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Tuberculosis (T.B.) remains a prominent global cause of health challenges and death, exacerbated by drug-resistant strains such as multidrug-resistant tuberculosis MDR-TB and extensively drug-resistant tuberculosis XDR-TB. For an effective disease management strategy, it is crucial to understand the dynamics of T.B. infection and the impacts of treatment. In the present article, we employ AI-based machine learning techniques to investigate the immunity impact of medications. SEIPR epidemiological model is incorporated with MDR-TB for compartments susceptible to disease, exposed to risk, infected ones, preventive or resistant to initial treatment, and recovered or healed population. These masses' natural trends, effects, and interactions are formulated and described in the present study. Computations and stability analysis are conducted upon endemic and disease-free equilibria in the present model for their global scenario. Both numerical and AI-based nonlinear autoregressive exogenous NARX analyses are presented with incorporating immediate treatment and delay in treatment. This study shows that the active patients and MDR-TB, both strains, exist because of the absence of permanent immunity to T.B. Furthermore, patients who have recovered from tuberculosis may become susceptible again by losing their immunity and contributing to transmission again. This article aims to identify patterns and predictors of treatment success. The findings from this research can contribute to developing more effective tuberculosis interventions., Competing Interests: Declaration of competing interest I have no conflict of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Lung cavitation is associated with heightened TB transmission and poor treatment outcomes. This study aimed to determine the relationship between systemic inflammation and lung cavitation in drug-resistant TB patients with and without HIV co-infection., Methods: Plasma samples were obtained from 128 participants from the CAPRISA 020 Individualized M(X)drug-resistant TB Treatment Strategy Study (InDEX) prior to treatment initiation. Lung cavitation was present in 61 of the 128 drug-resistant TB patients with 93 being co-infected with HIV. The plasma cytokine and chemokine levels were measured using the 27-Plex Human Cytokine immunoassay. Modified Poisson regression models were used to determine the association between plasma cytokine/chemokine expression and lung cavitation in individuals with drug-resistant TB., Results: Higher Interleukin-6 plasma levels (adjusted risk ratio [aRR] 1.405, 95% confidence interval [CI] 1.079-1.829, p = 0.011) were associated with a higher risk of lung cavitation in the multivariable model adjusting for age, sex, body mass index, HIV status, smoking and previous history of TB. Smoking was associated with an increased risk of lung cavitation (aRR 1.784, 95% CI 1.167-2.729, p = 0.008). An HIV positive status and a higher body mass index, were associated with reduced risk of lung cavitation (aRR 0.537, 95% CI 0.371-0.775, p = 0.001 and aRR 0.927, 95% CI 0.874-0.983, p = 0.012 respectively)., Conclusion: High plasma interleukin-6 levels are associated with an increased risk of cavitary TB highlighting the role of interleukin-6 in the immunopathology of drug-resistant TB., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Polyautoimmunity or multiple autoimmune syndrome (MAIS) is increasingly being recognized in pediatric clinical practice, often in conjunction with systemic lupus erythematosus (SLE). Besides multi-organ autoimmunity, children with SLE are often at a higher risk of developing infections including tuberculosis. The tendency to develop infections and multiple autoimmune diseases in childhood SLE often occurs in the absence of monogenic primary immunodeficiency disease. Conversely, children with inborn errors of immunity, of which selective IgA deficiency (sIgAD) is the most common, may develop recurrent infections and autoimmune disorders including SLE. Herein, we report a child with MAIS (including SLE) and sIgAD who developed drug-resistant tuberculosis, which was managed successfully with second-line anti-tubercular drug therapy. To the best of our knowledge, this combination of rare findings has not been reported previously in the pediatric literature. Although a majority of patients with sIgAD are either asymptomatic or have mild infections/autoimmunity, the index child had a myriad of infectious illnesses and multi-organ autoimmunity. Our case highlights the prudence of thoroughly evaluating children with SLE for other autoimmune diseases and vice versa. Given the higher probability of inherited disorders, including early complement deficiencies and monogenic interferonopathies, in childhood SLE compared with adult SLE, it may be prudent to perform a basic immunological workup (for example, immunoglobulin levels, 50% hemolytic complement) in such patients. A more extensive immunological and genetic evaluation (including next-generation sequencing) may also be required in the presence of unusual clinical or laboratory features, a positive family history, or a complicated clinical course., (© 2022 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.)

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., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Lyu, Lin, Gao, Jia, Zhu, Li, Dong, Sun, Shu, Pan, Zhang and Li.)

Background: Multidrug-resistant (MDR) tuberculosis has low treatment success rates, and new treatment strategies are needed. We explored whether treatment with active vitamin D3 (vitD) and phenylbutyrate (PBA) could improve conventional chemotherapy by enhancing immune-mediated eradication of Mycobacterium tuberculosis., Methods: A clinically relevant model was used consisting of human macrophages infected with M. tuberculosis isolates (n = 15) with different antibiotic resistance profiles. The antimicrobial effect of vitD+PBA, was tested together with rifampicin or isoniazid. Methods included colony-forming units (intracellular bacterial growth), messenger RNA expression analyses (LL-37, β-defensin, nitric oxide synthase, and dual oxidase 2), RNA interference (LL-37-silencing in primary macrophages), and Western blot analysis and confocal microscopy (LL-37 and LC3 protein expression)., Results: VitD+PBA inhibited growth of clinical MDR tuberculosis strains in human macrophages and strengthened intracellular growth inhibition of rifampicin and isoniazid via induction of the antimicrobial peptide LL-37 and LC3-dependent autophagy. Gene silencing of LL-37 expression enhanced MDR tuberculosis growth in vitD+PBA-treated macrophages. The combination of vitD+PBA and isoniazid were as effective in reducing intracellular MDR tuberculosis growth as a >125-fold higher dose of isoniazid alone, suggesting potent additive effects of vitD+PBA with isoniazid., Conclusions: Immunomodulatory agents that trigger multiple immune pathways can strengthen standard MDR tuberculosis treatment and contribute to next-generation individualized treatment options for patients with difficult-to-treat pulmonary tuberculosis., (© The Author(s) 2021. Published by Oxford University Press for the Infectious Diseases Society of America.)

The biomarker significance of IL-35, chemokines (CXCL9 and CXCL10) and human beta-defensins (hBD2 and hBD3) was determined in pulmonary tuberculosis (TB) of 105 Iraqi patients; 37 had active disease, 41 had multi-drug resistant (MDR) PTB and 27 had a relapse of TB. A control sample of 79 healthy persons was also included. Serum levels of markers were assessed using enzyme-linked immunosorbent assay kits. Kruskal-Wallis test together with Dunn-Bonferroni post hoc test revealed significance differences between patients and controls in levels of IL-35, CXCL9, CXCL10 and hBD3, while hBD2 showed no significant difference. Receiver operating characteristic analysis demonstrated that CXCL10 and hBD3 were the most significant markers in predicting TB, particularly active disease. Logistic regression analysis proposed the susceptibility role of CXCL10 in TB. Gender- and age-dependent variations were also observed. Spearman's rank correlation analysis showed different correlations between markers in each group of patients and controls. In conclusion, CXCL10 was up-regulated in serum of TB patients, while hBD3 showed down-regulated level. Both serum proteins are possible candidate biomarkers for evaluation of TB progression, particularly in active disease., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains as a leading infectious cause of death worldwide. The increasing number of multidrug-resistant TB (MDR-TB) cases contributes to the poor control of the TB epidemic. Currently, little is known about the immunological requirements of protective responses against MDR-TB. This is of major relevance to identify immune markers for treatment monitoring and targets for adjuvant immunotherapies. Here, we hypothesized that MDR-TB patients display unique immunophenotypical features and immune cell migration dynamics compared to drug-sensitive TB (DS-TB). Hence, we prospectively conducted an extensive characterization of the immune profile of MDR-TB patients at different time points before and after pharmacological therapy. For this purpose, we focused on the leukocyte expression of chemokine receptors, distribution of different monocyte and lymphocyte subsets, plasma levels of chemotactic factors, and in vitro migration capacity of immune cells. Our comparative cohort consisted of DS-TB patients and healthy volunteer donors (HD). Our results demonstrate some unique features of leukocyte migration dynamics during MDR-TB. These include increased and prolonged circulation of CD3+ monocytes, CCR4+ monocytes, EM CD4+ T cells, EM/CM CD8+ T cells, and CXCR1+CXCR3+ T cells that is sustained even after the administration of anti-TB drugs. We also observed shared characteristics of both MDR-TB and DS-TB that include CCR2+ monocyte depletion in the blood; high plasma levels of MPC-1, CCL-7, and IP-10; and increased responsiveness of leukocytes to chemotactic signals in vitro . Our study contributes to a better understanding of the MDR-TB pathobiology and uncovers immunological readouts of treatment efficacy., Competing Interests: The authors declare no conflict of interest., (Copyright © 2021 Ranferi Ocaña-Guzmán et al.)

