Interleukin-11 drives early lung inflammation during Mycobacterium tuberculosis infection in genetically susceptible mice

Aberrant adaptive immune response underlies genetic susceptibility to tuberculosis

Mycobacterium tuberculosis (Mtb) remains a major threat worldwide, although only a fraction of infected individuals develops tuberculosis (TB). TB susceptibility is shaped by multiple genetic factors, and we performed comparative immunological analysis of two mouse strains to uncover relevant mechanisms underlying susceptibility and resistance. C57BL/6 mice are relatively TB-resistant, whereas I/St mice are prone to develop severe TB, partly due to the MHC-II allelic variant that shapes suboptimal CD4+ T cell receptor repertoire. We investigated the repertoires of lung-infiltrating helper T cells and B cells at the progressed stage in both strains. We found that lung CD4+ T cell repertoires of infected C57BL/6 but not I/St mice contained convergent TCR clusters with functionally confirmed Mtb specificity. Transcriptomic analysis revealed a more prominent Th1 signature in C57BL/6, and expression of pro-inflammatory IL-16 in I/St lung-infiltrating helper T cells. The two strains also showed distinct Th2 signatures. Furthermore, the humoral response of I/St mice was delayed, less focused, and dominated by IgG/IgM isotypes, whereas C57BL/6 mice generated more Mtb antigen-focused IgA response. We conclude that the inability of I/St mice to produce a timely and efficient anti-Mtb adaptive immune responses arises from a suboptimal helper T cell landscape that also impacts the humoral response, leading to diffuse inflammation and severe disease.

Inflammatory immune profiles associated with disease severity in pulmonary tuberculosis patients with moderate to severe clinical TB or anemia

Background

Immune control of Mycobacterium tuberculosis (Mtb) infection is largely influenced by the extensive disease heterogeneity that is typical for tuberculosis (TB). In this study, the peripheral inflammatory immune profile of different sub-groups of pulmonary TB patients was explored based on clinical disease severity, anemia of chronic disease, or the radiological extent of lung disease.

Methods

Plasma samples were obtained from n=107 patients with active pulmonary TB at the time of diagnosis and after start of standard chemotherapy. A composite clinical TB symptoms score, blood hemoglobin status and chest X-ray imaging were used to sub-group TB patients into 1.) mild and moderate-severe clinical TB, 2.) anemic and non-anemic TB, or 3.) limited and extensive lung involvement. Plasma levels of biomarkers associated with inflammation pathways were assessed using a Bio-Plex Magpix 37-multiplex assay. In parallel, Th1/Th2 cytokines were quantified with a 27-multiplex in matched plasma and cell culture supernatants from whole blood stimulated with M. tuberculosis-antigens using the QuantiFERON-TB Gold assay.

Results

Clinical TB disease severity correlated with low blood hemoglobin levels and anemia but not with radiological findings in this study cohort. Multiplex protein analyses revealed that distinct clusters of inflammation markers and cytokines separated the different TB disease sub-groups with variable efficacy. Several top-ranked markers overlapped, while other markers were unique with regards to their importance to differentiate the TB disease severity groups. A distinct immune response profile defined by elevated levels of BAFF, LIGHT, sTNF-R1 and 2, IP-10, osteopontin, chitinase-3-like protein 1, and IFNα2 and IL-8, were most effective in separating TB patients with different clinical disease severity and were also promising candidates for treatment monitoring. TB patients with mild disease displayed immune polarization towards mixed Th1/Th2 responses, while pro-inflammatory and B cell stimulating cytokines as well as immunomodulatory mediators predominated in moderate-severe TB disease and anemia of TB.

Conclusions

Our data demonstrated that clinical disease severity in TB is associated with anemia and distinct inflammatory immune profiles. These results contribute to the understanding of immunopathology in pulmonary TB and define top-ranked inflammatory mediators as biomarkers of disease severity and treatment prognosis.

