, Mihret A
Tuberculosis (Edinb)
· 2024 Sep · PMID 39094295
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BACKGROUND: Current tuberculosis (TB) diagnostic tests primarily rely on sputum samples, yet many TB patients cannot produce sputum. This study explored whether saliva could be used instead of sputum to diagnose pulmonar...BACKGROUND: Current tuberculosis (TB) diagnostic tests primarily rely on sputum samples, yet many TB patients cannot produce sputum. This study explored whether saliva could be used instead of sputum to diagnose pulmonary TB (PTB). METHOD: The study included 32 patients with confirmed PTB and 30 patients with other respiratory diseases (ORD). Saliva from all study participants was subjected to quantitative (qPCR) assays targeting the IS1081 gene for detection of M. tuberculosis complex DNA. RESULTS: The sensitivity of saliva IS1081 qPCR was 65.6 % (95 % CI 48.4-80.2 %) with positive results for 21/32 PTB cases, while the specificity was 96.7 % (95 % CI 85.9-99.6 %) with negative results for 29/30 participants with ORD. Sensitivity improved to 72.4 % (95 % CI 54.6-86.0 %) when sputum-Xpert was used as the reference standard, while remaining similar at 65.5 % (95 % CI 47.4-80.7 %) when culture was used as the reference standard. In receiver operating characteristic (ROC) curve analysis, the area under the curve (AUC) for saliva IS1081 qPCR was 82.5 % (95 % CI 71.7-93.3 %). CONCLUSION: Saliva testing offers a promising alternative to sputum for TB diagnosis among confirmed PTB cases. Larger multicenter studies, encompassing diverse clinical TB characteristics, are needed to provide improved estimates of diagnostic sensitivity and specificity.
Delayed sputum conversion has been associated with a higher risk of treatment failure or relapse among drug susceptible smear-positive pulmonary tuberculosis patients. Several contributing factors have been identified in...Delayed sputum conversion has been associated with a higher risk of treatment failure or relapse among drug susceptible smear-positive pulmonary tuberculosis patients. Several contributing factors have been identified in many studies, but the results varied across regions and countries. Therefore, the current study aimed to develop a predictive model that explained the factors affecting time to sputum conversion within two months after initiating antituberculosis agents among Malaysian with drug-susceptible smear-positive pulmonary tuberculosis patients. Retrospective data of pulmonary tuberculosis patients followed up at a tertiary hospital in the Northern region of Malaysia from 2013 until 2018 were collected and analysed. Nonlinear mixed-effect modelling software (NONMEM 7.3.0) was used to develop parametric survival models. The final model was further validated using Kaplan-Meier-visual predictive check (KM-VPC) approach, kernel-based hazard rate estimation method and sampling-importance resampling (SIR) method. A total of 224 patients were included in the study, with 34.4 % (77/224) of the patients remained positive at the end of 2 months of the intensive phase. Gompertz hazard function best described the data. The hazard of sputum conversion decreased by 39 % and 33 % for moderate and advanced lesions as compared to minimal baseline of chest X-ray severity, respectively (adjusted hazard ratio (aHR), 0.61; 95 % confidence intervals (95 % CI), (0.44-0.84) and 0.67, 95 % CI (0.53-0.84)). Meanwhile, the hazard also decreased by 59 % (aHR, 0.41; 95 % CI, (0.23-0.73)) and 48 % (aHR, 0.52; 95 % CI, (0.35-0.79)) between active and former drug abusers as compared to non-drug abuser, respectively. The successful development of the internally and externally validated final model allows a better estimation of the time to sputum conversion and provides a better understanding of the relationship with its predictors.
Pandit A, Thapa J, Sadaula A
… +11 more, Suzuki Y, Nakajima C, Mikota SK, Subedi N, Shrestha BK, Shimozuru M, Shrestha B, Raya B, Chaudhary S, Paudel S, Tsubota T
Tuberculosis (TB) is an emerging threat to the survival of elephants in Nepal. We investigated the lung tissue samples from nine elephants that died from 2019 to 2022 in Nepal using culture, conventional PCR, and loop-me...Tuberculosis (TB) is an emerging threat to the survival of elephants in Nepal. We investigated the lung tissue samples from nine elephants that died from 2019 to 2022 in Nepal using culture, conventional PCR, and loop-mediated isothermal amplification (LAMP) and then performed genotyping of five PCR-positive isolates to understand the possible transmission dynamics of Mycobacterium tuberculosis (Mtb). Results showed that two-thirds (6/9) of elephants were confirmed to be infected from Mtb by LAMP, 5/9 by PCR, and 4/9 by culture. Genotyping of Mtb isolates showed that elephants were infected with the Indo-Oceanic and Beijing lineages including an isoniazid-resistant Beijing lineage. MIRU-VNTR-based phylogeny, gyrA, and katG sequencing showed the possibility of ongoing transmission of Indo-Oceanic lineages and likely transmission of the drug-resistant Beijing lineage from human to elephant. Implementation of comprehensive surveillance and preventive measures are urgently needed to address this zoonotic disease and protect elephants from TB in Nepal.
