Article

Recombinant antigen production for assays of intradermoreaction for diagnosis and surveillance of tuberculosis.

Laboratory of Forensic Molecular Genetics, Institute of Criminology, 80010-100 Curitiba, Brazil.
Journal of Biotechnology (Impact Factor: 3.18). 07/2011; 156(1):56-8. DOI: 10.1016/j.jbiotec.2011.07.015
Source: PubMed

ABSTRACT The goal of the present work was to develop reagents with potential for tuberculosis diagnosis. Genetic sequences of Mycobacterium tuberculosis secretion antigens were amplified by PCR, cloned into the Gateway(®) system, and expressed in Escherichia coli. The recombinant M. tuberculosis proteins were purified by metal affinity chromatography and preparative gel SDS-PAGE electrophoresis followed by electroelution and removal of endotoxins using Triton X-114. In total, seven recombinant proteins were obtained (ESAT-6, CFP10, TB10.3, TB10.4, MTSP11, MPT70, and MPT83). Delayed hypersensitivity reactions (DHR) was evaluated in Cavia porcellus and compared to the response using a standard purified protein derivative (PPD). All seven recombinant proteins produced a positive induration reaction in an intradermal test in guinea pigs previously sensitized with M. tuberculosis. When applied together, at a concentration of each recombinant protein 0.04 mg/mL, the intradermoreaction in C. porcellus was significantly higher than that obtained by standard PPD (p-value=0.00386).

0 Bookmarks
 · 
148 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: The emergence of multi- and extensively-drug resistant strains of Mycobacterium tuberculosis makes the development of novel anti-tubercular compounds and the identification of alternative mycobacterial drugable targets urgent priorities. Recently, type VII secretion systems (T7SS) have been discovered in mycobacteria. The genome of M. tuberculosis encodes 5 of such systems (ESX-1 to -5), three of which have been characterized and shown to be essential for viability (ESX-3, ESX-5) or virulence (ESX-1, ESX-5). Because of their crucial role in host-pathogen interactions as well as their involvement in basic biological processes of tubercle bacilli, T7SS/ESX represent promising targets for novel anti-tuberculosis drugs. Here, we review the current knowledge of the T7SS/ESX and their impact on M. tuberculosis physiology and virulence. Finally, we discuss the possible approaches to develop T7SS/ESX inhibitors.
    Current pharmaceutical design 11/2013; · 4.41 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background & objectives: Purified protein derivative (PPD) is currently the only available skin test reagent used worldwide for the diagnosis of tuberculosis (TB). The aim of this study was to develop a Mycobacterium tuberculosis specific skin test reagent, without false positive results due to Bacillus Calmette-Guerin (BCG) vaccination using recombinant antigens. Methods: Proteins in PPD IC-65 were analyzed by tandem mass spectrometry and compared to proteins in M. tuberculosis culture filtrate; 54 proteins were found in common. Top candidates MPT64, ESAT 6, and CFP 10 were overexpressed in Escherichia coli expression strains and purified as recombinant proteins. To formulate optimal immunodiagnostic PPD cocktails, the antigens were evaluated by skin testing guinea pigs sensitized with M. tuberculosis H37Rv and BCG. Results: For single antigens and a cocktail mixture of these antigens, best results were obtained using 3 μg/0.1 ml, equivalent to 105 TU (tuberculin units). Each animal was simultaneously tested with PPD IC-65, 2 TU/0.1 ml, as reference. Reactivity of the multi-antigen cocktail was greater than that of any single antigen. The skin test results were between 34.3 and 76.6 per cent the level of reactivity compared to that of the reference when single antigens were tested and 124 per cent the level of reactivity compared to the reference for the multi-antigen cocktail. Interpretation & conclusions: Our results showed that this specific cocktail could represent a potential candidate for a new skin diagnostic test for TB.
    The Indian Journal of Medical Research 11/2012; 136(5):799-807. · 2.06 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The emergence of multi- and extensively-drug resistant strains of Mycobacterium tuberculosis makes the development of novel anti-tubercular compounds and the identification of alternative mycobacterial drugable targets urgent priorities. Recently, type VII secretion systems (T7SS) have been discovered in mycobacteria. The genome of M. tuberculosis encodes 5 of such systems (ESX-1 to -5), three of which have been characterized and shown to be essential for viability (ESX-3, ESX-5) or virulence (ESX-1, ESX-5). Because of their crucial role in host-pathogen interactions as well as their involvement in basic biological processes of tubercle bacilli, T7SS/ESX represent promising targets for novel anti-tuberculosis drugs. Here, we review the current knowledge of the T7SS/ESX and their impact on M. tuberculosis physiology and virulence. Finally, we discuss the possible approaches to develop T7SS/ESX inhibitors
    Current Pharmaceutical Design 11/2013; 39. · 3.31 Impact Factor