Dr Thuong Thuong T Nguyen

Research Area: Immunology
Scientific Themes: Tropical Medicine & Global Health and Immunology & Infectious Disease

Dr Thuong is working in the Tuberculosis Research Group, with research interests in human genetics and macrophage function. Her Wellcome fellowship focuses on the pathogenesis of Mycobacterium tuberculosis (Mtb) dissemination, studying the interplay of macrophage and Mtb under the influence of both human host and bacterial pathogen genetic factors. To study macrophage response to Mtb infection or ligand stimulation, Thuong has established real-time, functional readouts of activity within the phagosome, such as hydrolytic activity and radical production. These assays allow functional analysis of macrophage activity in TB patients, which should contribute to understanding of disease development.

There are no collaborations listed for this principal investigator.

Vijay S, Vinh DN, Hai HT, Ha VTN, Dung VTM, Dinh TD, Nhung HN, Tram TTB, Aldridge BB, Hanh NT et al. 2017. Influence of Stress and Antibiotic Resistance on Cell-Length Distribution in Mycobacterium tuberculosis Clinical Isolates. Front Microbiol, 8 (NOV), pp. 2296. | Show Abstract | Read more

Mycobacterial cellular variations in growth and division increase heterogeneity in cell length, possibly contributing to cell-to-cell variation in host and antibiotic stress tolerance. This may be one of the factors influencing Mycobacterium tuberculosis persistence to antibiotics. Tuberculosis (TB) is a major public health problem in developing countries, antibiotic persistence, and emergence of antibiotic resistance further complicates this problem. We wanted to investigate the factors influencing cell-length distribution in clinical M. tuberculosis strains. In parallel we examined M. tuberculosis cell-length distribution in a large set of clinical strains (n = 158) from ex vivo sputum samples, in vitro macrophage models, and in vitro cultures. Our aim was to understand the influence of clinically relevant factors such as host stresses, M. tuberculosis lineages, antibiotic resistance, antibiotic concentrations, and disease severity on the cell size distribution in clinical M. tuberculosis strains. Increased cell size and cell-to-cell variation in cell length were associated with bacteria in sputum and infected macrophages rather than liquid culture. Multidrug-resistant (MDR) strains displayed increased cell length heterogeneity compared to sensitive strains in infected macrophages and also during growth under rifampicin (RIF) treatment. Importantly, increased cell length was also associated with pulmonary TB disease severity. Supporting these findings, individual host stresses, such as oxidative stress and iron deficiency, increased cell-length heterogeneity of M. tuberculosis strains. In addition we also observed synergism between host stress and RIF treatment in increasing cell length in MDR-TB strains. This study has identified some clinical factors contributing to cell-length heterogeneity in clinical M. tuberculosis strains. The role of these cellular adaptations to host and antibiotic tolerance needs further investigation.

Thao LTP, Heemskerk AD, Geskus RB, Mai NTH, Ha DTM, Chau TTH, Phu NH, Chau NVV, Caws M, Lan NH et al. 2017. Prognostic models for 9 month mortality in tuberculous meningitis. Clin Infect Dis, | Show Abstract | Read more

Background: Tuberculous meningitis (TBM) is the most severe form of extra-pulmonary tuberculosis. We developed and validated prognostic models for 9-month mortality in HIV-uninfected and HIV-infected adults with TBM. Methods: We included 1699 subjects from four randomized clinical trials and one prospective observational study conducted at two major referral hospitals in Southern Vietnam from 2001-2015. Modelling was based on multivariable Cox proportional hazards regression. The final prognostic models were validated internally and temporally, and displayed using nomograms and a web-based app (https://thaole.shinyapps.io/tbmapp/). Results: A total of 951 HIV-uninfected and 748 HIV-infected subjects with TBM were included, of whom 219/951 (23.0%) and 384/748 (51.3%) died during 9-month follow-up. Common predictors for increased mortality in both populations were higher Medical Research Council (MRC) disease severity grade and lower cerebrospinal fluid lymphocyte cells count. In HIV-uninfected subjects, older age, previous tuberculosis, not receiving adjunctive dexamethasone, and focal neurological signs were additional risk factors; in HIV-infected subjects, lower weight, lower peripheral blood CD4 cell count, and abnormal plasma sodium were additional risk factors. The areas under the receiver operating characteristic curves (AUCs) for the final prognostic models were 0.77 (HIV-uninfected population) and 0.78 (HIV-infected population), demonstrating markedly better discrimination than the MRC grade (AUC 0.66 and 0.70) or the Glasgow Coma Score (AUC 0.68 and 0.71) alone. Conclusions: The developed models showed good performance and could be used in clinical practice to assist doctors in identifying TBM patients at high risk of death and at increased need of supportive care.