Background: A therapeutic vaccine that prevents recurrent tuberculosis would be a major advance in the development of shorter treatment regimens. We aimed to assess the safety and immunogenicity of the ID93 + GLA-SE vaccine at various doses and injection schedules in patients with previously treated tuberculosis., Methods: This randomised, double-blind, placebo-controlled, phase 2a trial was conducted at three clinical sites near Cape Town, South Africa. Patients were recruited at local clinics after receiving 4 months of tuberculosis treatment, and screened for eligibility after providing written informed consent. Participants were aged 18-60 years, BCG-vaccinated, HIV-uninfected, and diagnosed with drug-sensitive pulmonary tuberculosis. Eligible patients had completed standard treatment for pulmonary tuberculosis in the past 28 days. Participants were enrolled after completing standard treatment and randomly assigned sequentially to receive vaccine or placebo in three cohorts: 2 μg intramuscular ID93 + 2 μg GLA-SE on days 0 and 56 (cohort 1); 10 μg ID93 + 2 μg GLA-SE on days 0 and 56 (cohort 2); 2 μg ID93 + 5 μg GLA-SE on days 0 and 56 and placebo on day 28 (cohort 3); 2 μg ID93 + 5 μg GLA-SE on days 0, 28, and 56 (cohort 3); or placebo on days 0 and 56 (cohorts 1 and 2), with the placebo group for cohort 3 receiving an additional injection on day 28. Randomisation was in a ratio of 3:1 for ID93 + GLA-SE and saline placebo in cohorts 1 and 2, and in a ratio of 3:3:1 for (2 ×) ID93 + GLA-SE, (3 ×) ID93 + GLA-SE, and placebo in cohort 3. The primary outcomes were safety and immunogenicity (vaccine-specific antibody response and T-cell response). For the safety outcome, participants were observed for 30 min after each injection, injection site reactions and systemic adverse events were monitored until day 84, and serious adverse events and adverse events of special interest were monitored for 6 months after the last injection. Vaccine-specific antibody responses were measured by serum ELISA, and T-cell responses after stimulation with vaccine antigens were measured in cryopreserved peripheral blood mononuclear cells specimens using intracellular cytokine staining followed by flow cytometry. This study is registered with ClinicalTrials.gov, number NCT02465216., Findings: Between June 17, 2015, and May 30, 2016, we assessed 177 patients for inclusion. 61 eligible patients were randomly assigned to receive: saline placebo (n=5) or (2 ×) 2 μg ID93 + 2 μg GLA-SE (n=15) on days 0 and 56 (cohort 1); saline placebo (n=2) or (2 ×) 10 μg ID93 + 2 μg GLA-SE (n=5) on days 0 and 56 (cohort 2); saline placebo (n=5) on days 0, 28 and 56, or 2 μg ID93 + 5 μg GLA-SE (n=15) on days 0 and 56 and placebo injection on day 28, or (3 ×) 2 μg ID93 + 5 μg GLA-SE (n=14) on days 0, 28, and 56 (cohort 3). ID93 + GLA-SE induced robust and durable antibody responses and specific, polyfunctional CD4 T-cell responses to vaccine antigens. Two injections of the 2 μg ID93 + 5 μg GLA-SE dose induced antigen-specific IgG and CD4 T-cell responses that were significantly higher than those with placebo and persisted for the 6-month study duration. Mild to moderate injection site pain was reported after vaccination across all dose combinations, and induration and erythema in patients given 2 μg ID93 + 5 μg GLA-SE in two or three doses. One participant had grade 3 erythema and induration at the injection site. No vaccine-related serious adverse events were observed., Interpretation: Vaccination with ID93 + GLA-SE was safe and immunogenic for all tested regimens. These data support further evaluation of ID93 + GLA-SE in therapeutic vaccination strategies to improve tuberculosis treatment outcomes., Funding: Wellcome Trust (102028/Z/13/Z)., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The role of interleukin-22 (IL-22) in the pathogenesis or tissue repair in human tuberculosis (TB) remains to be established. Here, we aimed to explore the ex-vivo and in-vitro T helper 22 (Th22) response in TB patients and healthy donors (HD) induced by different local multi-drug-resistant (MDR) Mvcobacterium tuberculosis (Mtb) strains. For this purpose, peripheral blood mononuclear cells from drug-susceptible (S-TB) MDR-TB patients and HD were stimulated with local MDR strains and the laboratory strain H37Rv. IL-22 and IL-17 expression and senescent status were assessed in CD4 + and CD8 + cells by flow cytometry, while IL-22 amount was measured in plasma and culture supernatants by enzyme-linked immunosorbent assay (ELISA). We found lower IL-22 amounts in plasma from TB patients than HD, together with a decrease in the number of circulating T cells expressing IL-22. In a similar manner, all Mtb strains enhanced IL-22 secretion and expanded IL-22 + cells within CD4 + and CD8 + subsets, being the highest levels detected in S-TB patients. In MDR-TB, low systemic and Mtb-induced Th22 responses associated with high sputum bacillary load and bilateralism of lung lesions, suggesting that Th22 response could be influencing the ability of MDR-TB patients to control bacillary growth and tissue damage. In addition, in MDR-TB patients we observed that the higher the percentage of IL-22 + cells, the lower the proportion of programmed cell death 1 (PD-1) + or CD57 + T cells. Furthermore, the highest proportion of senescent T cells was associated with severe lung lesions and bacillary load. Thus, T cell senescence would markedly influence Th22 response mounted by MDR-TB patients., (© 2020 British Society for Immunology.)

Several explanations have been suggested concerning the variety in bacille Calmette-Guerin (BCG) vaccine efficacy on strains of Mycobacterium tuberculosis (Mtb). This study aimed to compare the effect of BCG vaccination history in the prevention of the occurrence of Mtb-Beijing and non-Beijing strains. In this cross-sectional study, 64 patients with pulmonary tuberculosis (TB) were recruited from the Iranian border provinces (North West and West). Isolates were subjected to restriction fragment length polymorphism (RFLP) analysis, using the insertion sequence IS6110 as a probe (IS6110 RFLP) and drug susceptibility testing using the proportion method. Samples were analyzed with Gel Compare II 6.6 and spss version 18. The mean age [standard deviation (SD)] of the patients was 54·4 (SD = 17·0). Overall, 49 cases (76·56%) had no BCG vaccination scar. The prevalence of Beijing strains was 9·38% and drug resistance proportion among the isolates was 14·1% (nine cases). There was a significant relationship between Beijing strains and tuberculosis (TB)-drug resistance in isolates (χ 2  = 26·29, P < 0·001). There was also a strong association between vaccination history and Beijing strains (χ 2  = 13·23, P = 0·002). Also, a statistical relationship was observed between Beijing strains and drug-resistant TB among patients with a history of vaccination (χ 2  = 7·47, P = 0·002). This association was not maintained in the unvaccinated group (P = 0·102). These findings confirm the claim that the vaccine has different effects on different subspecies of tuberculosis. The cause of the high probability of drug resistance in patients with Beijing-TB and vaccination history requires further investigation with a higher sample size., (© 2020 British Society for Immunology.)

The current emergence of multi-, extensively-, extremely-, and total-drug resistant strains of Mycobacterium tuberculosis poses a major health, social, and economic threat, and stresses the need to develop new therapeutic strategies. The notion of phage therapy against bacteria has been around for more than a century and, although its implementation was abandoned after the introduction of drugs, it is now making a comeback and gaining renewed interest in Western medicine as an alternative to treat drug-resistant pathogens. Mycobacteriophages are genetically diverse viruses that specifically infect mycobacterial hosts, including members of the M. tuberculosis complex. This review describes general features of mycobacteriophages and their mechanisms of killing M. tuberculosis , as well as their advantages and limitations as therapeutic and prophylactic agents against drug-resistant M. tuberculosis strains. This review also discusses the role of human lung micro-environments in shaping the availability of mycobacteriophage receptors on the M. tuberculosis cell envelope surface, the risk of potential development of bacterial resistance to mycobacteriophages, and the interactions with the mammalian host immune system. Finally, it summarizes the knowledge gaps and defines key questions to be addressed regarding the clinical application of phage therapy for the treatment of drug-resistant tuberculosis.

