Host Immune Responses Differ between M. africanum- and M. tuberculosis-Infected Patients following Standard Anti-tuberculosis Treatment - PubMed (original) (raw)
Comparative Study
. 2016 May 18;10(5):e0004701.
doi: 10.1371/journal.pntd.0004701. eCollection 2016 May.
Leopold D Tientcheu 1 2 3, Schadrac C Agbla 1 5, Jayne S Sutherland 1, Ifedayo M Adetifa 6 7, Simon Donkor 1, Edwin Quinten 4, Mohammed Daramy 1, Martin Antonio 1 8 9, Beate Kampmann 1, Tom H M Ottenhoff 4, Hazel M Dockrell 2, Martin O Ota 1 10
Affiliations
- PMID: 27192147
- PMCID: PMC4871581
- DOI: 10.1371/journal.pntd.0004701
Comparative Study
Host Immune Responses Differ between M. africanum- and M. tuberculosis-Infected Patients following Standard Anti-tuberculosis Treatment
Leopold D Tientcheu et al. PLoS Negl Trop Dis. 2016.
Abstract
Epidemiological differences exist between Mycobacterium africanum (Maf)- and Mycobacterium tuberculosis (Mtb)-infected patients, but to date, contributing host factors have not been characterised. We analysed clinical outcomes, as well as soluble markers and gene expression profiles in unstimulated, and ESAT6/CFP-10-, whole-Maf- and Mtb-stimulated blood samples of 26 Maf- and 49 Mtb-HIV-negative tuberculosis patients before, and after 2 and 6 months of anti-tuberculosis therapy. Before treatment, both groups had similar clinical parameters, but differed in few cytokines concentration and gene expression profiles. Following treatment the body mass index, skinfold thickness and chest X-ray scores showed greater improvement in the Mtb- compared to Maf-infected patients, after adjusting for age, sex and ethnicity (p = 0.02; 0.04 and 0.007, respectively). In addition, in unstimulated blood, IL-12p70, IL12A and TLR9 were significantly higher in Maf-infected patients, while IL-15, IL-8 and MIP-1α were higher in Mtb-infected patients. Overnight stimulation with ESAT-6/CFP-10 induced significantly higher levels of IFN-γ and TNF-α production, as well as gene expression of CCL4, IL1B and TLR4 in Mtb- compared to Maf-infected patients. Our study confirms differences in clinical features and immune genes expression and concentration of proteins associated with inflammatory processes between Mtb- and Maf-infected patients following anti-tuberculosis treatment These findings have public health implications for treatment regimens, and biomarkers for tuberculosis diagnosis and susceptibility.
Conflict of interest statement
The authors have declared that no competing interests exist.
Figures
Fig 1. Kinetics of the clinical outcomes in Maf- and _Mtb_-infected patients following treatment.
Line plots show the predicted mean and its 95% CI of Log transformed Body Mass Index (BMI) and Skinfold Thickness (SFT) in Maf- and _Mtb_-infected groups at 0, 2 and 6 months of treatment, Chest X-ray (CXR) was not Log transformed. Wald test through contrasts analysis following a random-intercept model adjusted for age, sex and ethnicity was used to assess interaction between lineage group and time point on clinical response. Maf group (dashed lines) and Mtb group (solid lines) respectively. P-values of the interactions are shown.
Fig 2. Differential cytokine production between Maf- and _Mtb_-infected patients before and after treatment.
Whole blood incubated overnight with medium only (I), revealed differences in the concentrations of IL12p70 (A), PDGF-ββ (B), MIP-1α (C), IL-15 (D) and IL-8 (E) between Mtb- and _Maf_-infected patients at 6 month of treatment. (II) Only ESAT-6/CFP-10 stimulation induced significant differences in cytokine production between Mtb- and _Maf_-infected patients above the background level of IFN-γ (A), IL-2 (B), IL-1ra (C), TNF-α (D), GM-CSF (E) and Rantes (F). Dot plots show log-2 transformed cytokine concentrations measured with Bio-Plex assay. Horizontal bars indicate median cytokine concentration by lineage groups, _Maf_-infected patients (closed circles, n = 26 and 20) and _Mtb_-infected patients (open circles, n = 49 and 31) respectively at 0 and 6 months of TB treatment. Log-2 transformed cytokine concentrations were compared between lineage groups using a random-intercept model adjusted for age, sex and ethnicity, and Sidak multiple comparison correction. Contrasts analysis was used after estimation to compute the difference in each cytokine concentration between lineage groups and used Wald test for assessing the significance at each time point. P-values of the differences are shown.
Fig 3. Kinetics of cytokines production between Maf- and _Mtb_-infected groups following treatment.
The kinetics of cytokine expression showing either strong or weak evidence of difference between lineage groups following overnight incubation with Medium alone (I) or ESAT-6/CFP-10 (II). Line plots show the predicted mean and its 95% confidence interval (95% CI) of log-2 transformed cytokines concentration in Maf- and _Mtb_-infected groups at 0, 2 and 6 months of treatment. Wald test through contrasts analysis following a random-intercept model adjusted for age, sex and ethnicity was used to assess interaction between lineage group and time point on cytokine production. The legend shows _Maf_-infected group (dashed lines) and _Mtb_-infected group (solid lines) respectively. P-values of the interactions are shown.
Fig 4. Gene expression profiles differ between Maf- and _Mtb_-infected patients before and after treatment.
dcRT-MLPA was performed on RNA extracted from whole blood incubated overnight with medium only (A), ESAT-6/CFP-10 (B) and live Maf (C). Median gene expression levels (peak areas normalized to GAPDH and log2 transformed) of the indicated genes are shown in box-and-whisker plots. Equal number of samples were analysed at 0 and 6 months of treatment in each group of _Maf_-infected (n = 20; white boxes) and _Mtb_-infected (n = 31; grey boxes) patients, respectively. Log-2 transformed gene expression data were compared between the groups using contrast analysis following a random-intercept model adjusted for age, sex and ethnicity, and Sidak multiple comparison correction. Wald test was used to assess the significance at each time point. P-values of significant differences are shown.
Fig 5. Kinetics of gene expression in Maf- and _Mtb_-infected groups following treatment.
The expression kinetics of genes that showed significant differences between Maf- and _Mtb_-infected groups following overnight incubation with Medium alone (A), ESAT-6/CFP-10 (B) and live Maf (C). Line plots show the predicted mean and its 95% CI of log2 transformed gene expression levels in Maf- and _Mtb_-infected groups at 0, 2 and 6 months of treatment. Wald test through contrasts analysis following a random-intercept model adjusted for age, sex and ethnicity was used to assess interaction between lineage group and time point on gene expression. The legend shows Maf-infected group (dashed lines) and Mtb-infected group (solid lines) respectively. P-values of the interactions are shown.
Fig 6. Ingenuity network of direct relationship among genes and cytokines differentially expressed between Maf- and _Mtb_-infected patients.
Ingenuity network showing 13 of the 23 pro-inflammatory cytokines and genes that were differentially expressed between Maf- and Mtb- infected patients, centred on NF-κ complex. Genes or cytokines that were higher in Mtb- compared to _Maf_- infected patients are depicted in red, those that were lower in green.
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