Expression Of Tuberculosis Research Articles

Effects of SNPs on TNF-α and IL-10 cytokine expression in TB and HIV patients in the Capricorn district, Limpopo Province, South Africa.

The impact of Tuberculosis (TB) places an immense burden on the health care system. Infection with Human Immunodeficiency Virus (HIV) is a significant risk factor in the development and progression of TB disease. Single Nucleotide Polymorphisms (SNPs) in the promoter region of Interleukin-10 (IL-10) and Tumour Necrotic Factor-Alpha (TNF-α) may play a major role in the disease mechanism and understanding these mechanisms might prove to be a useful diagnostic tool in evaluating the immune regulation and progression of the disease. This study aimed to determine the relationship between cytokine levels and gene variants of Interleukin-10 and Tumour Necrotic Factor Alpha in TB and HIV-infected participants. Cytokine levels were determined by ELISA, and SNPs were determined by MassArray®. The levels of TNF-α were higher in the TB group than the HIV (p < 0.001) and TB-HIV (p = 0.011) groups, but similar to the TNF-α levels in the control group. In the HIV group, IL-10 levels were higher than those of the TB (p < 0.001) and control groups (p = 0.039), whereas there was no difference between the IL-10 levels in the HIV and the TB-HIV infection groups. The ratio was determined and there were no differences between the four infection groups. In this study, no associations were detected between the circulating plasma levels of TNF-α and IL-10 and their genotypes. Our data showed that the gene variants were not associated with circulating plasma levels of TNF-α and IL-10 in our study population. A pro-inflammatory environment was found in the TB and TB-HIV groups, which is suggesting of bacterial clearance, while an anti-inflammatory environment was found in the HIV group, which suggests the suppression of viral replication.

Role of non-coding rnas in tuberculosis and their potential for clinical applications.

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains the leading cause of mortality due to infectious diseases, only surpassed in 2020 by COVID-19. Despite the development in diagnostics, therapeutics, and evaluation of new vaccines for TB, this infectious disease remains uncontrollable due to the emergence of multi-drug resistant (MDR) and extremely-drug resistant (XDR) TB, among other factors. The development in transcriptomics (RNomics) has enabled the study of gene expression in TB. It is considered that non-coding RNAs (ncRNAs) from host [microRNAs (miRNAs)] and Mtb [small RNAs (sRNAs)] are important elements in TB pathogenesis, immune resistance, and susceptibility. Many studies have shown the importance of host miRNAs in regulating immune response against Mtb via in vitro and in vivo mice models. The bacterial sRNAs play a major role in survival, adaptation, and virulence. Here, we review the characterization and function of host and bacteria ncRNAs in TB and their potential use in clinical applications as diagnostic, prognostic, and therapeutic biomarkers.

Gene Expression Study of Host and Mycobacterium tuberculosis Interactions in the Manifestation of Acute Tuberculosis.

Mycobacterium tuberculosis (M.tb) could induce type IV hypersensitivity. The chemotaxis of the leukocytes toward the site of infection and producing matrix metalloproteinases (MMPs) are key factors in the immune pathogenesis of tuberculosis (TB). Mononuclear cells were isolated from bronchoalveolar lavage (BAL) specimens, and the target from genomic DNA was used for qPCR TB diagnosis and cDNA for specific RT-qPCR gene expression. The subjects were then classified into TB+ and TB- groups, and the expression levels of CFP-10, ESAT-6, CCR1, CCR12 and MMP3,9 were evaluated. The mean level of CCR1 expression in TB+ and TB- patients' BAL was 1.71 ± 0.78 and 0.5 ± 0.22, respectively, which was statistically different (p = 0.01). The CCR2 level, in TB+ (2.07 ± 1.4), was higher than in TB- patients (1.42 ± 0.89, p = 0.01). The MMP9 expression in TB+ was 2.56 ± 0.68, also higher than in TB- patients (1.13 ± 0.35), while MMP3 was lower in TB+ (0.22 ± 0.09) than in TB- (0.64 ± 0.230, p = 0.05). The CCR2/CCR1 and MMP3/MMP9 balance in TB+ were reduced, compared to the TB-. The CFP-10 and ESAT-6 were highly expressed in TB+ patients. The CFP-10 expression had a strong negative correlation with albumin (r = - 0.93, p = 0.001), and a negative correlation with neutrophil (r = - 0.444, p = 0.1 with 90% CI). The MMP-9 expression showed a positive correlation with WBC count (r = 0.61, p = 0.02), in TB+, and had a negative correlation with BMI (r = 0.59, p = 0.02) in TB-. The M.tb CFP-10 might be implicated in lowering CCR2 and MMP3 expression in favour of M.tb dissemination. Moreover, the balance of CCR2/CCR1 and MMP3/MMP9 can be used as prognostic factors in the severity of TB.

