Combination of host susceptibility and Mycobacterium tuberculosis virulence define gene expression profile in the host

Department of Immunology, Max Planck Institute for Infection Biology, Berlin, Germany.
European Journal of Immunology (Impact Factor: 4.03). 12/2009; 39(12):3369-84. DOI: 10.1002/eji.200939615
Source: PubMed


Progression and outcome of tuberculosis is governed by extensive crosstalk between pathogen and host. Analyses of global changes in gene expression during immune response to infection with Mycobacterium tuberculosis (M.tb) can help identify molecular markers of disease state and progression. Global distribution of M.tb strains with different degrees of virulence and drug resistance, especially for the immunocompromised host, make closer analyses of host responses more pressing than ever. Here, we describe global transcriptional responses of inducible nitric oxide synthase-deficient (iNOS(-/-)) and WT mice infected with two related M.tb strains of markedly different virulence, namely the M.tb laboratory strains H37Rv and H37Ra. Both hosts exhibited highly similar resistance to infection with H37Ra. In contrast, iNOS(-/-) mice rapidly succumbed to H37Rv, whereas WT mice developed chronic course of disease. By differential analyses, virulence-specific changes in global host gene expression were analyzed to identify molecular markers characteristic for chronic versus acute infection. We identified several markers unique for different stages of disease progression and not previously associated with virulence-specific host responses in tuberculosis.

