Comparative analysis of genomic characteristics and Immune response between a mycobacterium tuberculosis strains cultured continuously for 25 years and H37Rv.

Tuberculosis (TB) continues to pose a significant global health challenge, emphasizing the critical need for effective preventive measures. Although many studies have tried to develop new attenuated vaccines, there is no effective TB vaccine. In this study, we report a novel attenuated M. tb strain, CHVAC-25, cultured continuously for 25 years in the laboratory. The CHVAC-25 exhibited significantly reduced virulence compared to both the virulent H37Rv strain in C57BL/6 J and SCID mice. The comparative genomic analysis identified 93 potential absent genomic segments and 65 single nucleotide polymorphic sites across 47 coding genes. Notably, the deletion mutation of ppsC (Rv2933) involved in PDIM synthesis, likely contributes to CHVAC-25 virulence attenuation. Furthermore, the comparative analysis of immune responses between H37Rv and CHVAC-25-infected macrophages showed that CHVAC-25 triggered a robust upregulation of 173 genes, particularly cytokines crucial for combating M. tb infection. Additionally, the survival of CHVAC-25 was significantly reduced compared to H37Rv in macrophages. These findings reiterate the possibility of obtaining attenuated M. tb strains through prolonged laboratory cultivation, echoing the initial conception of H37Ra nearly a century ago. Additionally, the similarity of CHVAC-25 to genotypes associated with attenuated M. tb vaccine positions it as a promising candidate for TB vaccine development.

Identification of important modules and biomarkers in tuberculosis based on WGCNA.

Background: Tuberculosis (TB) is a significant public health concern, particularly in China. Long noncoding RNAs (lncRNAs) can provide abundant pathological information regarding etiology and could include candidate biomarkers for diagnosis of TB. However, data regarding lncRNA expression profiles and specific lncRNAs associated with TB are limited. Methods: We performed ceRNA-microarray analysis to determine the expression profile of lncRNAs in peripheral blood mononuclear cells (PBMCs). Weighted gene co-expression network analysis (WGCNA) was then conducted to identify the critical module and genes associated with TB. Other bioinformatics analyses, including Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), and co-expression networks, were conducted to explore the function of the critical module. Finally, real-time quantitative polymerase chain reaction (qPCR) was used to validate the candidate biomarkers, and receiver operating characteristic analysis was used to assess the diagnostic performance of the candidate biomarkers. Results: Based on 8 TB patients and 9 healthy controls (HCs), a total of 1,372 differentially expressed lncRNAs were identified, including 738 upregulated lncRNAs and 634 downregulated lncRNAs. Among all lncRNAs and mRNAs in the microarray, the top 25% lncRNAs (3729) and top 25% mRNAs (2824), which exhibited higher median expression values, were incorporated into the WGCNA. The analysis generated 16 co-expression modules, among which the blue module was highly correlated with TB. GO and KEGG analyses showed that the blue module was significantly enriched in infection and immunity. Subsequently, considering module membership values (>0.85), gene significance values (>0.90) and fold-change value (>2 or < 0.5) as selection criteria, the top 10 upregulated lncRNAs and top 10 downregulated lncRNAs in the blue module were considered as potential biomarkers. The candidates were then validated in an independent validation sample set (31 TB patients and 32 HCs). The expression levels of 8 candidates differed significantly between TB patients and HCs. The lncRNAs ABHD17B (area under the curve [AUC] = 1.000) and ENST00000607464.1 (AUC = 1.000) were the best lncRNAs in distinguishing TB patients from HCs. Conclusion: This study characterized the lncRNA profiles of TB patients and identified a significant module associated with TB as well as novel potential biomarkers for TB diagnosis.

The incremental value of Mycobacterium tuberculosis trace nucleic acid detection in CT-guided percutaneous biopsy needle rinse solutions for the diagnosis of tuberculosis.