W141 Evaluation of interleukin-22 and its’ expression in tuberculosis: A pilot study

W141 Evaluation of interleukin-22 and its’ expression in tuberculosis: A pilot study

High miRNA-378 expression has high diagnostic values for pulmonary tuberculosis and predicts adverse outcomes

BackgroundPulmonary tuberculosis (TB) is a chronic infectious disease. microRNA (miR)-378 is involved in TB diagnosis. This study explored the effects of miR-378 on TB patients.MethodsA total of 126 TB patients were selected, including 63 active TB and 63 latent TB, with 62 healthy subjects as controls. Serum miR-378 expression was detected. The diagnostic value of miR-378 in TB was analyzed using the ROC curve. Immune inflammatory factor levels were detected and their correlations with miR-378 expression were analyzed. The drug resistance of active TB patients was recorded after standard treatment. miR-378 expression in drug-resistant TB patients was detected. The effects of miR-378 on adverse outcome incidence were analyzed.ResultsmiR-378 expression was highly expressed in TB and the expression was higher in the active group than the latent group. Serum miR-378 expression > 1.490 had high sensitivity and specificity in TB diagnosis. miR-378 expression was correlated with TB clinical indexes. IL-4, IL-6, and IL-1β levels were highly expressed, while IFN-γ, TNF-α, and IL-12 levels were lowly expressed in TB patients. Serum miR-378 level in the active group was positively correlated with serum IL-4, IL-6, and IL-1β, and negatively correlated with serum IFN-γ, TNF-α, and IL-12 concentrations. miR-378 expression was downregulated in the TB treated, single (SDR TB) and multi-drug resistance (MDR TB) groups, the miR-378 expression in SDR TB and MDR TB groups was higher than the TB treated group and lower in the SDR TB group than the MDR TB group. High miR-378 expression predicted higher adverse outcome incidence.ConclusionsHigh miR-378 expression assisted TB diagnosis and predicted adverse outcomes.

Doxycycline host-directed therapy in human pulmonary tuberculosis

BACKGROUNDMatrix metalloproteinases (MMPs) are key regulators of tissue destruction in tuberculosis (TB) and may be targets for host-directed therapy. We conducted a phase II double-blind, randomized, controlled trial investigating doxycycline, a licensed broad-spectrum MMP inhibitor, in patients with pulmonary TB.METHODSThirty patients with pulmonary TB were enrolled within 7 days of initiating anti-TB treatment and randomly assigned to receive either 100 mg doxycycline or placebo twice a day for 14 days, in addition to standard care.RESULTSWhole blood RNA-sequencing demonstrated that doxycycline accelerated restoration of dysregulated gene expression in TB towards normality, rapidly down-regulating type I and II interferon and innate immune response genes, and up-regulating B-cell modules relative to placebo. The effects persisted for 6 weeks after doxycycline discontinuation, concurrent with suppressed plasma MMP-1. Doxycycline significantly reduced sputum MMP-1, -8, -9, -12 and -13, suppressed type I collagen and elastin destruction, reduced pulmonary cavity volume without altering sputum mycobacterial loads, and was safe.CONCLUSIONAdjunctive doxycycline with standard anti-TB treatment suppressed pathological MMPs in PTB patients. Larger studies on adjunctive doxycycline to limit TB immunopathology are merited.TRIAL REGISTRATIONClinicalTrials.gov NCT02774993.FUNDINGSingapore National Medical Research Council (NMRC/CNIG/1120/2014, NMRC/Seedfunding/0010/2014, NMRC/CISSP/2015/009a); the Singapore Infectious Diseases Initiative (SIDI/2013/013); National University Health System (PFFR-28 January 14, NUHSRO/2014/039/BSL3-SeedFunding/Jul/01); the Singapore Immunology Network Immunomonitoring platform (BMRC/IAF/311006, H16/99/b0/011, NRF2017_SISFP09); an ExxonMobil Research Fellowship, NUHS Clinician Scientist Program (NMRC/TA/0042/2015, CSAINV17nov014); the UK Medical Research Council (MR/P023754/1, MR/N006631/1); a NUS Postdoctoral Fellowship (NUHSRO/2017/073/PDF/03); The Royal Society Challenge Grant (CHG\R1\170084); the Sir Henry Dale Fellowship, Wellcome Trust (109377/Z/15/Z); and A*STAR.