Cardiomyocyte-Restricted Expression of IL11 Causes Cardiac Fibrosis, Inflammation, and Dysfunction

Cardiac fibrosis is a common pathological process in heart disease, representing a therapeutic target. Transforming growth factor β (TGFβ) is the canonical driver of cardiac fibrosis and was recently shown to be dependent on interleukin 11 (IL11) for its profibrotic effects in fibroblasts. In the opposite direction, recombinant human IL11 has been reported as anti-fibrotic and anti-inflammatory in the mouse heart. In this study, we determined the effects of IL11 expression in cardiomyocytes on cardiac pathobiology and function. We used the Cre-loxP system to generate a tamoxifen-inducible mouse with cardiomyocyte-restricted murine Il11 expression. Using protein assays, bulk RNA-sequencing, and in vivo imaging, we analyzed the effects of IL11 on myocardial fibrosis, inflammation, and cardiac function, challenging previous reports suggesting the cardioprotective potential of IL11. TGFβ stimulation of cardiomyocytes caused Il11 upregulation. Compared to wild-type controls, Il11-expressing hearts demonstrated severe cardiac fibrosis and inflammation that was associated with the upregulation of cytokines, chemokines, complement factors, and increased inflammatory cells. IL11 expression also activated a program of endothelial-to-mesenchymal transition and resulted in left ventricular dysfunction. Our data define species-matched IL11 as strongly profibrotic and proinflammatory when secreted from cardiomyocytes and further establish IL11 as a disease factor.

Interleukin-11 receptor subunit α-1 is required for maximal airway responsiveness to methacholine after acute exposure to ozone

Interleukin (IL)-11, a multifunctional cytokine, contributes to numerous biological processes, including adipogenesis, hematopoiesis, and inflammation. Asthma, a respiratory disease, is notably characterized by reversible airway obstruction, persistent lung inflammation, and airway hyperresponsiveness (AHR). Nasal insufflation of IL-11 causes AHR in wild-type mice while lung inflammation induced by antigen sensitization and challenge, which mimics features of atopic asthma in humans, is attenuated in mice genetically deficient in IL-11 receptor subunit α-1 (IL-11Rα1-deficient mice), a transmembrane receptor that is required conjointly with glycoprotein 130 to transduce IL-11 signaling. Nevertheless, the contribution of IL-11Rα1 to characteristics of nonatopic asthma is unknown. Thus, based on the aforementioned observations, we hypothesized that genetic deficiency of IL-11Rα1 attenuates lung inflammation and increases airway responsiveness after acute inhalation exposure to ozone (O3), a criteria pollutant and nonatopic asthma stimulus. Accordingly, 4 and/or 24 h after cessation of exposure to filtered room air or O3, we assessed lung inflammation and airway responsiveness in wild-type and IL-11Rα1-deficient mice. With the exception of bronchoalveolar lavage macrophages and adiponectin, which were significantly increased and decreased, respectively, in O3-exposed IL-11Rα1-deficient as compared with O3-exposed wild-type mice, no other genotype-related differences in lung inflammation indices that we quantified were observed in O3-exposed mice. However, airway responsiveness to acetyl-β-methylcholine chloride (methacholine) was significantly diminished in IL-11Rα1-deficient as compared with wild-type mice after O3 exposure. In conclusion, these results demonstrate that IL-11Rα1 minimally contributes to lung inflammation but is required for maximal airway responsiveness to methacholine in a mouse model of nonatopic asthma.

Metabolic biological markers for diagnosing and monitoring the course of tuberculosis

The international biomedical community has been currently facing a need to find a simple and most accessible type of analysis that helps to diagnose tuberculosis (TB) with the maximum reliability even before the onset of clinical manifestations. Tuberculosis results in more deaths than any other pathogen, second only to pneumonia caused by the SARS-CoV-2 virus, but the majority of infected people remain asymptomatic. In addition, it is important to develop methods to distinguish various forms of tuberculosis infection course at early stages and to reliably stratify patients into appropriate groups (persons with a rapidly progressing infection, chronic course, latent infection carriers). Immunometabolism investigates a relationship between bioenergetic pathways and specific functions of immune cells that has recently become increasingly important in scientific research. The host anti-mycobacteria immune response in tuberculosis is regulated by a number of metabolic networks that can interact both cooperatively and antagonistically, influencing an outcome of the disease. The balance between inflammatory and immune reactions limits the spread of mycobacteria in vivo and protects from developing tuberculosis. Cytokines are essential for host defense, but if uncontrolled, some mediators may contribute to developing disease and pathology. Differences in plasma levels of metabolites between individuals with advanced infection, LTBI and healthy individuals can be detected long before the onset of the major related clinical signs. Changes in amino acid and cortisol level may be detected as early as 12 months before the onset of the disease and become more prominent at verifying clinical diagnosis. Assessing serum level of certain amino acids and their ratios may be used as additional diagnostic markers of active pulmonary TB. Metabolites, including serum fatty acids, amino acids and lipids may contribute to detecting active TB. Metabolic profiles indicate about increased indolamine 2.3-dioxygenase 1 (IDO1) activity, decreased phospholipase activity, increased adenosine metabolite level, and fibrous lesions in active vs. latent infection. TB treatment can be adjusted based on individual patient metabolism and biomarker profiles. Thus, exploring immunometabolism in tuberculosis is necessary for development of new therapeutic strategies.