Introduction: Tuberculosis (TB) diagnosis still faces challenges with high proportion of bacteriologic test negative incidences worldwide. We assessed the diagnostic value of digital PCR (dPCR) analysis of ultramicro Mycobacterium tuberculosis (M.tb) nucleic acid in CT-guided percutaneous biopsy needle rinse solution (BNRS) for TB. Methods: BNRS specimens were consecutively collected and total DNA was purified. The concentrations of M.tb-specific IS6110 and IS1081 were quantified using droplet dPCR. The diagnostic performances of BNRS-dPCR and its sensitivity in comparison with conventional tests were analyzed. Results: A total of 106 patients were enrolled, 63 of whom were TB (48 definite and 15 clinically suspected TB) and 43 were non-TB. The sensitivity of BNRS IS6110 OR IS1081-dPCR for total, confirmed and clinically suspected TB was 66.7%, 68.8% and 60.0%, respectively, with a specificity of 97.7%. Its sensitivity was higher than that of conventional etiological tests, including smear microscopy, mycobacterial culture and Xpert using sputum and BALF samples. The positive detection rate in TB patients increased from 39.3% for biopsy AFB test alone to 73.2% when combined with BNRS-dPCR, and from 71.4% for biopsy M.tb molecular detection alone to 85.7% when combined with BNRS-dPCR. Conclusion: Our results preliminarily indicated that BNRS IS6110 OR IS1081-dPCR is a feasible etiological test, which has the potential to be used as a supplementary method to augment the diagnostic yield of biopsy and improve TB diagnosis.

The role of Mycobacterium tuberculosis acetyltransferase and protein acetylation modifications in tuberculosis.

Tuberculosis (TB) is a widespread infectious disease caused by Mycobacterium tuberculosis (M. tb), which has been a significant burden for a long time. Post-translational modifications (PTMs) are essential for protein function in both eukaryotic and prokaryotic cells. This review focuses on the contribution of protein acetylation to the function of M. tb and its infected macrophages. The acetylation of M. tb proteins plays a critical role in virulence, drug resistance, regulation of metabolism, and host anti-TB immune response. Similarly, the PTMs of host proteins induced by M. tb are crucial for the development, treatment, and prevention of diseases. Host protein acetylation induced by M. tb is significant in regulating host immunity against TB, which substantially affects the disease's development. The review summarizes the functions and mechanisms of M. tb acetyltransferase in virulence and drug resistance. It also discusses the role and mechanism of M. tb in regulating host protein acetylation and immune response regulation. Furthermore, the current scenario of isoniazid usage in M. tb therapy treatment is examined. Overall, this review provides valuable information that can serve as a preliminary basis for studying pathogenic research, developing new drugs, exploring in-depth drug resistance mechanisms, and providing precise treatment for TB.

Mycobacterium tuberculosis induces host autophagic ferritin degradation for enhanced iron bioavailability and bacterial growth.

ABBREVIATIONS: Mtb, Mycobacterium tuberculosis; TB, tuberculosis; NCOA4, nuclear receptor coactivator 4; p38, p38 protein kinase; AKT1, AKT serine/threonine kinase 1; TRIM21, tripartite motif containing 21; FTH1, ferritin heavy chain 1; FTL, ferritin light chain; HERC2, HECT and RLD domain containing E3 ubiquitin protein ligase 2.

Mycobacterium tuberculosis hijacks host TRIM21- and NCOA4-dependent ferritinophagy to enhance intracellular growth.

Ferritin, a key regulator of iron homeostasis in macrophages, has been reported to confer host defenses against Mycobacterium tuberculosis (Mtb) infection. Nuclear receptor coactivator 4 (NCOA4) was recently identified as a cargo receptor in ferritin degradation. Here, we show that Mtb infection enhanced NCOA4-mediated ferritin degradation in macrophages, which in turn increased the bioavailability of iron to intracellular Mtb and therefore promoted bacterial growth. Of clinical relevance, the upregulation of FTH1 in macrophages was associated with tuberculosis (TB) disease progression in humans. Mechanistically, Mtb infection enhanced NCOA4-mediated ferritin degradation through p38/AKT1- and TRIM21-mediated proteasomal degradation of HERC2, an E3 ligase of NCOA4. Finally, we confirmed that NCOA4 deficiency in myeloid cells expedites the clearance of Mtb infection in a murine model. Together, our findings revealed a strategy by which Mtb hijacks host ferritin metabolism for its own intracellular survival. Therefore, this represents a potential target for host-directed therapy against tuberculosis.