The expression profile evaluation of Mir-125b in tuberculosis and non-small cell lung cancer patients

Background and Aim: Worldwide, lung cancer, specifically nonsmall-cell lung cancer (NSCLC), is one of the most preventable and common cancer types. Tuberculosis (TB) is a major global public health threat, and the most important infectious disease throughout history in the world. Having TB before lung cancer significantly correlates with mortality due to lung cancer. TB and lung cancer have similar symptoms, and TB has symptoms identical to malignancy, so sometimes its diagnosis is confused with lung cancer. The miRNAs are biological molecules that play critical regulatory roles in the physiological and pathological processes. In several research types, many miRNAs have been studied, which showed the alternation of expression in TB and NSCLC separately. In this research paper, the expression of mir-125b was examined, which is commonly altered in TB and NSCLC. Materials and Methods: Thirty patients with NSCLC, thirty patients with TB who were new cases, and thirty healthy individuals were contributed to this research. The expression pattern of mir-125b was evaluated and compared in TB and NSCLC patients with healthy controls, using the real-time polymerase chain reaction method. Results: As a result, the expression of mir-125b was lower in TB and NSCLC patients than in healthy controls. Conclusion: Therefore, mir-125b can be used as a prognostic biomarker in TB and NSCLC diseases. The expression pattern of mir-125b could be useful to follow-up on the biological pathways that have essential roles in these diseases.

Proteomic profiling of peripheral blood mononuclear cells isolated from patients with tuberculosis and diabetes copathogenesis - A pilot study.

BackgroundDiabetes is an important risk factor for developing tuberculosis. This association leads to exacerbation of tuberculosis symptoms and delayed treatment of both the diseases. Molecular mechanism and biomarkers/drug targets related to copathogenesis of tuberculosis and diabetes are still poorly understood. In this study, proteomics based 2D-MALDI/MS approach was employed to identify host signature proteins which are altered during copathogenesis of tuberculosis and diabetes.MethodsComparative proteome of human peripheral blood mononuclear cells (PBMCs) from healthy controls, tuberculosis and diabetes patients in comparison to comorbid diabetes and tuberculosis patients was analyzed. Gel based proteomics approach followed by in gel trypsin digestion and peptide identification by mass spectrometry was used for signature protein identification.ResultsTotal of 18 protein spots with differential expression in tuberculosis and diabetes copathogenesis (TBDM) patients in comparison to other groups were identified. These proteins belonged to four functional categories i.e. structural, cell cycle/growth regulation, signaling and intermediary metabolism. These include Vimentin, tubulin beta chain protein, Actin related protein 2/3 complex subunit 2, coffilin 1 (Structural), PDZ LIM domain protein, Rho-GDP dissociation inhibitor, Ras related protein Rab (signaling), superoxide dismutase, dCTPpyrophosphatase 1, Transcription initiation factor TFIID subunit 12, three isoforms of Peptidylprolylcis-trans isomerase A, SH3 domain containing protein (metabolism), three isoforms of Protein S100A9 and S100A8 (cell cycle progression/growth regulation).ConclusionProteins identified to be differentially expressed in TBDM patient can act as potent biomarkers and as predictors for copathogenesis of tuberculosis and diabetes.

