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PubMed | Minority, Imperial College London, National Institute for Research in Tuberculosis, National Health Research Institute and 2 more.
Type: Journal Article | Journal: Journal of immunology (Baltimore, Md. : 1950) | Year: 2015

Pulmonary tuberculosis (TB) is characterized by oxidative stress and lung tissue destruction by matrix metalloproteinases (MMPs). The interplay between these distinct pathological processes and the implications for TB diagnosis and disease staging are poorly understood. Heme oxygenase-1 (HO-1) levels were previously shown to distinguish active from latent TB, as well as successfully treated Mycobacterium tuberculosis infection. MMP-1 expression is also associated with active TB. In this study, we measured plasma levels of these two important biomarkers in distinct TB cohorts from India and Brazil. Patients with active TB expressed either very high levels of HO-1 and low levels of MMP-1 or the converse. Moreover, TB patients with either high HO-1 or MMP-1 levels displayed distinct clinical presentations, as well as plasma inflammatory marker profiles. In contrast, in an exploratory North American study, inversely correlated expression of HO-1 and MMP-1 was not observed in patients with other nontuberculous lung diseases. To assess possible regulatory interactions in the biosynthesis of these two enzymes at the cellular level, we studied the expression of HO-1 and MMP-1 in M. tuberculosis-infected human and murine macrophages. We found that infection of macrophages with live virulent M. tuberculosis is required for robust induction of high levels of HO-1 but not MMP-1. In addition, we observed that CO, a product of M. tuberculosis-induced HO-1 activity, inhibits MMP-1 expression by suppressing c-Jun/AP-1 activation. These findings reveal a mechanistic link between oxidative stress and tissue remodeling that may find applicability in the clinical staging of TB patients.


Kumar N.P.,National Institutes of Health | Kumar N.P.,National Institute for Research in Tuberculosis | Sridhar R.,Government Stanley Medical Hospital | Nair D.,National Institute for Research in Tuberculosis | And 4 more authors.
Immunology | Year: 2015

Summary: Type 2 diabetes mellitus (DM) is associated with expanded frequencies of mycobacterial antigen-specific CD4+ T helper type 1 (Th1) and Th17 cells in individuals with active pulmonary tuberculosis (TB). No data are available on the role of CD8+ T and natural killer (NK) cells in TB with coincident DM. To identify the role of CD8+ T and NK cells in pulmonary TB with diabetes, we examined mycobacteria-specific immune responses in the whole blood of individuals with TB and DM (TB-DM) and compared them with those without DM (TB-NDM). We found that TB-DM is characterized by elevated frequencies of mycobacterial antigen-stimulated CD8+ T cells expressing type 1 [interferon-γ and interleukin-2 (IL-2)] and type 17 (IL-17F) cytokines. We also found that TB-DM is characterized by expanded frequencies of TB antigen-stimulated NK cells expressing type 1 (tumour necrosis factor-α) and type 17 (IL-17A and IL-17F) cytokines. In contrast, CD8+ T cells were associated with significantly diminished expression of the cytotoxic markers perforin, granzyme B and CD107a both at baseline and following antigen or anti-CD3 stimulation, while NK cells were associated with significantly decreased antigen-stimulated expression of CD107a only. This was not associated with alterations in CD8+ T-cell or NK cell numbers or subset distribution. Therefore, our data suggest that pulmonary TB complicated with type 2 DM is associated with an altered repertoire of cytokine-producing and cytotoxic molecule-expressing CD8+ T and NK cells, possibly contributing to increased pathology. © 2015 John Wiley & Sons Ltd .


Andrade B.B.,U.S. National Institutes of Health | Pavan Kumar N.,National Institutes of Health | Mayer-Barber K.D.,U.S. National Institutes of Health | Barber D.L.,U.S. National Institutes of Health | And 8 more authors.
PLoS ONE | Year: 2013

