Project description:Extensively drug resistant tuberculosis (XDR-TB) showed many different characteristics including the extreme drug resistance versus the drug sensitive clinical isolates (DS-TB), to know better about the reasons we used the tuberculosis host cells named as THP-1 (one kind of the macrophage cells) to be infected by the XDR-TB and DS-TB.DS strain A36 and the XDR strain B42 and was typical and selected by our lab. Then the total RNA of infected or uninfected THP-1 cells was extract and purified for the analysis by the chip (22K Human Genome chip representing the 21522 ORF of human with the oligonucleotide probe of 70 mer from CapitalBio Corp., Beijing, China). The results reflected the different expressed genes involved in apoptosis, secreted cytokines and signal pathway and so on. Those results might indicate the how the XDR-TB cause the pathogenesis.
Project description:Extensively drug resistant tuberculosis (XDR-TB) showed many different characteristics including the extreme drug resistance versus the drug sensitive clinical isolates (DS-TB), to know better about the reasons we used the tuberculosis host cells named as THP-1 (one kind of the macrophage cells) to be infected by the XDR-TB and DS-TB.DS strain A36 and the XDR strain B42 and was typical and selected by our lab. Then the total RNA of infected or uninfected THP-1 cells was extract and purified for the analysis by the chip (22K Human Genome chip representing the 21522 ORF of human with the oligonucleotide probe of 70 mer from CapitalBio Corp., Beijing, China). The results reflected the different expressed genes involved in apoptosis, secreted cytokines and signal pathway and so on. Those results might indicate the how the XDR-TB cause the pathogenesis. In this study, the well grown THP-1 cells were separated and cultured in three ampoules. Cells in one ampoules were infected with XDR-TB strain of B42. Cells in another ampoules were infected with DS-TB strain of A36, with the cells in the third one were not infected and just treated with PBS as the control. Then the dual channel method was used for detecting the hybridization of B42 vs the control or A36 vs control. This work was repeated for three times.
Project description:Transcriptional profile comparison among Beijing and non-Beijing M. tuberculosis isolates. Three M. tuberculosis strains were compared. The laboratory reference strain, H37Rv, belongs to the Euro-American or lineage 4. Two clinical isolates of the East-Asian or lineage 2: 98_1663 is a pre-Beijing or Group 1 isolate, and HN878 is a Beijing or Group 5 isolate. Three replicates were performed for each comparison using two different biological samples.
Project description:Autophagy is a conserved lysosomal-dependent cellular degradation process shown to play a key role in immune defense against Mycobacterium tuberculosis inside host macrophages. Induction of autophagy enhances mycobacterial phagosome acquisition of lysosomal hydrolases, resulting in the destruction of intracellular M. tuberculosis reference strain H37Rv and strains belonging to the East African Indian genotype. However, our previous study showed that strains belonging to the hypervirulent M. tuberculosis Beijing genotype have a special ability to resist autophagic killing but the mechanism involved remains unclear. In this study, we carried out whole transcriptome analyses of host macrophages infected with the autophagy resistant Beijing strain compared to that of H37Rv. Our results identified several genes that are differentially regulated in the Beijing strain-infected host cells including those function in the lysosome positioning pathway. Host macrophages depleted of Kxd1 and Pleckhm2, two proteins in this pathway, can now enhance the lysosomal hydrolase acquisition into the Beijing phagosomes and restrict the bacterial survival upon autophagy induction. High-content image analysis showed an increase in lysosome numbers at the cell periphery in host cells infected with the autophagy resistant Beijing strain in a Pleckhm2-dependent manner. Taken together, these data indicated that the M. tuberculosis Beijing strain escapes autophagic elimination by upregulating the lysosome positioning pathway resulting in an increase in lysosome relocation toward the cell periphery and therefore sparing the mycobacteria from autophagic restriction. Our work thus identified new strategy employed by M. tuberculosis to evade autophagy which may provide potential new targets for drug discovery against tuberculosis
Project description:We report the application of RNA sequencing to assess the expression dynamics of miRNAs and their isoforms over time upon infection with a panel of six intracellular bacteria (Mycobacterium tuberculosis H37Rv, Mycobacterium tuberculosis Beijing strain GC1237, Mycobacterium bovis BCG, Salmonella typhimurium strain Keller, Staphloccocus epidermidis and Yersinia pseudotuberculosis)
Project description:Tuberculosis continues as an important public health problem. Particularly considering Beijing-family strains of Mycobacterium tuberculosis, which have been associated with drug-resistance and hypervirulence. The Beijing-like SIT190 (BL) is the most prevalent Beijing strain in Colombia. The pathogenic mechanism and immune response against this pathogen is unknown. Thus, we compared the course of pulmonary TB in BALB/c mice infected with Classical-Beijing strain 391 and BL strain 323. The disease course was different among infected animals with Classical-Beijing and BL strain. Mice infected with BL had a 100% mortality at 45 days post-infection (dpi), with high bacillary loads and massive pneumonia, whereas infected animals with Classical-Beijing survived until 60 dpi and showed extensive pneumonia and necrosis. Lung RNA extraction was carried out at early (day 3 dpi), intermediate (day14 dpi), and late (days 28 and 60 dpi) time points of infection. Transcriptional analysis of infected mice with Classical-Beijing showed several over-expressed genes, associated with a pro-inflammatory profile, including those for coding for CCL3 and CCL4 chemokines, both biomarkers of disease severity. Contrary, mice infected with BL displayed a profile which included the over-expression of several genes associated with immune- suppression, including Nkiras, Dleu2 and Sphk2, highlighting an anti-inflammatory milieu which would allow high bacterial replication followed by an intense inflammatory response. In summary, both Beijing strains induced a non-protective immune response which induced extensive tissue damage, BL strain induced rapidly extensive pneumonia and death, whereas Classical-Beijing strain produced slower extensive pneumonia later associated with extensive necrosis.
Project description:Mycobacterium tuberculosis (MTB) Beijing genotype is associated with high virulence and drug resistance worldwide. In Colombia, the Beijing genotype circulates since 1997 predominantly on the pacific coast, being the Beijing-Like SIT-190 more prevalent. This genotype conforms to a drug-resistant cluster and shows a fatal outcome in patients. To better understand virulence determinants, we performed a transcriptomic analysis with a Beijing-Like SIT-190 isolate (BL-323), and Beijing-Classic SIT-1 isolate (BC-391) in progressive tuberculosis (TB) murine model. RNA was extracted from mice lungs on days 3, 14, 28, and 60. On average, 0.6% of the total reads mapped against MTB genomes and of those, 90% against coding genes. The strains were independently associated as determined by hierarchical cluster and multidimensional scaling analysis. Gene ontology showed that in strain BL-323 enriched functions were related to host immune response and hypoxia, while proteolysis and protein folding were enriched in the BC-391 strain. Altogether, our results suggested a differential transcriptional program when evaluating these two closely related strains. The data presented here could potentially impact the control of this emerging, highly virulent and drug resistance genotype.