Pleiotropic Effect of IL-6 Produced by B-Lymphocytes During Early Phases of Adaptive Immune Responses Against TB Infection

The role of B cells migrating to the lung and forming follicles during tuberculosis (TB) inflammation is still the subject of debate. In addition to their antibody production and antigen-presenting functions, B cells secrete different cytokines and chemokines, thus participating in complex networks of innate and adaptive immunity. Importantly, lung B-cells produce high amounts of the pleiotropic gp130 cytokine IL-6. Its role during TB infection remains controversial, partly due to the fact that IL-6 is produced by different cell types. To investigate the impact of IL-6 produced by B cells on TB susceptibility and immune responses, we established a mouse strain with specific IL-6 deficiency in B cells (CD19cre-IL-6fl/fl, B-IL-6KO) on the B6 genetic background. Selective abrogation of IL-6 in B cells resulted in shortening the lifespan of TB-infected B-IL-6KO mice compare to the wild-type controls. We provide evidence that at the initial TB stages B cells serve as a critical source of IL-6. In the lung, the effect of IL-6 deficiency in B cells is associated rather with B and T cell functioning, than with macrophage polarization. TB-infected B-IL-6KO mice displayed diminished sizes of B cells themselves, CD4⁺IFN-γ⁺, Th17⁺, and CD4⁺CXCR5⁺ follicular T cell populations. The pleiotropic effect of B-cell-derived IL-6 on T-cells demonstrated in our study bridges two major lymphocyte populations and sheds some light on B- and T-cells interactions during the stage of anti-TB response when the host switches on a plethora of acquired immune reactions.

Interleukin 11 (IL-11): Role(s) in Breast Cancer Bone Metastases

Bone metastases represent the main problem related to the progression of breast cancer, as they are the main cause of death for these patients. Unfortunately, to date, bone metastases are incurable and represent the main challenge for the researcher. Chemokines and cytokines affect different stages of the metastatic process, and in bone metastases, interleukin (IL) -6, IL-8, IL-1β, and IL-11 participate in the interaction between cancer cells and bone cells. This review focuses on IL-11, a pleiotropic cytokine that, in addition to its well-known effects on several tissues, also mediates certain signals in cancer cells. In particular, as IL-11 works on bone remodeling, it plays a relevant role in the osteolytic vicious cycle of bone resorption and tumour growth, which characterizes bone metastasis. IL-11 appears as a candidate for anti-metastatic therapy. Even if different therapeutic approaches have considered IL-11 and the downstream-activated gp130 signaling pathways activated downstream of gp130, further studies are needed to decipher the contribution of the different cytokines and their mechanisms of action in breast cancer progression to define therapeutic strategies.

The Role of gp130 Cytokines in Tuberculosis

Protective immune responses to Mycobacterium tuberculosis (Mtb) infection substantially depend on a delicate balance within cytokine networks. Thus, immunosuppressive therapy by cytokine blockers, as successfully used in the management of various chronic inflammatory diseases, is often connected with an increased risk for tuberculosis (TB) reactivation. Hence, identification of alternative therapeutics which allow the treatment of inflammatory diseases without compromising anti-mycobacterial immunity remains an important issue. On the other hand, in the context of novel therapeutic approaches for the management of TB, host-directed adjunct therapies, which combine administration of antibiotics with immunomodulatory drugs, play an increasingly important role, particularly to reduce the duration of treatment. In both respects, cytokines/cytokine receptors related to the common receptor subunit gp130 may serve as promising target candidates. Within the gp130 cytokine family, interleukin (IL)-6, IL-11 and IL-27 are most explored in the context of TB. This review summarizes the differential roles of these cytokines in protection and immunopathology during Mtb infection and discusses potential therapeutic implementations with respect to the aforementioned approaches.