Background:Tuberculosis (TB) is associated with oxidative stress and the induction of host anti-oxidants to counteract this response. Heme oxygenase-1 (HO-1) is a critical promoter of cytoprotection in diverse disease models including mycobacterial infection. Nevertheless, the pattern of expression of HO-1 in human tuberculosis has not been studied. Here, we examine expression of HO-1 in M. tuberculosis-exposed and -infected individuals and test its ability to distinguish active from latent and successfully treated TB cases. In addition, we assess correlations between plasma levels of HO-1 and cytokines closely associated with the immunopathogenesis of TB.Methods:Cross-sectional and longitudinal analyses of levels of HO-1, acute phase proteins and pro-inflammatory cytokines were performed in plasma samples from individuals with active pulmonary, extra-pulmonary or latent TB infection and healthy controls as part of a prospective cohort study in South India.Results:Systemic levels of HO-1 were dramatically increased in individuals with active pulmonary and extra-pulmonary tuberculosis and particularly those with bilateral lung lesions and elevated bacillary loads in sputum. HO-1 levels effectively discriminated active from latent tuberculosis with higher predictive values than either C-reactive protein or serum amyloid protein. Moreover, there was a marked reduction in HO-1 levels in active TB cases following anti-tuberculous therapy but not in those who failed treatment. Pulmonary TB patients displaying the highest concentrations of HO-1 in plasma exhibited significantly elevated plasma levels of interleukin (IL)-10, interferon (IFN)-γ and IL-17 and diminished levels of tumor necrosis factor (TNF)-α.Conclusion:These findings establish HO-1 levels as a potentially useful parameter for distinguishing active from latent or treated pulmonary tuberculosis, that is superior in this respect to the measurement of other acute inflammatory proteins.


Andrade B.B.,U.S. National Institutes of Health | Pavan Kumar N.,National Institutes of Health | Pavan Kumar N.,National Institute for Research in Tuberculosis | Sridhar R.,Government Stanley Medical Hospital | And 6 more authors.
Chest | Year: 2014

Background: The increased prevalence of type 2 diabetes mellitus (T2DM) in countries endemic for TB poses a serious complication in the clinical management of this major infectious disease. Understanding the impact of T2DM on TB and the determinants of comorbidity is critical in responding to this growing public health problem with better therapeutic approaches. Here, we performed an exploratory study assessing a series of biologic parameters that could serve as markers of pathogenesis in TB with T2DM. Methods: Cross-sectional analyses of levels of heme oxygenase-1 (HO-1), acute phase proteins, tissue metalloproteinases, and tissue inhibitors of metalloproteinase (TIMPs) as well as cytokines and chemokines were performed in plasma samples from individuals with active pulmonary TB or with coincident TB and T2DM from South India. Results: Compared with patients with TB without diabetes, those with coincident T2DM exhibited increased Mycobacterium tuberculosis bacillary loads in sputum. Plasma levels of HO-1 but not of other acute phase proteins were higher in patients with TB and T2DM than in patients without diabetes, independent of bacillary sputum loads. HO-1 concentrations also positively correlated with random plasma glucose, circulating glycosylated hemoglobin, and low-density lipoprotein levels. Moreover, patients with coincident TB and T2DM exhibited increased plasma levels of TIMP-4 and elevated peripheral blood neutrophil counts, which, when considered together with HO-1, resulted in increased power to discriminate individuals with active TB with and without T2DM. Conclusions: Elevated plasma levels of HO-1 and TIMP-4 and peripheral blood neutrophil counts are potential single and combined markers of pathogenesis in TB and T2DM. © 2014 American College of Chest Physicians.


Kumar N.P.,National Institutes of Health International Center for Excellence in Research | Sridhar R.,Government Stanley Medical Hospital | Banurekha V.V.,National Institute for Research in Tuberculosis | Nair D.,National Institute for Research in Tuberculosis | And 4 more authors.
PLoS ONE | Year: 2013

Background: Th1 and Th17 responses are known to play an important role in immunity to pulmonary tuberculosis (PTB), although little is known about their role in extrapulmonary forms of tuberculosis (TB). Methods: To identify the role of Th1, Th17, and Th22 cells in multi-focal TB lymphadenitis (TBL), we examined mycobacteria-specific immune responses in the whole blood of individuals with PTB (n = 20) and compared them with those with TBL (n = 25). Results: Elevated frequencies of CD4+ T cells expressing IFN- γ, TNF-α, and IL-2 were present in individuals with TBL compared with those with PTB at baseline and in response to ESAT-6 and CFP-10. Similarly, increased frequencies of CD4+ T cells expressing IL-17A, IL-17F, and IFN-γ were also present in individuals with TBL at baseline and following ESAT-6 and CFP-10 stimulation although no significant difference in frequency of Th22 cells was observed. Finally, frequencies of Th1 (but not Th17) cells exhibited a significantly negative correlation with natural regulatory T cell frequencies at baseline. Conclusions: Multi-focal TB lymphadenitis is therefore characterized by elevated frequencies of Th1 and Th17 cells, indicating that Th1 and Th17 responses in TB disease are probably correlates of disease severity rather than of protective immunity.