Toxin-Antitoxin Systems Alter Adaptation of Mycobacterium smegmatis to Environmental Stress.

Toxin-antitoxin (TA) systems are ubiquitous genetic elements in prokaryotes, but their biological importance is poorly understood. Mycobacterium smegmatis contains eight putative TA systems. Previously, seven TAs have been studied, with five of them being verified as functional. Here, we show that Ms0251-0252 is a novel TA system in that expression of the toxin Ms0251 leads to growth inhibition that can be rescued by the antitoxin Ms0252. To investigate the functional roles of TA systems in M. smegmatis, we deleted the eight putative TA loci and assayed the mutants for resistance to various stresses. Deletion of all eight TA loci resulted in decreased survival under starvation conditions and altered fitness when exposed to environmental stresses. Furthermore, we showed that deletion of the eight TA loci decreased resistance to phage infection in Sauton medium compared with the results using 7H10 medium, suggesting that TA systems might have different contributions depending on the nutrient environment. Furthermore, we found that MazEF specifically played a dominant role in resistance to phage infection. Finally, transcriptome analysis revealed that MazEF overexpression led to differential expression of multiple genes, including those related to iron acquisition. Altogether, we demonstrate that TA systems coordinately function to allow M. smegmatis to adapt to changing environmental conditions. IMPORTANCE Toxin-antitoxin (TA) systems are mechanisms for rapid adaptation of bacteria to environmental changes. Mycobacterium smegmatis, a model bacterium for studying Mycobacterium tuberculosis, encodes eight putative TA systems. Here, we constructed an M. smegmatis mutant with deletions of all eight TA-encoding genes and evaluated the resistance of these mutants to environmental stresses. Our results showed that different TA systems have overlapping and, in some cases, opposing functions in adaptation to various stresses. We suggest that complementary TA modules may function together to regulate the bacterial stress response, enabling adaptation to changing environments. Together, this study provides key insights into the roles of TA systems in resistance to various environmental stresses, drug tolerance, and defense against phage infection.

Use of Pleural Fluid Digital PCR Analysis to Improve the Diagnosis of Pleural Tuberculosis.

The diagnosis of pleural tuberculosis (TB) remains difficult due to the paucity of Mycobacterium tuberculosis in pleural fluid (PF). This study aimed to improve pleural TB diagnosis using highly sensitive digital PCR (dPCR) technique. A total of 310 patients with evidence of PF were consecutively enrolled, 183 of whom suffered from pleural TB and 127 from non-TB. PF samples were prospectively collected and total DNA was extracted. The copy numbers of M. tuberculosis insertion sequence (IS) 6110 and IS1081 in DNA were quantified using dPCR. The overall area under the curve of IS6110-dPCR was greater than that of IS1081-dPCR (0.85 versus 0.79). PF IS6110 OR IS1081-dPCR (according to their cut-off values, "positive" was defined as either of them was positive, while "negative" was defined as both of them were negative) had higher sensitivity and equal specificity compared with single target-dPCR. The sensitivity of PF IS6110 OR IS1081-dPCR for total, definite, and probable pleural TB was 59.0% (95% CI = 51.5% to 66.2%), 72.8% (95% CI = 62.6% to 81.6%), and 45.1% (95% CI = 34.6% to 55.8%), respectively. Its specificity was 100% (95% CI = 97.1% to 100.0%). PF IS6110 OR IS1081-dPCR showed a higher sensitivity than smear microscopy (57.4% versus 7.1%), mycobacterial culture (55.3% versus 31.8%), and Xpert MTB/RIF (57.6% versus 23.0%). Long antituberculosis treatment time (>1 month) was found to be associated with negative dPCR results in pleural TB patients. This study indicates that PF IS6110 OR IS1081-dPCR is an accurate molecular assay, which is more sensitive than routine etiological tests and has the potential to enhance the definite diagnosis of pleural TB. IMPORTANCE Pleural TB is one of the most frequent causes of pleural effusion, especially in areas with high burden of TB. Due to the paucibacillary nature of the disease, the diagnostic sensitivities of all available bacteriological and molecular tests remain poor. There is an urgent need to develop new efficient methods. Digital PCR (dPCR) is the third generation of PCR that enables the exact quantification of trace nucleic acids in samples. This study evaluates the diagnostic performance of pleural fluid (PF) dPCR analysis for pleural TB, and shows that PF IS6110 OR IS1081-dPCR has a higher sensitivity than routine etiological tests such as smear microscopy, mycobacterial culture, and Xpert MTB/RIF. This work provides a new choice for improving the definite diagnosis of pleural TB.