Tuberculosis is the world's most deadly infectious disease, with 10 million people falling ill and 1.5 million people dying from the disease every year. With the increasing number of drug-resistant Mycobacterium tuberculosis (MTB) strains and prevalence of coinfection of MTB with human immunodeficiency virus, many challenges remain in the prevention and treatment of tuberculosis. Therefore, the development of safe and effective tuberculosis vaccines is an urgent issue. In this study, we identified cytotoxic T lymphocyte epitopes on drug resistance-associated membrane protein efflux pumps of MTB, the ATP-binding cassette and the major facilitator superfamilies. First, three online software were used to predict HLA-A2-restricted epitopes. Then, the candidate epitopes were confirmed with the T2A2 cell binding affinity and peptide/MHC (pMHC) complex stability assays and in vitro immune activity experiments. Two drug-resistant T lymphocyte epitopes, designated Rv1218c-p24 and Rv2477c-p182, were selected, and their immunogenic activities studied in vivo in genetically engineered mice. The immune activities of these two epitopes were improved with the help of complete Freund's adjuvant (CFA). The epitopes identified here provide a foundation for the diagnosis and treatment of patients infected with drug resistant and the future development of a multiepitope vaccine., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 Yan Lin et al.)

Tuberculosis (TB) has been a transmittable human disease for many thousands of years, and M. tuberculosis is again the number one cause of death worldwide due to a single infectious agent. The intense 6- to 10-month process of multi-drug treatment, combined with the adverse side effects that can run the spectrum from gastrointestinal disturbances to liver toxicity or peripheral neuropathy are major obstacles to patient compliance and therapy completion. The consequent increase in multidrug resistant TB (MDR-TB) and extensively drug resistant TB (XDR-TB) cases requires that we increase our arsenal of effective drugs, particularly novel therapeutic approaches. Over the millennia, host and pathogen have evolved mechanisms and relationships that greatly influence the outcome of infection. Understanding these evolutionary interactions and their impact on bacterial clearance or host pathology will lead the way toward rational development of new therapeutics that favor enhancing a host protective response. These host-directed therapies have recently demonstrated promising results against M. tuberculosis , adding to the effectiveness of currently available anti-mycobacterial drugs that directly kill the organism or slow mycobacterial replication. Here we review the host-pathogen interactions during M. tuberculosis infection, describe how M. tuberculosis bacilli modulate and evade the host immune system, and discuss the currently available host-directed therapies that target these bacterial factors. Rather than provide an exhaustive description of M. tuberculosis virulence factors, which falls outside the scope of this review, we will instead focus on the host-pathogen interactions that lead to increased bacterial growth or host immune evasion, and that can be modulated by existing host-directed therapies., (Copyright © 2020 Abreu, Giri and Quinn.)

Tuberculosis (TB) is an opportunistic infection 20 to 74 times more frequent in immunocompromised patients compared to the general population. The prevalence with renal transplant had a 0.5% to 15% incidence. The infection could be pulmonary or extrapulmonary (EPTB). The EPTB accounts for almost 20% of TB cases in immunocompetent people and 50% in positive human immunodeficiency virus cases. In this case report, we present a patient who attended the emergency room because of chronic diarrhea, abdominal pain, loss of weight, nocturne diaphoresis, and intermittent fever. A computed tomography scan showed retroperitoneal ganglionic conglomeration. He got into an exploratory laparotomy for histopathology specimens and paraganglionic fluid culture to a Gene Xpert MTB-RIF Assay G4, positive for rifampicin resistance tuberculosis. After an individualized treatment, trying to protect the graft's remaining function, the patient returned with acute abdominal pain and pancreatic enzymes elevation; the antibiotic management had to be suspended until the return of renal function., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Patient immune status might be indicative of the variance in bacterial genetics in drug-resistant tuberculous pleuritis and could be used for predicting the risk of multi-drug resistant tuberculous pleuritis (MDR-TB)., Objective: To determine the significance of Th2/Th1 ratio and concentration of PD-L1 in the pleural effusions for prediction of MDR-TB., Methods: We measured the ratio of Th2 to Th1 T cells from pleural effusions in 373 tuberculous pleuritis patients. We also measured the concentration of programmed death ligand-1 (PD-L1) in the pleural effusions of these patients. Afterwards, we determined the optimal cut-off value for predicting the occurrence of multi-drug resistant tuberculous based on the Youden index, diagnostic evaluation test, and receiver operation curve. Multiple logistic analysis was employed to identify the independent risk factors for MDR-TB occurrence., Results: The area under the curve (AUC) of the Th2 to Th1 ratio was 0.66 and the concentration of PD-L1 was 0.71. Based on the combined detection of PD-L1 concentration in pleural effusion and the Th2 to Th1 ratio, our AUC was 0.81 and had a specificity of 0.92. Only a combined detection was able to identify patients developing multidrug-resistant tuberculosis. Multiple logistic analysis showed that a high concentration of PD-L1 and a high Th2 to Th1 ratio in pleural effusions were indicative of an immunocompromised status. Therefore, these measurements might be independent risk factors for the occurrence of multidrug-resistant tuberculous., Conclusion: Evaluation of immune status based on PD-L1 pleural concentration and Th2 to Th1 ratio might predict the risk of MDR-TB occurrence.

Background: Macrophages play a key role in the infection process, and alternatively activated macrophages (M2 polarization) play important roles in persistent infection via the immune escape of pathogens. This suggests that immune escape of pathogens from host immunity is an important factor to consider in treatment failure and multidrug-resistant tuberculosis (MDR-TB)/extensively drug-resistant tuberculosis (XDR-TB). In this study, we investigated the association between macrophage polarization and MDR-TB/XDR-TB and the association between macrophage polarization and the anti-TB drugs used., Methods: iNOS and arginase-1, a surface marker of polarized macrophages, were quantified by immunohistochemical staining and imaging analysis of lung tissues of patients who underwent surgical treatment for pulmonary TB. Drug susceptibility/resistance and the type and timing of anti-tuberculosis drugs used were investigated., Results: The M2-like polarization rate and the ratio of the M2-like polarization rate to the M1-like polarization rate were significantly higher in the MDR-TB/XDR-TB group than in the DS-TB group. The association between a high M2-like polarization rate and MDR-TB/XDR-TB was more pronounced in patients with a low M1-like polarization rate. Younger age and a higher M2-like polarization rate were independent associated factors for MDR-TB/XDR-TB. The M2-like polarization rate was significantly higher in patients who received anti-TB drugs containing pyrazinamide continuously for 4 or 6 weeks than in those who received anti-TB drugs not containing pyrazinamide., Conclusions: The M2-like polarization of macrophages is associated with MDR-TB/XDR-TB and anti-TB drug regimens including pyrazinamide or a combination of pyrazinamide, prothionamide and cycloserine.

The aim of the present study was to examine characteristics of tuberculosis (TB) patients with different clinical forms and to study the frequency of Regulatory T cells (Treg cells) and Activated T cells in patients with new active and relapse TB. Forty-five pulmonary TB patients and a control group of 15 healthy individuals were enrolled in this study. Of the 45 TB patients, 15 were new cases with drug-susceptible active TB and 30 were relapsed cases (15 drug-susceptible and 15 multidrug resistant-TB). The age of study participants ranged from 21 to 68 years old. According to sex presentation, males were appreciably highly affected than females with a sex ratio of 2. The patients reported a mean recent weight loss of 8.9 kg. The Erythrocyte Sedimentation Rate was high in TB group, far exceeding the normal value. The results revealed that the number of CD3+ CD4+ T-cells significantly decreased whereas the level of blood Treg cells and expression of activation markers CD38 and HLA-DR on CD4+ T-cells significantly increased in TB group compared with the control group (p&lt;0.05). The frequency of Treg cells was significantly higher in the TB group than the control group. Both the patients with new active TB and relapse TB demonstrated significantly higher levels of CD4+FoxP3+ Treg compared to healthy subjects (p&lt;0.05). A high and significant percentage of Treg cells were found in patients with DS active TB than patients with MDR relapse TB. Interestingly, the frequency of CD4+FoxP3+ cells also differs according to the sputum smear microscopy status. The presence of high numbers of Treg cells and corresponding high immune activation may be an unfavourable factor that can predispose individuals to different clinical forms of TB, including relapse TB.