Van Toi P, Pouplin T, Tho NDK, Phuong PN, Chau TTH, Thuong Thuong NT, Heemskerk D, Hien TT, Thwaites GE. 2017. High-performance liquid chromatography with time-programmed fluorescence detection for the quantification of Levofloxacin in human plasma and cerebrospinal fluid in adults with tuberculous meningitis. J Chromatogr B Analyt Technol Biomed Life Sci, 1061-1062 pp. 256-262. | Show Abstract | Read more

An accurate and reliable high-performance liquid chromatography with time-programmed fluorescence detection was developed and validated to measure levofloxacin in human plasma and cerebrospinal fluid (CSF). After solid phase extraction process using Evolute® ABN 96 fixed well plate; levofloxacin and internal standard-enoxacin were separated using a mobile phase consisting of phosphate buffer 10mM with 0.025% triethylamine pH 3.0 - acetonitrile (88:12, v/v) on a Purosphere RP-8e column (5μm, 125×4.0mm) at a flow rate of 1.2mL/min at 35°C. The excitation/emission wavelengths were set to 269/400nm and 294/500nm, for enoxacin and levofloxacin, respectively. The method was linear over the concentration range of 0.02 to 20.0μg/mL with a limit of detection of 0.01μg/mL. The relative standard deviation of intra-assay and inter-assay precision for levofloxacin at four quality controls concentrations (0.02, 0.06, 3.0 and 15.0μg/mL) were less than 7% and the accuracies ranged from 96.75% to 101.9% in plasma, and from 93.00% to 98.67% in CSF. The validated method was successfully applied to quantify levofloxacin in a considerable quantity of plasma (826) and CSF (477) samples collected from 232 tuberculous meningitis patients, and the preliminary intensive pharmacokinetics analysis from 14 tuberculous meningitis patients in Vietnam is described in this paper.

Heemskerk AD, Nguyen MTH, Dang HTM, Vinh Nguyen CV, Nguyen LH, Do TDA, Nguyen TTT, Wolbers M, Day J, Le TTP et al. 2017. Clinical Outcomes of Patients With Drug-Resistant Tuberculous Meningitis Treated With an Intensified Antituberculosis Regimen. Clin Infect Dis, 65 (1), pp. 20-28. | Show Abstract | Read more

Background: Drug-resistant tuberculous meningitis (TBM) is difficult to diagnose and treat. Mortality is high and optimal treatment is unknown. We compared clinical outcomes of drug-resistant and -susceptible TBM treated with either standard or intensified antituberculosis treatment. Methods: We analyzed the influence of Mycobacterium tuberculosis drug resistance on the outcomes of patients with TBM enrolled into a randomized controlled trial comparing a standard, 9-month antituberculosis regimen (containing rifampicin 10 mg/kg/day) with an intensified regimen with higher-dose rifampicin (15 mg/kg/day) and levofloxacin (20 mg/kg/day) for the first 8 weeks. The primary endpoint of the trial was 9-month survival. In this subgroup analysis, resistance categories were predefined as multidrug resistant (MDR), isoniazid resistant, rifampicin susceptible (INH-R), and susceptible to rifampicin and isoniazid (INH-S + RIF-S). Outcome by resistance categories and response to intensified treatment were compared and estimated by Cox regression. Results: Of 817 randomized patients, 322 had a known drug resistance profile. INH-R was found in 86 (26.7%) patients, MDR in 15 (4.7%) patients, rifampicin monoresistance in 1 patient (0.3%), and INH-S + RIF-S in 220 (68.3%) patients. Multivariable regression showed that MDR (hazard ratio [HR], 5.91 [95% confidence interval {CI}, 3.00-11.6]), P < .001), was an independent predictor of death. INH-R had a significant association with the combined outcome of new neurological events or death (HR, 1.58 [95% CI, 1.11-2.23]). Adjusted Cox regression, corrected for treatment adjustments, showed that intensified treatment was significantly associated with improved survival (HR, 0.34 [95% CI, .15-.76], P = .01) in INH-R TBM. Conclusions: Early intensified treatment improved survival in patients with INH-R TBM. Targeted regimens for drug-resistant TBM should be further explored. Clinical Trials Registration: ISRCTN61649292.