Effects of Bedaquiline on Antimicrobial Activity and Cytokine Secretion of Macrophages Infected with Multidrug-Resistant Mycobacterium tuberculosis Strains.

Background: Bedaquiline (Bdq) exerts bactericidal effects against drug-susceptible and drug-resistant Mycobacterium tuberculosis strains, including multidrug-resistant M. tuberculosis strains (MDR-MTBs). However, few reported investigations exist regarding Bdq effects on MDR-MTBs-infected macrophages activities and cytokine secretion. Here, Bdq bactericidal activities against MDR-MTBs and related cellular immune mechanisms were explored. Methods: Macrophages infected with MDR-MTBs or H37Rv received Bdq treatments (4 h/8 h/24 h/48 h) at 1 × the minimum inhibitory concentration (1 × MIC), 10 × MIC and 20 × MIC. Intracellular colony-forming units (CFUs) and culture supernatant IL-12/23 p40, TNF-α, IL-6, and IL-10 were determined using the Luminex® 200TM system. Normally distributed continuous data (mean ± standard deviation) were analyzed using t-test or F-test (SPSS 25.0, P < 0.05 deemed statistically significant). Results: (1) 100% of Bdq-treated macrophages (all doses applied over 4-48 h) survived with 0% inhibition of proliferation observed. (2) Intracellular CFUs of Bdq-treated MDR-MTBs-infected macrophages decreased over 4-48 h of treatment, were lower than preadministration and control CFUs, decreased with increasing Bdq dose, and resembled H37Rv-infected group CFUs (48 h). (3) For MDR-MTBs-infected macrophages (various Bdq doses), IL-12/23 p40 levels resembled preadministration group levels and exceeded controls (4 h); TNF-α levels exceeded preadministration group levels (24 h/48 h) and controls (24 h); IL-12/23 p40 and TNF-α levels resembled H37Rv-infected group levels (4 h/8 h/24 h/48 h); IL-6 levels exceeded preadministration and H37Rv-infected group levels (24 h/48 h) and controls (24 h); IL-10 levels resembled preadministration and H37Rv-infected group levels (4 h/8 h/24 h/48 h) and were lower than controls (24 h/48 h); IL-12/23 p40 and IL-10 levels remained unchanged as intracellular CFUs changed, with IL-12/23 p40 levels exceeding controls (4 h) and IL-10 levels remaining lower than controls (24 h/48 h); TNF-α and IL-6 levels increased as intracellular CFUs decreased (24 h/48 h) and exceed controls (24 h). Conclusion: Bdq was strongly bactericidal against intracellular MDR-MTBs and H37Rv in a time-dependent, concentration-dependent manner. Bdq potentially exerted immunomodulatory effects by inducing high-level Th1 cytokine expression (IL-12/23 p40, TNF-α) and low-level Th2 cytokine expression (IL-10).

Flunarizine suppresses Mycobacterium tuberculosis growth via calmodulin-dependent phagosome maturation.

Tuberculosis (TB), an infectious bacterial disease caused by Mycobacterium tuberculosis (Mtb), is a major cause of death worldwide. Multidrug-resistant TB remains a public health crisis and thus novel effective treatments, such as host-directed therapies (HDTs), are urgently required to overcome the challenges of TB infection. In this study, we evaluated 4 calcium modulators for their effects on Mtb growth in macrophages. Only flunarizine enhanced the bactericidal ability of macrophages against Mtb, which was induced by an increase in phosphorylated calcium/calmodulin (CaM)-dependent protein kinase II (pCaMKII) levels. We further discovered that the expression of CaM was decreased in Mtb-infected macrophages and restored following flunarizine treatment; this was associated with phagolysosome maturation and acidification. Consistent with these findings, the anti-TB ability of macrophages was reduced following the silencing of CaM or inhibition of CAMKII activity. In conclusion, our results demonstrated that flunarizine enhanced the bactericidal ability of macrophages and clarified its CaM-pCAMKII-dependent mechanism. Therefore, our findings strongly support further studies of this currently approved drug as an HDT candidate for TB therapy.