BTLA-Expressing Dendritic Cells in Patients With Tuberculosis Exhibit Reduced Production of IL-12/IFN-α and Increased Production of IL-4 and TGF-β, Favoring Th2 and Foxp3+ Treg Polarization.

Little is known about how tuberculosis (TB) impairs dendritic cell (DC) function and anti-TB immune responses. We previously showed that the B and T lymphocyte attenuator (BTLA), an immune inhibitory receptor, is involved in TB pathogenesis. Here, we examined whether BTLA expression in TB affects phenotypic and functional aspects of DCs. Active TB patients exhibited higher expression of BTLA in myeloid dendritic cells (mDCs) and plasmacytoid DCs (pDCs) subsets compared with healthy controls (HCs). BTLA expression was similarly high in untreated TB, TB relapse, and sputum-bacillus positive TB, but anti-TB therapy reduced TB-driven increases in frequencies of BTLA+ DCs. BTLA+ DCs in active TB showed decreased expression of the DC maturation marker CD83, with an increased expression of CCR7 in mDCs. BTLA+ DCs in active TB displayed a decreased ability to express HLA-DR and to uptake foreign antigen, with a reduced expression of the co-stimulatory molecule CD80, but not CD86. Functionally, BTLA+ DCs in active TB showed a decreased production of IL-12 and IFN-α as well as a reduced ability to stimulate allogeneic T-cell proliferative responses. BTLA+ mDCs produced larger amounts of IL-4 and TGF-β than BTLA− mDCs in both HCs and APT patients. BTLA+ DCs from active TB patients showed a reduced ability to stimulate Mtb antigen-driven Th17 and Th22 polarizations as compared to those from HCs. Conversely, these BTLA+ DCs more readily promoted the differentiation of T regulatory cells (Treg) and Th2 than those from HCs. These findings suggest that TB-driven BTLA expression in DCs impairs the expression of functional DC surrogate markers and suppress the ability of DCs to induce anti-TB Th17 and Th22 response while promoting Th2 and Foxp3+ Tregs.

Long Non-Coding RNA NEAT1 Enhances Histone Methylation Through Regulating MLL5-Mediated Foxp3 Expression in Tuberculosis

Backgrounds: Tuberculosis (TB) is a leading infectious disease and cause of death worldwide. Abnormal expression of long non-coding RNAs (lncRNAs) has been demonstrated in a number of immune cells in TB patients, indicating that lncRNAs may be involved in immune regulation during TB. In this study, we aim to explore the effects of nuclear enriched abundant transcript 1 (NEAT1) on immunity in regulatory T (Treg) cells from a mouse model of TB. Methods: After TB bacteria inoculation, pathological changes in the lung of TB mice occurred with increased neutrophils and macrophages. The expression of NEAT1, MLL5 and Foxp3 was measured and their role in TB was evaluated with GapmeR or siRNA interference in Treg cells. NEAT1 was highly expressed in the nucleus of Treg cells from TB mice. NEAT1 interacted with MLL5 to enhance the binding of H3K4me3 to the Foxp3 promoter in Treg cells from TB mice. Findings: Proportions of CD3, CD3+CD4+ and CD3+CD8+ cells, IFN-γ and IgG levels were decreased in Treg cells from TB mice. NEAT1 or MLL5 silencing increased proportions of CD3, CD3+CD4+ and CD3+CD8+ cells and Treg cell proliferation. On the other hand, NEAT1 or MLL5 silencing increased the levels of IFN-γ, IL-10, IL-17, IL-6, IL-1β, IL-9 and reduced immunosuppressive effect of Treg cells from TB mice. Interpretation: Taken together, this study demonstrated that NEAT1 may be involved in TB progression via MLL5-mediated demethylation of H3K4me3 in the Foxp3 promoter region in Treg cells. Funding: This study was supported by National Natural Science Foundation of China (No. U1404814). Declaration of Interest: None Ethical Approval: The study was approved by the Animal Ethics Committee of The First Affiliated Hospital of Zhengzhou University. All animal experiments were carried out in accordance with the Guide for the Care and Use of Laboratory Animals provided by the National Institute of Health.

Dynamics of T-cell IFN-γ and miR-29a expression during active pulmonary tuberculosis.