Graustein AD, Horne DJ, Fong JJ, Schwarz F, Mefford HC, Peterson GJ, Wells RD, Musvosvi M, Shey M, Hanekom WA et al. 2017. The SIGLEC14 null allele is associated with Mycobacterium tuberculosis- and BCG-induced clinical and immunologic outcomes. Tuberculosis (Edinb), 104 pp. 38-45. | Show Abstract | Read more

Humans exposed to Mycobacterium tuberculosis (Mtb) have variable susceptibility to tuberculosis (TB) and its outcomes. Siglec-5 and Siglec-14 are members of the sialic-acid binding lectin family that regulate immune responses to pathogens through inhibitory (Siglec-5) and activating (Siglec-14) domains. The SIGLEC14 coding sequence is deleted in a high proportion of individuals, placing a SIGLEC5-like gene under the expression of the SIGLEC14 promoter (the SIGLEC14 null allele) and causing expression of a Siglec-5 like protein in monocytes and macrophages. We hypothesized that the SIGLEC14 null allele was associated with Mtb replication in monocytes, T-cell responses to the BCG vaccine, and clinical susceptibility to TB. The SIGLEC14 null allele was associated with protection from TB meningitis in Vietnamese adults but not with pediatric TB in South Africa. The null allele was associated with increased IL-2 and IL-17 production following ex-vivo BCG stimulation of blood from 10 week-old South African infants vaccinated with BCG at birth. Mtb replication was increased in THP-1 cells overexpressing either Siglec-5 or Siglec-14 relative to controls. To our knowledge, this is the first study to demonstrate an association between SIGLEC expression and clinical TB, Mtb replication, or BCG-specific T-cell cytokines.

Thuong NTT, Heemskerk D, Tram TTB, Thao LTP, Ramakrishnan L, Ha VTN, Bang ND, Chau TTH, Lan NH, Caws M et al. 2017. Leukotriene A4 Hydrolase Genotype and HIV Infection Influence Intracerebral Inflammation and Survival From Tuberculous Meningitis. J Infect Dis, 215 (7), pp. 1020-1028. | Show Abstract | Read more

Background: Tuberculous meningitis (TBM) is the most devastating form of tuberculosis, yet very little is known about the pathophysiology. We hypothesized that the genotype of leukotriene A4 hydrolase (encoded by LTA4H), which determines inflammatory eicosanoid expression, influences intracerebral inflammation, and predicts survival from TBM. Methods: We characterized the pretreatment clinical and intracerebral inflammatory phenotype and 9-month survival of 764 adults with TBM. All were genotyped for single-nucleotide polymorphism rs17525495, and inflammatory phenotype was defined by cerebrospinal fluid (CSF) leukocyte and cytokine concentrations. Results: LTA4H genotype predicted survival of human immunodeficiency virus (HIV)-uninfected patients, with TT-genotype patients significantly more likely to survive TBM than CC-genotype patients, according to Cox regression analysis (univariate P = .040 and multivariable P = .037). HIV-uninfected, TT-genotype patients had high CSF proinflammatory cytokine concentrations, with intermediate and lower concentrations in those with CT and CC genotypes. Increased CSF cytokine concentrations correlated with more-severe disease, but patients with low CSF leukocytes and cytokine concentrations were more likely to die from TBM. HIV infection independently predicted death due to TBM (hazard ratio, 3.94; 95% confidence interval, 2.79-5.56) and was associated with globally increased CSF cytokine concentrations, independent of LTA4H genotype. Conclusions: LTA4H genotype and HIV infection influence pretreatment inflammatory phenotype and survival from TBM. LTA4H genotype may predict adjunctive corticosteroid responsiveness in HIV-uninfected individuals.

Seshadri C, Thuong NTT, Mai NTH, Bang ND, Chau TTH, Lewinsohn DM, Thwaites GE, Dunstan SJ, Hawn TR. 2017. A polymorphism in human MR1 is associated with mRNA expression and susceptibility to tuberculosis. Genes Immun, 18 (1), pp. 8-14. | Show Abstract | Read more

The MR1 antigen-presenting system is conserved among mammals and enables T cells to recognize small molecules produced by bacterial pathogens, including Mycobacterium tuberculosis (M.tb). However, it is not known whether MR1-mediated antigen presentation is important for protective immunity against mycobacterial disease. We hypothesized that genetic control of MR1 expression correlates with clinical outcomes of tuberculosis infection. We performed an MR1 candidate gene association study and identified an intronic single-nucleotide polymorphism (rs1052632) that was significantly associated with susceptibility to tuberculosis in a discovery and validation cohort of Vietnamese adults with tuberculosis. Stratification by site of disease revealed that rs1052632 genotype GG was strongly associated with the development of meningeal tuberculosis (odds ratio=2.99; 95% confidence interval (CI) 1.64-5.43; P=0.00006). Among patients with meningeal disease, absence of the G allele was associated with an increased risk of death (hazard ratio=3.86; 95% CI 1.49-9.98; P=0.005). Variant annotation tools using public databases indicate that rs1052632 is strongly associated with MR1 gene expression in lymphoblastoid cells (P=0.004) and is located within a transcriptional enhancer in epithelial keratinocytes. These data support a role for MR1 in the pathogenesis of human tuberculosis by revealing that rs1052632 is associated with MR1 gene expression and susceptibility to tuberculosis in Vietnam.