NF-κB-mediated TET2-dependent TNF promoter demethylation drives Mtb-upregulation TNF expression in macrophages.

Tumor necrosis factor (TNF) is essential for the host defense against tuberculosis (TB). However, scarcity or excessive TNF production in macrophages can also increase susceptibility to TB. The precise mechanisms underlying how Mycobacterium tuberculosis (Mtb) induces TNF over-expression are unclear. Here, we show that Mtb infection significantly increases 5-hydroxylmethylocytosine (5hmC) levels in the TNF promoter. Luciferase reporter assays identify the precise methylated CpG sites that are essential to regulating TNF promoter activity. Infection simultaneously promotes the expression of the TET2 demethylase in macrophages. After inhibiting NF-κB or knocking down TET2, we found that TNF promoter demethylation levels is increased while Mtb-induced TNF expression decrease. Here, NF-κB binds to TET2 and mediates its recruitment to the TNF promoter to induce TNF demethylation. Finally, we show that TLR2 activation during Mtb infection promotes NF-κB translocation into the nucleus which is important for NF-κB-mediated TET2-dependent TNF promoter demethylation thus helps drive Mtb-induced TNF expression. Targeting this axis might be a novel strategy for host-directed therapy against TB.

The Activities and Secretion of Cytokines Caused by Delamanid on Macrophages Infected by Multidrug-Resistant Mycobacterium tuberculosis Strains.

Background: Delamanid (Dlm) is an effective drug against drug-susceptible and drug-resistant Mycobacterium tuberculosis strains, including Multidrug-resistant Mycobacterium tuberculosis (MDR-MTB). There are few reports on the activity and secretion of cytokines caused by Dlm on macrophages infected by MDR-MTB strains. Therefore, this article aims to observe the bactericidal activity and secretion of cytokines of the macrophages infected by MDR-MTB strains after Dlm was administered, so as to provide a basis for further perfecting the mechanism of Dlm. Methods: Samples were respectively collected to count the intracellular colony-forming unit (CFU) of macrophages infected by MDR-MTB or H37Rv strains at 4, 8, 24, and 48 h after Dlm at MIC, 10MIC, and 20MIC were administered. Samples were respectively collected to detect the level of IL-12/23 p40, TNF-α, IL-6, and IL-10 in the culture supernatant of macrophages infected by MDR-MTB or H37Rv strains at 4, 24, and 48 h after Dlm at MIC were administered. The levels of four cytokines in the culture supernatant were measured using the Luminex® 200™ (Luminex, USA) according to the manufacturer's instructions. Data were analyzed by SPSS 25.0 software. The continuous data in normal distribution were expressed as mean ± standard deviation ( x¯ ± s) and analyzed by t or F test. P<0.05 was considered statistically significant. Results: (1) After Dlm was applied to macrophages infected by MDR-MTB strains:(A) The intracellular CFU gradually decreased, reached the lowest value at 48 h, and was lower than that of Dlm before administration and infection group (P<0.05). (B) The intracellular CFU was further reduced after increasing Dlm dose to 10MIC and 20MIC, and the latter was lower than that of the former (P<0.05). (C) The intracellular CFU of MDR-MTB group was higher than that of H37Rv group at 4~48 h after administration (P<0.05). (2) After Dlm at MIC dose was applied to macrophages infected by MDR-MTB strains: (A) The level of IL-12/23 p40 at any time didn't change compared with that of Dlm before administration (P>0.05), while the level of IL-12/23 p40 at 4 h was higher than that of the infection group (P<0.05). The levels of TNF-α at 24 and 48 h were higher than that of Dlm before administration (P<0.05), but were similar to that of the infection group (P>0.05). In addition, the levels of IL-12/23 p40 and TNF-α at any time were similar to that of the H37Rv group after administration (P>0.05). (B) The levels of IL-6 at 24 and 48 h were higher than that of Dlm before administration (P<0.05), but were similar to that of H37Rv group (P>0.05) and were lower than that of infection group (P<0.05). The level of IL-10 at any time didn't change compared with that of Dlm before administration (P>0.05), but was lower than that of the infection group at 4~48 h and was lower than that of the H37Rv group at 24 h (P<0.05). (C) The level of IL-12/23 p40 and IL-10 didn't change with the change of intracellular CFU (P<0.05), while the level of TNF-α and IL-6 increased with the intracellular CFU decreasing, and the increase level of TNF-α was lower than that of the infection group (P<0.05). Conclusions: Dlm had strong bactericidal activity against intracellular MDR-MTB, which was time-dependent and concentration-dependent. Its bactericidal activity against intracellular MDR-MTB strains was weaker than that against drug-susceptible tuberculosis strains. Dlm might have immunomodulatory effect, inducing low expression of Th2 cytokines IL-6 and IL-10 at different times after administration.

