Project description:The century-old Mycobacterium bovis Bacillus Calmette-Guerin (BCG) remains the only licensed vaccine against tuberculosis (TB). Despite this, there is still a lot to learn about the immune response induced by BCG, both in terms of phenotype and specificity. Here, we investigated the BCG-specific gene expression changes induced in PBMCs and CD4 memory T cells by BCG in individuals pre- and 8m post vaccination. We also determined whether reactivity against a peptide pool defined in individuals with controlled latent TB infection (MTB300), and with peptides homologous to peptides found in BCG, was boosted following BCG vaccination.
Project description:Tuberculosis (TB) is one of major causes of death worldwide. Bacillus Calmette-Guerin (BCG) is the only licensed TB vaccine and its inability to protect against adult pulmonary TB can be due to genetic differences among strains described since the 1940s. In this work, we compared the proteomic profile of the surface-associated proteins from M. bovis BCG Moreau, the Brazilian vaccine strain, and the BCG Pasteur reference strain. The methodology used was 2D-gel electrophoresis combined with mass spectrometry techniques (MALDI-TOF/TOF). We identified 115 proteins. Of these, 24 proteins showed differential expression between the two BCG strains. Furthermore, 27 proteins previously described as displaying moonlighting function were identified, 8 of these proteins showed variation in abundance comparing BCG Moreau to Pasteur and 2 of them presented two different domain hits.
Project description:Global gene expression analysis of Mycobacterium bovis BCG following Triclosan treatment using Affymetrix GeneChip arrays. Results from this study provide insight into the molecular mechanisms underlying the cellular response of Mycobacterium bovis BCG to Triclosan
Project description:In the present study, we employed Affymetrix Mycobacterium bovis BCG GeneChip arrays to investigate the dynamics of global gene expression profiles during the cellular response of Mycobacterium bovis BCG to Sodium Hypochlorite, which involved initial growth inhibition and metabolism. Keywords: Transcriptome study
Project description:In the present study, we employed Affymetrix Mycobacterium bovis BCG GeneChip arrays to investigate the dynamics of global gene expression profiles during the cellular response of Mycobacterium bovis BCG to Peracetic acid, which involved initial growth inhibition and metabolism. Keywords: Transcriptome study
Project description:In the present study, we employed Affymetrix Mycobacterium bovis BCG GeneChip arrays to investigate the dynamics of global gene expression profiles during the cellular response of Mycobacterium bovis BCG to hydrogen peroxide, which involved initial growth inhibition and metabolism. Keywords: Transcriptome study
Project description:Mycobacterium tuberculosis is the causative agent of tuberculosis, a disease that affects one-third of the world’s population. The sole extant vaccine for tuberculosis is the live attenuated Mycobacterium bovis bacille Calmette-Guerin (BCG). We examined 13 representative BCG strains from around the world to ascertain their ability to express DosR-regulated dormancy antigens. These are known to be recognized by T-cells of M. tuberculosis infected individuals, especially those harboring latent infections. Differences in expression of these antigens could be valuable for use as diagnostic markers to distinguish BCG vaccination from latent tuberculosis. We determined that all BCG strains were defective for induction of two dormancy genes, narK2 (Rv1737c) and narX (Rv1736c). NarK2 is known to be necessary for nitrate respiration during anaerobic dormancy. Analysis of the narK2/X promoter region revealed a base substitution mutation in all tested BCG strains and M. bovis in comparison to the M. tuberculosis sequence. We also show that nitrate reduction by BCG strains during dormancy was greatly reduced compared to M. tuberculosis and varied between tested strains. Several dormancy regulon transcriptional differences were also identified among the strains, as well as variation in their growth and survival. These findings demonstrate defects in DosR regulon expression during dormancy and phenotypic variation between commonly used BCG vaccine strains. 12 different BCG strains were examined as well as M. tuberculosis H37Rv and M. bovis. Two arrays per strain were analyzed, one with the addition of nitric oxide and the other utilizing hypoxia treatment, both conditions shown to induce expression of the dormancy regulon. The reference sample for each array was log phase M. tuberculosis H37Rv.
Project description:Mycobacterial Ser/Thr kinases play a critical role in bacterial physiology and pathogenesis. Linking kinases to the substrates they phosphorylate in vivo, thereby elucidating their exact functions, is still a challenge. The aim of this work was to associate protein phosphorylation in mycobacteria with important subsequent macro cellular events by identifying the physiological substrates of PknG in Mycobacterium bovis BCG. The study compared the phosphoproteome dynamics during the batch growth of M. bovis BGC versus the respective PknG knock-out mutant (ΔPknG-BCG) strains.