PURPOSE: To determine if host urinary biomarker profiles could distinguish between tubercular uveitis (TBU) and other uveitic diseases (OUD) in patients with and without HIV infection. METHODS: Concentrations of 29 diffe...PURPOSE: To determine if host urinary biomarker profiles could distinguish between tubercular uveitis (TBU) and other uveitic diseases (OUD) in patients with and without HIV infection. METHODS: Concentrations of 29 different host biomarkers were measured in urine samples using the Luminex platform. Data were analyzed to describe differences between patients diagnosed with and without TBU and with and without HIV co-infection. RESULTS: One-hundred-and-eighteen urine samples were collected and 39% participants were diagnosed as TBU+. Mean age TBU+ was 39.3±13.6 years with 45.7% males. Anterior and panuveitis and unilateral involvement were most common. 32.6% were TBU+HIV+ (median CD4+=215) while 40.2% were OUD+HIV+ (median CD4+=234). Only sVEGF3 was decreased in TBU+ versus OUD+ (p=0.03), regardless of HIV status. Some biomarkers were significantly raised in HIV+ TBU+ compared to HIV- TBU+: sIL-6Rα, CD30, sRAGE , sTNFR I&-II, IP-10, MIP-1β, sEGFR and Ferritin. HIV+ OUD+ had increased sVEGFR3, CD30, sIL-6Rα, IP-10, sTNFR I&-II, Ferritin and Haptoglobin compared to HIV- OUD+. VEGF-A (p = 0.04) was decreased in HIV+ OUD+ versus HIV- OUD+. CONCLUSION: Decreased urinary concentrations of VEGFR3 were observed in TBU+ compared to TBU-. HIV+ individuals demonstrated increased concentrations of multiple urinary analytes when compared to HIV- patients with uveitis.
As one of the factors affecting the treatment outcomes, drug tolerance in mycobacteriosis has not been paid due attention. Genome-wide association studies on 607 Mycobacterium tuberculosis clinical isolates with phenotyp...As one of the factors affecting the treatment outcomes, drug tolerance in mycobacteriosis has not been paid due attention. Genome-wide association studies on 607 Mycobacterium tuberculosis clinical isolates with phenotypic drug susceptibility test data revealed that a K114N mutation on the rv2820c gene was highly enriched in capreomycin-resistant isolates (32/213, 15.02%). However, the mutation was also observed in capreomycin-sensitive isolates (10/394, 2.53%). In most cases (31/42, 73.81%), the rv2820c K114N mutation occurred in isolates with the known capreomycin resistance conferring mutation rrs A1401G. In contrast, the general frequency of the rv2820c K114N mutation was low in 7061 genomes downloaded from the National Center for Biotechnology Information database. To determine the impact of this mutation on the antimycobacterial activity of capreomycin, the intact rv2820c gene and the rv2820c K114N mutant were over-expressed in Mycobacterium smegmatis (Ms), and the results of susceptibility tests showed that the rv2820c K114N mutation did not affect the minimum inhibition concentration (MIC) of capreomycin. Subsequently, the data of time-kill assays showed that, it took only 2 h of capreomycin treatment (40 μg/ml, 5 × MIC) to kill 99.9% bacterial cells of Ms MC155 pMV261::rv2820c, while it took 6 h to achieve that for Ms MC155 pMV261::rv2820c. Taken together, these data suggested that the rv2820c K114N mutation is related with capreomycin tolerance, which merits further investigation.