Thuong NTT, Thwaites GE. 2017. Treatment-Associated Inflammatory Deterioration in Tuberculous Meningitis: Unpicking the Paradox. J Infect Dis, 215 (5), pp. 665-667. | Read more

Thuong NTT, Tram TTB, Dinh TD, Thai PVK, Heemskerk D, Bang ND, Chau TTH, Russell DG, Thwaites GE, Hawn TR et al. 2016. MARCO variants are associated with phagocytosis, pulmonary tuberculosis susceptibility and Beijing lineage. Genes Immun, 17 (7), pp. 419-425. | Show Abstract | Read more

Macrophage receptor with collagenous structure (MARCO) has an important role in the phagocytosis of Mycobacterium tuberculosis (M. tuberculosis). We hypothesized that MARCO polymorphisms are associated with phagocytosis, tuberculosis (TB) disease susceptibility and presentation, and infecting lineage. We used a human cellular model to examine how MARCO genotype mediates the immune response; a case-control study to investigate tuberculosis host genetic susceptibility; and a host-pathogen genetic analysis to study host-pathogen interactions. Two MARCO heterozygous (AG) genotypes (single-nucleotide polymorphisms rs2278589 and rs6751745) were associated with impaired phagocytosis of M. tuberculosis trehalose 6,6'-dimycolate-cord factor and β-glucan-coated beads in macrophages. The heterozygous genotypes of rs2278589 and rs6751745 were also associated with increased risk of pulmonary TB (PTB; rs2278589, P=0.001, odds ratio (OR)=1.6; rs6751745, P=0.009, OR=1.4), and with severe chest X-ray abnormalities (P=0.007, OR=1.6). These two genotypes were also associated with the Beijing lineage (rs2278589, P=0.001, OR=1.7; rs6751745, P=0.01, OR=1.5). Together, these results suggest that MARCO polymorphisms may regulate phagocytosis of M. tuberculosis and susceptibility and severity of PTB. They also suggest MARCO genotype and Beijing strains may interact to increase the risk of PTB.

Graustein AD, Horne DJ, Arentz M, Bang ND, Chau TTH, Thwaites GE, Caws M, Thuong NTT, Dunstan SJ, Hawn TR. 2015. TLR9 gene region polymorphisms and susceptibility to tuberculosis in Vietnam. Tuberculosis (Edinb), 95 (2), pp. 190-196. | Show Abstract | Read more

Humans exposed to Mycobacterium tuberculosis (Mtb) show variation in susceptibility to infection and differences in tuberculosis (TB) disease outcome. Toll-like receptor 9 (TLR9) is a pattern recognition receptor that mediates recognition of Mtb and modulates Mtb-specific T-cell responses. Using a case-population design, we evaluated whether single nucleotide polymorphisms (SNPs) in the TLR9 gene region are associated with susceptibility to pulmonary or meningeal TB as well as neurologic presentation and mortality in the meningeal TB group. In a discovery cohort (n = 352 cases, 382 controls), three SNPs were associated with TB (all forms, p < 0.05) while three additional SNPs neared significance (0.05 < p < 0.1). When these six SNPs were evaluated in a validation cohort (n = 339 cases, 367 controls), one was significant (rs352142) while another neared significance (rs352143). When the cohorts were combined, rs352142 was most strongly associated with meningeal tuberculosis (dominant model; p = 0.0002, OR 2.36, CI 1.43-3.87) while rs352143 was associated with pulmonary tuberculosis (recessive model; p = 0.006, OR 5.3, CI 1.26-31.13). None of the SNPs were associated with mortality. This is the first demonstration of an association between a TLR9 gene region SNP and tuberculous meningitis. In addition, this extends previous findings that support associations of TLR9 SNPs with pulmonary tuberculosis.