Interleukin-11 signaling underlies fibrosis, parenchymal dysfunction, and chronic inflammation of the airway

Interleukin (IL)-11 evolved as part of the innate immune response. In the human lung, IL-11 upregulation has been associated with viral infections and a range of fibroinflammatory diseases, including idiopathic pulmonary fibrosis. Transforming growth factor-beta (TGFβ) and other disease factors can initiate an autocrine loop of IL-11 signaling in pulmonary fibroblasts, which, in a largely ERK-dependent manner, triggers the translation of profibrotic proteins. Lung epithelial cells also express the IL-11 receptor and transition into a mesenchymal-like state in response to IL-11 exposure. In mice, therapeutic targeting of IL-11 with antibodies can arrest and reverse bleomycin-induced pulmonary fibrosis and inflammation. Intriguingly, fibroblast-specific blockade of IL-11 signaling has anti-inflammatory effects, which suggests that lung inflammation is sustained, in part, through IL-11 activity in the stroma. Proinflammatory fibroblasts and their interaction with the damaged epithelium may represent an important but overlooked driver of lung disease. Initially thought of as a protective cytokine, IL-11 is now increasingly recognized as an important determinant of lung fibrosis, inflammation, and epithelial dysfunction.

Structural Understanding of Interleukin 6 Family Cytokine Signaling and Targeted Therapies: Focus on Interleukin 11

Cytokines are small signaling proteins that have central roles in inflammation and cell survival. In the half-century since the discovery of the first cytokines, the interferons, over fifty cytokines have been identified. Amongst these is interleukin (IL)-6, the first and prototypical member of the IL-6 family of cytokines, nearly all of which utilize the common signaling receptor, gp130. In the last decade, there have been numerous advances in our understanding of the structural mechanisms of IL-6 family signaling, particularly for IL-6 itself. However, our understanding of the detailed structural mechanisms underlying signaling by most IL-6 family members remains limited. With the emergence of new roles for IL-6 family cytokines in disease and, in particular, roles of IL-11 in cardiovascular disease, lung disease, and cancer, there is an emerging need to develop therapeutics that can progress to clinical use. Here we outline our current knowledge of the structural mechanism of signaling by the IL-6 family of cytokines. We discuss how this knowledge allows us to understand the mechanism of action of currently available inhibitors targeting IL-6 family cytokine signaling, and most importantly how it allows for improved opportunities to pharmacologically disrupt cytokine signaling. We focus specifically on the need to develop and understand inhibitors that disrupt IL-11 signaling.

Roles of interleukin-11 during acute bacterial pneumonia

Interleukin-11 (IL-11) is an interleukin-6 (IL-6) family cytokine shown to play a protective role in acute inflammatory settings including systemic infection. In this study we addressed the role of IL-11 in acute bacterial pneumonia using a mouse model of E. coli pneumonia. Compared with other related cytokines, IL-11 protein was maintained at high levels in the lung at baseline, with only mild alterations in whole lung and BALF levels during acute infection. The primary source of IL-11 in the lung was the epithelium, but steady state production was not dependent on the inflammatory transcription factor nuclear factor kappa B in cells of either myeloid or epithelial lineage. Blockade of IL-11 with neutralizing antibodies resulted in a mild but significant decrease in neutrophil recruitment and increase in pulmonary edema during pneumonia, without detectable alterations in bacterial clearance. Exogenous IL-11 administration, however, had no effect at baseline or during infection. Overall, we conclude that maintenance of lung IL-11 concentrations may influence acute pulmonary inflammation during infection, albeit modestly.