PURPOSE: This study target the synthesis of 22 salicylhydrazones derivatives to apply in vitro screening to explore their potential in the search for new anti-TB prototypes drugs. METHODS: The minimum inhibitory concentr...PURPOSE: This study target the synthesis of 22 salicylhydrazones derivatives to apply in vitro screening to explore their potential in the search for new anti-TB prototypes drugs. METHODS: The minimum inhibitory concentration (MIC) were evaluated against Mycobacterium tuberculosis (Mtb) HRv and clinical isolates. Drug combination assay, cytotoxicity assay, ethidium bromide accumulation assay (EtBr) and in silico analysis regarding the absorption, distribution, metabolism, excretion and toxicity (ADMET) and pharmacological properties were also performed. RESULTS: Three most promising compounds were selected (10, 11 and 18) to proceed with screening tests. Compound 18 presented the lowest MIC value (0.49 μg/mL) against Mtb HRv strain, followed by compounds 11 (3.9 μg/mL) and 10 (7.8 μg/mL). All compounds showed activity against drug susceptible and resistant clinical isolates. Cytotoxicity results were promising for all salicylhydrazones, with SI values up to 4,205 for compound 18. The derivative 10 was the only one that demonstrated a non-promising cytotoxicity scenario for a single cell line. All derivatives showed an additive effect (FICI >0.5 to 4.0) in combination with isoniazid, ethambutol and rifampicin. CONCLUSION: All salicylhydrazones showed potential in the screening tests performed in this study and compound 18 stood out due to its activity against susceptible and resistant bacilli at low concentrations and low cytotoxicity.
BACKGROUND: Spinal Tuberculosis (STB) is a common cause of spinal malformation caused by extrapulmonary tuberculosis in developing countries, which seriously affects the quality of life of patients. It was found that the...BACKGROUND: Spinal Tuberculosis (STB) is a common cause of spinal malformation caused by extrapulmonary tuberculosis in developing countries, which seriously affects the quality of life of patients. It was found that the expression of miRNAs in macrophages was stable, specific and readily available after Mycobacterium tuberculosis (MTB) infection. Our research group determined the differential expression of miR-29a-3p in the vertebra of spinal tuberculosis and intervertebral disc lesions through RNAs chip screening and bioinformatics analysis. However, the specific molecular mechanism of miR-29a-3p in the inflammatory response of spinal tuberculosis remains unclear. OBJECTIVE: In this study, we mainly discussed the expression of miR-29a-3p in the focal tissue of spinal tuberculosis and the role and molecular mechanism of miR-29a-3p mediated by METTL3 in the inflammatory response of spinal tuberculosis. METHODS: The tissues of 15 cases of lumbar degenerative diseases and vertebral lesions of spinal tuberculosis were collected, and the THP-1 macrophage model infected by Mycobacterium tuberculosis was constructed, and verified by qRT-PCR, Western blot, fluorescence in situ hybridization, immunohistochemistry, Cell fluorescence and ELISA. RESULTS AND CONCLUSION: We found that the expression of miR-29a-3p was significantly down-regulated in the vertebral body and disc lesion tissues of patients with spinal tuberculosis. Overexpression of miR-29a-3p inhibited the levels of inflammatory factors including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6), and inhibition of miR-29a-3p expression promoted the release of the levels of TNF-α, IL-1β and IL-6 inflammatory factors. Our study also shows that knockout of methyltransferase 3 (METTL3) can significantly reduce the expression of miR-29a-3p and promote the release of pro-inflammatory cytokines in macrophages.
Gonzalez-Muñiz OE, Rodriguez-Carlos A, Santos-Mena A
… +5 more, Jacobo-Delgado YM, Gonzalez-Curiel I, Rivas-Santiago C, Navarro-Tovar G, Rivas-Santiago B
Research suggests that both tuberculosis (TB) and type 2 diabetes mellitus (T2DM) have an immuno-endocrine imbalance characterized by dysregulated proinflammatory molecules and hormone levels (high cortisol/DHEA ratio),...Research suggests that both tuberculosis (TB) and type 2 diabetes mellitus (T2DM) have an immuno-endocrine imbalance characterized by dysregulated proinflammatory molecules and hormone levels (high cortisol/DHEA ratio), impeding an effective immune response against Mycobacterium tuberculosis (Mtb) driven by cytokines, antimicrobial peptides (AMPs), and androgens like DHEA. Insulin, sulfonylurea derivatives, and metformin are commonly used glucose-lowering drugs in patients suffering from TB and T2DM. For this comorbidity, metformin is an attractive target to restore the immunoendocrine mechanisms dysregulated against Mtb. This study aimed to assess whether metformin influences cortisol and DHEA synthesis in adrenal cells and if these hormones influence the expression of proinflammatory cytokines and AMPs in Mtb-infected macrophages. Our results suggest that metformin may enhance DHEA synthesis while maintaining cortisol homeostasis. In addition, supernatants from metformin-treated adrenal cells decreased mycobacterial loads in macrophages, which related to rising proinflammatory cytokines and AMP expression (HBD-2 and 3). Intriguingly, we find that HBD-3 and LL-37 can modulate steroid synthesis in adrenal cells with diminished levels of cortisol and DHEA, highlighting the importance of crosstalk communication between adrenal hormones and these effectors of innate immunity. We suggest that metformin's effects can promote innate immunity against Mtb straight or through modulation of corticosteroid hormones.
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...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 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....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.