Campo M, Randhawa AK, Dunstan S, Farrar J, Caws M, Bang ND, Lan NN, Hong Chau TT, Horne DJ, Thuong NT et al. 2015. Common polymorphisms in the CD43 gene region are associated with tuberculosis disease and mortality. Am J Respir Cell Mol Biol, 52 (3), pp. 342-348. | Show Abstract | Read more

CD43, a surface glycoprotein, regulates Mycobacterium tuberculosis macrophage binding, replication, and proinflammatory cytokine induction in a murine model. We hypothesized that single-nucleotide polymorphisms (SNPs) in the CD43 gene region are associated with human tuberculosis (TB) susceptibility. We performed a case-population study in discovery (352 TB cases and 382 control subjects) and validation cohorts (339 TB cases and 376 control subjects). We examined whether 11 haplotype-tagging SNPs in the CD43 gene region were associated with tuberculous meningitis (TBM) and pulmonary TB (PTB) in Vietnam. Three SNPs from the CD43 gene region were associated with TB susceptibility with a genotypic model. The association fit a recessive genetic model and was greater for TBM than for PTB (for TBM: rs4788172, odds ratio [OR], 1.64; 95% confidence interval [CI], 1.04-2.59, rs17842268 [OR, 2.20; 95% CI, 1.29-3.76, and rs12596308 [OR, 2.38; 95% CI, 1.47-3.89]). Among TBM cases, rs17842268 was associated with decreased survival (hazard ratio, 2.7; 95% CI, 1.1-6.5; P = 0.011). In addition, rs12596308 and rs17842268 were associated with focal neurologic deficit at TBM presentation. Our data suggest that CD43 polymorphisms are associated with TB susceptibility, disease manifestations, and worse outcomes. To our knowledge, this is the first report that links CD43 genetic variants with susceptibility and outcome from a disease.

Seshadri C, Thuong NTT, Yen NTB, Bang ND, Chau TTH, Thwaites GE, Dunstan SJ, Hawn TR. 2014. A polymorphism in human CD1A is associated with susceptibility to tuberculosis. Genes Immun, 15 (3), pp. 195-198. | Show Abstract | Read more

CD1 proteins are antigen-presenting molecules that evolved to present lipids rather than peptides to T cells. However, unlike major histocompatibility complex genes, CD1 genes show low rates of polymorphism and have not been clearly associated with human disease. We report that an intronic polymorphism in CD1A (rs411089) is associated with susceptibility to tuberculosis in two cohorts of Vietnamese adults (combined cohort odds ratio 1.78; 95% confidence interval: 1.24-2.57; P=0.001). These data strengthen the hypothesis that CD1A-mediated lipid antigen presentation is important for controlling tuberculosis in humans.

Campo M, Randhawa AK, Dunstan S, Farrar J, Caws M, Bang ND, Lan NN, Chau TTH, Horne DJ, Thuong NT et al. 2014. Common Polymorphisms In The Cd43 Gene Region Are Associated With Tuberculosis Susceptibility And Mortality AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE, 189

Seshadri C, Thuong NTT, Yen NTB, Bang ND, Chau TTH, Thwaites GE, Dunstan SJ, Hawn TR. 2014. A polymorphism in human CD1A is associated with susceptibility to tuberculosis Genes and Immunity, 15 (3), pp. 195-198. | Show Abstract | Read more

CD1 proteins are antigen-presenting molecules that evolved to present lipids rather than peptides to T cells. However, unlike major histocompatibility complex genes, CD1 genes show low rates of polymorphism and have not been clearly associated with human disease. We report that an intronic polymorphism in CD1A (rs411089) is associated with susceptibility to tuberculosis in two cohorts of Vietnamese adults (combined cohort odds ratio 1.78; 95% confidence interval: 1.24-2.57; P=0.001). These data strengthen the hypothesis that CD1A-mediated lipid antigen presentation is important for controlling tuberculosis in humans. Copyright © 2014 Macmillan Publishers Limited.

Thuong NTT, Hawn TR, Chau TTH, Bang ND, Yen NTB, Thwaites GE, Teo YY, Seielstad M, Hibberd M, Lan NTN et al. 2012. Epiregulin (EREG) variation is associated with susceptibility to tuberculosis. Genes Immun, 13 (3), pp. 275-281. | Show Abstract | Read more

Although host genetics influences susceptibility to Mycobacterium tuberculosis, the human genes regulating pathogenesis remain largely unknown. We used M. tuberculosis-stimulated macrophage gene expression profiling in conjunction with a case-control genetic association study to discover epiregulin (EREG), as a novel candidate tuberculosis (TB) susceptibility gene. Using a genome-wide association study dataset, we found that among the 21 genes with greater than 50-fold induction, EREG had the most polymorphisms associated with TB. We genotyped haplotype-tagging polymorphisms in discovery (N = 337 cases, N = 380 controls) and validation (N = 332 cases) datasets and an EREG polymorphism (rs7675690) was associated with susceptibility to TB (genotypic comparison; corrected P = 0.00007). rs7675690 was also associated more strongly with infections caused by the Beijing lineage of M. tuberculosis when compared with non-Beijing strains (controls vs Beijing, OR 7.81, P = 8.7 × 10(-5); non-Beijing, OR 3.13, P = 0.074). Furthermore, EREG expression was induced in monocytes and peripheral blood mononuclear cells stimulated with M. tuberculosis as well as TLR4 and TLR2/1/6 ligands. In murine macrophages, EREG expression induced by M. tuberculosis was MYD88- and TLR2-dependent. Together, these data provide the first evidence for an important role for EREG as a susceptibility gene for human TB.