Tuberculosis (TB) is a chronic disease mainly caused by Mycobacterium tuberculosis . The function of T cells usually decreased and even exhausted in severe TB such as multiple drug resistant TB (MDR-TB), which might lead to the failure of treatment in return. The mechanism of T cell dysfunction in TB is still not clear. In this study we set up a mouse model of T cell dysfunction by persistent M. tuberculosis antigen stimulation and investigated the therapeutic role of interleukin 2 (IL-2) in it. C57BL/6 mice were primed with Mycobacterium bovis Bacillus Calmette-Guérin (BCG) and boosted repeatedly with a combination of M. tuberculosis fusion proteins Mtb10.4-HspX (MH) plus ESAT6-Ag85B-MPT64 <190-198> -Mtb8.4-Rv2626c (LT70) or MH plus ESAT6 and CFP10 with adjuvant of N, N'-dimethyl-N, N'-dioctadecylammonium bromide (DDA) plus polyinosinic-polycytidylic acid (Poly I:C). Following persistent antigen stimulation, the mice were treated with IL-2 and the therapeutic effects were analyzed. The results showed that compared with the mice that received transient antigen stimulation (boost twice), persistent antigen stimulation (boost more than 10 times) resulted in decrease of antigen specific IFN-γ and IL-2 production, reduction of memory CD8 + T cells, over-expression of immune checkpoint programmed cell death protein 1 (PD-1), and impaired the protective immunity against bacterial challenge. Treating the T cell functionally exhausted mice with IL-2 restored antigen-specific T cell responses and protective efficacy. In conclusion, persistent stimulation with M. tuberculosis antigens induced T cell dysfunction, which could be restored by complement of IL-2., (Copyright © 2019 Liu, Li, Niu, Ma, Chen, Zhang, Peng, Gan, Ma and Zhu.)

Context: Treatment of the patients with multidrug-resistant tuberculosis (MDR-TB)/HIV coinfection in a state of severely suppressed immune system remains under efficient., Aims: The aim of this study was to assess the effectiveness of adjuvant immunoglobulin therapy in TB/HIV patients., Settings and Design: The relationship between biochemical indexes in the patients with MDR-TB/HIV co-infection and adjuvant immunoglobulin therapy., Materials and Methods: The study involved 52 HIV-positive patients with MDR-TB and CD4+ lymphocyte cells below 50 cells/μCL. Patients in control group (Group 1) and in basic group (Group 2) received standard treatment with second-line antituberculosis agents and antiretroviral agents. In addition patients in basic group were treated by immunoglobulin G intravenously. The evaluation of biochemical parameters such as bilirubin level, thymol test, the activity of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyltransferase (GGT) was carried out on automatic analyzer HumaStar 300 at the beginning and after 0.5-8 months of treatment. Statistical analysis was performed using the Statistica 10.0 software (Stat. Soft Inc., USA). Kruskal-Wallis, ANOVA, and Chi-square tests were used in this study., Results: After 8 months of treatment, studied biochemical indexes were lower in Group 2 than in patients from Group 1. For example, the number of patients in Group 2 with increased bilirubin level was 1.7 times more than in Group 1 (p < 0.05), with increased ALT, AST, or GGT activity in 2.5 times (p < 0.01), 2.7 times (p < 0.01), or 2.4 times (p < 0.05) correspondently, comparatively with Group 1., Conclusion: The usage of immunoglobulins intravenously in the group of patients with MDR-TB associated with HIV infection, with CD4+ level <50 cells/μCL, is appropriate and essential because it improves treatment outcome., Competing Interests: None

Background: Mycobacterium tuberculosis can grow in hostile intracellular environment of macrophages by actively evading macrophage-associated antibacterial activities. The stress response factor contributes this process by releasing inflammatory cytokine Interleukin 6 (IL-6). IL-6 screening of patients with TB may be useful to monitor the progress of infection and to infer the risk of progression to active disease. Vitamin D has a critical role in the innate immune system, in the circulating metabolite and supports induction of pleiotropic antimicrobial responses, through the production of antimicrobial peptides, particularly cathelicidin and its active metabolite. 1,25-dihydoxyvitamin D, has long been known to enhance immune response to mycobacteria. In this study, we have studied the role of IL-6 and Vitamin D3 in M. tuberculosis., Materials and Methods: Three groups involved in this study are Control, Category I (newly diagnosed TB) and MDR TB patients. The serum levels of IL-6 and vitamin D3 were measured using chemiluminescence and fully-automated enzyme-linked immunosorbent assay respectively., Results: The serum levels of IL-6 were significantly increased, whereas vitamin D3 decreased in TB multidrug-resistant group of patients compared to the newly diagnosed TB patients., Conclusion: IL-6 appears to be the major cytokine elaborated by mycobacteria infection as well as play a role in the clinical manifestations and pathological events and hence may function as a potent biomarker of tuberculosis. Since, Vitamin D increases activity of cell-mediated immunity; it can be used as a supplementation during tuberculosis therapy., (Copyright © 2018 Tuberculosis Association of India. Published by Elsevier B.V. All rights reserved.)

The spectre of the coming post-antibiotic age demands novel therapies for infectious diseases. Tuberculosis (TB), caused by Mycobacterium tuberculosis , is the single deadliest infection throughout human history. M. tuberculosis has acquired antibiotic resistance at an alarming rate with some strains reported as being totally drug resistant. Host-directed therapies (HDTs) attempt to overcome the evolution of antibiotic resistance by targeting relatively immutable host processes. Here, I hypothesise the induction of hypoxia via anti-angiogenic therapy will be an efficacious HDT against TB. I argue that anti-angiogenic therapy is a modernisation of industrial revolution era sanatoria treatment for TB, and present a view of the TB granuloma as a 'bacterial tumour' that can be treated with anti-angiogenic therapies to reduce bacterial burden and spare host immunopathology. I suggest two complementary modes of action, induction of bacterial dormancy and activation of host hypoxia-induced factor (HIF)-mediated immunity, and define the experimental tools necessary to test this hypothesis., (© 2019 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.)

The widespread availability and use of modern synthetic therapeutic agents have led to a massive decline in ethnomedical therapies. However, these synthetic agents often possess toxicity leading to various adverse effects. For instance, anti-tubercular treatment (ATT) is toxic, lengthy, and severely impairs host immunity, resulting in posttreatment vulnerability to reinfection and reactivation of tuberculosis (TB). Incomplete ATT enhances the risk for the generation of multidrug- or extensively drug-resistant (MDR or XDR, respectively) variants of Mycobacterium tuberculosis (M. tb ), the TB-causing microbe. Therefore, a new therapeutic approach that minimizes these risks is urgently needed to combat this deadly disease and prevent future TB epidemics. Previously, we have shown that the phytochemical bergenin induces T helper 1 (Th1)- and Th17 cell-based protective immune responses and potently inhibits mycobacterial growth in a murine model of M. tb infection, suggesting bergenin as a potential adjunct agent to TB therapy. Here, we combined ATT therapy with bergenin and found that this combination reduces immune impairment and the length of treatment in mice. We observed that co-treatment with the anti-TB drug isoniazid and bergenin produces additive effects and significantly reduces bacterial loads compared with isoniazid treatment alone. The bergenin co-treatment also reduced isoniazid-induced immune impairment; promoted long-lasting, antigen-specific central memory T cell responses; and acted as a self-propelled vaccine. Of note, bergenin treatment significantly reduced the bacterial burden of a multidrug-resistant TB strain. These observations suggest that bergenin is a potent immunomodulatory agent that could be further explored as a potential adjunct to TB therapy., (© 2019 Kumar et al.)

Purpose of Review: In the light of poor management outcomes of antibiotic-resistant respiratory tract infection (RTI)-associated sepsis syndrome and multidrug-resistant tuberculosis (MDR-TB), new management interventions based on host-directed therapies (HDTs) are warranted to improve morbidity, mortality and long-term functional outcomes. We review developments in potential HDTs based on precision cancer therapy concepts applicable to RTIs including MDR-TB., Recent Findings: Immune reactivity, tissue destruction and repair processes identified during studies of cancer immunotherapy share common pathogenetic mechanisms with RTI-associated sepsis syndrome and MDR-TB. T-cell receptors (TCRs) and chimeric antigen receptors targeting pathogen-specific or host-derived mutated molecules (major histocompatibility class-dependent/ major histocompatibility class-independent) can be engineered for recognition by TCR γδ and natural killer (NK) cells. T-cell subsets and, more recently, NK cells are shown to be host-protective. These cells can also be activated by immune checkpoint inhibitor (ICI) or derived from allogeneic sources and serve as potential for improving clinical outcomes in RTIs and MDR-TB., Summary: Recent developments of immunotherapy in cancer reveal common pathways in immune reactivity, tissue destruction and repair. RTIs-related sepsis syndrome exhibits mixed immune reactions, making cytokine or ICI therapy guided by robust biomarker analyses, viable treatment options.