IFN-γ is crucial for protection against Mycobacterium tuberculosis. miR-29 was recently shown to non-redundantly inhibit IFN-γ. Here, we investigated IFN-γ and miR-29a expression dynamics of CD4(+) T cells from patients during active tuberculosis (TB) (n = 32) and in household contacts who were latently M. tuberculosis infected (n = 19) from Ghana. Whereas M. tuberculosis-specific IFN-γ expression was similar during TB chemotherapy, superantigen stimulation indicated generally impaired IFN-γ expression in TB patients. No interdependency between miR-29a and IFN-γ expression of T cells was observed. However, miR-29a was differentially expressed in T cells during chemotherapy. We concluded that differential miR-29a expression in active TB was not causative for impaired IFN-γ expression.

Regulation of matrix metalloproteinase‐1, ‐3, and ‐9 inMycobacterium tuberculosis‐dependentrespiratory networks by the rapamycin‐sensitive PI3K/p70S6Kcascade

This study was designed to investigate the role of the phosphatidyl inositol 3-kinase (PI3K)/AKT/p70(S6K) signaling path on regulation of primary normal human bronchial epithelial cell-derived matrix metalloproteinase (MMP)-1, -3, and -9 expression in tuberculosis (TB). These MMPs are key in pathological extracellular matrix degradation in TB. Normal human bronchial epithelials were stimulated with conditioned medium from monocytes infected with virulent TB (CoMTb) and components of the PI3K/AKT signaling pathway blocked using specific chemical inhibitors and siRNA. MMP gene expression was measured by RT-PCR and secretion by ELISA, luminex, or zymography. Phospho-p70 S6K was detected by Western blot analysis and activity blocked by rapamycin. Chemical blockade of the proximal catalytic PI3K p110 subunit augmented MMP-1 and MMP-9 in a dose-dependent manner (all P<0.001) but suppressed MMP-3 (P<0.01). Targeted siRNA studies identified the p110α isoform as key causing 5-fold increase in TB network-dependent MMP-1 secretion to 4900 ± 1100 pg/ml. Specific inhibition of the AKT node suppressed all 3 MMPs. Phospho-p70(S6K) was identified in the cellular model, and rapamycin, a p70(S6K) inhibitor, inhibited MMP-1 (P<0.001) and MMP-3 (P<0.01) but not MMP-9. Controls were epithelial cells that were unstimulated or exposed to conditioned medium from monocytes not exposed to TB. In summary, blockade of the proximal PI3K catalytic subunit increases MMP-1 and MMP-9, whereas rapamycin decreased both MMP-1 and MMP-3. The regulation of the PI3K path in TB is complex, MMP specific, and a potential immunotherapeutic target in diseases characterized by tissue destruction.

Functionally relevant decreases in activatory receptor expression on NK cells are associated with pulmonary tuberculosis in vivo and persist after successful treatment

Correlates for the initiation of Mycobacterium tuberculosis hominis (Mth) replication from latency are needed in order to improve Mth control. In order to analyze if perturbations of peripheral NK cells may be associated with exit from Mth latency, sequential patients with newly diagnosed lung tuberculosis (TB) were studied. Peripheral NK cells were analyzed by cytofluorometry, in vitro culture and functional assays. At the onset of lung TB, imbalances in NK cell subsets were evident. Decreased CD56(bright)CD16(+/-) subsets with significantly compromised NKp30 and NKp46 expression and with specifically decreased gamma-IFN production upon triggering were evident. These features were not completely restored when purified NK cells were cultured in vitro. Culture supplementation with alpha-IFN increased only NKp30 expression in TB and healthy donors. Extensive peripheral NK cell triggering was evident in these patients, as shown by the expression of NK cell activation markers and of the lymph node-homing chemokine receptor CCR7 on CD16(+) CD56(dull) cells. Significant persistence of decreased NKp30 and NKp46 after successful treatment with a standard four-drug regimen was detected after full recovery. NK cell function is deeply affected in patients at the onset of pulmonary TB. The involvement of multiple activatory receptors may provide a relevant contribution to the spread of mycobacteria exiting from latency.