Kumar N.P.,National Institutes of Health | Kumar N.P.,National Institute for Research in Tuberculosis | Sridhar R.,Government Stanley Medical Hospital | Banurekha V.V.,National Institute for Research in Tuberculosis | And 5 more authors.
Annals of the American Thoracic Society | Year: 2013

Rationale: Type 2 diabetes mellitus is a major risk factor for the development of active tuberculosis, although the biological basis underlying this susceptibility remains poorly characterized. Objectives and Methods: To identify the influence of coincident diabetes mellitus on cytokine levels in pulmonary tuberculosis, we examined circulating levels of a panel of cytokines and chemokines in the plasma of individuals with tuberculosis with diabetes and compared them with those of individuals without diabetes. Measurements and Main Results: Tuberculosis with diabetes is characterized by elevated circulating levels of type 1 (IFN-g, tumor necrosis factor-A, and IL-2), type 2 (IL-5), and type 17 (IL-17A) cytokines but decreased circulating levels of IL-22. This was associated with increased systemic levels of other proinflammatory cytokines (IL-1b, IL-6, and IL-18) and an antiinflammatory cytokine (IL-10) but not type 1 IFNs. Moreover, tuberculosis antigen- stimulated whole blood also showed increased levels of proinflammatory cytokines. Finally, type 1 and type 17 cytokines in plasma exhibit a significant positive correlation with hemoglobin A1C levels, indicating that impaired control of diabetes is associated with this proinflammatory milieu. Multivariate analysis revealed that the association of proinflammatory cytokines with diabetes mellitus was not influenced by age, sex, or other metabolic parameters. Conclusions: Our data reveal that tuberculosis with diabetes is characterized by heightened cytokine responsiveness, indicating that chronic inflammation underlying type 2 diabetes potentially contributes to increased immune pathology and poor control in tuberculosis infection. Copyright © 2013 by the American Thoracic Society.


PubMed | Government General Hospital, Government Kilpauk Medical Hospital, National Institute for Research in Tuberculosis, National Institutes of Health International Center for Excellence in Research and 2 more.
Type: | Journal: Cytokine | Year: 2016

Type 1, Type 17 and other pro-inflammatory cytokines are known to play an important role in resistance to pulmonary tuberculosis. The role of these cytokines in tuberculous lymphadenitis (TBL) is not well characterized.To estimate the systemic and mycobacterial antigen - stimulated cytokine concentrations of Type 1, Type 17, other pro-inflammatory and regulatory cytokines in TBL, we examined both the systemic and the antigen-specific concentrations of these cytokines in TBL (n=31) before and after chemotherapy, and compared them with those with latent tuberculosis infection (LTB, n=31).We observed significantly reduced systemic concentrations of the pro-inflammatory cytokines - IL-1 and IL-18 but not other Type 1 or Type 17 cytokines in TBL compared to LTB. Following standard anti-tuberculosis (TB) treatment, we observed a significant increase in the concentrations of both IL-1 and IL-18. In addition, we also observed significantly reduced baseline or mycobacterial - antigen or mitogen stimulated concentrations of IL-1 and IL-18 in TBL individuals. Similar to systemic cytokine concentrations, anti-TB treatment resulted in significantly increased concentrations of these cytokines following antigen stimulation.TBL is therefore, characterized by reduced systemic and antigen-specific concentrations of IL-1 and IL-18, which are reversible following anti-TB treatment, indicating that these cytokines are potential correlates of protective immunity in TBL.