Thuong NTT, Dunstan S. 2010. Human genetic susceptibility to tuberculous meningitis in Vietnamese population Kekkaku, 85 (3), pp. 171-175. | Show Abstract

A case-control study of TLR2 candidate found that genotype 597CC was associated with susceptibility to tuberculous meningitis (TBM) (OR = 3.26) 1) . SNP C558T on TIRAP was found to be associated with increased susceptibility to TBM in this same Vietnamese cohort 2 ) (OR= 3.02). The co-inheritance of TLR2 SNP T597C and TIRAP SNP C558T increases susceptibility to TBM (OR = 5.4). The interaction between polymorphisms on TLR2 and TIRAP in TB patients and M. tuberculosis strains shows that individuals with the C allele of TLR2 T597C are more likely to have TBM caused by the Beijing genotype (OR=1.91) than other individuals. TBM patients with CC genotype of TLR2 T597C have higher risk of disease caused by the Beijing genotype (OR=4.48). This provides evidence that M.tuberculosis genotype influences clinical disease phenotype 3) . A genome-wide case-control association study of 250,000 SNPs indicated that there are SNP marker profiles which are specifically associated with the susceptibility to, or protection from, clinical phenotypes of TB (data not yet published). Microarrays were used to determine gene expression profiles of over 38,500 genes from ex-vivo M.tuberculosis stimulated macrophages isolated from latent (LTB), PTB and TBM. These results suggest that distinct macrophage responses are associated with different clinical forms of tuberculosis and that the innate immune response may regulate clinical outcomes 4) . Overall, the work presented in these studies contributes to the current knowledge of the genetic basis of TB, and more specifically of TBM, and provides novel insights into the molecular pathogenesis of TB.

Thuong NTT, Dunstan SJ, Chau TTH, Thorsson V, Simmons CP, Quyen NTH, Thwaites GE, Thi Ngoc Lan N, Hibberd M, Teo YY et al. 2008. Identification of tuberculosis susceptibility genes with human macrophage gene expression profiles. PLoS Pathog, 4 (12), pp. e1000229. | Show Abstract | Read more

Although host genetics influences susceptibility to tuberculosis (TB), few genes determining disease outcome have been identified. We hypothesized that macrophages from individuals with different clinical manifestations of Mycobacterium tuberculosis (Mtb) infection would have distinct gene expression profiles and that polymorphisms in these genes may also be associated with susceptibility to TB. We measured gene expression levels of >38,500 genes from ex vivo Mtb-stimulated macrophages in 12 subjects with 3 clinical phenotypes: latent, pulmonary, and meningeal TB (n = 4 per group). After identifying differentially expressed genes, we confirmed these results in 34 additional subjects by real-time PCR. We also used a case-control study design to examine whether polymorphisms in differentially regulated genes were associated with susceptibility to these different clinical forms of TB. We compared gene expression profiles in Mtb-stimulated and unstimulated macrophages and identified 1,608 and 199 genes that were differentially expressed by >2- and >5-fold, respectively. In an independent sample set of 34 individuals and a subset of highly regulated genes, 90% of the microarray results were confirmed by RT-PCR, including expression levels of CCL1, which distinguished the 3 clinical groups. Furthermore, 6 single nucleotide polymorphisms (SNPs) in CCL1 were found to be associated with TB in a case-control genetic association study with 273 TB cases and 188 controls. To our knowledge, this is the first identification of CCL1 as a gene involved in host susceptibility to TB and the first study to combine microarray and DNA polymorphism studies to identify genes associated with TB susceptibility. These results suggest that genome-wide studies can provide an unbiased method to identify critical macrophage response genes that are associated with different clinical outcomes and that variation in innate immune response genes regulate susceptibility to TB.