New therapeutics to augment current approaches and shorten treatment duration are of critical importance for combating tuberculosis (TB), especially those with novel mechanisms of action to counter the emergence of drug-resistant TB. Host-directed therapy (HDT) offers a novel strategy with mechanisms that include activating immune defense mechanisms or ameliorating tissue damage. These and related concepts will be discussed along with issues that emerged from the workshop organized by the Stop TB Working Group on New Drugs, held at the Gordon Research Conference for Tuberculosis Drug Development in Lucca, Italy in June 2017, titled "Strategic Discussion on Repurposing Drugs & Host Directed Therapies for TB." In this review, we will highlight recent data regarding drugs, pathways, and concepts that are important for successful development of HDTs for TB., (© The Author(s) 2018. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Objective: The evolution of antibiotic resistance is far outpacing the development of new antibiotics, causing global public health concern about infections that will increasingly be unresponsive to antimicrobials. This risk of emerging antibiotic resistance may be meaningfully altered in highly AIDS-immunocompromised populations. Such populations fundamentally alter the bacterial evolutionary landscape in two ways, which we seek to model and analyze. First, widespread, population-level immunoincompetence creates a novel host environment with disrupted selective pressures. Second, within AIDS-prevalent populations, the recommendation that antibiotics be taken to treat and prevent opportunistic infection raises the risk of selection for drug-resistant pathogens., Design: To determine the impact of HIV/AIDS on the emergence of antibiotic resistance-specifically in the developing world where high prevalence and economic challenges complicate disease management., Methods: We present an SEIR epidemiological model of bacterial infection, and parametrize it to capture HIV/AIDS-attributable emergence of resistance under conditions of both high and low HIV/AIDS prevalence., Results: We demonstrate that HIV/AIDS-immunocompromised hosts can be responsible for a disproportionately greater contribution to emergence of resistance than would be expected based on population-wide HIV/AIDS prevalence alone., Conclusions: As such, the AIDS-immunocompromised have the potential become wellsprings of novel, resistant, opportunistic pathogen strains that can propagate into the broader global community. We discuss how public health policies for HIV/AIDS management can shape the evolutionary environment for opportunistic bacterial infections., Competing Interests: The authors have declared that no competing interests exist.

Drug-resistant tuberculosis represents a global emergency, requiring new drugs. We found that minocycline was highly potent in laboratory strains of Mycobacterium tuberculosis and that 30 drug-susceptible and multidrug/extensively drug-resistant clinical strains were susceptible to clinically achievable concentrations. In the hollow fiber system model, lung concentration-time profiles of 7 mg/kg/day human-equivalent minocycline dose achieved bacterial kill rates equivalent to those of first-line antituberculosis agents. Minocycline killed extracellular bacilli directly. Minocycline also killed intracellular bacilli indirectly, via concentration-dependent granzyme A-driven apoptosis. Moreover, minocycline demonstrated dose-dependent antiinflammatory activity and downregulation of extracellular matrix-based remodeling pathways and, thus, could protect patients from tuberculosis immunopathology. In RNA sequencing of repetitive samples from the hollow fiber system and in independent protein abundance experiments, minocycline demonstrated dose-dependent inhibition of sonic hedgehog-patched-gli signaling. These findings have implications for improved lung remodeling and for dual immunomodulation and direct microbial kill-based treatment shortening regimens for drug-susceptible and drug-resistant latent and active M. tuberculosis infection., (© The Author(s) 2018. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Background: Despite exerted efforts to control and treat Mycobacterium tuberculosis (MTB) strains, Tuberculosis (TB) remains a public health menace. The emergence of complex drug-resistant profiles, such as multi-drug resistant and extensively drug-resistant MTB strains, emphasizes the need for early diagnosis of resistant cases, shorter treatment options, and effective medical interventions., Objective: Solutions for better clinical management of drug-resistant cases are either pathogencentered (novel chemotherapy agents) or host-directed approaches (modulating host immune response to prevent MTB invasion and pathogenesis)., Results: Despite the overall potentiality of several chemotherapy agents, it is feared that their effectiveness could be challenged by sequential pathogen adaptation tactics. On the contrary, host-directed therapy options might offer a long-term conceivable solution., Conclusion: This review discusses the main suggestions proposed so far to resolve the clinical challenges associated with drug resistance, in the context of TB. These suggestions include novel drug delivery approaches that could optimize treatment outcome and increase patients' compliance to the treatment., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

There are severa influencing factors that affect the burden of tuberculosis (TB), including host immune responses and migration. For example, co-infection of parasitic infections with TB suppresses protective immune response against TB. As such, migration is one of the important influencing factors that affect the TB burden, especially in multidrug-resistant (MDR-TB). In this article, these important and neglected factors are discussed., (Copyright © 2019 IMSS. Published by Elsevier Inc. All rights reserved.)

Tuberculosis (TB) has become the most deadly infectious diseases due to epidemics of HIV/AIDS and multidrug-resistant/extensively drug-resistant TB (MDR-/XDR-TB). Although person-to-person transmission contributes to MDR-TB, it remains unknown whether infection with MDR strains resembles infection with drug-sensitive (DS) TB strains, manipulating limited or broad immune responses. To address these questions, macaques were infected with MDR strain V791 and a drug-sensitive Erdman strain of TB. MDR bacilli burdens in the airway were significantly higher than those of the Erdman control after pulmonary exposure. This productive MDR strain infection upregulated the expression of caspase 3 in macrophages/monocytes and induced appreciable innate-like effector responses of CD3-negative lymphocytes and Ag-specific γδ T-cell subsets. Concurrently, MDR strain infection induced broad immune responses of T-cell subpopulations producing Th1, Th17, Th22, and CTL cytokines. Furthermore, MDR bacilli, like the Erdman strain, were capable of inducing typical TB disease characterized by weight loss, lymphocytopenia, and severe TB lesions. For the first time, our results suggest that MDR-TB infection acts like DS to induce high bacterial burdens in the airway (transmission advantage), innate/adaptive immune responses, and disease processes. Because nonhuman primates are biologically closer to humans than other species, our data may provide useful information for predicting the effects of primary MDR strain infection after person-to-person transmission. The findings also support the hypothesis that a vaccine or host-directed adjunctive modality that is effective for drug-sensitive TB is likely to also impact MDR-TB.

Short-course regimens for multidrug-resistant tuberculosis (MDR-TB) are urgently needed. Limited data suggest that the new drug bedaquiline (BDQ) may have the potential to shorten MDR-TB treatment to less than 6 months when used in conjunction with standard anti-TB drugs. However, the feasibility of BDQ in shortening MDR-TB treatment duration remains to be established. Mathematical modeling provides a platform to investigate different treatment regimens and predict their efficacy. We developed a mathematical model to capture the immune response to TB inside a human host environment. This model was then combined with a pharmacokinetic-pharmacodynamic model to simulate various short-course BDQ-containing regimens. Our modeling suggests that BDQ could reduce MDR-TB treatment duration to just 18 weeks (4 months) while still maintaining a very high treatment success rate (100% for daily BDQ for 2 weeks, or 95% for daily BDQ for 1 week during the intensive phase). The estimated time to bacterial clearance of these regimens ranges from 27 to 33 days. Our findings provide the justification for empirical evaluation of short-course BDQ-containing regimens. If short-course BDQ-containing regimens are found to improve outcomes, then we anticipate clear cost savings and a subsequent improvement in the efficiency of national TB programs., (Copyright © 2018 American Society for Microbiology.)

Identifying a blood circulating cellular biomarker that can be used to assess severity of disease and predict the time to culture conversion (TCC) in patients with multidrug resistant tuberculosis (MDR-TB) would facilitate monitoring response to treatment and may be of value in the design of future drug trials. We report on the frequency of blood Ki67 + HLA-DR - CD4+ T regulatory (Treg) cells in predicting microbiological outcome before initiating second-line treatment for MDR-TB. Fifty-one patients with MDR-TB were enrolled and followed over 18 months; a subset of patients was sputum culture (SC) negative at baseline ( n = 9). SC positive patients were divided into two groups, based on median TCC: rapid responders (≤71 days TCC; n = 21) and slow responders (>71 days TCC; n = 21). Whole blood at baseline, months 2 and 6 was stimulated with M tuberculosis (Mtb) antigens and Treg cells were then identified as CD3 + CD4 + CD25 hi FoxP3 + CD127 - CD69 - and further delineated as Ki67 + HLA-DR - Treg. The frequency of these cells was significantly enlarged at baseline in SC positive relative to SC negative and smear positive relative to smear negative patients and in those with lung cavitation. This difference was further supported by unsupervised hierarchical clustering showing a significant grouping at baseline of total and early differentiated memory Treg cells in slow responders. Conversely, there was a clustering of a lower proportion of Treg cells and activated IFNγ-expressing T cells at baseline in the rapid responders. Examining changes over time revealed a more gradual reduction of Treg cells in slow responders relative to rapid responders to treatment. Receiver operating curve analysis showed that baseline Mtb-stimulated Ki67 + HLA-DR - Treg cells could predict the TCC of MDR-TB treatment response with 81.2% sensitivity and 85% specificity (AUC of 0.87, p < 0.0001), but this was not the case after 2 months of treatment. In conclusion, our data show that the frequency of a highly defined Mtb-stimulated blood Treg cell population at baseline can discriminate MDR-TB disease severity and predict time to culture clearance.