Local Cytokine Expression Profiling in Patients with Specific Autoimmune Uveitic Entities

Purpose: To evaluate expression of cytokines GM-CSF, IL-11, IL-12p40, IL-12p70, IL-27p28, IL-35, APRIL, BAFF, TWEAK, and LIGHT in uveitis.Methods: Aqueous humor samples from patients with active uveitis associated with Behçet's disease (BD), sarcoidosis, HLA-B27-related inflammation, and Vogt-Koyanagi-Harada (VKH) disease and control patients were assayed with a multiplex assay.Results: Comparing all patients to controls, GM-CSF, IL-11, IL-12p40, APRIL, and BAFF were significantly increased, whereas LIGHT was significantly decreased. IL-11 and BAFF were the most strongly upregulated, being elevated 19.7-fold and 14.1-fold, respectively, compared with controls. IL-11 was significantly highest in HLA-B27 uveitis. GM-CSF, IL-11, and IL-12p40 were significantly higher in nongranulomatous uveitis (BD and HLA-B27) than in granulomatous uveitis (sarcoidosis and VKH), whereas APRIL and TWEAK were significantly higher in granulomatous uveitis.Conclusions: IL-11-driven immune responses might be more potent in nongranulomatous uveitis, particularly in HLA-B27 uveitis. BAFF and APRIL might contribute to B cell-driven autoimmune response in uveitis.

Emerging roles for Interleukin-11 in disease

Interleukin (IL)-11 belongs to the IL-6 family of cytokines, discovered over 30 years ago. While early studies focused on the ability of IL-11 to stimulate megakaryocytopoiesis, the importance of this cytokine to inflammatory disease and cancers is only just beginning to be uncovered. This review outlines recent advances in our understanding of IL-11 biology, and highlights the development of novel therapeutics with the potential for clinical targeting of signaling by this cytokine in multiple diseases.

A new model for chronic and reactivation tuberculosis: Infection with genetically attenuated Mycobacterium tuberculosis in mice with polar susceptibility

TB infection in mice develops relatively rapidly which interferes with experimental dissection of immune responses and lung pathology features that differ between genetically susceptible and resistant hosts. Earlier we have shown that the M. tuberculosis strain lacking four of five Rpf genes (ΔACDE) is seriously attenuated for growth in vivo. Using this strain, we assessed key parameters of lung pathology, immune and inflammatory responses in chronic and reactivation TB infections in highly susceptible I/St and more resistant B6 mice. ΔACDE mycobacteria progressively multiplied only in I/St lungs, whilst in B6 lung CFU counts decreased with time. Condensed TB foci apeared in B6 lungs at week 4 of infection, whilst in I/St their formation was delayed. At the late phase of infection, in I/St lungs TB foci fused resulting in extensive pneumonia, whereas in B6 lungs pathology was limited to condensed foci. Macrophage and neutrophil populations characteristically differed between I/St and B6 mice at early and late stages of infection: more neutrophils accumulated in I/St and more macrophages in B6 lungs. The expression level of chemokine genes involved in neutrophil influx was higher in I/St compared to B6 lungs. B6 lung cells produced more IFN-γ, IL-6 and IL-11 at the early and late phases of infection. Overall, using a new mouse model of slow TB progression, we demonstrate two important features of ineffective infection control underlined by shifts in lung inflammation: delay in early granuloma formation and fusion of granulomas resulting in consolidated pneumonia late in the infectious course.

B-lymphocytes forming follicle-like structures in the lung tissue of tuberculosis-infected mice: Dynamics, phenotypes and functional activity

During tuberculosis (TB) infection, B cells form follicles in close vicinity of lung granuloma. We assessed the dynamics of follicle formation, surface phenotypes and functional activity of lung B cells during TB course in genetically susceptible mice. The follicles appeared early post infection and peaked at weeks 7-8. Lung B cells resembled classical B2 cells (CD19⁺IgMloIgD^hiCD1d^-CD21/35^intCD5^-CD11b^-CD43^-), but differed from them by the absence of B2 marker CD23. Lung B-cells constitutively expressed MHC II molecules, presented mycobacterial antigens to immune CD4⁺ T-cells and produced high amounts of IL-6 and IL-11, but no classical type 1 (TNF-α, IFN-γ), or anti-inflammatory (IL-10, TGF-β) cytokines. The total antibody response in tuberculous lung showed almost no specificity to mycobacteria. A panel of monoclonal antibodies obtained from lung B cells contained only few clones with reactivity to mycobacteria. Our results suggest that anti-TB B cell response in the lung has clear pathological and doubtful protective role.