Caws M, Thwaites G, Dunstan S, Hawn TR, Lan NTN, Thuong NTT, Stepniewska K, Huyen MNT, Bang ND, Loc TH et al. 2008. The influence of host and bacterial genotype on the development of disseminated disease with Mycobacterium tuberculosis. PLoS Pathog, 4 (3), pp. e1000034. | Show Abstract | Read more

The factors that govern the development of tuberculosis disease are incompletely understood. We hypothesized that some strains of Mycobacterium tuberculosis (M. tuberculosis) are more capable of causing disseminated disease than others and may be associated with polymorphisms in host genes responsible for the innate immune response to infection. We compared the host and bacterial genotype in 187 Vietnamese adults with tuberculous meningitis (TBM) and 237 Vietnamese adults with uncomplicated pulmonary tuberculosis. The host genotype of tuberculosis cases was also compared with the genotype of 392 cord blood controls from the same population. Isolates of M. tuberculosis were genotyped by large sequence polymorphisms. The hosts were defined by polymorphisms in genes encoding Toll-interleukin 1 receptor domain containing adaptor protein (TIRAP) and Toll-like receptor-2 (TLR-2). We found a significant protective association between the Euro-American lineage of M. tuberculosis and pulmonary rather than meningeal tuberculosis (Odds ratio (OR) for causing TBM 0.395, 95% confidence intervals (C.I.) 0.193-0.806, P = 0.009), suggesting these strains are less capable of extra-pulmonary dissemination than others in the study population. We also found that individuals with the C allele of TLR-2 T597C allele were more likely to have tuberculosis caused by the East-Asian/Beijing genotype (OR = 1.57 [95% C.I. 1.15-2.15]) than other individuals. The study provides evidence that M. tuberculosis genotype influences clinical disease phenotype and demonstrates, for the first time, a significant interaction between host and bacterial genotypes and the development of tuberculosis.

Cited:

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Thuong NTT, Dunstan SJ, Chau TTH, Thorsson V, Simmons CP, Quyen NTH, Thwaites GE, Lan NTN, Hibberd M, Teo YY et al. 2008. Identification of tuberculosis susceptibility genes with human macrophage gene expression profiles PLoS Pathogens, 4 (12), | Show Abstract | Read more

Although host genetics influences susceptibility to tuberculosis (TB), few genes determining disease outcome have been identified. We hypothesized that macrophages from individuals with different clinical manifestations of Mycobacterium tuberculosis (Mtb) infection would have distinct gene expression profiles and that polymorphisms in these genes may also be associated with susceptibility to TB. We measured gene expression levels of > 38,500 genes from ex vivo Mtb-stimulated macrophages in 12 subjects with 3 clinical phenotypes: latent, pulmonary, and meningeal TB (n = 4 per group). After identifying differentially expressed genes, we confirmed these results in 34 additional subjects by real-time PCR. We also used a case-control study design to examine whether polymorphisms in differentially regulated genes were associated with susceptibility to these different clinical forms of TB. We compared gene expression profiles in Mtb-stimulated and unstimulated macrophages and identified 1,608 and 199 genes that were differentially expressed by > 2- and > 5-fold, respectively. In an independent sample set of 34 individuals and a subset of highly regulated genes, 90% of the microarray results were confirmed by RT-PCR, including expression levels of CCL1, which distinguished the 3 clinical groups. Furthermore, 6 single nucleotide polymorphisms (SNPs) in CCL1 were found to be associated with TB in a case-control genetic association study with 273 TB cases and 188 controls. To our knowledge, this is the first identification of CCL1 as a gene involved in host susceptibility to TB and the first study to combine microarray and DNA polymorphism studies to identify genes associated with TB susceptibility. These results suggest that genome-wide studies can provide an unbiased method to identify critical macrophage response genes that are associated with different clinical outcomes and that variation in innate immune response genes regulate susceptibility to TB. © 2008 Thuong et al.

Thuong NTT, Hawn TR, Thwaites GE, Chau TTH, Lan NTN, Quy HT, Hieu NT, Aderem A, Hien TT, Farrar JJ, Dunstan SJ. 2007. A polymorphism in human TLR2 is associated with increased susceptibility to tuberculous meningitis. Genes Immun, 8 (5), pp. 422-428. | Show Abstract | Read more

Tuberculous meningitis (TBM) results from the haematogenous dissemination of Mycobacterium tuberculosis from the lung to the brain. Dissemination is believed to occur early during infection, before the development of adaptive immunity. Toll-like receptor 2 (TLR2) mediates recognition of M. tuberculosis and initiates the innate immune response to infection. We hypothesized that polymorphisms in the TLR2 gene influence bacterial dissemination and the development of TBM. A case-control study was designed to test the hypothesis. Cases of bacteriologically confirmed pulmonary tuberculosis (TB) (n=183) and TBM (n=175), and cord blood controls (n=389) were enrolled in Vietnam. TLR2 genotype 597CC was associated with susceptibility to TB (odds ratio (OR)=2.22, 95% confidence interval (CI): 1.23-3.99). The association was found with meningeal rather than pulmonary TB (TBM vs control, OR=3.26, 95% CI: 1.72-6.18), and was strongest when miliary TB was found on chest radiography (controls vs TBM with miliary TB, OR=5.28, 95% CI: 2.20-12.65). Furthermore, the association increased with the severity of neurologic symptoms (grade I TBM, OR=1.93, 95% CI: 0.54-6.92; grade II, OR=3.32, 95% CI: 0.84-13.2; and grade III, OR=5.70, 95% CI: 1.81-18.0). These results demonstrate a strong association of TLR2 SNP T597C with the development of TBM and miliary TB and indicate that TLR2 influences the dissemination of M. tuberculosis.