Mycobacterium tuberculosis ( M. tb ), the causative bacterial agent responsible for tuberculosis (TB) continues to afflict millions of people worldwide. Although the human immune system plays a critical role in containing M. tb infection, elimination proves immensely more challenging. Consequently, there has been a worldwide effort to eradicate, and limit the spread of M. tb through the conventional use of first-line antibiotics. Unfortunately, with the emergence of drug resistant and multi-drug resistant strains of M. tb the archetypical antibiotics no longer provide the same ascendancy as they once did. Furthermore, when administered, these first-line antibiotics commonly present severe complications and side effects. The biological antioxidant glutathione (GSH) however, has been demonstrated to have a profound mycobactericidal effect with no reported adverse consequences. Therefore, we examined if N-Acetyl Cysteine (NAC), the molecular precursor to GSH, when supplemented in combination with suboptimal levels of standalone first-line antibiotics would be sufficient to completely clear M. tb infection within in vitro derived granulomas from healthy subjects and individuals with type 2 diabetes (T2DM). Our results revealed that by virtue of immune modulation, the addition of NAC to subprime levels of isoniazid (INH) and rifampicin (RIF) was indeed capable of inducing complete clearance of M. tb among healthy individuals.

Purpose: Mendelian suceptibility to mycobacterial disease (MSMD) is a rare primary immunodeficiency predisposing to severe disease caused by mycobacteria and other intracellular pathogens. Delay in diagnosis can have an impact on the patient's prognosis., Methods: We evaluated the IFN-γ circuit by studying IFN-γ production after mycobacterial challenge as well as IL-12Rβ1 expression and STAT4 phosphorylation in response to IL-12p70 stimulation in whole blood of a 6-year-old Peruvian girl with disseminated recurrent mycobacterial infection diagnosed as multidrug-resistant tuberculosis. Genetic studies with Sanger sequencing were used to identify the causative mutation. Microbiological studies based on PCR reactions were used to diagnose the specific mycobacterial species., Results: We identified a homozygous mutation in the IL12RB1 gene (p. Arg211*) causing abolished expression of IL-12Rβ1 and IL-12 response. MSMD diagnosis led to a microbiological reevaluation of the patient, revealing a BCG vaccine-related infection instead of tuberculosis. Treatment was then adjusted, with good response., Conclusions: We report the first Peruvian patient with IL-12Rβ1 deficiency. Specific mycobacterial species diagnosis within Mycobacterium tuberculosis complex is still challenging in countries with limited access to PCR-based microbiological diagnostic techniques. Awareness of MSMD warning signs and accurate microbiological diagnosis of mycobacterial infections are of the utmost importance for optimal diagnosis and management of affected patients.

The study of subpopulation structure of IFNγ-producing T cells in patients with pulmonary tuberculosis revealed a decrease in the number of CD3 + IFNγ + cells against the background of significantly increased IFNγ secretion in vitro irrespective of the clinical form of the disease and drug sensitivity of M. tuberculosis, most strongly expressed in case of the disseminated tuberculosis. In patients with infiltrative drug-sensitive and drug-resistant pulmonary tuberculosis, increased number of Th1/Th17 lymphocytes (CD4 + IFNγ + IL-17A + ) and, conversely, decreased number of blood γδT cells was detected.

Objective: To investigate the relationship between changes in CD4- and CD8-positive immune cells and TNF-α in the peripheral blood of patients affected by multidrug-resistant and extensively drug-resistant tuberculosis., Patients and Methods: 179 patients suffering from tuberculosis treated in the Chest Hospital of Hebei from April 2010 to December 2015 were selected for the study. There were 47 cases affected by drug-resistant tuberculosis and 132 cases affected by non-drug-resistant tuberculosis. The control group included 183 healthy subjects examined during the same period. ELISA was used to compare and analyze serum levels of TNF-α, CD4- and CD8-positive cell levels, and CD4/CD8 ratio in the two groups., Results: CD4- and CD8-positive cell count, CD4/CD8 ratio, and serum TNF-a were significantly higher in patients with drug-resistant tuberculosis compared with healthy controls and the non-drug-resistant tuberculosis patients (p < 0.05). There was a positive correlation between TNF-α level and CD4/CD8 ratio (r=0.892, p < 0.05). Before treatment, the differences in the levels of TNF-a in the different groups of drug-resistant patients were insignificant (p >0.05). After treatment, the levels of TNF-a in the different groups of drug-resistant patients were decreased, except for patients with extensively drug-resistant tuberculosis, whose levels were significantly decreased compared with before treatment (t = 0.648, p>0.05). The differences in the levels of TNF-α in the other groups of patients before and after treatment were statistically significant (t = 8.497, 6.258, 5.346, p < 0.05, fully sensitive tuberculosis single drug-resistant tuberculosis, multidrug-resistant tuberculosis, respectively)., Conclusions: The level of TNF-α plays a critical role in the evaluation of the severity of patients with drug-resistant tuberculosis and it has a clinical value.

It is urgent to find an optimised therapy regimen for the control of MDR-TB globally. This study aimed to evaluate the efficiacy and safety of a combined regimen of rhIL-2 injection and standard chemotherapy within 18-month duration in a randomized controlled trial conducted in 14 centres in eastern China. From Jan. 2009 to July. 2016, 271 MDR-TB cases were enrolled and followed up in two groups, 142 cases in study group while 129 cases in control group. Clinical efficacy, safety and immune activity (Th1, Th17, Treg, IFN-γ, IL-17) among the two groups were evaluated and compared. After 24-month following up, cure rate in IL-2 group show higher than that in control group (56% VS 36%, P < 0.01). Rate of mycobacterium clearance (sputum negative) within 3 months was significantly higher in IL-2 group (74% VS 59%, P < 0.05) with no adverse events raised. Patients after rhIL-2 treatment showed increasing of Th1 populations and decreasing of Th17 and Regulatory T cells (Treg) populations, while levels of IL-17A, ROR-γt, and Foxp3 mRNA decreased and level of IFN-γ mRNA increased in PBMCs. Thus, rhIL-2 combined regimen within shorter duration achieved high conversion and success rates and improved Th1/Th17 immune responses, with no safety concerns emerging in MDR-TB patients.

BACKGROUND Presently, studies of factors associated with drug-resistant tuberculosis (TB) focus on patients' socio-demographic characteristics and living habits, to the exclusion of biochemical indicators, especially immune factors. This study was carried out to determine whether immune factors are associated with drug-resistant TB. MATERIAL AND METHODS A total of 227 drug-resistant pulmonary TB patients and 225 drug-susceptible pulmonary TB patients were enrolled in this study. Information on socio-demographic characteristics and biochemical indicators were obtained through their clinical records. Non-conditional logistic regression was used to analyze the association of these indicators with drug-resistant TB. RESULTS There were significant differences in re-treatment, marital status, alanine aminotransferase (ALT), blood uric acid (BUA), carcino-embryonic antigen (CEA), T-spot, and CD3 and CD4 counts between the 2 groups. In multivariable analysis, re-treatment [Odds Ratio (OR)=5.290, 95% Confidence Interval [CI]=2.652-10.551); CD3 (OR=1.034, 95% CI=1.001-1.068); CD4 (OR=1.035, 95% CI =1.001-1.070) and IgM (OR=1.845, 95% CI=1.153-2.952) were associated with drug-resistant TB. CONCLUSIONS These results suggest the need for greater attention to re-treatment cases and immune function when treating drug-resistant TB.

Mycobacterium tuberculosis (Mtb) is one of the most life-threatening mycobacterial species which is increasing the death rate due to emerging multi-drug resistant (MDR) strains. Concerned health authorities worldwide are interested in developing an effective vaccine to prevent the spread of Mtb. After years of research, including successful identification of many Mtb immunogenic molecules, effective therapeutic agents or a vaccine have yet to be found. However, among the identified Mtb immunogenes, antigen 85 (Ag85) complex (Ag85A, Ag85B, and Ag85C) is receiving attention from scientists as it allows bacteria to evade the host immune response by preventing formation of phagolysosomes for eradication of infection. Due to their importance, A85 molecules are being utilized as tools in diagnostic methods and in the construction of new vaccines, such as recombinant attenuated vaccines, DNA vaccines, and subunit vaccines. This paper represents a comprehensive review of studies on Mtb molecules examining pathogenicity, biochemistry, immunology, and the role of Mtb in therapeutic or vaccine research., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The United States Renal Data System showed 1.2% and 1.6% incidences of tuberculosis (TB) in patients on peritoneal dialysis and hemodialysis (HD), respectively. Kidney transplant (KTX) patients have higher rates. We studied the epidemiology and outcome of TB in patients with kidney dysfunction in a tertiary care hospital in the past decade. We examined data of patients with TB with and without kidney dysfunction from 2006 to 2015 through an electronic system. Statistical analysis was completed using Stata software, Chicago, IL, USA. We found 581 patients with active TB of whom 37 had renal dysfunction including chronic kidney disease, HD, and KTX. No difference was found in the prevalence, age, or gender predilection. The age ranged from 1 to 95 with a mean (standard deviation) of 38.6 (21.1) years. The incidence of TB is 3 per 100,000. The number of patients per year with active TB ranges from 52 to 128 and 3 to 4 in the general population and kidney dysfunction group, respectively. Sixty-five percent of patients with kidney dysfunction had pulmonary TB, 5% had pleurisy, and 30% had extrapulmonary TB. Eighty-four percent of patients with kidney dysfunction completed the course of treatment with 16% treatment failure and 0.4% developed multidrug-resistant TB; 8% were lost to follow-up and 8% died during the treatment period. This study showed no gender predilection for TB in the general population and immunocompromised. Duration of symptoms before diagnosis of TB was shorter in kidney dysfunction patients in comparison to the general population. TB cultures were the most positive tests whereas bronchoalveolar lavage and skin test were the least positive for detecting TB in the kidney dysfunction group. Improvement in registries and screening is required to enhance the capturing rate and detection among this group, as well as providing accurate data to health authorities and the public about the magnitude, future trends, treatments, and outcomes regarding TB in kidney dysfunction.

