Browsing by Author "Parida, Shreemanta K."

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    Analysis of host responses to secreted, latent and reactivation Mycobacterium tuberculosis antigens in a multi-site study of subjects with different TB and HIV infection states in sub-Saharan Africa
    (Public Library of Science, 2013-09-10) Sutherland, Jayne S.; Lalor, Maeve K.; Black, Gillian F.; Ambrose, Lyn R.; Loxton, Andre G.; Chegou, Novel N.; Kassa, Desta; Mihret, Adane; Howe, Rawleigh; Mayanja-Kizza, Harriet; Gomez, Marie P.; Donkor, Simon; Franken, Kees; Boom, W. Henry; Thiel, Bonnie A.; Crampin, Amelia C.; Hanekom, Willem; Klein, Michel R.; Parida, Shreemanta K.; Ota, Martin; Walzl, Gerhard; Ottenhoff, Tom H. M.; Dockrell, Hazel M.; Kaufmann, Stefan H. E.
    Background: Tuberculosis (TB) remains a global health threat with 9 million new cases and 1.4 million deaths per year. In order to develop a protective vaccine, we need to define the antigens expressed by Mycobacterium tuberculosis (Mtb), which are relevant to protective immunity in high-endemic areas. Methods: We analysed responses to 23 Mtb antigens in a total of 1247 subjects with different HIV and TB status across 5 geographically diverse sites in Africa (South Africa, The Gambia, Ethiopia, Malawi and Uganda). We used a 7-day whole blood assay followed by IFN-γ ELISA on the supernatants. Antigens included PPD, ESAT-6 and Ag85B (dominant antigens) together with novel resuscitation-promoting factors (rpf), reactivation proteins, latency (Mtb DosR regulon-encoded) antigens, starvation-induced antigens and secreted antigens. Results: There was variation between sites in responses to the antigens, presumably due to underlying genetic and environmental differences. When results from all sites were combined, HIV- subjects with active TB showed significantly lower responses compared to both TST- and TST+ contacts to latency antigens (Rv0569, Rv1733, Rv1735, Rv1737) and the rpf Rv0867; whilst responses to ESAT-6/CFP-10 fusion protein (EC), PPD, Rv2029, TB10.3, and TB10.4 were significantly higher in TST+ contacts (LTBI) compared to TB and TST- contacts fewer differences were seen in subjects with HIV co-infection, with responses to the mitogen PHA significantly lower in subjects with active TB compared to those with LTBI and no difference with any antigen. Conclusions: Our multi-site study design for testing novel Mtb antigens revealed promising antigens for future vaccine development. The IFN-γ ELISA is a cheap and useful tool for screening potential antigenicity in subjects with different ethnic backgrounds and across a spectrum of TB and HIV infection states. Analysis of cytokines other than IFN-γ is currently on-going to determine correlates of protection, which may be useful for vaccine efficacy trials.
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    Biomarkers of inflammation, immunosuppression and stress with active disease are revealed by metabolomic profiling of tuberculosis patients
    (Public Library of Science, 2012-07-23) Weiner, January; Parida, Shreemanta K.; Maertzdorf, Jeroen; Black, Gillian F.; Repsilber, Dirk; Telaar, Anna; Mohney, Robert P.; Arndt-Sullivan, Cordelia; Ganoza, Christian A.; Fae, Kellen C.; Walzl, Gerhard; Kaufmann, Stefan H. E.
    Although tuberculosis (TB) causes more deaths than any other pathogen, most infected individuals harbor the pathogen without signs of disease. We explored the metabolome of >400 small molecules in serum of uninfected individuals, latently infected healthy individuals and patients with active TB. We identified changes in amino acid, lipid and nucleotide metabolism pathways, providing evidence for anti-inflammatory metabolomic changes in TB. Metabolic profiles indicate increased activity of indoleamine 2,3 dioxygenase 1 (IDO1), decreased phospholipase activity, increased abundance of adenosine metabolism products, as well as indicators of fibrotic lesions in active disease as compared to latent infection. Consistent with our predictions, we experimentally demonstrate TB-induced IDO1 activity. Furthermore, we demonstrate a link between metabolic profiles and cytokine signaling. Finally, we show that 20 metabolites are sufficient for robust discrimination of TB patients from healthy individuals. Our results provide specific insights into the biology of TB and pave the way for the rational development of metabolic biomarkers for TB. © 2012 Weiner et al.