Hawn TR, Dunstan SJ, Thwaites GE, Simmons CP, Thuong NT, Lan NTN, Quy HT, Chau TTH, Hieu NT, Rodrigues S et al. 2006. A polymorphism in Toll-interleukin 1 receptor domain containing adaptor protein is associated with susceptibility to meningeal tuberculosis. J Infect Dis, 194 (8), pp. 1127-1134. | Show Abstract | Read more

BACKGROUND: Although meningitis is the most severe form of infection caused by Mycobacterium tuberculosis, the immunopathogenesis of this disease is poorly understood. We tested the hypothesis that polymorphisms in Toll-interleukin 1 receptor domain containing adaptor protein (TIRAP), an adaptor protein that mediates signals from Toll-like receptors activated by mycobacteria, are associated with susceptibility to tuberculosis (TB). METHODS: We used a case-population study design in Vietnam with cord-blood control samples (n = 392) and case patients (n = 358) who had either pulmonary (n = 183) or meningeal (n = 175) TB. RESULTS: The TIRAP single-nucleotide polymorphism (SNP) C558T was associated with increased susceptibility to TB, with a 558T allele frequency of 0.035 in control samples versus 0.074 in case patients (odds ratio [OR], 2.25; P < .001). Subgroup analysis revealed that SNP 558T was more strongly associated with susceptibility to meningeal TB (OR, 3.02; P < .001) than to pulmonary TB (OR, 1.55; P = .22). In comparison to the 558CC genotype, the 558TT genotype was associated with decreased whole-blood interleukin-6 production, which suggests that TIRAP influences disease susceptibility by modulating the inflammatory response. CONCLUSIONS: These results provide the first evidence of an association of a TIRAP SNP with the risk of any disease and also suggest that the Toll-like receptor pathway influences susceptibility to meningeal and pulmonary TB by different immune mechanisms.

Thuong NTT, Dunstan SJ, Dung NM, Charlieu J-P, Loan HT, Wills B, Solomon T, Farrar JJ. 2006. Polymorphisms of the gene coding for copper/zinc superoxide dismutase (SOD1) in patients with Japanese encephalitis. Ann Trop Med Parasitol, 100 (7), pp. 631-636. | Show Abstract | Read more

Japanese encephalitis is the commonest form of encephalitis globally. Most cases develop characteristic encephalitis but some also present with flaccid paralysis. The paralysis is secondary to damage at the alpha motor neurone, the site that is also damaged in amyotrophic lateral sclerosis (ALS). The gene coding for superoxide dismutase 1 (SOD1) is thought to be involved in ALS and may also be linked to susceptibility to Japanese encephalitis. To investigate this possibility, polymorphisms in the SOD1 gene were investigated, in 61 cases of Japanese encephalitis, 61 matched controls and 171 population controls, in Vietnam. Novel polymorphisms, found only in three of the cases and one of the population controls, may be involved with susceptibility to Japanese encephalitis and potentially to other flavivirus infections that lead to damage to the cells of the anterior horn. Further research on this possible association is required.

Thuong NTT, Dunstan SJ, Dung NM, Charlieu JP, Loan HT, Wills B, Solomon T, Farrar JJ. 2006. Polymorphisms of the gene coding for copper/zinc superoxide dismutase (SOD1) in patients with Japanese encephalitis 100 (7), pp. 631-636. | Show Abstract | Read more

Japanese encephalitis is the commonest form of encephalitis globally. Most cases develop characteristic encephalitis but some also present with flaccid paralysis. The paralysis is secondary to damage at the alpha motor neurone, the site that is also damaged in amyotrophic lateral sclerosis (ALS). The gene coding for superoxide dismutase 1 (SOD1) is thought to be involved in ALS and may also be linked to susceptibility to Japanese encephalitis. To investigate this possibility, polymorphisms in the SOD1 gene were investigated, in 61 cases of Japanese encephalitis, 61 matched controls and 171 population controls, in Vietnam. Novel polymorphisms, found only in three of the cases and one of the population controls, may be involved with susceptibility to Japanese encephalitis and potentially to other flavivirus infections that lead to damage to the cells of the anterior horn. Further research on this possible association is required. © 2006 The Liverpool School of Tropical Medicine.

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