Mesenchymal stromal cells (MSC) have strong immunomodulatory properties and therefore can be used to control inflammation and tissue damage. It was suggested recently that MSC injections can be used to treat multi-drug resistant tuberculosis (TB). However, MSC trafficking and immunomodulatory effects of MSC injections during Mycobacterium tuberculosis (Mtb) infection have not been studied. To address this issue we have analyzed MSC distribution in tissues and local immunological effects of MSC injections in Mtb infected and uninfected mice. After intravenous injection, MSC accumulated preferentially in the lungs where they were located as cell aggregates in the alveolar walls. Immunological analysis of MSC effects included detection of activated, IFN-γ and IL-4 producing CD4+ lymphocytes, the frequency analysis of dendritic cells (CD11c+F4/80) and macrophages (CD11c-F4/80+) located in the lungs, the expression of IA/IE and CD11b molecules by these cells, and evaluation of 23 cytokines/chemokines in lung lysates. In the lungs of uninfected mice, MSC transfer markedly increased the percentage of IFN-γ+ CD4+ lymphocytes and dendritic cells, elevated levels of IA/IE expression by dendritic cells and macrophages, augmented local production of type 2 cytokines (IL-4, IL-5, IL-10) and chemokines (CCL2, CCL3, CCL4, CCL5, CXCL1), and downregulated type 1 and hematopoietic cytokines (IL-12p70, IFN-γ, IL-3, IL-6, GM-CSF). Compared to uninfected mice, Mtb infected mice had statistically higher "background" frequency of activated CD69+ and IFN-γ+ CD4+ lymphocytes and dendritic cells, and higher levels of cytokines in the lungs. The injections of MSC to Mtb infected mice did not show statistically significant effects on CD4+ lymphocytes, dendritic cells and macrophages, only slightly shifted cytokine profile, and did not change pathogen load or slow down TB progression. Lung section analysis showed that in Mtb infected mice, MSC could not be found in the proximity of the inflammatory foci. Thus, in healthy recipients, MSC administration dramatically changed T-cell function and cytokine/chemokine milieu in the lungs, most likely, due to capillary blockade. But, during Mtb infection, i.e., in the highly-inflammatory conditions, MSC did not affect T-cell function and the level of inflammation. The findings emphasize the importance of the evaluation of MSC effects locally at the site of their predominant post-injection localization and question MSC usefulness as anti-TB treatment.

Objective: To identify plasma markers predictive of therapeutic response in patients with multidrug resistant tuberculosis (MDR-TB)., Methods: Fifty HIV-negative patients with active pulmonary MDR-TB were analysed for six soluble analytes in plasma at the time of initiating treatment (baseline) and over six months thereafter. Patients were identified as sputum culture positive or negative at baseline. Culture positive patients were further stratified by the median time to sputum culture conversion (SCC) as fast responders (< 76 days) or slow responders (≥ 76 days). Chest X-ray scores, body mass index, and sputum smear microscopy results were obtained at baseline., Results: Unsupervised hierarchical clustering revealed that baseline plasma levels of IP-10/CXCL10, VEGF-A, SAA and CRP could distinguish sputum culture and cavitation status of patients. Among patients who were culture positive at baseline, there were significant positive correlations between plasma levels of CRP, SAA, VEGF-A, sIL-2Rα/CD40, and IP-10 and delayed SCC. Using linear discriminant analysis (LDA) and Receiver Operating Curves (ROC), we showed that a combination of MCP-1/CCL2, IP-10, sIL-2Rα, SAA, CRP and AFB smear could distinguish fast from slow responders and were predictive of delayed SCC with high sensitivity and specificity., Conclusion: Plasma levels of specific chemokines and inflammatory markers measured before MDR-TB treatment are candidate predictive markers of delayed SCC. These findings require validation in a larger study.

Treatment failure and resistance amplification are common among patients with rifampin-resistant tuberculosis (TB). Drug susceptibility testing (DST) for second-line drugs is recommended for these patients, but logistical difficulties have impeded widespread implementation of second-line DST in many settings. To provide a quantitative perspective on the decision to scale up second-line DST, we synthesize literature on the prevalence of second-line drug resistance, the expected clinical and epidemiologic benefits of using second-line DST to ensure that patients with rifampin-resistant TB receive effective regimens, and the costs of implementing (or not implementing) second-line DST for all individuals diagnosed with rifampin-resistant TB. We conclude that, in most settings, second-line DST could substantially improve treatment outcomes for patients with rifampin-resistant TB, reduce transmission of drug-resistant TB, prevent amplification of drug resistance, and be affordable or even cost-saving. Given the large investment made in each patient treated for rifampin-resistant TB, these payoffs would come at relatively small incremental cost. These anticipated benefits likely justify addressing the real challenges faced in implementing second-line DST in most high-burden settings., (Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

C5a anaphylatoxin is a component of the complement system involved in the modulation of T-cell polarization. Herein we investigated whether C5a receptors, C5aR and C5L2, modulate the cytokine profiles induced by Mycobacterium tuberculosis (Mtb). We analyzed the impact of both receptors on T helper cell polarization induced by the multidrug resistant outbreak strain named M, which is a poor IFN-γ inducer compared with the laboratory strain H37Rv. To this aim, we first blocked C5aR or C5L2 of peripheral blood monocytes (Mo) from patients with tuberculosis and healthy donors, then we stimulated the Mo either with H37Rv or the M strain, and finally we analyzed cytokine profiles of Mo/macrophages (MΦ) and CD4 + T-cells. We found that: (i) Mtb modulated the expression of both C5a receptors, (ii) C5aR inhibited the expansion of CD4 + IFN-γ + lymphocytes stimulated by the M strain but not by H37Rv, (iii) both receptors modulated the Mo/MΦ cytokine expression induced by Mtb. We conclude that C5aR, but not C5L2, plays a role in T helper cell polarization induced by Mtb and that this effect is strain- and donor-dependent. We speculate that the epidemiologically successful M strain takes advantage of this C5aR-mediated inhibition of Th1 polarization to survive within the host., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Globally, about 4.5% of new tuberculosis (TB) cases are multi-drug-resistant (MDR), i.e. resistant to the two most powerful first-line anti-TB drugs. Indeed, 480,000 people developed MDR-TB in 2015 and 190,000 people died because of MDR-TB. The MDR Mycobacterium tuberculosis M family, which belongs to the Haarlem lineage, is highly prosperous in Argentina and capable of building up further drug resistance without impairing its ability to spread. In this study, we sequenced the whole genomes of a highly prosperous M-family strain (Mp) and its contemporary variant, strain 410, which produced only one recorded tuberculosis case in the last two decades. Previous reports have demonstrated that Mp induced dysfunctional CD8 + cytotoxic T cell activity, suggesting that this strain has the ability to evade the immune response against M. tuberculosis. Comparative analysis of Mp and 410 genomes revealed non-synonymous polymorphisms in eleven genes and five intergenic regions with polymorphisms between both strains. Some of these genes and promoter regions are involved in the metabolism of cell wall components, others in drug resistance and a SNP in Rv1861, a gene encoding a putative transglycosylase that produces a truncated protein in Mp. The mutation in Rv3787c, a putative S-adenosyl-l-methionine-dependent methyltransferase, is conserved in all of the other prosperous M strains here analysed and absent in non-prosperous M strains. Remarkably, three polymorphic promoter regions displayed differential transcriptional activity between Mp and 410. We speculate that the observed mutations/polymorphisms are associated with the reported higher capacity of Mp for modulating the host's immune response., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