Histone deacetylase inhibitors impair the host immune response against Mycobacterium tuberculosis infection.

Histone deacetylase inhibitors (HDACi), a novel class of anti-cancer drug, have been recently reported to suppress host immunity and increase susceptibility to infection. Tuberculosis, a leading infectious disease killer caused by Mycobacterium tuberculosis (M.tb), is basically the product of the interaction between bacterial virulence and host resistance. However, the effects of HDACi in host immunity against M.tb is largely unknown. In this study, we found that HDACi including Trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA) significantly impaired phagocytosis and killing activity of macrophage. In line with these findings, we noted that M.tb induced reactive oxygen species (ROS) production and autophagy are significantly suppressed by TSA. Transcriptome analysis revealed that the suppression of autophagy by TSA might due to its inhibiting autophagy-regulating genes such as CACNA2D3, which regulates intracellular Ca2+ levels. Finally, we confirmed that HDACi including TSA and SAHA significantly exacerbated the histopathological damage and M.tb load in the lung of M.tb infected mice. Taken together, our results indicated that HDACi at least TSA and SAHA significantly impaired macrophage immunity against M.tb and therefore increase susceptibility to TB, our findings raised the concern that the potential side effects of HDACi on latent TB reactivation should be considered in clinic.

The Polymorphism rs17525495 of LTA4H Is Associated with Susceptibility of Crohn's Disease instead of Intestinal Tuberculosis in a Chinese Han Population.

BACKGROUND: Because of the similarity of intestinal tuberculosis and Crohn's disease in disease phenotype, differential diagnosis has always been a clinical problem. Arachidonic acid metabolites play an important role in the inflammatory response of intestinal tuberculosis and Crohn's disease. Recent studies have shown that the polymorphism locus in the promoter region of LTA4H gene affects LTB4 expression level and the susceptibility to extrapulmonary tuberculosis. Thus, we identified a total of 148 patients with intestinal tuberculosis, 145 with Crohn's disease, and 700 normal controls in this study. METHODS: All the study participants were local Han people from Jiangxi Province in the past eleven years. DNA was extracted from the paraffin-embedded specimens or the whole blood. The LTA4H promoter SNP (rs17525495) was genotyped with TaqMan assay. RESULTS: The T-alleles frequency was not significantly increased in patients with intestinal tuberculosis compared with healthy control group (p=0.630; OR=1.07; 95%CI=0.81-1.41), while patients with Crohn's disease have significantly increased T allele frequency compared with healthy population (p=0.032; OR=1.34; 95%CI=1.03-1.75). During treatment, the presence of the T allele significantly increased the proportion of Crohn's patients requiring glucocorticoids (p<0.05). CONCLUSIONS: The T allele of LTA4H gene SNP (rs17525495) is a risk factor for Crohn's disease instead of intestinal tuberculosis. More importantly, there may be a potential association of the different genotypes of rs17525495 with the treatment efficacy of 5-ASA and glucocorticoids in patients with Crohn's disease. The association between LTA4H polymorphism and drugs therapeutic effects might contribute to the practice of precision medicine and the prediction of clinical outcomes.

Anti-Mycobacterium tuberculosis Terpenoids from Resina Commiphora.