Therapeutic Effect of Recombinant Mutated Interleukin 11 in the Mouse Model of Tuberculosis

Earlier we demonstrated that blocking of interleukin 11 (IL-11) by systemic administration of anti-IL-11 antibodies attenuates severity of Mycobacterium tuberculosis infection in mice. The substitution W147A in the IL-11 molecule creates the form of cytokine capable to disrupt gp130/IL11R signaling complex formation, thus serving as a high-affinity specific antagonist of IL-11-mediated signaling. We hypothesized that this mutant form of IL-11 may serve as an effective tool for inhibition of native IL-11 activity in vivo. We established the recombinant W147A mutant form of IL-11 in an optimized Escherichia coli expression system and administered it as the aerosol in the lungs of M. tuberculosis-susceptible I/St mice infected with M. tuberculosis Our results show that this therapeutic approach markedly inhibits tuberculous inflammation in lungs, increases the survival time of infected animals, and decreases expression of key inflammatory factors at the RNA and protein levels. These findings are a step toward clinical evaluation of the anti-IL-11 therapy for tuberculosis.

IL-11 signaling as a therapeutic target for cancer

IL-11 is a member of the IL-6 family of cytokines. While it was discovered over 20 years ago, we have very little understanding of the role of IL-11 during normal homeostasis and disease. Recently, IL-11 has gained interest for its newly recognized role in the pathogenesis of diseases that are attributed to deregulated mucosal homeostasis, including gastrointestinal cancers. IL-11 can increase the tumorigenic capacity of cells, including survival of the cell or origin, proliferation of cancerous cells and survival of metastatic cells at distant organs. Here we outline our current understanding of IL-11 biology and recent advances in our understanding of its role in cancer. We advocate that inhibition of IL-11 signaling may represent an emerging therapeutic opportunity for numerous cancers.

Emerging roles for IL-11 signaling in cancer development and progression: Focus on breast cancer

Interleukin (IL)-11 is a member of the IL-6 family of cytokines that is defined by the shared use of the GP130 signal transducing receptor subunit. In addition of its long recognized activities as a hemopoietic growth factor, IL-11 has an emerging role in epithelial cancer biology. Through the activation of the GP130-Janus kinase signaling cascade and associated transcription factor STAT3, IL-11 can confer many of the tumor intrinsic 'hallmark' capabilities to neoplastic cells, if they express the ligand-specific IL-11Rα receptor subunit. Accordingly, IL-11 signaling has recently been identified as a rate-limiting step for the growth tumors arising from the mucosa of the gastrointestinal tract. However, there is less appreciation for a potential role of IL-11 to support breast cancer progression, apart from its well documented capacity to facilitate bone metastasis. Here we review evidence that IL-11 expression in breast cancer correlates with poor disease outcome and discuss some of the molecular mechanisms that are likely to underpin these observations. These include the capacity of IL-11 to stimulate survival and proliferation of cancer cells alongside angiogenesis of the primary tumor and of metastatic progenies at distant organs. We review current strategies to interfere with IL-11 signaling and advocate that inhibition of IL-11 signaling may represent an emerging therapeutic opportunity for numerous cancers.

IP-10 and MIG are compartmentalized at the site of disease during pleural and meningeal tuberculosis and are decreased after antituberculosis treatment

The diagnosis of active tuberculosis (TB) disease remains a challenge, especially in high-burden settings. Cytokines and chemokines are important in the pathogenesis of TB. Here we investigate the usefulness of circulating and compartmentalized cytokines/chemokines for diagnosis of TB. The levels of multiple cytokines/chemokines in plasma, pleural fluid (PF), and cerebrospinal fluid (CSF) were determined by Luminex liquid array-based multiplexed immunoassays. Three of 26 cytokines/chemokines in plasma were significantly different between TB and latent tuberculosis infection (LTBI). Among them, IP-10 and MIG had the highest diagnostic values, with an area under the receiver operating characteristic curve (ROC AUC) of 0.92 for IP-10 and 0.86 for MIG for distinguishing TB from LTBI. However, IP-10 and MIG levels in plasma were not different between TB and non-TB lung disease. In contrast, compartmentalized IP-10 and MIG in the PF and CSF showed promising diagnostic values in discriminating TB and non-TB pleural effusion (AUC = 0.87 for IP-10 and 0.93 for MIG), as well as TB meningitis and non-TB meningitis (AUC = 0.9 for IP-10 and 0.95 for MIG). A longitudinal study showed that the plasma levels of IP-10, MIG, granulocyte colony-stimulating factor (G-CSF), and gamma interferon (IFN-γ) decreased, while the levels of MCP-1/CCL2 and eotaxin-1/CCL11 increased, after successful treatment of TB. Our findings provide a practical methodology for discriminating active TB from LTBI by sequential IFN-γ release assays (IGRAs) and plasma IP-10 testing, while increased IP-10 and MIG at the site of infection (PF or CSF) can be used as a marker for distinguishing pleural effusion and meningitis caused by TB from those of non-TB origins.