We have reported previously that T cells from patients with multi-drug-resistant tuberculosis (MDR-TB) express high levels of interleukin (IL)-17 in response to the MDR strain M (Haarlem family) of Mycobacterium tuberculosis (M. tuberculosis). Herein, we explore the pathways involved in the induction of Th17 cells in MDR-TB patients and healthy tuberculin reactors [purified protein derivative healthy donors (PPD + HD)] by the M strain and the laboratory strain H37Rv. Our results show that IL-1β and IL-6 are crucial for the H37Rv and M-induced expansion of IL-17 + interferon (IFN)-γ - and IL-17 + IFN-γ + in CD4 + T cells from MDR-TB and PPD + HD. IL-23 plays an ambiguous role in T helper type 1 (Th1) and Th17 profiles: alone, IL-23 is responsible for M. tuberculosis-induced IL-17 and IFN-γ expression in CD4 + T cells from PPD + HD whereas, together with transforming growth factor (TGF-β), it promotes IL-17 + IFN-γ - expansion in MDR-TB. In fact, spontaneous and M. tuberculosis-induced TGF-β secretion is increased in cells from MDR-TB, the M strain being the highest inducer. Interestingly, Toll-like receptor (TLR)-2 signalling mediates the expansion of IL-17 + IFN-γ - cells and the enhancement of latency-associated protein (LAP) expression in CD14 + and CD4 + T cells from MDR-TB, which suggests that the M strain promotes IL-17 + IFN-γ - T cells through a strong TLR-2-dependent TGF-β production by antigen-presenting cells and CD4 + T cells. Finally, CD4 + T cells from MDR-TB patients infected with MDR Haarlem strains show higher IL-17 + IFN-γ - and lower IL-17 + IFN-γ + levels than LAM-infected patients. The present findings deepen our understanding of the role of IL-17 in MDR-TB and highlight the influence of the genetic background of the infecting M. tuberculosis strain on the ex-vivo Th17 response., (© 2016 British Society for Immunology.)

Aim: Safer and shorter antituberculosis treatment (ATT) regimens represent the unmet medical need., Patients & Methods: The patients were randomly assigned into two arms: the first (n = 137) received once-daily sublingual honey lozenge formulated with botanical immunomodulator Immunoxel and the second (n = 132) received placebo lozenges along with conventional ATT. Immunoxel and placebo arms were demographically similar: 102 versus 106 had drug-susceptible TB; 28 versus 20 multidrug-resistant TB (MDR-TB); 7 versus 7 extensively drug-resistant TB (XDR-TB); and 22 versus 20 TB-HIV. The primary end point was sputum smear conversion., Results: After 1 month 87 out 132 (65.9%) of Immunoxel recipients became sputum smear negative, whereas 32 out of 127 (25.2%) in placebo group had converted (p < 0.0001). Sputum clearance produced by Immunoxel was equally effective across all forms of TB. In the immunotherapy arm the average weight gain was 2 kg, but placebo recipients gained only 0.6 kg. Immunoxel reduced TB-associated inflammation as evidenced by defervescence and normalization of elevated leukocyte counts and erythrocyte sedimentation rate. No adverse effects were seen at any time. The liver function tests indicate that ATT-caused hepatotoxicity was counteracted by Immunoxel. These results are in agreement with prior 20 trials of Immunoxel conducted over the past 17 years., Conclusion: Immunoxel is affordable, safe, effective, fast-acting, commercially available immunotherapeutic intervention to supplement conventional TB chemotherapy. Clinicaltrials.gov ID: NCT01061593.

Mycobacterium tuberculosis remains a global health threat largely due to the lengthy duration of curative antibiotic treatment, contributing to medical nonadherence and the emergence of drug resistance. This prolonged therapy is likely due to the presence of M. tuberculosis persisters, which exhibit antibiotic tolerance. Inorganic polyphosphate [poly(P)] is a key regulatory molecule in the M. tuberculosis stringent response mediating antibiotic tolerance. The polyphosphate kinase PPK1 is responsible for poly(P) synthesis in M. tuberculosis, while the exopolyphosphatases PPX1 and PPX2 and the GTP synthase PPK2 are responsible for poly(P) hydrolysis. In the present study, we show by liquid chromatography-tandem mass spectrometry that poly(P)-accumulating M. tuberculosis mutant strains deficient in ppx1 or ppk2 had significantly lower intracellular levels of glycerol-3-phosphate (G3P) and 1-deoxy-xylulose-5-phosphate. Real-time PCR revealed decreased expression of genes in the G3P synthesis pathway in each mutant. The ppx1-deficient mutant also showed a significant accumulation of metabolites in the tricarboxylic acid cycle, as well as altered arginine and NADH metabolism. Each poly(P)-accumulating strain showed defective biofilm formation, while deficiency of ppk2 was associated with increased sensitivity to plumbagin and meropenem and deficiency of ppx1 led to enhanced susceptibility to clofazimine. A DNA vaccine expressing ppx1 and ppk2, together with two other members of the M. tuberculosis stringent response, M. tuberculosis rel and sigE, did not show protective activity against aerosol challenge with M. tuberculosis, but vaccine-induced immunity enhanced the killing activity of isoniazid in a murine model of chronic tuberculosis. In summary, poly(P)-regulating factors of the M. tuberculosis stringent response play an important role in M. tuberculosis metabolism, biofilm formation, and antibiotic sensitivity in vivo., (Copyright © 2016, American Society for Microbiology. All Rights Reserved.)

Tuberculosis (TB), although a curable disease, remains a major cause of morbidity and mortality worldwide. It is necessary to develop a short-term therapy with reduced drug toxicity in order to improve adherence rate and control disease burden. Granulocyte-macrophage colony-stimulating factor (GM-CSF) may be a key cytokine in the treatment of pulmonary TB since it primes the activation and differentiation of myeloid and non-myeloid precursor cells, inducing the release of protective Th1 cytokines. In this work, we administrated by intratracheal route recombinant adenoviruses encoding GM-CSF (AdGM-CSF). This treatment produced significant bacterial elimination when administered in a single dose at 60 days of infection with drug sensitive or drug resistant Mtb strains in a murine model of progressive disease. Moreover, AdGM-CSF combined with primary antibiotics produced more rapid elimination of pulmonary bacterial burdens than conventional chemotherapy suggesting that this form of treatment could shorten the conventional treatment., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Multidrug-resistant tuberculosis (MDR-TB) often causes persistent infection and chemotherapy failure, which brings heavy burden of society and family. Many immune cell subsets and regulatory mechanisms may operate throughout the various stages of infection. The presence of regulatory T cells (Tregs) is thought to be an important mechanism that TB successfully evades the immune system. Tregs play a central role in the prevention of autoimmunity and in the control of immune responses. The role of Tregs in MDR-TB infection and persistence is inadequately documented. The current study was designed to determine whether CD4 + CD25+ regulatory T cells may modulate innate immunity (such as NK cells) against human tuberculosis. Our results indicated that the numbers of CD4 + CD25+ Treg cells increased in MDR-TB patients' blood, and the cytokine production of IL-10 increased from MDR-patients compared with healthy subjects, along with the lower activity and low CD69 expression of NK cells in patients. These results suggested that immunity to MDR-TB patients induced circulating CD4 + CD25+ T regulatory cells expansion, which may be related to the persistence of Mycobacterium tuberculosis (M. tb) infection, and to the balance between effectors immune responses and suppression immune responses., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Multi-drug-resistant (MDR) tuberculosis is a major public health problem worldwide. Drug resistance arises due to non-compliance of antibiotic therapy. Herein, we explored the therapeutic options available ranging from conservative treatment approaches to alternate adjunct therapies such as mesenchymal stromal cell (MSC) therapy interventions. It is attractive to understand the scientific rationale of using cells as drugs, in particular mesenchymal stem/stromal cells. The review dwells and attempts to analyze the mechanistic approaches of the current treatment modalities to modern therapies. MSCs have demonstrated profound capacity to regenerate and repair. They appear to modulate that the activities of dendritic cells regulate T cells, both in vivo and in vitro. While there seems to be some benefit of such therapies, its use warrants further research. The merits and de-merits of autologous therapy/allogeneic therapy are ill understood. The challenges of requirement of large number of cells for infusion, the route of administration, choice of timing are complex issues that need to be addressed. Furthermore, the host immune responses, environmental factors and epigenetic mechanisms compound the problem. Although, clinical studies are being performed using autologous MSCs in different inflammatory models, it is important that such an intervention should be based on sound scientific rationale. The current review examines the immunomodulatory properties of MSCs, its interactions with other cell types, in assessing the basis for autologous/allogeneic cell-based therapies in the treatment of XDR/MDR tuberculosis.