PubMed | National Health Research Institute, National Institutes of Health International Center for Excellence in Research, Government Stanley Medical Hospital and National Institute for Research in Tuberculosis
Type: | Journal: Cytokine | Year: 2016

Type 2 diabetes mellitus (T2DM) is recognized as major risk factor for the progress of active pulmonary tuberculosis (PTB), although the mechanistic link between diabetes and tuberculosis remains poorly characterized. Moreover, the influence of poorly controlled diabetes on the baseline levels of adipocytokines in the context of tuberculosis has not been explored in detail. To characterize the influence of coexistent DM on adipocytokine levels in pulmonary or latent TB (LTB), we examined circulating levels of adipocytokines in the plasma of individuals with PTB-DM or LTB-DM and compared them with those without DM (PTB or LTB). PTB-DM or LTB-DM is characterized by diminished circulating levels of adiponectin and adipsin and/or heightened circulating levels of leptin, visfatin and PAI-1. In addition, adiponectin and adipsin exhibit a significant negative correlation, whereas leptin, visfatin and PAI-1 display a significant positive correlation with HbA1C levels and random blood glucose levels. Therefore, our data reveal that PTB-DM or LTB-DM is characterized by alterations in the systemic levels of adipocytokines, indicating that altered adipose tissue inflammation underlying Type 2 diabetes potentially contributes to pathogenesis of TB disease.


Kumar N.P.,National Institutes of Health International Center for Excellence in Research | Kumar N.P.,National Institute for Research in Tuberculosis | Sridhar R.,Government Stanley Medical Hospital | Banurekha V.V.,National Institute for Research in Tuberculosis | And 5 more authors.
Journal of Infectious Diseases | Year: 2013

Background. Type 2 diabetes mellitus (DM) is a major risk factor for the development of active pulmonary tuberculosis, although the immunological mechanisms underlying this interaction remain unexplored. The influence of poorly controlled diabetes on pathogen-specific T-helper 1 (Th1) and T-helper 17 (Th17) responses have not been examined.Methods. To identify the role of Th1 and Th17 cells in tuberculosis with coincident DM, we examined mycobacteria-specific immune responses in the whole blood of individuals who had tuberculosis with DM and compared them to those in individuals who had tuberculosis without DM.Results. Tuberculosis coincident with DM is characterized by elevated frequencies of monofunctional and dual-functional CD4+ Th1 cells following Mycobacterium tuberculosis antigen stimulation and elevated frequencies of Th17 subsets at both baseline and following antigen stimulation. This was associated with increased systemic (plasma) levels of both Th1 and Th17 cytokines and decreased baseline frequencies of natural regulatory T cells but not interleukin 10 or transforming growth factor β.Conclusions. Therefore, our data reveal that tuberculosis in persons with DM is characterized by elevated frequencies of Th1 and Th17 cells, indicating that DM is associated with an alteration in the immune response to tuberculosis, leading to a biased induction of Th1-and Th17-mediated cellular responses and likely contributing to increased immune pathology in M. tuberculosis infection. © 2013 The Author.


George P.J.,National Institutes of Healthnternational Center for Excellence in Research | Kumar N.P.,National Institutes of Healthnternational Center for Excellence in Research | Sridhar R.,Government Stanley Medical Hospital | Hanna L.E.,National Institute for Research in Tuberculosis | And 5 more authors.
PLoS Neglected Tropical Diseases | Year: 2014

Helminth infections are known to modulate innate and adaptive immune responses in active and latent tuberculosis (TB). However, the role of helminth infections in modulating responses associated with inflammation and immune activation (reflecting disease activity and/or severity) in TB is not known.We measured markers of inflammation and immune activation in active pulmonary TB individuals (ATB) with co-incidental Strongyloides stercoralis (Ss) infection. These included systemic levels of acute phase proteins, matrix metalloproteinases and their endogenous inhibitors and immune activation markers. As a control, we measured the systemic levels of the same molecules in TB-uninfected individuals (NTB) with or without Ss infection.Our data confirm that ATB is associated with elevated levels of the various measured molecules when compared to those seen in NTB. Our data also reveal that co-incident Ss infection in ATB individuals is associated with significantly decreased circulating levels of acute phase proteins, matrix metalloproteinases, tissue inhibitors of matrix metalloproteinases as well as the systemic immune activation markers, sCD14 and sCD163. These changes are specific to ATB since they are absent in NTB individuals with Ss infection.Our data therefore reveal a profound effect of Ss infection on the markers associated with TB disease activity and severity and indicate that co-incidental helminth infections might dampen the severity of TB disease. © 2014.

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