6 Reads
  • Source
    • "A subset of 10 articles each of the closely related protozoan parasites Leishmania [47]–[56], Toxoplasma [57]–[66] and Plasmodium [67]–[76] were included for comparison. In addition, 10 articles of Trichuris [77]–[86] and Schistosoma [87]–[96] parasitic worm experiments, and 10 articles of Mycobacterium [97]–[106] experiments as a non-parasitic infection model were included in order to contrast the quality of method reporting in Trypanosoma experiments to other models and to determine the applicability of the checklist to different experimental systems. "
    [Show abstract] [Hide abstract]
    ABSTRACT: There is a growing concern both inside and outside the scientific community over the lack of reproducibility of experiments. The depth and detail of reported methods are critical to the reproducibility of findings, but also for making it possible to compare and integrate data from different studies. In this study, we evaluated in detail the methods reporting in a comprehensive set of trypanosomiasis experiments that should enable valid reproduction, integration and comparison of research findings. We evaluated a subset of other parasitic (Leishmania, Toxoplasma, Plasmodium, Trichuris and Schistosoma) and non-parasitic (Mycobacterium) experimental infections in order to compare the quality of method reporting more generally. A systematic review using PubMed (2000-2012) of all publications describing gene expression in cells and animals infected with Trypanosoma spp was undertaken based on PRISMA guidelines; 23 papers were identified and included. We defined a checklist of essential parameters that should be reported and have scored the number of those parameters that are reported for each publication. Bibliometric parameters (impact factor, citations and h-index) were used to look for association between Journal and Author status and the quality of method reporting. Trichuriasis experiments achieved the highest scores and included the only paper to score 100% in all criteria. The mean of scores achieved by Trypanosoma articles through the checklist was 65.5% (range 32-90%). Bibliometric parameters were not correlated with the quality of method reporting (Spearman's rank correlation coefficient <-0.5; p>0.05). Our results indicate that the quality of methods reporting in experimental parasitology is a cause for concern and it has not improved over time, despite there being evidence that most of the assessed parameters do influence the results. We propose that our set of parameters be used as guidelines to improve the quality of the reporting of experimental infection models as a pre-requisite for integrating and comparing sets of data.
    PLoS ONE 07/2014; 9(7):e101131. DOI:10.1371/journal.pone.0101131 · 3.23 Impact Factor
  • Source
    • "The small number of clinical isolates (3 pairs) used for GTP, limited by the cost of microarray slides, and scarcity of RNA from clinical samples (reported in earlier studies [1]), was a limitation of the study. However while most previous studies performed GTP with laboratory Mtb strains like H37Rv, H37Ra [24], [25], [26], [27], [28], we performed GTP with 3 pairs (6 isolates) of clinical isolates and H37Rv, which is comparable to earlier reports (1–3 patient isolates) [1]. The lack of quantitative validation of the genes is another limitation of the study. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The identification of multidrug resistant (MDR), extensively and totally drug resistant Mycobacterium tuberculosis (Mtb), in vulnerable sites such as Mumbai, is a grave threat to the control of tuberculosis. The current study aimed at explaining the rapid expression of MDR in Directly Observed Treatment Short Course (DOTS) compliant patients, represents the first study comparing global transcriptional profiles of 3 pairs of clinical Mtb isolates, collected longitudinally at initiation and completion of DOTS. While the isolates were drug susceptible (DS) at onset and MDR at completion of DOTS, they exhibited identical DNA fingerprints at both points of collection. The whole genome transcriptional analysis was performed using total RNA from H37Rv and 3 locally predominant spoligotypes viz. MANU1, CAS and Beijing, hybridized on MTBv3 (BuG@S) microarray, and yielded 36, 98 and 45 differentially expressed genes respectively. Genes encoding transcription factors (sig, rpoB), cell wall biosynthesis (emb genes), protein synthesis (rpl) and additional central metabolic pathways (ppdK, pknH, pfkB) were found to be down regulated in the MDR isolates as compared to the DS isolate of the same genotype. Up regulation of drug efflux pumps, ABC transporters, trans-membrane proteins and stress response transcriptional factors (whiB) in the MDR isolates was observed. The data indicated that Mtb, without specific mutations in drug target genes may persist in the host due to additional mechanisms like drug efflux pumps and lowered rate of metabolism. Furthermore this population of Mtb, which also showed reduced DNA repair activity, would result in selection and stabilization of spontaneous mutations in drug target genes, causing selection of a MDR strain in the presence of drug pressures. Efflux pump such as drrA may play a significant role in increasing fitness of low level drug resistant cells and assist in survival of Mtb till acquisition of drug resistant mutations with least fitness cost.
    PLoS ONE 01/2013; 8(1):e54717. DOI:10.1371/journal.pone.0054717 · 3.23 Impact Factor
  • Source
    • "The pathobiological importance of this genotype diversity has been confirmed by demonstrating enhanced spread of strains of particular lineages, e.g., in the context of multidrug resistance [26], defining lineage-specific disease characteristics [27], [28], and confirming host–pathogen co-evolution and specific host–pathogen interactions [29]–[31]. Very recently, we demonstrated significant levels of phylogenetically based transcriptome diversity of clinical MTBC isolates upon infection of mouse macrophages using microarrays [24]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Recently, the diversity of the Mycobacterium tuberculosis complex (MTBC) population structure has been described in detail. Based on geographical separation and specific host pathogen co-evolution shaping MTBC virulence traits, at least 20 major lineages/genotypes have evolved finally leading to a clear influence of strain genetic background on transmissibility, clinical presentation/outcome, and resistance development. Therefore, high resolution genotyping for characterization of strains in larger studies is mandatory for understanding mechanisms of host-pathogen-interaction and to improve tuberculosis (TB) control. Single nucleotide polymorphisms (SNPs) represent the most reliable markers for lineage classification of clinical isolates due to the low levels of homoplasy, however their use is hampered either by low discriminatory power or by the need to analyze a large number of genes to achieve higher resolution. Therefore, we carried out de novo sequencing of 26 genes (approx. 20000 bp per strain) in a reference collection of MTBC strains including all major genotypes to define a highly discriminatory gene set. Overall, 161 polymorphisms were detected of which 59 are genotype-specific, while 13 define deeper branches such as the Euro-American lineage. Unbiased investigation of the most variable set of 11 genes in a population based strain collection (one year, city of Hamburg, Germany) confirmed the validity of SNP analysis as all strains were classified with high accuracy. Taken together, we defined a diagnostic algorithm which allows the identification of 17 MTBC phylogenetic lineages with high confidence for the first time by sequencing analysis of just five genes. In conclusion, the diagnostic algorithm developed in our study is likely to open the door for a low cost high resolution sequence/SNP based differentiation of the MTBC with a very high specificity. High throughput assays can be established which will be needed for large association studies that are mandatory for detailed investigation of host-pathogen-interaction during TB infection.
    PLoS ONE 07/2012; 7(7):e39855. DOI:10.1371/journal.pone.0039855 · 3.23 Impact Factor
Show more