Complex pattern of interleukin-11-induced inflammation revealed by mathematically modeling the dynamics of C-reactive protein

Inflammation underlies many diseases and is an undesired effect of several therapy modalities. Biomathematical modeling can help unravel the complex inflammatory processes and the mechanisms triggering their emergence. We developed a model for induction of C-reactive protein (CRP), a clinically reliable marker of inflammation, by interleukin (IL)-11, an approved cytokine for treatment of chemotherapy-induced thrombocytopenia. Due to paucity of information on the mechanisms underlying inflammation-induced CRP dynamics, our model was developed by systematically evaluating several models for their ability to retrieve variable CRP profiles observed in IL-11-treated breast cancer patients. The preliminary semi-mechanistic models were designed by non-linear mixed-effects modeling, and were evaluated by various performance criteria, which test goodness-of-fit, parsimony and uniqueness. The best-performing model, a robust population model with minimal inter-individual variability, uncovers new aspects of inflammation dynamics. It shows that CRP clearance is a nonlinear self-controlled process, indicating an adaptive anti-inflammatory reaction in humans. The model also reveals a dual IL-11 effect on CRP elevation, whereby the drug has not only a potent immediate influence on CRP incline, but also a long-term influence inducing elevated CRP levels for several months. Consistent with this, model simulations suggest that periodic IL-11 therapy may result in prolonged low-grade (chronic) inflammation post treatment. Future application of the model can therefore help design improved IL-11 regimens with minimized long-term CRP toxicity. Our study illuminates the dynamics of inflammation and its control, and provides a prototype for progressive modeling of complex biological processes in the medical realm and beyond.

Analysis of the lung transcriptome in Mycobacterium tuberculosis-infected mice reveals major differences in immune response pathways between TB-susceptible and resistant hosts

Using whole genome microarrays, we compared changes in gene expression patterns in the lungs of TB-resistant A/Sn and TB-susceptible I/St mice at day 14 following infection with Mycobacterium tuberculosis H37Rv. Analyses of differentially expressed genes for representation of gene ontology terms and activation of regulatory pathways revealed interstrain differences in antigen presentation, NK, T and B cell activation pathways. In general, resistant A/Sn mice exhibited a more complex pattern and stronger activation of host defense pathways compared to the TB-susceptible I/St mouse strain. In addition, in I/St mice elevated activation of genes involved in neutrophil response was observed and confirmed by quantitative RT-PCR and histopathology. Furthermore, a specific post infection upregulation of cysteine protease inhibitors was found in susceptible I/St mice.

Interleukin-11, an interleukin-6-like cytokine, is a promising predictor for bladder cancer prognosis

Numerous studies have suggested that interleukin 11 (IL-11) has roles in human gastric, prostate and bone cancer and endometrial carcinoma. Hence, we evaluated the expression of IL-11 in bladder cancer and the correlation of IL-11 levels and clinico-pathological features. The expression of IL-11 in primary human bladder cell culture, human bladder cancer cell lines, transitional cell carcinoma (TCC) and non-cancerous bladder tissues (NATs) were analyzed by western blotting. Enzyme-linked immunosorbent assay (ELISA) for urinary IL-11 was performed to compare the IL-11 levels in healthy subjects and subjects diagnosed with bladder cancer. Our study suggested that the expression of IL-11 in human bladder cancer cell lines and TCC was downregulated compared with primary human bladder cell culture and matched NATs. We also demonstrated reduced urinary levels of IL-11 in subjects with bladder cancer compared with healthy subjects. Furthermore, we revealed that the levels of IL-11 were associated with tumor grade and stage. The results suggested that reduced levels of IL-11 may play an important role in the carcinogenesis and progression of TCC. They also indicated that IL-11 may be a promising predictor for prognosis of TCC.