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    Potential of host markers produced by infection phase-dependent antigen-stimulated cells for the diagnosis of tuberculosis in a highly endemic area
    (Public Library of Science, 2012-06-05) Chegou, Novel N.; Essone, Paulin N.; Loxton, Andre G.; Stanley, Kim; Black, Gillian F.; Van der Spuy, Gian D.; Van Helden, Paul D.; Franken, Kees L.; Parida, Shreemanta K.; Klein, Michel R.; Kaufmann, Stefan H. E.; Ottenhoff, Tom H. M.; Walzl, Gerhard
    Background: Recent interferon gamma (IFN-γ)-based studies have identified novel Mycobacterium tuberculosis (M.tb) infection phase-dependent antigens as diagnostic candidates. In this study, the levels of 11 host markers other than IFN-γ, were evaluated in whole blood culture supernatants after stimulation with M.tb infection phase-dependent antigens, for the diagnosis of TB disease. Methodology and Principal Findings: Five M.tb infection phase-dependent antigens, comprising of three DosR-regulon-encoded proteins (Rv2032, Rv0081, Rv1737c), and two resucitation promoting factors (Rv0867c and Rv2389c), were evaluated in a case-control study with 15 pulmonary TB patients and 15 household contacts that were recruited from a high TB incidence setting in Cape Town, South Africa. After a 7-day whole blood culture, supernatants were harvested and the levels of the host markers evaluated using the Luminex platform. Multiple antigen-specific host markers were identified with promising diagnostic potential. Rv0081-specific levels of IL-12(p40), IP-10, IL-10 and TNF-α were the most promising diagnostic candidates, each ascertaining TB disease with an accuracy of 100%, 95% confidence interval for the area under the receiver operating characteristics plots, (1.0 to 1.0). Conclusions: Multiple cytokines other than IFN-γ in whole blood culture supernatants after stimulation with M.tb infection phase-dependent antigens show promise as diagnostic markers for active TB. These preliminary findings should be verified in well-designed diagnostic studies employing short-term culture assays. © 2012 Chegou et al.
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    Potential of novel Mycobacterium tuberculosis infection phase-dependent antigens in the diagnosis of TB disease in a high burden setting
    (BioMed Central, 2012-01) Chegou, Novel N.; Black, Gillian F.; Loxton, Andre G.; Stanley, Kim; Essone, Paulin N.; Klein, Michel R.; Parida, Shreemanta K.; Kaufmann, Stefan H. E.; Doherty, T. Mark; Friggen, Annemieke H.; Franken, Kees L.; Ottenhoff, Tom H.; Walzl, Gerhard
    Abstract Background Confirming tuberculosis (TB) disease in suspects in resource limited settings is challenging and calls for the development of more suitable diagnostic tools. Different Mycobacterium tuberculosis (M.tb) infection phase-dependent antigens may be differentially recognized in infected and diseased individuals and therefore useful as diagnostic tools for differentiating between M.tb infection states. In this study, we assessed the diagnostic potential of 118 different M.tb infection phase-dependent antigens in TB patients and household contacts (HHCs) in a high-burden setting. Methods Antigens were evaluated using the 7-day whole blood culture technique in 23 pulmonary TB patients and in 19 to 21 HHCs (total n = 101), who were recruited from a high-TB incidence community in Cape Town, South Africa. Interferon-gamma (IFN-γ) levels in culture supernatants were determined by ELISA. Results Eight classical TB vaccine candidate antigens, 51 DosR regulon encoded antigens, 23 TB reactivation antigens, 5 TB resuscitation promoting factors (rpfs), 6 starvation and 24 other stress response-associated TB antigens were evaluated in the study. The most promising antigens for ascertaining active TB were the rpfs (Rv0867c, Rv2389c, Rv2450c, Rv1009 and Rv1884c), with Areas under the receiver operating characteristics curves (AUCs) between 0.72 and 0.80. A combination of M.tb specific ESAT-6/CFP-10 fusion protein, Rv2624c and Rv0867c accurately predicted 73% of the TB patients and 80% of the non-TB cases after cross validation. Conclusions IFN-γ responses to TB rpfs show promise as TB diagnostic candidates and should be evaluated further for discrimination between M.tb infection states.