Regulatory role of 1, 25-dihydroxyvitamin D 3 and vitamin D receptor gene variants on intracellular granzyme A expression in pulmonary tuberculosis

Vitamin D receptor (VDR) genotypes have been shown to be associated with differential susceptibility or resistance to tuberculosis. The influence of FokI, BsmI, ApaI and TaqI variants of VDR gene on 1, 25(OH) 2 D 3 modulated granzyme A expression of cytotoxic lymphocytes induced by culture filtrate antigen (CFA) of Mycobacterium tuberculosis was studied in 40 pulmonary tuberculosis (PTB) patients and 49 normal healthy subjects (NHS) by flow cytometry. In both the study groups, addition of 1, 25(OH) 2 D 3 (10 − 7 M) significantly reduced the percentage of granzyme A positive cells in both unstimulated (NHS, p < 0.0001; PTB, p = 0.02) and stimulated culture conditions (CFA, NHS, p < 0.0001; PTB, p = 0.0001) which correlated positively with the IFN-γ levels (unstimulated, p = 0.01; CFA stimulated, p = 0.004) in NHS. The ApaI aa genotype and bbaaTT extended genotype were associated with a significantly decreased percentage of granzyme A positive cells in NHS ( p < 0.05). Our results suggest that 1, 25(OH) 2 D 3 suppresses granzyme A probably by down-regulating Th1 cytokine response. Moreover, the VDR gene variants might regulate cytotoxic T-cell response via 1, 25(OH) 2 D 3 mediated suppression of granzyme A expression in tuberculosis.

Orally Administered Mycobacterium vaccae Modulates Expression of Immunoregulatory Molecules in BALB/c Mice with Pulmonary Tuberculosis

The environmental saprophyte Mycobacterium vaccae induces a Th1 response and cytotoxic T cells that recognize M. tuberculosis, and by subcutaneous injection, it is therapeutic for pulmonary tuberculosis (TB) induced by high-dose challenge in BALB/c mice. However, M. vaccae also drives regulatory T cells that inhibit Th2 responses, and this is seen in allergy models, not only following subcutaneous injection but also after oral administration. An oral immunotherapeutic for TB would be clinically useful, so we investigated M. vaccae given orally by gavage at 28-day intervals in the TB model. We used two different protocols: starting the oral M. vaccae either 1 day before or 32 days after infection with M. tuberculosis. Throughout the infection (until 120 days), we monitored outcome (CFU), molecules involved in the development of immunoregulation (Foxp3, hemoxygenase 1, idoleamine 2,3-dioxygenase, and transforming growth factor beta [TGF-beta]), and indicators of cytokine balance (tumor necrosis factor, inducible nitric oxide synthase, interleukin-4 [IL-4], and IL-4delta2; an inhibitory splice variant of IL-4 associated with improved outcome in human TB). Oral M. vaccae had a significant effect on CFU and led to increased expression of Th1 markers and of IL-4delta2, while suppressing IL-4, Foxp3, and TGF-beta. When administered 1 day before infection, oral M. vaccae induced a striking peak of expression of hemoxygenase 1. In conclusion, we show novel information about the expression in TB of murine IL-4delta2 and molecules involved in immunoregulation and show that these can be modulated by oral administration of a saprophytic mycobacterium. A clinical trial of oral M. vaccae in extensively drug-resistant TB might be justified.

NK cell activity in tuberculosis is associated with impaired CD11a and ICAM‐1 expression: a regulatory role of monocytes in NK activation