Four new compounds including two new sesquiterpenoid dimers, commiphoroids E (1) and F (2), a new triterpenoid (3), and a new sesquiterpenoid (4), along with three known terpenoids (5-7) were isolated from Resina Commiphora, whose structures were identified by NMR spectra, HRESIMS, and X-ray diffraction analysis. Compounds 1 and 2 both bear an O-bridge ring and feature a plausible [4 + 2] Diels-Alder cycloaddition reaction. Antimycobacterial activities show that all the tested compounds (200 µM) could inhibit the growth of both sensitive and clinically multi-drug resistant (MDR) isolated strains. In addition, cellular toxicity of the isolates against human cancer cells and THP-1 monocyte cells was examined.

Simultaneous detection of IgG and IgM antibodies against a recombinant polyprotein PstS1-LEP for tuberculosis diagnosis.

BACKGROUND: Commercial serological tests for the diagnosis of tuberculosis (TB) show poor sensitivity and specificity, and a new approach to antigen screening is required to improve the accuracy of serodiagnosis. METHODS: Using an indirect enzyme-linked immunosorbent assay (ELISA), we evaluated the responses of IgG and IgM antibodies to the recombinant PstS1-LEP protein expressed in Escherichia coli, a polyprotein of PstS1 and line multi-epitopes polypeptide (LEP). RESULTS: The mixture of anti-human IgG and IgM added to a well [Ig(G + M)], which was different from the combination of IgG and IgM (IgG + IgM), had a stronger immunoreactivity to PstS1-LEP than the single antibody. IgG and Ig(G + M), but not IgM against the PstS1-LEP protein effectively distinguished TB patients from patients with nontuberculous pulmonary disease (NTBPD) and healthy controls (HCs). Compared with IgG, the sensitivities of Ig(G + M) and IgG + IgM varied from 71.4% to 77.6% and 72.7% in pulmonary TB (PTB) patients and from 42.1% to 64.0% and 55.8% in extrapulmonary TB (EPTB) patients, respectively. The specificity of Ig(G + M) did not decrease, and was higher than that provided by IgG + IgM in HCs with positive tuberculin skin test. CONCLUSION: These findings suggest that PstS1-LEP can act as a candidate for detecting Ig(G + M) in serum from PTB and EPTB patients.

[Quantitative proteomic analysis of streptomycin resistant and sensitive clinical isolates of Mycobacterium tuberculosis].

OBJECTIVE: To identify specific antigens related to streptomycin resistant (SMr) Mycobacterium tuberculosis. METHODS: Cellular proteins were extracted from SMr clinical isolate 01108, SM-sensitive clinical isolate 01105 and H37Rv. Differential expression proteins were identified with isobaric tags for relative and absolute quantitation (iTRAQ) combined with Nano LC-MS/MS technology. RESULTS: Approximately 194 and 146 differential expression proteins were identified in 01108 strain compared with the proteomic profiles of 01105 strain and H37Rv, respectively, and 121 proteins were identified in 01108 strain compared with the proteomic profiles of both 01105 strain and H37Rv. Identified proteins showed a pI (isoelectric point) variation between 3.74-12.48 and a molecular mass (M) range between 7.63 and 326.2 kDa. Differential expression proteins were mainly associated with metabolism (involved in intermediary metabolism, respiration, and lipid metabolism) and took part in catalysis and binding function. Seven ribosomal proteins (Rv0056, Rv0641, Rv0652, Rv0701, Rv1630, Rv2442c and Rv2785c) and seven proteins (the ratios > 1.20 or < 0.55) were commonly down-regulated in 01108 strain compared with both 01105 strain and H37Rv, i. e. the thiol peroxidase (Rv1932), acyl carrier protein dehydrogenase (Rv0824c), 30S ribosomal protein S15 (Rv2785c), acetone acid dehydrogenase E2 part (Rv2215), two-component transcriptional regulatory protein (Rv3133c) and Hypothetical protein (Rv2466e and Rv2626c). CONCLUSION: Differential expression proteins were found in SMr strain compared with both SM-sensitive strain and H37Rv. Further studies are needed to assess the role of these differential expression proteins in SM resistance.