Although the role of natural killer (NK) cells in mycobacterial infections is unclear, it has been postulated that they contribute to protective immunity through the production of interferon (IFN)-gamma. In this study, we evaluate the effect of interleukin (IL)-10, IL-15 and IL-18 on NK lytic activity through the expression of CD16, CD11a and CD69 molecules and the induction of IFN-gamma production in patients with tuberculosis (TB) and healthy individuals (N). Our results showed an impairment of NK lytic activity and a gradual down-regulation of costimulatory and adhesion molecules on NK cells which were dependent on the severity of the disease. NK lytic activity was increased by exogenous IL-15 and IL-18 in both TB and N, and by neutralization of endogenous IL-10 only in TB; IL-15 and IL-18 increased CD69 receptor expression, while anti-IL-10 up-regulated CD16 and CD11a expression in TB. Mycobacterium tuberculosis reduced the number of intracellular adhesion molecule (ICAM)-1(+) CD14(+) cells, but in the presence of IL-15, IL-18 and anti-IL-10 its expression was up-regulated. In cells from TB patients, the observed effects of IL-15 and IL-18 on NK function were not dependent on IL-10 modulation of the surface expression of activator/adhesion molecules. In the absence of monocytes, IL-10 activated NK cells, suggesting an indirect effect on their function. Furthermore, in TB patients the depletion of monocytes increased the production of IFN-gamma by NK cells. Therefore, monocytes from TB patients regulated the NK function involving IL-10 which, through an indirect mechanism, led to the down-regulation of costimulatory/adhesion molecules and/or IFN-gamma production.

Interleukin-18 expression by alveolar epithelial cells type II in tuberculosis and sarcoidosis

The aims of the present study were to characterize the localization of interleukin-18 (IL-18) expression in lung tissue specimens from patients with pulmonary tuberculosis, sarcoidosis and controls, and to determine whether human alveolar epithelial cells type II (AEC-II) are able to generate IL-18 in primary culture. IL-18 was determined using semiquantitative reverse-transcription-PCR and localized in lungs using in situ hybridization. IL-18 protein levels were determined using the enzyme-linked immunosorbent assay and western blot analysis. Alveolar epithelial cells type II (AEC-II) were stimulated in vitro by proinflammatory cytokines, lipopolysaccharides, and whole cell lysate from Mycobacterium tuberculosis. IL-18 mRNA expression was significantly increased in the lungs affected by tuberculosis and sarcoidosis. In situ hybridization revealed different sites of expression in tuberculosis and sarcoidosis lungs, with AEC-II as one major source of IL-18 in the alveolar compartment. Basal IL-18 expression could be detected in normal AEC-II. Whole cell lysate from M. tuberculosis, but not lipopolysaccharide, led to a strong increase of IL-18 mRNA accumulation in AEC-II. Resting AEC-II secreted only small amounts of IL-18, but intracellular IL-18 protein levels increased in a time-dependent manner during culture. Proinflammatory cytokines tumour necrosis factor-alpha, IL-1beta, and interferon-gamma altered IL-18 mRNA expression and mature protein secretion of human AEC-II. These findings indicate a possible role for AEC-II and AEC-II-derived IL-18 in pathomechanisms of granulomatous lung diseases.

Expression of the IL-12 Receptor β1 and β2 Subunits in Human Tuberculosis

AbstractTo determine whether the Th1 response in tuberculosis correlated with IL-12R expression, we measured expression of the IL-12Rβ1 and IL-12Rβ2 subunits, as well as IL-12Rβ2 mRNA expression in tuberculosis patients and healthy tuberculin reactors. In tuberculosis patients, IFN-γ production by Mycobacterium tuberculosis-stimulated PBMC was reduced, the percentages of T cells expressing IL-12Rβ1 and IL-12Rβ2 were significantly decreased, and IL-12Rβ2 mRNA expression was also markedly reduced. In contrast, in pleural fluid and lymph nodes at the site of disease in tuberculosis patients, in which IFN-γ production is enhanced, IL-12Rβ2 mRNA expression was also increased. In M. tuberculosis-stimulated peripheral blood T cells from tuberculosis patients, anti-IL-10 and anti-TGF-β enhanced IL-12Rβ1 and IL-12Rβ2 expression, and IFN-γ production. In M. tuberculosis-stimulated peripheral blood T cells from healthy tuberculin reactors, recombinant IL-10 and TGF-β reduced IL-12Rβ1 and IL-12Rβ2 expression, as well as IFN-γ production. In combination with prior studies showing increased production of TGF-β by blood monocytes from tuberculosis patients, this suggests that increased TGF-β production is the underlying abnormality that reduces IL-12Rβ1 and IL-12Rβ2 expression in tuberculosis. Our findings provide evidence that IL-12R expression correlates well with IFN-γ production in human tuberculosis, and that expression of IL-12Rβ1 and IL-12Rβ2 may play a central role in mediating a protective Th1 response.